National Library of Energy BETA

Sample records for accident conditions view

  1. Graphite Oxidation Simulation in HTR Accident Conditions

    SciTech Connect (OSTI)

    El-Genk, Mohamed

    2012-10-19

    Massive air and water ingress, following a pipe break or leak in steam-generator tubes, is a design-basis accident for high-temperature reactors (HTRs). Analysis of these accidents in both prismatic and pebble bed HTRs requires state-of-the-art capability for predictions of: 1) oxidation kinetics, 2) air helium gas mixture stratification and diffusion into the core following the depressurization, 3) transport of multi-species gas mixture, and 4) graphite corrosion. This project will develop a multi-dimensional, comprehensive oxidation kinetics model of graphite in HTRs, with diverse capabilities for handling different flow regimes. The chemical kinetics/multi-species transport model for graphite burning and oxidation will account for temperature-related changes in the properties of graphite, oxidants (O2, H2O, CO), reaction products (CO, CO2, H2, CH4) and other gases in the mixture (He and N2). The model will treat the oxidation and corrosion of graphite in geometries representative of HTR core component at temperatures of 900°C or higher. The developed chemical reaction kinetics model will be user-friendly for coupling to full core analysis codes such as MELCOR and RELAP, as well as computational fluid dynamics (CFD) codes such as CD-adapco. The research team will solve governing equations for the multi-dimensional flow and the chemical reactions and kinetics using Simulink, an extension of the MATLAB solver, and will validate and benchmark the model's predictions using reported experimental data. Researchers will develop an interface to couple the validated model to a commercially available CFD fluid flow and thermal-hydraulic model of the reactor , and will perform a simulation of a pipe break in a prismatic core HTR, with the potential for future application to a pebble-bed type HTR.

  2. DOE - NNSA/NFO -- News & Views Accident Trap

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Accident Traps Four Workers 1,800 Feet below Ground Photo - rescue from 1,800 feet below ... Thousands of workers have completed millions of accident-free hours at this heavy industry ...

  3. Fission product release from irradiated LWR fuel under accident conditions

    SciTech Connect (OSTI)

    Strain, R.V.; Sanecki, J.E.; Osborne, M.F.

    1984-01-01

    Fission product release from irradiated LWR fuel is being studied by heating fuel rod segments in flowing steam and an inert carrier gas to simulate accident conditions. Fuels with a range of irradiation histories are being subjected to several steam flow rates over a wide range of temperatures. Fission product release during each test is measured by gamma spectroscopy and by detailed examination of the collection apparatus after the test has been completed. These release results are complemented by a detailed posttest examination of samples of the fuel rod segment. Results of release measurements and fuel rod characterizations for tests at 1400 through 2000/sup 0/C are presented in this paper.

  4. Hypothetical accident conditions thermal analysis of the 5320 package

    SciTech Connect (OSTI)

    Hensel, S.J.; Gromada, R.J.

    1995-12-31

    An axisymmetric model of the 5320 package was created to perform hypothetical accident conditions (HAC) thermal calculations. The analyses assume the 5320 package contains 359 grams of plutonium-238 (203 Watts) in the form of an oxide powder at a minimum density of 2.4 g/cc or at a maximum density of 11.2 g/cc. The solution from a non-solar 100 F ambient steady-state analysis was used as the initial conditions for the fire transient. A 30 minute 1,475 F fire transient followed by cooling via natural convection and thermal radiation to a 100 F non-solar environment was analyzed to determine peak component temperatures and vessel pressures. The 5320 package was considered to be horizontally suspended within the fire during the entire transient.

  5. Electrical equipment performance under severe accident conditions (BWR/Mark 1 plant analysis): Summary report

    SciTech Connect (OSTI)

    Bennett, P.R.; Kolaczkowski, A.M.; Medford, G.T.

    1986-09-01

    The purpose of the Performance Evaluation of Electrical Equipment during Severe Accident States Program is to determine the performance of electrical equipment, important to safety, under severe accident conditions. In FY85, a method was devised to identify important electrical equipment and the severe accident environments in which the equipment was likely to fail. This method was used to evaluate the equipment and severe accident environments for Browns Ferry Unit 1, a BWR/Mark I. Following this work, a test plan was written in FY86 to experimentally determine the performance of one selected component to two severe accident environments.

  6. Probabilistic assessment of spent fuel shipping cask response to severe transportation accident conditions. Report summary

    SciTech Connect (OSTI)

    Fischer, L.E.; Kimura, C.Y.; Witte, M.C.

    1985-01-01

    The licensing of commercial nuclear spent shipping casks in the United States is regulated by 10CFR71. In order to be licensed, casks must be designed not to fail under hypothetical test conditions specified in Appendix B of this regulation. Questions have been raised about the suitability of these tests in simulating actual transportation accident conditions. Our study addresses the adequacy of current regulations by comparing real-world accident conditions with regulatory test specifications using more complete accident statistics and more sophisticated structural analyses than have been used in studies to date. Our objective is to evaluate the protection provided by current regulations against severe accident conditions for commercial spent nuclear fuel casks that are transported by truck or rail. The complete spectrum of truck and rail accidents will be reviewed in order to determine the frequency (or infrequency) of cask failures during transportation accidents. 3 references, 1 figure.

  7. Key Parameters for Operator Diagnosis of BWR Plant Condition during a Severe Accident

    SciTech Connect (OSTI)

    Clayton, Dwight A.; Poore, III, Willis P.

    2015-01-01

    The objective of this research is to examine the key information needed from nuclear power plant instrumentation to guide severe accident management and mitigation for boiling water reactor (BWR) designs (specifically, a BWR/4-Mark I), estimate environmental conditions that the instrumentation will experience during a severe accident, and identify potential gaps in existing instrumentation that may require further research and development. This report notes the key parameters that instrumentation needs to measure to help operators respond to severe accidents. A follow-up report will assess severe accident environmental conditions as estimated by severe accident simulation model analysis for a specific US BWR/4-Mark I plant for those instrumentation systems considered most important for accident management purposes.

  8. Accident Conditions versus Regulatory Test for NRC-Approved UF6 Packages

    SciTech Connect (OSTI)

    MILLS, G. SCOTT; AMMERMAN, DOUGLAS J.; LOPEZ, CARLOS

    2003-01-01

    The Nuclear Regulatory Commission (NRC) approves new package designs for shipping fissile quantities of UF{sub 6}. Currently there are three packages approved by the NRC for domestic shipments of fissile quantities of UF{sub 6}: NCI-21PF-1; UX-30; and ESP30X. For approval by the NRC, packages must be subjected to a sequence of physical tests to simulate transportation accident conditions as described in 10 CFR Part 71. The primary objective of this project was to relate the conditions experienced by these packages in the tests described in 10 CFR Part 71 to conditions potentially encountered in actual accidents and to estimate the probabilities of such accidents. Comparison of the effects of actual accident conditions to 10 CFR Part 71 tests was achieved by means of computer modeling of structural effects on the packages due to impacts with actual surfaces, and thermal effects resulting from test and other fire scenarios. In addition, the likelihood of encountering bodies of water or sufficient rainfall to cause complete or partial immersion during transport over representative truck routes was assessed. Modeled effects, and their associated probabilities, were combined with existing event-tree data, plus accident rates and other characteristics gathered from representative routes, to derive generalized probabilities of encountering accident conditions comparable to the 10 CFR Part 71 conditions. This analysis suggests that the regulatory conditions are unlikely to be exceeded in real accidents, i.e. the likelihood of UF{sub 6} being dispersed as a result of accident impact or fire is small. Moreover, given that an accident has occurred, exposure to water by fire-fighting, heavy rain or submersion in a body of water is even less probable by factors ranging from 0.5 to 8E-6.

  9. Creep behavior of a nuclear pressure vessel under severe accident conditions

    SciTech Connect (OSTI)

    Beghini, M.; Bertini, L.; Vitale, E.

    1996-12-31

    The results of a study on the creep behavior of the vessel lower head under severe accident conditions are reported. An experimental program aimed at the evaluation of the creep properties of A533grB steel at high temperature (800--1,100 C) and under biaxial loading is summarized and the main results reported. A Finite Element simulation of the lower head under severe accident conditions allows to show the effect of the main parameters affecting the time to rupture.

  10. Thermal-stress analysis of a Fort St. Vrain core-support block under accident conditions

    SciTech Connect (OSTI)

    Carruthers, L.M.; Butler, T.A.; Anderson, C.A.

    1982-01-01

    A thermoelastic stress analysis of a graphite core support block in the Fort St. Vrain High Temperature Gas Cooled Reactor is described. The support block is subjected to thermal stresses caused by a loss of forced circulation accident of the reactor system. Two- and three-dimensional finite element models of the core support block are analyzed using the ADINAT and ADINA codes, and results are given that verify the integrity of this structural component under the given accident condition.

  11. Assessment of potential doses to workers during postulated accident conditions at the Waste Isolation Pilot Plant

    SciTech Connect (OSTI)

    Hoover, M.D.; Newton, G.J.; Farrell, R.F.

    1996-06-01

    This qualitative hazard evaluation systematically assessed potential doses to workers during postulated accident conditions at the U.S. Department of Energy`s Waste Isolation Pilot Plant (WIPP). Postulated accidents included the spontaneous ignition of a waste drum, puncture of a waste drum by a forklift, dropping of a waste drum from a forklift, and simultaneous dropping of seven drums during a crane failure. The descriptions and estimated frequencies of occurrence for these accidents were developed by the Hazard and Operability Study for CH TRU Waste Handling System (WCAP 14312). The estimated materials at risk, damage ratios, airborne release fractions and respirable fractions for these accidents were taken from the 1995 Safety Analysis Report (SAR) update and from the DOE handbook Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities (DOE-HDBK-3010-94). A Monte Carlo simulation was used to estimate the range of worker exposures that could result from each accident. Guidelines for evaluating the adequacy of defense-in-depth for worker protection at WIPP were adopted from a scheme presented by the International Commission on Radiological Protection in its publication on Protection from Potential Exposure: A Conceptual Framework (ICRP Publication 64). Probabilities of exposures greater than 5, 50, and 300 rem were less than 10{sup -2}, 10{sup -4}, and 10{sup -6} per year, respectively. In conformance with the guidance of DOE standard 3009-94, Appendix A (draft), we emphasize that use of these evaluation guidelines is not intended to imply that these numbers constitute acceptable limits for worker exposure under accident conditions. However, in conjunction with the extensive safety assessment in the 1995 SAR update, these results indicate that the Carlsbad Area Office strategy for the assessment of hazards and accidents assures the protection of workers, as well as members of the public and the environment.

  12. Fuel Accident Condition Simulator (FACS) Furnace for Post-Irradiation Heating Tests of VHTR Fuel Compacts

    SciTech Connect (OSTI)

    Paul A Demkowicz; Paul Demkowicz; David V Laug

    2010-10-01

    Abstract Fuel irradiation testing and post-irradiation examination are currently in progress as part of the Next Generation Nuclear Plant Fuels Development and Qualification Program. The PIE campaign will include extensive accident testing of irradiated very high temperature reactor fuel compacts to verify fission product retention characteristics at high temperatures. This work will be carried out at both the Idaho National Laboratory (INL) and the Oak Ridge National Laboratory, beginning with accident tests on irradiated fuel from the AGR-1 experiment in 2010. A new furnace system has been designed, built, and tested at INL to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, Eu, and I) and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator (FACS) furnace system, as well as preliminary system calibration results.

  13. PRESSURE INTEGRITY OF 3013 CONTAINER UNDER POSTULATED ACCIDENT CONDITIONS

    SciTech Connect (OSTI)

    Rawls, G.

    2010-02-01

    A series of tests was carried out to determine the threshold for deflagration-to-detonation transition (DDT), structural loading, and structural response of the Department of Energy 3013 storage systems for the case of an accidental explosion of evolved gas within the storage containers. Three experimental fixtures were used to examine the various issues and three mixtures consisting of either stoichiometric hydrogen-oxygen, stoichiometric hydrogen-oxygen with added nitrogen, or stoichiometric hydrogen-oxygen with an added nitrogen-helium mixture were tested. Tests were carried out as a function of initial pressure from 1 to 3.5 bar and initial temperature from room temperature to 150 C. The elevated temperature tests resulted in a slight increase in the threshold pressure for DDT. The elevated temperature tests were performed to ensure the test results were bounding. Because the change was not significant the elevated temperature data are not presented in the paper. The explosions were initiated with either a small spark or a hot surface. Based on the results of these tests under the conditions investigated, it can be concluded that DDT of a stoichiometric hydrogen-oxygen mixture (and mixtures diluted with nitrogen and helium) within the 3013 containment system does not pose a threat to the structural integrity of the outer container.

  14. Assessment of potential doses to workers during postulated accident conditions at the Waste Isolation Pilot Plant

    SciTech Connect (OSTI)

    Hoover, M.D.; Farrell, R.F.; Newton, G.J.

    1995-12-01

    The recent 1995 WIPP Safety Analysis Report (SAR) Update provided detailed analyses of potential radiation doses to members of the public at the site boundary during postulated accident scenarios at the U.S. Department of Energy`s Waste Isolation Pilot Plant (WIPP). The SAR Update addressed the complete spectrum of potential accidents associated with handling and emplacing transuranic waste at WIPP, including damage to waste drums from fires, punctures, drops, and other disruptions. The report focused on the adequacy of the multiple layers of safety practice ({open_quotes}defense-in-depth{close_quotes}) at WIPP, which are designed to (1) reduce the likelihood of accidents and (2) limit the consequences of those accidents. The safeguards which contribute to defense-in-depth at WIPP include a substantial array of inherent design features, engineered controls, and administrative procedures. The SAR Update confirmed that the defense-in-depth at WIPP is adequate to assure the protection of the public and environment. As a supplement to the 1995 SAR Update, we have conducted additional analyses to confirm that these controls will also provide adequate protection to workers at the WIPP. The approaches and results of the worker dose assessment are summarized here. In conformance with the guidance of DOE Standard 3009-94, we emphasize that use of these evaluation guidelines is not intended to imply that these numbers constitute acceptable limits for worker exposures under accident conditions. However, in conjunction with the extensive safety assessment in the 1995 SAR Update, these results indicate that the Carlsbad Area Office strategy for the assessment of hazards and accidents assures the protection of workers, members of the public, and the environment.

  15. Estimate of radionuclide release characteristics into containment under severe accident conditions. Final report

    SciTech Connect (OSTI)

    Nourbakhsh, H.P.

    1993-11-01

    A detailed review of the available light water reactor source term information is presented as a technical basis for development of updated source terms into the containment under severe accident conditions. Simplified estimates of radionuclide release and transport characteristics are specified for each unique combination of the reactor coolant and containment system combinations. A quantitative uncertainty analysis in the release to the containment using NUREG-1150 methodology is also presented.

  16. The Fuel Accident Condition Simulator (FACS) furnace system for high temperature performance testing of VHTR fuel

    SciTech Connect (OSTI)

    Paul A. Demkowicz; David V. Laug; Dawn M. Scates; Edward L. Reber; Lyle G. Roybal; John B. Walter; Jason M. Harp; Robert N. Morris

    2012-10-01

    The AGR-1 irradiation of TRISO-coated particle fuel specimens was recently completed and represents the most successful such irradiation in US history, reaching peak burnups of greater than 19% FIMA with zero failures out of 300,000 particles. An extensive post-irradiation examination (PIE) campaign will be conducted on the AGR-1 fuel in order to characterize the irradiated fuel properties, assess the in-pile fuel performance in terms of coating integrity and fission metals release, and determine the fission product retention behavior during high temperature safety testing. A new furnace system has been designed, built, and tested to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000 degrees C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, and Eu), iodine, and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator furnace system and the associated fission gas monitoring system, as well as preliminary system calibration results.

  17. Status report of advanced cladding modeling work to assess cladding performance under accident conditions

    SciTech Connect (OSTI)

    B.J. Merrill; Shannon M. Bragg-Sitton

    2013-09-01

    Scoping simulations performed using a severe accident code can be applied to investigate the influence of advanced materials on beyond design basis accident progression and to identify any existing code limitations. In 2012 an effort was initiated to develop a numerical capability for understanding the potential safety advantages that might be realized during severe accident conditions by replacing Zircaloy components in light water reactors (LWRs) with silicon carbide (SiC) components. To this end, a version of the MELCOR code, under development at the Sandia National Laboratories in New Mexico (SNL/NM), was modified by replacing Zircaloy for SiC in the MELCOR reactor core oxidation and material properties routines. The modified version of MELCOR was benchmarked against available experimental data to ensure that present SiC oxidation theory in air and steam were correctly implemented in the code. Additional modifications have been implemented in the code in 2013 to improve the specificity in defining components fabricated from non-standard materials. An overview of these modifications and the status of their implementation are summarized below.

  18. DYNAMIC ANALYSIS OF HANFORD UNIRRADIATED FUEL PACKAGE SUBJECTED TO SEQUENTIAL LATERAL LOADS IN HYPOTHETICAL ACCIDENT CONDITIONS

    SciTech Connect (OSTI)

    Wu, T

    2008-04-30

    Large fuel casks present challenges when evaluating their performance in the Hypothetical Accident Conditions (HAC) specified in the Code of Federal Regulations Title 10 part 71 (10CFR71). Testing is often limited by cost, difficulty in preparing test units and the limited availability of facilities which can carry out such tests. In the past, many casks were evaluated without testing by using simplified analytical methods. This paper presents a numerical technique for evaluating the dynamic responses of large fuel casks subjected to sequential HAC loading. A nonlinear dynamic analysis was performed for a Hanford Unirradiated Fuel Package (HUFP) [1] to evaluate the cumulative damage after the hypothetical accident Conditions of a 30-foot lateral drop followed by a 40-inch lateral puncture as specified in 10CFR71. The structural integrity of the containment vessel is justified based on the analytical results in comparison with the stress criteria, specified in the ASME Code, Section III, Appendix F [2], for Level D service loads. The analyzed cumulative damages caused by the sequential loading of a 30-foot lateral drop and a 40-inch lateral puncture are compared with the package test data. The analytical results are in good agreement with the test results.

  19. Oxidation of SiC cladding under Loss of Coolant Accident (LOCA) conditions in LWRs

    SciTech Connect (OSTI)

    Lee, Y.; Yue, C.; Arnold, R. P.; McKrell, T. J.; Kazimi, M. S.

    2012-07-01

    An experimental assessment of Silicon Carbide (SiC) cladding oxidation rate in steam under conditions representative of Loss of Coolant Accidents (LOCA) in light water reactors (LWRs) was conducted. SiC oxidation tests were performed with monolithic alpha phase tubular samples in a vertical quartz tube at a steam temperature of 1140 deg. C and steam velocity range of 1 to 10 m/sec, at atmospheric pressure. Linear weight loss of SiC samples due to boundary layer controlled reaction of silica scale (SiO{sub 2} volatilization) was experimentally observed. The weight loss rate increased with increasing steam flow rate. Over the range of test conditions, SiC oxidation rates were shown to be about 3 orders of magnitude lower than the oxidation rates of zircaloy 4. A SiC volatilization correlation for developing laminar flow in a vertical channel is formulated. (authors)

  20. Neutronics and Fuel Performance Evaluation of Accident Tolerant Fuel under Normal Operation Conditions

    SciTech Connect (OSTI)

    Xu Wu; Piyush Sabharwall; Jason Hales

    2014-07-01

    This report details the analysis of neutronics and fuel performance analysis for enhanced accident tolerance fuel, with Monte Carlo reactor physics code Serpent and INL’s fuel performance code BISON, respectively. The purpose is to evaluate two of the most promising candidate materials, FeCrAl and Silicon Carbide (SiC), as the fuel cladding under normal operating conditions. Substantial neutron penalty is identified when FeCrAl is used as monolithic cladding for current oxide fuel. From the reactor physics standpoint, application of the FeCrAl alloy as coating layer on surface of zircaloy cladding is possible without increasing fuel enrichment. Meanwhile, SiC brings extra reactivity and the neutron penalty is of no concern. Application of either FeCrAl or SiC could be favorable from the fuel performance standpoint. Detailed comparison between monolithic cladding and hybrid cladding (cladding + coating) is discussed. Hybrid cladding is more practical based on the economics evaluation during the transition from current UO2/zircaloy to Accident Tolerant Fuel (ATF) system. However, a few issues remain to be resolved, such as the creep behavior of FeCrAl, coating spallation, inter diffusion with zirconium, etc. For SiC, its high thermal conductivity, excellent creep resistance, low thermal neutron absorption cross section, irradiation stability (minimal swelling) make it an excellent candidate materials for future nuclear fuel/cladding system.

  1. Boiling water reactor fuel behavior at burnup of 26 GWd/tonne U under reactivity-initiated accident conditions

    SciTech Connect (OSTI)

    Nakamura, Takehiko; Yoshinaga, Makio . Dept. of Reactor Safety Research); Sobajima, Makoto ); Ishijima, Kiyomi; Fujishiro, Toshio . Dept. of Reactor Safety Research)

    1994-10-01

    Irradiated boiling water reactor (BWR) fuel behavior under reactivity-initiated accident (RIA) conditions was investigated in the Nuclear Safety Research Reactor (NSRR) of the Japan Atomic Energy Research Institute. Short test fuel rods, refabricated from a commercial 7 x 7 type BWR fuel rod at a burnup of 26 GWd/ tonne U, were pulse irradiated in the NSRR under simulated cooled startup RIA conditions of the BWRs. Thermal energy from 230 J/g fuel (55 cal/g fuel) to 410 J/g fuel (98 cal/g fuel) was promptly subjected to the test fuel rods by pulse irradiation within [approximately] 10 ms. The peak fuel enthalpies are believed to be the same as the prompt energy depositions. The test fuel rods demonstrated characteristic behavior of the irradiated fuel rods under the accident conditions, such as enhanced pellet cladding mechanical interaction (PCMI) and fission gas release. However, all the fuel rods survived the accident conditions with considerable margins. Simulations by the FRAP-T6 code and fresh fuel rod tests under the same RIA conditions highlighted the burnup effects on the accident fuel performance. The tests and the simulation suggested that the BWR fuel would possibly fail by a cladding burst due to fission gas release during the cladding temperature escalation rather than the PCMI under the cold startup RIA conditions of a severe power burst.

  2. Generation IV benchmarking of TRISO fuel performance models under accident conditions. Modeling input data

    SciTech Connect (OSTI)

    Blaise Collin

    2014-09-01

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: the modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release; the modeling of the AGR-1 and HFR-EU1bis safety testing experiments; and, the comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from ''Case 5'' of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. ''Case 5'' of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to ''effects of the numerical calculation method rather than the physical model''[IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison with each other. The participants should read this document

  3. High-Burnup BWR Fuel Behavior Under Simulated Reactivity-Initiated Accident Conditions

    SciTech Connect (OSTI)

    Nakamura, Takehiko; Kusagaya, Kazuyuki; Fuketa, Toyoshi; Uetsuka, Hiroshi

    2002-06-15

    Boiling water reactor (BWR) fuel at 56 to 61 GWd/tonne U was pulse irradiated in the Nuclear Safety Research Reactor (NSRR) to investigate fuel behavior under cold startup reactivity-initiated accident conditions. Current Japanese 8 x 8 type Step II BWR fuel from Fukushima Daini Unit 2 was refabricated to short segments, and thermal energy from 272 to 586 J/g (65 to 140 cal/g) was promptly inserted to the test rods. Cladding deformation of the BWR fuel by the pulse irradiation was smaller than that of pressurized water reactor (PWR) fuels. However, cladding failure occurred in tests with fuel at burnup of 61 GWd/tonne U at fuel enthalpies of 260 to 360 J/g (62 to 86 cal/g) during the early stages of transients, while the cladding remained cool. The failure was comparable to the one observed in high-burnup PWR fuel tests, in which embrittled cladding with dense hydride precipitation near the outer surface was fractured due to pellet cladding mechanical interaction. Transient fission gas release by the pulse irradiation was {approx}9.6 to 17% depending on the peak fuel enthalpy.

  4. Early results from an experimental program to determine the behavior of containment piping penetration bellows subjected to severe accident conditions

    SciTech Connect (OSTI)

    Lambert, L.D.; Parks, M.B.

    1994-09-01

    Containment piping penetration bellows are an integral part of the pressure boundary in steel containments in the United States (US). Their purpose is to minimize loading on the containment shell caused by differential movement between the piping and the containment. This differential movement is typically caused by thermal gradients generated during startup and shutdown of the reactor, but can be caused by earthquake, a loss-of-coolant accident (LOCA), or ``severe`` accidents. In the event of a severe accident, the bellows would be subjected to pressure, temperature, and deflection well beyond the design basis. Most bellows are installed such that they would be subjected to elevated internal pressure, elevated temperature, axial compression, and lateral deflection during a severe accident. A few bellows would be subjected to external pressure and axial elongation, as well as elevated temperature and lateral deflection. The purpose of this experimental program is to examine the potential for leakage of containment bellows during a severe accident. The test series subjects bellows to various levels and combinations of internal pressure, elevated temperature, axial compression or elongation, and lateral deformation. The experiments are being conducted in two parts. For Part 1, all bellows specimens are tested in ``like-new`` condition, without regard for the possible degrading effect of corrosion that has been observed in some containment piping bellows in the US Part I testing, which included 13 bellows tests, has been completed. The second part of the experimental program, in which bellows are subjected to simulated corrosive environments prior to testing, has just just begun. The Part I experiments have shown that bellows in ``like-new`` condition can withstand elevated temperatures and pressures along with large deformations before leaking. In most cases, the like-new bellows were fully compressed without developing any leakage.

  5. Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

    SciTech Connect (OSTI)

    Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

    1984-04-01

    The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables.

  6. Revisiting Insights from Three Mile Island Unit 2 Postaccident Examinations and Evaluations in View of the Fukushima Daiichi Accident

    SciTech Connect (OSTI)

    Rempe, Joy; Farmer, Mitchell; Corradini, Michael; Ott, Larry; Gauntt, Randall; Powers, Dana

    2012-11-01

    The Three Mile Island Unit 2 (TMI-2) accident, which occurred on March 28, 1979, led industry and regulators to enhance strategies to protect against severe accidents in commercial nuclear power plants. Investigations in the years after the accident concluded that at least 45% of the core had melted and that nearly 19 tonnes of the core material had relocated to the lower head. Postaccident examinations indicate that about half of that material formed a solid layer near the lower head and above it was a layer of fragmented rubble. As discussed in this paper, numerous insights related to pressurized water reactor accident progression were gained from postaccident evaluations of debris, reactor pressure vessel (RPV) specimens, and nozzles taken from the RPV. In addition, information gleaned from TMI-2 specimen evaluations and available data from plant instrumentation were used to improve severe accident simulation models that form the technical basis for reactor safety evaluations. Finally, the TMI-2 accident led the nuclear community to dedicate considerable effort toward understanding severe accident phenomenology as well as the potential for containment failure. Because available data suggest that significant amounts of fuel heated to temperatures near melting, the events at Fukushima Daiichi Units 1, 2, and 3 offer an unexpected opportunity to gain similar understanding about boiling water reactor accident progression. To increase the international benefit from such an endeavor, we recommend that an international effort be initiated to (a) prioritize data needs; (b) identify techniques, samples, and sample evaluations needed to address each information need; and (c) help finance acquisition of the required data and conduct of the analyses.

  7. Computational Assessment of the GT-MHR Graphite Core Support Structural Integrity in Air-Ingress Accident Condition

    SciTech Connect (OSTI)

    Jong B. Lim; Eung S. Kim; Chang H. Oh; Richard R. Schultz; David A. Petti

    2008-10-01

    The objective of this project was to perform stress analysis for graphite support structures of the General Atomics’ 600 MWth GT-MHR prismatic core design using ABAQUS ® (ver. 6.75) to assess their structural integrity in air-ingress accident conditions where the structure weakens over time due to oxidation damages. The graphite support structures of prismatic type GT-MHR was analyzed based on the change of temperature, burn-off and corrosion depth during the accident period predicted by GAMMA, a multi-dimensional gas multi-component mixture analysis code developed in the Republic of Korea (ROK)/United States (US) International –Nuclear Engineering Research Initiative (I-NERI) project. Both the loading and thermal stresses were analyzed, but the thermal stress was not significant, leaving the loading stress to be the major factor. The mechanical strengths are exceeded between 11 to 11.5 days after loss-of-coolant-accident (LOCA), corresponding to 5.5 to 6 days after the start of natural convection.

  8. Comparisons of the SCDAP computer code with bundle data under severe accident conditions. [PWR; BWR

    SciTech Connect (OSTI)

    Allison, C.M.; Beers, G.H.

    1983-01-01

    The SCDAP computer code, which is being developed under the sponsorship of the United States Nuclear Regulatory Commission, models the progression of light water reactor core damage including core heatup, core disruption and debris formation, debris heatup, and debris melting. SCDAP is being used to help identify and understand the phenomena that control core behavior during a severe accident, to help quantify uncertainties in risk assessment analysis, and to support planning and interpretation of severe fuel damage experiments and data. Comparisons between SCDAP calculations and the experimental data showed good agreement. Calculated and measured bundle temperatures for SFD-ST were within 200 K for the entire bundle and within 20 K for maximum cladding temperatures. For ESSI-2, calculated and measured maximum cladding temperatures were within 50 K, and the extensive liquefaction and relocation that was calculated was in agreement with experimental results.

  9. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions

    SciTech Connect (OSTI)

    Heames, T.J. ); Williams, D.A.; Johns, N.A.; Chown, N.M. ); Bixler, N.E.; Grimley, A.J. ); Wheatley, C.J. )

    1990-10-01

    This document provides a description of a model of the radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident. This document serves as the user's manual for the computer code called VICTORIA, based upon the model. The VICTORIA code predicts fission product release from the fuel, chemical reactions between fission products and structural materials, vapor and aerosol behavior, and fission product decay heating. This document provides a detailed description of each part of the implementation of the model into VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided. The VICTORIA code was developed upon a CRAY-XMP at Sandia National Laboratories in the USA and a CRAY-2 and various SUN workstations at the Winfrith Technology Centre in England. 60 refs.

  10. A view of treatment process of melted nuclear fuel on a severe accident plant using a molten salt system

    SciTech Connect (OSTI)

    Fujita, R.; Takahashi, Y.; Nakamura, H.; Mizuguchi, K.; Oomori, T.

    2013-07-01

    At severe accident such as Fukushima Daiichi Nuclear Power Plant Accident, the nuclear fuels in the reactor would melt and form debris which contains stable UO2-ZrO2 mixture corium and parts of vessel such as zircaloy and iron component. The requirements for solution of issues are below; -) the reasonable treatment process of the debris should be simple and in-situ in Fukushima Daiichi power plant, -) the desirable treatment process is to take out UO{sub 2} and PuO{sub 2} or metallic U and TRU metal, and dispose other fission products as high level radioactive waste; and -) the candidate of treatment process should generate the smallest secondary waste. Pyro-process has advantages to treat the debris because of the high solubility of the debris and its total process feasibility. Toshiba proposes a new pyro-process in molten salts using electrolysing Zr before debris fuel being treated.

  11. Study of Air Ingress Across the Duct During the Accident Conditions

    SciTech Connect (OSTI)

    Hassan, Yassin

    2013-05-06

    The goal of this project is to study the fundamental physical phenomena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a rupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefore, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that minimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlying phenomena. The combination of inter-diffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. This project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses; and, Perform computational fluid dynamics analysis of air ingress phenomena.

  12. TRUMP-BD: A computer code for the analysis of nuclear fuel assemblies under severe accident conditions

    SciTech Connect (OSTI)

    Lombardo, N.J.; Marseille, T.J.; White, M.D.; Lowery, P.S.

    1990-06-01

    TRUMP-BD (Boil Down) is an extension of the TRUMP (Edwards 1972) computer program for the analysis of nuclear fuel assemblies under severe accident conditions. This extension allows prediction of the heat transfer rates, metal-water oxidation rates, fission product release rates, steam generation and consumption rates, and temperature distributions for nuclear fuel assemblies under core uncovery conditions. The heat transfer processes include conduction in solid structures, convection across fluid-solid boundaries, and radiation between interacting surfaces. Metal-water reaction kinetics are modeled with empirical relationships to predict the oxidation rates of steam-exposed Zircaloy and uranium metal. The metal-water oxidation models are parabolic in form with an Arrhenius temperature dependence. Uranium oxidation begins when fuel cladding failure occurs; Zircaloy oxidation occurs continuously at temperatures above 13000{degree}F when metal and steam are available. From the metal-water reactions, the hydrogen generation rate, total hydrogen release, and temporal and spatial distribution of oxide formations are computed. Consumption of steam from the oxidation reactions and the effect of hydrogen on the coolant properties is modeled for independent coolant flow channels. Fission product release from exposed uranium metal Zircaloy-clad fuel is modeled using empirical time and temperature relationships that consider the release to be subject to oxidation and volitization/diffusion ( bake-out'') release mechanisms. Release of the volatile species of iodine (I), tellurium (Te), cesium (Ce), ruthenium (Ru), strontium (Sr), zirconium (Zr), cerium (Cr), and barium (Ba) from uranium metal fuel may be modeled.

  13. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions. Revision 1

    SciTech Connect (OSTI)

    Heams, T J; Williams, D A; Johns, N A; Mason, A; Bixler, N E; Grimley, A J; Wheatley, C J; Dickson, L W; Osborn-Lee, I; Domagala, P; Zawadzki, S; Rest, J; Alexander, C A; Lee, R Y

    1992-12-01

    The VICTORIA model of radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident is described. It has been developed by the USNRC to define the radionuclide phenomena and processes that must be considered in systems-level models used for integrated analyses of severe accident source terms. The VICTORIA code, based upon this model, predicts fission product release from the fuel, chemical reactions involving fission products, vapor and aerosol behavior, and fission product decay heating. Also included is a detailed description of how the model is implemented in VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided.

  14. Accident Investigations

    Directives, Delegations, and Requirements [Office of Management (MA)]

    1996-04-26

    To prescribe requirements for conducting investigations of certain accidents occurring at Department of Energy (DOE) operations and sites; to improve the environment, safety and health for DOE, contractors, and the public; and to prevent the recurrence of such accidents. Chg 2, 4-26-96

  15. Accident Investigations

    Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-10-26

    To prescribe requirements for conducting investigations of certain accidents occurring at Department of Energy (DOE) operations and sites; to improve the environment , safety and health for DOE, contractors, and the public; and to prevent the recurrence of such accidents. Chg 1, 10-26-95. Cancels parts of DOE 5484.1

  16. Boiling Water Reactor Fuel Behavior Under Reactivity-Initiated-Accident Conditions at Burnup of 41 to 45 GWd/tonne U

    SciTech Connect (OSTI)

    Nakamura, Takehiko; Yoshinaga, Makio; Takahashi, Masato; Okonogi, Kazunari; Ishijima, Kiyomi

    2000-02-15

    Boiling water reactor (BWR) fuel at burnup of 41 to 45 GWd/tonne U was pulse irradiated in the Nuclear Safety Research Reactor (NSRR) to investigate fuel behavior under cold startup reactivity-initiated-accident conditions. Current Japanese BWR fuel, 8 x 8BJ type (Step I), from Fukushima-Daiichi Unit 3 was refabricated into short segments, and the test rods were promptly subjected to thermal energy from 293 to 607 J/g (70 to 145 cal/g) within {approx}20 ms. The fuel cladding was ductile enough to survive the prompt deformation due to pellet cladding mechanical interaction, while the plastic hoop strain reached 1.5% at the peak location. Transient fission gas release by the pulse irradiation varied from 3.1 to 8.2%, depending on the peak fuel enthalpy and the steady-state operation conditions.

  17. Accident Investigations

    Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-03-04

    This Order prescribes organizational responsibilities, authorities, and requirements for conducting investigations of certain accidents occurring at DOE sites, facilities, areas, operations, and activities. Supersedes DOE O 225.1A. Cancels DOE G 225.1A-1.

  18. Accident management information needs

    SciTech Connect (OSTI)

    Hanson, D.J.; Ward, L.W.; Nelson, W.R.; Meyer, O.R. (EG and G Idaho, Inc., Idaho Falls, ID (USA))

    1990-04-01

    In support of the US Nuclear Regulatory Commission (NRC) Accident Management Research Program, a methodology has been developed for identifying the plant information needs necessary for personnel involved in the management of an accident to diagnose that an accident is in progress, select and implement strategies to prevent or mitigate the accident, and monitor the effectiveness of these strategies. This report describes the methodology and presents an application of this methodology to a Pressurized Water Reactor (PWR) with a large dry containment. A risk-important severe accident sequence for a PWR is used to examine the capability of the existing measurements to supply the necessary information. The method includes an assessment of the effects of the sequence on the measurement availability including the effects of environmental conditions. The information needs and capabilities identified using this approach are also intended to form the basis for more comprehensive information needs assessment performed during the analyses and development of specific strategies for use in accident management prevention and mitigation. 3 refs., 16 figs., 7 tabs.

  19. Mechanistic prediction of fission-product release under normal and accident conditions: key uncertainties that need better resolution. [PWR; BWR

    SciTech Connect (OSTI)

    Rest, J.

    1983-09-01

    A theoretical model has been used for predicting the behavior of fission gas and volatile fission products (VFPs) in UO/sub 2/-base fuels during steady-state and transient conditions. This model represents an attempt to develop an efficient predictive capability for the full range of possible reactor operating conditions. Fission products released from the fuel are assumed to reach the fuel surface by successively diffusing (via atomic and gas-bubble mobility) from the grains to grain faces and then to the grain edges, where the fission products are released through a network of interconnected tunnels of fission-gas induced and fabricated porosity. The model provides for a multi-region calculation and uses only one size class to characterize a distribution of fission gas bubbles.

  20. Accident Response Group | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Accident Response Group

  1. Multiloop integral system test (MIST): Test Group 31, SBLOCA (small-break loss-of-coolant accident) with varied boundary conditions

    SciTech Connect (OSTI)

    Gloudemans, J.R. . Nuclear Power Div.)

    1989-07-01

    The multiloop integral system test (MIST) is part of a multiphase program started in 1983 to address small-break loss-of-coolant accidents (SBLOCAs) specific to Babcock and Wilcox-designed plants. MIST is sponsored by the US Nuclear Regulatory Commission, the Babcock and Wilcox Owners Group, the Electric Power Research Institute, and Babcock and Wilcox. The unique features of the Babcock and Wilcox design, specifically the hot leg U-bends and steam generators, prevented the use of existing integral system data or existing integral system facilities to address the thermal-hydraulic SBLOCA questions. MIST and two other supporting facilities were specifically designed and constructed for this program, and an existing facility --- the once-through integral system (OTIS) --- was also used. Data from MIST and the other facilities will be used to benchmark the adequacy of system codes, such as RELAP-5 and TRAC, for predicting abnormal plant transients. The MIST program is reported in 11 volumes. The program is summarized in Volume 1; Volumes 2 through 8 describe groups of tests by test type; Volume 9 presents inter-group comparisons; Volume 10 provides comparisons between the calculations of RELAP5 MOD2 and MIST observations, and Volume 11 presents the later, Phase 4 tests. This is Volume 3 pertaining to Test Group 31, Boundary Conditions Variations. The specifications, conduct, observations, and results of these tests are described. 8 refs., 328 figs., 15 tabs.

  2. The Effect of Accident Conditions on the Molten Core Material Relocation into the Lower Head of a PWR Vessel with Application to TMI-2

    SciTech Connect (OSTI)

    An Xuegao; Dhir, Vijay K.; Okrent, David

    2000-11-15

    The damage progression of the reactor core and the slumping mechanism of molten material to the lower head of the reactor vessel were examined through simulation of severe accident scenarios that lead to large-scale core damage. The calculations were carried out on a Three Mile Island Unit 2 configuration using the computer code SCDAP/RELAP5/MOD3.2.Different accident scenarios were simulated. The high-pressure injection and makeup flow rates were changed. The extreme case with no water being added during the accident was examined. Reflood by restart of coolant pump 2B was also studied. Finally, the size of the power-operated relief valve opening was also changed. The effects of these accident scenarios on the accident progression and the core damage process were studied.It is concluded that, according to code MOD3.2, the molten material slumped to the lower head of the reactor vessel when the junction of the top and side crusts failed after the molten pool had reached the periphery of the core. When the effective stress caused by pressure imbalance inside and outside of the crust became larger than the ultimate strength of the crust, the crust failed mechanically.

  3. Accident Investigation of the June 17, 2012, Construction Accident...

    Office of Environmental Management (EM)

    7, 2012, Construction Accident - Structural Steel Collapse at The Over pack Storage ... Accident Investigation of the June 17, 2012, Construction Accident - Structural Steel ...

  4. Severe Accident Studies

    Office of Environmental Management (EM)

    ... of fuel rods due to extreme thermal environment of the fire scenario Newhall Pass ... package * Analyze and update statistics for accidents (e.g., frequency of road ...

  5. December 2015 Most Viewed Documents for Fission And Nuclear Technologies |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information December 2015 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (1977) 432 System Definition and Analysis: Power Plant Design and Layout NONE (1996) 323 Stress analysis and evaluation of a rectangular pressure vessel. [For equipment for sampling Hanford tank

  6. June 2015 Most Viewed Documents for Fission And Nuclear Technologies |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information June 2015 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (1977) 305 System Definition and Analysis: Power Plant Design and Layout NONE (1996) 296 Stress analysis and evaluation of a rectangular pressure vessel. [For equipment for sampling Hanford tank radwaste]

  7. September 2013 Most Viewed Documents for Fission And Nuclear Technologies |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information September 2013 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (1977) 133 Stress analysis and evaluation of a rectangular pressure vessel. [For equipment for sampling Hanford tank radwaste] Rezvani, M.A.; Ziada, H.H. (Westinghouse Hanford Co., Richland, WA (United

  8. September 2015 Most Viewed Documents for Fission And Nuclear Technologies |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information September 2015 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (1977) 444 System Definition and Analysis: Power Plant Design and Layout NONE (1996) 273 Stress analysis and evaluation of a rectangular pressure vessel. [For equipment for sampling Hanford tank

  9. Microsoft Word - Unrelated Accident

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    For Immediate Release Truck Accident Did Not Involve WIPP Shipment CARLSBAD, N.M., October 1, 2009 - A Wednesday night truck accident north of Albuquerque on Highway 165 that involved an 18-wheeler is not related to Waste Isolation Pilot Plant (WIPP) transuranic waste shipments. Involved in the accident was a load of new, unused 55-gallon drums manufactured in Carlsbad that was en route to Richland, Washington. The Waste Isolation Pilot Plant is a U.S. Department of Energy facility designed to

  10. Accident resistant transport container

    DOE Patents [OSTI]

    Andersen, John A.; Cole, James K.

    1980-01-01

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  11. Accident resistant transport container

    DOE Patents [OSTI]

    Anderson, J.A.; Cole, K.K.

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  12. HTGR severe accident sequence analysis

    SciTech Connect (OSTI)

    Harrington, R.M.; Ball, S.J.; Kornegay, F.C.

    1982-01-01

    Thermal-hydraulic, fission product transport, and atmospheric dispersion calculations are presented for hypothetical severe accident release paths at the Fort St. Vrain (FSV) high temperature gas cooled reactor (HTGR). Off-site radiation exposures are calculated for assumed release of 100% of the 24 hour post-shutdown core xenon and krypton inventory and 5.5% of the iodine inventory. The results show conditions under which dose avoidance measures would be desirable and demonstrate the importance of specific release characteristics such as effective release height. 7 tables.

  13. Accident progression event tree analysis for postulated severe accidents at N Reactor

    SciTech Connect (OSTI)

    Wyss, G.D.; Camp, A.L.; Miller, L.A.; Dingman, S.E.; Kunsman, D.M. ); Medford, G.T. )

    1990-06-01

    A Level II/III probabilistic risk assessment (PRA) has been performed for N Reactor, a Department of Energy (DOE) production reactor located on the Hanford reservation in Washington. The accident progression analysis documented in this report determines how core damage accidents identified in the Level I PRA progress from fuel damage to confinement response and potential releases the environment. The objectives of the study are to generate accident progression data for the Level II/III PRA source term model and to identify changes that could improve plant response under accident conditions. The scope of the analysis is comprehensive, excluding only sabotage and operator errors of commission. State-of-the-art methodology is employed based largely on the methods developed by Sandia for the US Nuclear Regulatory Commission in support of the NUREG-1150 study. The accident progression model allows complex interactions and dependencies between systems to be explicitly considered. Latin Hypecube sampling was used to assess the phenomenological and systemic uncertainties associated with the primary and confinement system responses to the core damage accident. The results of the analysis show that the N Reactor confinement concept provides significant radiological protection for most of the accident progression pathways studied.

  14. Federally Led Accident Investigation Reports | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Federally Led Accident Investigation Reports Federally Led Accident Investigation Reports Includes Pre-March 2011 Type A Reports June 1, 1999 Type A Accident Investigation Board...

  15. Chernobyl Nuclear Accident | National Nuclear Security Administration |

    National Nuclear Security Administration (NNSA)

    (NNSA) Chernobyl Nuclear Accident Chernobyl Nuclear Accident Chernobyl, Ukraine A catastrophic nuclear accident occurs at Chernobyl Reactor #4 in the then Soviet Republic of Ukraine

  16. Enhanced Accident Tolerant LWR Fuels: Metrics Development

    SciTech Connect (OSTI)

    Shannon Bragg-Sitton; Lori Braase; Rose Montgomery; Chris Stanek; Robert Montgomery; Lance Snead; Larry Ott; Mike Billone

    2013-09-01

    The Department of Energy (DOE) Fuel Cycle Research and Development (FCRD) Advanced Fuels Campaign (AFC) is conducting research and development on enhanced Accident Tolerant Fuels (ATF) for light water reactors (LWRs). This mission emphasizes the development of novel fuel and cladding concepts to replace the current zirconium alloy-uranium dioxide (UO2) fuel system. The overall mission of the ATF research is to develop advanced fuels/cladding with improved performance, reliability and safety characteristics during normal operations and accident conditions, while minimizing waste generation. The initial effort will focus on implementation in operating reactors or reactors with design certifications. To initiate the development of quantitative metrics for ATR, a LWR Enhanced Accident Tolerant Fuels Metrics Development Workshop was held in October 2012 in Germantown, MD. This paper summarizes the outcome of that workshop and the current status of metrics development for LWR ATF.

  17. Next-generation nuclear fuel withstands high-temperature accident...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Next-generation nuclear fuel withstands high-temperature accident conditions IDAHO FALLS - A safer and more efficient nuclear fuel is on the horizon. A team of researchers at the ...

  18. Severe Accident Test Station Design Document

    SciTech Connect (OSTI)

    Snead, Mary A.; Yan, Yong; Howell, Michael; Keiser, James R.; Terrani, Kurt A.

    2015-09-01

    The purpose of the ORNL severe accident test station (SATS) is to provide a platform for evaluation of advanced fuels under projected beyond design basis accident (BDBA) conditions. The SATS delivers the capability to map the behavior of advanced fuels concepts under accident scenarios across various temperature and pressure profiles, steam and steam-hydrogen gas mixtures, and thermal shock. The overall facility will include parallel capabilities for examination of fuels and irradiated materials (in-cell) and non-irradiated materials (out-of-cell) at BDBA conditions as well as design basis accident (DBA) or loss of coolant accident (LOCA) conditions. Also, a supporting analytical infrastructure to provide the data-needs for the fuel-modeling components of the Fuel Cycle Research and Development (FCRD) program will be put in place in a parallel manner. This design report contains the information for the first, second and third phases of design and construction of the SATS. The first phase consisted of the design and construction of an out-of-cell BDBA module intended for examination of non-irradiated materials. The second phase of this work was to construct the BDBA in-cell module to test irradiated fuels and materials as well as the module for DBA (i.e. LOCA) testing out-of-cell, The third phase was to build the in-cell DBA module. The details of the design constraints and requirements for the in-cell facility have been closely captured during the deployment of the out-of-cell SATS modules to ensure effective future implementation of the in-cell modules.

  19. Accident Investigation of the June 17, 2012, Construction Accident -

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Structural Steel Collapse at The Over pack Storage Expansion #2 at the Naval Reactors Facility at the Idaho National Laboratory, Idaho Falls, Idaho | Department of Energy 7, 2012, Construction Accident - Structural Steel Collapse at The Over pack Storage Expansion #2 at the Naval Reactors Facility at the Idaho National Laboratory, Idaho Falls, Idaho Accident Investigation of the June 17, 2012, Construction Accident - Structural Steel Collapse at The Over pack Storage Expansion #2 at the

  20. Severe accident approach - final report. Evaluation of design measures for severe accident prevention and consequence mitigation.

    SciTech Connect (OSTI)

    Tentner, A. M.; Parma, E.; Wei, T.; Wigeland, R.; Nuclear Engineering Division; SNL; INL

    2010-03-01

    An important goal of the US DOE reactor development program is to conceptualize advanced safety design features for a demonstration Sodium Fast Reactor (SFR). The treatment of severe accidents is one of the key safety issues in the design approach for advanced SFR systems. It is necessary to develop an in-depth understanding of the risk of severe accidents for the SFR so that appropriate risk management measures can be implemented early in the design process. This report presents the results of a review of the SFR features and phenomena that directly influence the sequence of events during a postulated severe accident. The report identifies the safety features used or proposed for various SFR designs in the US and worldwide for the prevention and/or mitigation of Core Disruptive Accidents (CDA). The report provides an overview of the current SFR safety approaches and the role of severe accidents. Mutual understanding of these design features and safety approaches is necessary for future collaborations between the US and its international partners as part of the GEN IV program. The report also reviews the basis for an integrated safety approach to severe accidents for the SFR that reflects the safety design knowledge gained in the US during the Advanced Liquid Metal Reactor (ALMR) and Integral Fast Reactor (IFR) programs. This approach relies on inherent reactor and plant safety performance characteristics to provide additional safety margins. The goal of this approach is to prevent development of severe accident conditions, even in the event of initiators with safety system failures previously recognized to lead directly to reactor damage.

  1. April 2013 Most Viewed Documents for Fission And Nuclear Technologies |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information April 2013 Most Viewed Documents for Fission And Nuclear Technologies Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (null) 298 Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (null) 292 Graphite design handbook Ho, F.H. (1988) 216 System Definition and Analysis: Power Plant Design and Layout NONE

  2. July 2013 Most Viewed Documents for Fission And Nuclear Technologies |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information July 2013 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (1977) 286 Graphite design handbook Ho, F.H. (1988) 136 Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (1977) 123 Stress analysis and evaluation of a rectangular pressure vessel. [For

  3. June 2014 Most Viewed Documents for Fission And Nuclear Technologies |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information June 2014 Most Viewed Documents for Fission And Nuclear Technologies Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (1977) 78 Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (1977) 71 Review of thorium fuel reprocessing experience Brooksbank, R.E.; McDuffee, W.T.; Rainey, R.H. (1978) 70 Stress

  4. Accident Investigation Handbook

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    SENSI NOT MEAS UREMENT TIVE D DOE-HDBK-1 1208-2012 July 2012 DOE E HA ANDBOOK K Ac ccide ent and d Op pera ational Sa afety y An naly ysis Volume e I: Ac ccide ent A Analy ysis Tec chniq ques U.S. Depar rtmen nt of En nergy Was shingto on, D.C C. 205 85 DOE-HDBK-1208-2012 INTRODUCTION - HANDBOOK APPLICATION AND SCOPE Accident Investigations (AI) and Operational Safety Reviews (OSR) are valuable for evaluating technical issues, safety management systems and human performance and environmental

  5. Accident Investigation Report- Fire Report

    Energy.gov [DOE]

    On February 7, 2014, Deputy Assistant Secretary, Safety, Security, and Quality Programs Environmental Management, DOE, formally appointed an Accident Investigation Board to investigate an...

  6. Guidance for Radiation Accident Management

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Procedure Demonstration Introduction Radioactive materials are among the many kinds of hazardous substances emergency responders might have to deal with in an accident. It is ...

  7. First Responders and Criticality Accidents

    SciTech Connect (OSTI)

    Valerie L. Putman; Douglas M. Minnema

    2005-11-01

    Nuclear criticality accident descriptions typically include, but do not focus on, information useful to first responders. We studied these accidents, noting characteristics to help (1) first responders prepare for such an event and (2) emergency drill planners develop appropriate simulations for training. We also provide recommendations to help people prepare for such events in the future.

  8. Evaluation Metrics Applied to Accident Tolerant Fuels

    SciTech Connect (OSTI)

    Shannon M. Bragg-Sitton; Jon Carmack; Frank Goldner

    2014-10-01

    The safe, reliable, and economic operation of the nation’s nuclear power reactor fleet has always been a top priority for the United States’ nuclear industry. Continual improvement of technology, including advanced materials and nuclear fuels, remains central to the industry’s success. Decades of research combined with continual operation have produced steady advancements in technology and have yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. One of the current missions of the U.S. Department of Energy’s (DOE) Office of Nuclear Energy (NE) is to develop nuclear fuels and claddings with enhanced accident tolerance for use in the current fleet of commercial LWRs or in reactor concepts with design certifications (GEN-III+). Accident tolerance became a focus within advanced LWR research upon direction from Congress following the 2011 Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex. The overall goal of ATF development is to identify alternative fuel system technologies to further enhance the safety, competitiveness and economics of commercial nuclear power. Enhanced accident tolerant fuels would endure loss of active cooling in the reactor core for a considerably longer period of time than the current fuel system while maintaining or improving performance during normal operations. The U.S. DOE is supporting multiple teams to investigate a number of technologies that may improve fuel system response and behavior in accident conditions, with team leadership provided by DOE national laboratories, universities, and the nuclear industry. Concepts under consideration offer both evolutionary and revolutionary changes to the current nuclear fuel system. Mature concepts will be tested in the Advanced Test Reactor at Idaho National Laboratory beginning in Summer 2014 with additional concepts being

  9. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    SciTech Connect (OSTI)

    Su'ud, Zaki; Anshari, Rio

    2012-06-06

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  10. Structural assessment of accident loads

    SciTech Connect (OSTI)

    Wagenblast, G.R., Westinghouse Hanford

    1996-05-28

    Structural assessments were made for specific accident loads for specific catch, receiver, and storage tanks. The evaluation herein represents level-of-effort order-of-magnitude estimates of limiting loads that would lead to collapse or rupture of the tank and unmitigated loss of confinement for the waste. Structural capacities were established using failure criteria. Compliance with codes such as ACI, ASCE, ASME, RCRA, UBC, WAC, and DOE Orders was `NOT` maintained. Normal code practice is to prevent failure with margins consistent with expected variations in loads and strengths and confidence in analysis techniques. The evaluation herein represent estimates of code limits without code load factors or code strength reduction factors, and loading beyond such a limit is considered as an onset of some failure mode. The exact nature of the failure mode and its relation to a safe condition is a judgment of the analyst. Consequently, these `RESULTS SHALL NOT BE USED TO ESTABLISH OPERATING OR SAFETY LOAD LIMITS FOR THESE TANKS`.

  11. Severe Accident Studies | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Severe Accident Studies Severe Accident Studies Powerpoint discussing studies and conclusions on transportation accidents and safety. Severe Accident Studies (2.13 MB) More Documents & Publications Spent Fuel Transportation Risk Assessment DOE-STD-101-92 EIS-0218-SA-07: Supplement Analysis

  12. Accident tolerant fuel analysis

    SciTech Connect (OSTI)

    Smith, Curtis; Chichester, Heather; Johns, Jesse; Teague, Melissa; Tonks, Michael Idaho National Laboratory; Youngblood, Robert

    2014-09-01

    Safety is central to the design, licensing, operation, and economics of Nuclear Power Plants (NPPs). Consequently, the ability to better characterize and quantify safety margin holds the key to improved decision making about light water reactor design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margins management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway research and development (R&D) is to support plant decisions for risk-informed margins management by improving economics and reliability, and sustaining safety, of current NPPs. Goals of the RISMC Pathway are twofold: (1) Develop and demonstrate a risk-assessment method coupled to safety margin quantification that can be used by NPP decision makers as part of their margin recovery strategies. (2) Create an advanced ''RISMC toolkit'' that enables more accurate representation of NPP safety margin. In order to carry out the R&D needed for the Pathway, the Idaho National Laboratory is performing a series of case studies that will explore methods- and tools-development issues, in addition to being of current interest in their own right. One such study is a comparative analysis of safety margins of plants using different fuel cladding types: specifically, a comparison between current-technology Zircaloy cladding and a notional ''accident-tolerant'' (e.g., SiC-based) cladding. The present report begins the process of applying capabilities that are still under development to the problem of assessing new fuel designs. The approach and lessons learned from this case study will be included in future Technical Basis Guides produced by the RISMC Pathway. These guides will be the mechanism for developing the specifications for RISMC tools and for defining how plant decision makers should propose and

  13. Accident Tolerant Fuel Analysis

    SciTech Connect (OSTI)

    Curtis Smith; Heather Chichester; Jesse Johns; Melissa Teague; Michael Tonks; Robert Youngblood

    2014-09-01

    Safety is central to the design, licensing, operation, and economics of Nuclear Power Plants (NPPs). Consequently, the ability to better characterize and quantify safety margin holds the key to improved decision making about light water reactor design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margins management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway research and development (R&D) is to support plant decisions for risk-informed margins management by improving economics and reliability, and sustaining safety, of current NPPs. Goals of the RISMC Pathway are twofold: (1) Develop and demonstrate a risk-assessment method coupled to safety margin quantification that can be used by NPP decision makers as part of their margin recovery strategies. (2) Create an advanced “RISMC toolkit” that enables more accurate representation of NPP safety margin. In order to carry out the R&D needed for the Pathway, the Idaho National Laboratory is performing a series of case studies that will explore methods- and tools-development issues, in addition to being of current interest in their own right. One such study is a comparative analysis of safety margins of plants using different fuel cladding types: specifically, a comparison between current-technology Zircaloy cladding and a notional “accident-tolerant” (e.g., SiC-based) cladding. The present report begins the process of applying capabilities that are still under development to the problem of assessing new fuel designs. The approach and lessons learned from this case study will be included in future Technical Basis Guides produced by the RISMC Pathway. These guides will be the mechanism for developing the specifications for RISMC tools and for defining how plant decision makers should propose and

  14. Multiscale Multiphysics Developments for Accident Tolerant Fuel Concepts

    SciTech Connect (OSTI)

    Gamble, K. A.; Hales, J. D.; Yu, J.; Zhang, Y.; Bai, X.; Andersson, D.; Patra, A.; Wen, W.; Tome, C.; Baskes, M.; Martinez, E.; Stanek, C. R.; Miao, Y.; Ye, B.; Hofman, G. L.; Yacout, A. M.; Liu, W.

    2015-09-01

    U3Si2 and iron-chromium-aluminum (Fe-Cr-Al) alloys are two of many proposed accident-tolerant fuel concepts for the fuel and cladding, respectively. The behavior of these materials under normal operating and accident reactor conditions is not well known. As part of the Department of Energy’s Accident Tolerant Fuel High Impact Problem program significant work has been conducted to investigate the U3Si2 and FeCrAl behavior under reactor conditions. This report presents the multiscale and multiphysics effort completed in fiscal year 2015. The report is split into four major categories including Density Functional Theory Developments, Molecular Dynamics Developments, Mesoscale Developments, and Engineering Scale Developments. The work shown here is a compilation of a collaborative effort between Idaho National Laboratory, Los Alamos National Laboratory, Argonne National Laboratory and Anatech Corp.

  15. Phase II Accident Investigation Board Briefing | Department of...

    Office of Environmental Management (EM)

    Phase II Accident Investigation Board Briefing Phase II Accident Investigation Board Briefing Topic: Ted Wyka DOE, Provided a Brief on the Findings in the WIPP Accident ...

  16. Type B Accident Investigation on the February 17, 2004, Personal...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    on the February 17, 2004, Personal Injury Accident, Bettis Atomic Power Laboratory Type B Accident Investigation on the February 17, 2004, Personal Injury Accident, Bettis Atomic ...

  17. Naval Spent Fuel Rail Shipment Accident Exercise Objectives ...

    Office of Environmental Management (EM)

    Naval Spent Fuel Rail Shipment Accident Exercise Objectives Naval Spent Fuel Rail Shipment Accident Exercise Objectives PDF icon Naval Spent Fuel Rail Shipment Accident Exercise ...

  18. Environment/Health/Safety (EHS): Monthly Accident Statistics

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Personal Protective Equipment (PPE) Injury Review & Analysis Worker Safety and Health Program: PUB-3851 Monthly Accident Statistics Latest Accident Statistics Accident...

  19. Type B Accident Investigation Board Report on the October 8,...

    Energy.gov (indexed) [DOE]

    Type B Accident Investigation on the February 17, 2004, Personal Injury Accident, Bettis Atomic Power Laboratory Type B Accident Investigation of the Arc Flash at Brookhaven ...

  20. Site Specific Analyses of a Spent Nuclear Fuel Transportation Accident

    SciTech Connect (OSTI)

    Biwer, B. M.; Chen, S. Y.

    2003-02-24

    The number of spent nuclear fuel (SNF) shipments is expected to increase significantly during the time period that the United States' inventory of SNF is sent to a final disposal site. Prior work estimated that the highest accident risks of a SNF shipping campaign to the proposed geologic repository at Yucca Mountain were in the corridor states, such as Illinois. The largest potential human health impacts would be expected to occur in areas with high population densities such as urban settings. Thus, our current study examined the human health impacts from the most plausible severe SNF transportation accidents in the Chicago metropolitan area. The RISKIND 2.0 program was used to model site-specific data for an area where the largest impacts might occur. The results have shown that the radiological human health consequences of a severe SNF rail transportation accident on average might be similar to one year of exposure to natural background radiation for those persons living a nd working in the most affected areas downwind of the actual accident location. For maximally exposed individuals, an exposure similar to about two years of exposure to natural background radiation was estimated. In addition to the accident probabilities being very low (approximately 1 chance in 10,000 or less during the entire shipping campaign), the actual human health impacts are expected to be lower if any of the accidents considered did occur, because the results are dependent on the specific location and weather conditions, such as wind speed and direction, that were selected to maximize the results. Also, comparison of the results of longer duration accident scenarios against U.S. Environmental Protection Agency guidelines was made to demonstrate the usefulness of this site-specific analysis for emergency planning purposes.

  1. Type B Accident Investigation, Subcontractor Employee Personal...

    Office of Environmental Management (EM)

    Investigation, Subcontractor Employee Personal Protective Equipment Ignition Incident on ... Type B Accident Investigation, Subcontractor Employee Personal Protective Equipment ...

  2. ORISE: REAC/TS Radiation Accident Registries

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Accident Registries The Radiation Emergency Assistance Center/Training Site (REAC/TS) at the Oak Ridge Institute for Science and Education (ORISE) maintains a number of radiation accident registries that provide medical professionals with up-to-date radiation accident information. Information for these accident registries is gathered from many sources, including the World Health Organization, International Atomic Energy Agency, U.S. Nuclear Regulatory Commission, state radiological health

  3. Accident analysis and DOE criteria

    SciTech Connect (OSTI)

    Graf, J.M.; Elder, J.C.

    1982-01-01

    In analyzing the radiological consequences of major accidents at DOE facilities one finds that many facilities fall so far below the limits of DOE Order 6430 that compliance is easily demonstrated by simple analysis. For those cases where the amount of radioactive material and the dispersive energy available are enough for accident consequences to approach the limits, the models and assumptions used become critical. In some cases the models themselves are the difference between meeting the criteria or not meeting them. Further, in one case, we found that not only did the selection of models determine compliance but the selection of applicable criteria from different chapters of Order 6430 also made the difference. DOE has recognized the problem of different criteria in different chapters applying to one facility, and has proceeded to make changes for the sake of consistency. We have proposed to outline the specific steps needed in an accident analysis and suggest appropriate models, parameters, and assumptions. As a result we feed DOE siting and design criteria will be more fairly and consistently applied.

  4. Accident analysis of heavy water cooled thorium breeder reactor

    SciTech Connect (OSTI)

    Yulianti, Yanti; Su’ud, Zaki; Takaki, Naoyuki

    2015-04-16

    power reactor has a peak value before reactor has new balance condition. The analysis showed that temperatures of fuel and claddings during accident are still below limitations which are in secure condition.

  5. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    SciTech Connect (OSTI)

    S.O. Bader

    1999-10-18

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  6. Calculation notes that support accident scenario and consequence development for the subsurface leak remaining subsurface accident

    SciTech Connect (OSTI)

    Ryan, G.W., Westinghouse Hanford

    1996-07-12

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Subsurface Leak Remaining Subsurface. The calculations needed to quantify the risk associated with this accident scenario are included within.

  7. Calculation notes that support accident scenario and consequence development for the subsurface leak remaining subsurface accident

    SciTech Connect (OSTI)

    Ryan, G.W., Westinghouse Hanford

    1996-09-19

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Subsurface Leak Remaining Subsurface. The calculations needed to quantify the risk associated with this accident scenario are included within.

  8. ORISE: REAC/TS Radiation Accident Registries

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Accident Registries The Radiation Emergency Assistance CenterTraining Site (REACTS) at the Oak Ridge Institute for Science and Education (ORISE) maintains a number of radiation ...

  9. Recommendations for Analyzing Accidents Under NEPA

    Energy.gov [DOE]

    This DOE guidance clarifies and supplements "Recommendations for the Preparation of Environmental Assessments and Environmental Impact Statements." It focuses on principles of accident analyses under NEPA.

  10. DOE Accident Prevention and Investigation Program | Department...

    Office of Environmental Management (EM)

    The techniques and tools utilized in the investigation of "accidents" can be valuable in ... The information obtained through application of these techniques and tools serve as ...

  11. In a mining accident, first responders are working against

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    a mining accident, first responders are working against the clock and against a myriad of dangers such as debris, poisonous gases, flooding, explosive vapors, and unstable structures to assess the situation and rescue trapped miners. These unknown and potentially deadly conditions create a challenge for first responders and often limit their ability to assess the situation and respond in a timely matter. There is a need for a robotic system that could be used to support a mine rescue team,

  12. Improvement of Design Codes to Account for Accident Thermal Effects on Seismic Performance

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    IMPROVEMENT OF DESIGN CODES TO ACCOUNT FOR ACCIDENT THERMAL EFFECTS ON SEISMIC PERFORMANCE Amit H. Varma, Kadir Sener, Saahas Bhardwaj Purdue University Andrew Whittaker: Univ. of Buffalo INTRODUCTION  Project focuses on the effects of accident thermal conditions on the seismic performance of: a) Innovative steel-plate composite SC walls, and b) Conventional reinforced concrete RC walls. (c) Copyright by Amit Varma, Purdue University MOTIVATION  Steel faceplates are directly exposed to

  13. Analysis of Kuosheng Station Blackout Accident Using MELCOR 1.8.4

    SciTech Connect (OSTI)

    Wang, S.-J.; Chien, C.-S.; Wang, T.-C.; Chiang, K.-S

    2000-11-15

    The MELCOR code, developed by Sandia National Laboratories, is a fully integrated, relatively fast-running code that models the progression of severe accidents in commercial light water nuclear power plants (NPPs).A specific station blackout (SBO) accident for Kuosheng (BWR-6) NPP is simulated using the MELCOR 1.8.4 code. The MELCOR input deck for Kuosheng NPP is established based on Kuosheng NPP design data and the MELCOR users' guides. The initial steady-state conditions are generated with a developed self-initialization algorithm. The main severe accident phenomena and the fission product release fractions associated with the SBO accident were simulated. The predicted results are plausible and as expected in light of current understanding of severe accident phenomena. The uncertainty of this analysis is briefly discussed. The important features of the MELCOR 1.8.4 are described. The estimated results provide useful information for the probabilistic risk assessment (PRA) of Kuosheng NPP. This tool will be applied to the PRA, the severe accident analysis, and the severe accident management study of Kuosheng NPP in the near future.

  14. Light-water reactor accident classification

    SciTech Connect (OSTI)

    Washburn, B.W.

    1980-02-01

    The evolution of existing classifications and definitions of light-water reactor accidents is considered. Licensing practice and licensing trends are examined with respect to terms of art such as Class 8 and Class 9 accidents. Interim definitions, consistent with current licensing practice and the regulations, are proposed for these terms of art.

  15. SAF-230DE- Web Based Course: Accident Investigation Overview

    Energy.gov [DOE]

    This course that provides an overview of the fundamentals of accident investigation. The course is intended to meet the every five year refresher training requirement for DOE Federal Accident Investigators under DOE O 225.1B Accident Investigations.

  16. Commercial SNF Accident Release Fractions

    SciTech Connect (OSTI)

    J. Schulz

    2004-11-05

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the

  17. The Fukushima Daiichi Accident Study Information Portal

    SciTech Connect (OSTI)

    Shawn St. Germain; Curtis Smith; David Schwieder; Cherie Phelan

    2012-11-01

    This paper presents a description of The Fukushima Daiichi Accident Study Information Portal. The Information Portal was created by the Idaho National Laboratory as part of joint NRC and DOE project to assess the severe accident modeling capability of the MELCOR analysis code. The Fukushima Daiichi Accident Study Information Portal was created to collect, store, retrieve and validate information and data for use in reconstructing the Fukushima Daiichi accident. In addition to supporting the MELCOR simulations, the Portal will be the main DOE repository for all data, studies and reports related to the accident at the Fukushima Daiichi nuclear power station. The data is stored in a secured (password protected and encrypted) repository that is searchable and accessible to researchers at diverse locations.

  18. The potential impact of enhanced accident tolerant cladding materials on

    Office of Scientific and Technical Information (OSTI)

    reactivity initiated accidents in light water reactors (Journal Article) | DOE PAGES The potential impact of enhanced accident tolerant cladding materials on reactivity initiated accidents in light water reactors This content will become publicly available on January 1, 2018 Title: The potential impact of enhanced accident tolerant cladding materials on reactivity initiated accidents in light water reactors Here, advanced cladding materials with potentially enhanced accident tolerance will

  19. Mitigation of Severe Accident Consequences Using Inherent Safety Principles

    SciTech Connect (OSTI)

    R. A. Wigeland; J. E. Cahalan

    2009-12-01

    Sodium-cooled fast reactors are designed to have a high level of safety. Events of high probability of occurrence are typically handled without consequence through reliable engineering systems and good design practices. For accidents of lower probability, the initiating events are characterized by larger and more numerous challenges to the reactor system, such as failure of one or more major engineered systems and can also include a failure to scram the reactor in response. As the initiating conditions become more severe, they have the potential for creating serious consequences of potential safety significance, including fuel melting, fuel pin disruption and recriticality. If the progression of such accidents is not mitigated by design features of the reactor, energetic events and dispersal of radioactive materials may result. For severe accidents, there are several approaches that can be used to mitigate the consequences of such severe accident initiators, which typically include fuel pin failures and core disruption. One approach is to increase the reliability of the reactor protection system so that the probability of an ATWS event is reduced to less than 1 x 10-6 per reactor year, where larger accident consequences are allowed, meeting the U.S. NRC goal of relegating such accident consequences as core disruption to these extremely low probabilities. The main difficulty with this approach is to convincingly test and guarantee such increased reliability. Another approach is to increase the redundancy of the reactor scram system, which can also reduce the probability of an ATWS event to a frequency of less than 1 x 10-6 per reactor year or lower. The issues with this approach are more related to reactor core design, with the need for a greater number of control rod positions in the reactor core and the associated increase in complexity of the reactor protection system. A third approach is to use the inherent reactivity feedback that occurs in a fast reactor to

  20. The Nevada railroad system: Physical, operational, and accident characteristics

    SciTech Connect (OSTI)

    1991-09-01

    This report provides a description of the operational and physical characteristics of the Nevada railroad system. To understand the dynamics of the rail system, one must consider the system`s physical characteristics, routing, uses, interactions with other systems, and unique operational characteristics, if any. This report is presented in two parts. The first part is a narrative description of all mainlines and major branchlines of the Nevada railroad system. Each Nevada rail route is described, including the route`s physical characteristics, traffic type and volume, track conditions, and history. The second part of this study provides a more detailed analysis of Nevada railroad accident characteristics than was presented in the Preliminary Nevada Transportation Accident Characterization Study (DOE, 1990).

  1. Accident Tolerant Fuels for LWRs: A Perspective (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Accident Tolerant Fuels for LWRs: A Perspective Citation Details In-Document Search Title: Accident Tolerant Fuels for LWRs: A Perspective Authors: Zinkle, Steven ...

  2. Accident Investigation of the February 7, 2013, Scissor Lift...

    Energy Savers

    February 7, 2013, Scissor Lift Accident in the West Hackberry Brine Tank-14 Resulting in Injury, Strategic Petroleum Reserve West Hackberry, LA Accident Investigation of the ...

  3. Type B Accident Investigation Board Report Subcontractor Radioactive...

    Energy.gov (indexed) [DOE]

    Upon arrival, an incoming radiological survey was performed. PDF icon Type B Accident ... Preliminary Notice of Violation, Bechtel Jacobs Company, LLC - EA-2005-04 Type B Accident ...

  4. Accident Investigation of the February 5, 2014, Underground Salt...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Accident Investigation of the February 5, 2014, Underground Salt Haul Truck Fire at the Waste Isolation Pilot Plant, Carlsbad NM March 26, 2014 Accident Investigation of the ...

  5. Los Alamos National Laboratory Accident Investigation Board Corrective...

    Office of Environmental Management (EM)

    Accident Investigation Board Corrective Action Plan Update Los Alamos National Laboratory Accident Investigation Board Corrective Action Plan Update Topic: Status of the Corrective ...

  6. Type B Accident Investigation of the July 14, 2005, Americium...

    Energy Savers

    14, 2005, Americium Contamination Accident at the Sigma Facility, Los Alamos National Laboratory Type B Accident Investigation of the July 14, 2005, Americium Contamination ...

  7. Accident Investigation Report Phase II | Department of Energy

    Energy.gov (indexed) [DOE]

    On March 4, 2014, an Accident Investigation Board (the Board) was appointed by Matthew ... appointed an Accident Investigation Board to complete the investigation (Phase 2). ...

  8. Volume II - Accident and Operational Safety Analysis Handbook

    Energy.gov (indexed) [DOE]

    208-2012 July 2012 DOE HANDBOOK Accident and Operational Safety Analysis Volume II: ... This Department of Energy (DOE) Accident and Operational Safety Analysis Handbook ...

  9. Accident analysis of heavy water cooled thorium breeder reactor...

    Office of Scientific and Technical Information (OSTI)

    Accident analysis of heavy water cooled thorium breeder reactor Citation Details In-Document Search Title: Accident analysis of heavy water cooled thorium breeder reactor ...

  10. Type B Accident Investigation Board Report of the Savannah River...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Processing Facility on October 6, 2009 Type B Accident Investigation Board Report of the ... This report documents the results of the Type B Accident Investigation Board (Board) ...

  11. Type B Accident Investigation Board Report on the October 15...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Type B Accident Investigation Board Report on the October 15, 2001, Grout Injection ... Type B Accident Investigation Board Report on the October 15, 2001, Grout Injection ...

  12. ORISE: The Medical Basis for Radiation-Accident Preparedness...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    The Medical Basis for Radiation-Accident Preparedness: Medical Management Proceedings of the Fifth International REACTS Symposium on the Medical Basis for Radiation-Accident ...

  13. Development of Light Water Reactor Fuels with Enhanced Accident...

    Energy Savers

    Development of Light Water Reactor Fuels with Enhanced Accident Tolerance - Report to Congress Development of Light Water Reactor Fuels with Enhanced Accident Tolerance - Report to ...

  14. An evaluation of spindle-shaft seizure accident sequences for the Schenck Dynamic Balancer

    SciTech Connect (OSTI)

    Bott, T.F.; Fischer, S.R.

    1998-11-01

    This study was conducted at the request of the USDOE/AL Dynamic Balancer Project Team to develop a set of representative accident sequences initiated by rapid seizure of the spindle shaft of the Schenck dynamic balancing machine used in the mass properties testing activities in Bay 12-60 at the Pantex Plant. This Balancer is used for balancing reentry vehicles. In addition, the study identified potential causes of possible spindle-shaft seizure leading to a rapid deceleration of the rotating assembly. These accident sequences extend to the point that the reentry vehicle either remains in stable condition on the balancing machine or leaves the machine with some translational and rotational motion. Fault-tree analysis was used to identify possible causes of spindle-shaft seizure, and failure modes and effects analysis identified the results of shearing of different machine components. Cause-consequence diagrams were used to help develop accident sequences resulting from the possible effects of spindle-shaft seizure. To make these accident sequences physically reasonable, the analysts used idealized models of the dynamics of rotating masses. Idealized physical modeling also was used to provide approximate values of accident parameters that lead to branching down different accident progression paths. The exacerbating conditions of balancing machine over-speed and improper assembly of the fixture to the face plate are also addressed.

  15. Code System for Toxic Gas Accident Analysis.

    Energy Science and Technology Software Center (OSTI)

    2001-09-24

    Version 00 TOXRISK is an interactive program developed to aid in the evaluation of nuclear power plant control room habitability in the event of a nearby toxic material release. The program uses a model which is consistent with the approach described in the NRC Regulatory Guide 1.78. Release of the gas is treated as an initial puff followed by a continuous plume. The relative proportions of these as well as the plume release rate aremore » supplied by the user. Transport of the gas is modeled as a Gaussian distribution and occurs through the action of a constant velocity, constant direction wind. Dispersion or diffusion of the gas during transport is described by modified Pasquill-Gifford dispersion coefficients. Great flexibility is afforded the user in specifying the release description, meteorological conditions, relative geometry of the accident and plant, and the plant ventilation system characteristics. Two types of simulation can be performed: multiple case (parametric) studies and probabilistic analyses.« less

  16. Overview of the U.S. DOE Accident Tolerant Fuel Development Program

    SciTech Connect (OSTI)

    Jon Carmack; Frank Goldner; Shannon M. Bragg-Sitton; Lance L. Snead

    2013-09-01

    The United States Fuel Cycle Research and Development Advanced Fuels Campaign has been given the responsibility to conduct research and development on enhanced accident tolerant fuels with the goal of performing a lead test assembly or lead test rod irradiation in a commercial reactor by 2022. The Advanced Fuels Campaign has defined fuels with enhanced accident tolerance as those that, in comparison with the standard UO2-Zircaloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations and operational transients, as well as design-basis and beyond design-basis events. This paper provides an overview of the FCRD Accident Tolerant Fuel program. The ATF attributes will be presented and discussed. Attributes identified as potentially important to enhance accident tolerance include reduced hydrogen generation (resulting from cladding oxidation), enhanced fission product retention under severe accident conditions, reduced cladding reaction with high-temperature steam, and improved fuel-cladding interaction for enhanced performance under extreme conditions. To demonstrate the enhanced accident tolerance of candidate fuel designs, metrics must be developed and evaluated using a combination of design features for a given LWR design, potential improvements to that design, and the design of an advanced fuel/cladding system. The aforementioned attributes provide qualitative guidance for parameters that will be considered for fuels with enhanced accident tolerance. It may be unnecessary to improve in all attributes and it is likely that some attributes or combination of attributes provide meaningful gains in accident tolerance, while others may provide only marginal benefits. Thus, an initial step in program implementation will be the development of quantitative

  17. Analysis of PWR RCS Injection Strategy During Severe Accident

    SciTech Connect (OSTI)

    Wang, S.-J. [Institute of Nuclear Energy Research, Taiwan (China); Chiang, K.-S. [Institute of Nuclear Energy Research, Taiwan (China); Chiang, S.-C. [Taiwan Power Company, Taiwan (China)

    2004-05-15

    Reactor coolant system (RCS) injection is an important strategy for severe accident management of a pressurized water reactor (PWR) system. Maanshan is a typical Westinghouse PWR nuclear power plant (NPP) with large, dry containment. The severe accident management guideline (SAMG) of Maanshan NPP is developed based on the Westinghouse Owners Group (WOG) SAMG.The purpose of this work is to analyze the RCS injection strategy of PWR system in an overheated core condition. Power is assumed recovered as the vessel water level drops to the bottom of active fuel. The Modular Accident Analysis Program version 4.0.4 (MAAP4) code is chosen as a tool for analysis. A postulated station blackout sequence for Maanshan NPP is cited as a reference case for this analysis. The hot leg creep rupture occurs during the mitigation action with immediate injection after power recovery according to WOG SAMG, which is not desired. This phenomenon is not considered while developing the WOG SAMG. Two other RCS injection methods are analyzed by using MAAP4. The RCS injection strategy is modified in the Maanshan SAMG. These results can be applied for typical PWR NPPs.

  18. Release fractions for Rocky Flats specific accidents

    SciTech Connect (OSTI)

    Weiss, R.C.

    1992-09-01

    As Rocky Flats and other DOE facilities begin the transition process towards decommissioning, the nature of the scenarios to be studied in safety analysis will change. Whereas the previous emphasis in safety accidents related to production, now the emphasis is shifting to accidents related tc decommissioning and waste management. Accident scenarios of concern at Rocky Flats now include situations of a different nature and different scale than are represented by most of the existing experimental accident data. This presentation will discuss approaches@to use for applying the existing body of release fraction data to this new emphasis. Mention will also be made of ongoing efforts to produce new data and improve the understanding of physical mechanisms involved.

  19. Chernobyl accident: A comprehensive risk assessment

    SciTech Connect (OSTI)

    Vargo, G.J.; Poyarkov, V.; Baryakhtar, V.; Kukhar, V.; Los, I.

    1999-01-01

    The authors, all of whom are Ukrainian and Russian scientists involved with Chernobyl nuclear power plant since the April 1986 accident, present a comprehensive review of the accident. In addition, they present a risk assessment of the remains of the destroyed reactor and its surrounding shelter, Chernobyl radioactive waste storage and disposal sites, and environmental contamination in the region. The authors explore such questions as the risks posed by a collapse of the shelter, radionuclide migration from storage and disposal facilities in the exclusion zone, and transfer from soil to vegetation and its potential regional impact. The answers to these questions provide a scientific basis for the development of countermeasures against the Chernobyl accident in particular and the mitigation of environmental radioactive contamination in general. They also provide an important basis for understanding the human health and ecological risks posed by the accident.

  20. Crediting Tritium Deposition in Accident Analysis

    SciTech Connect (OSTI)

    Murphy, C.E. Jr.

    2001-06-20

    This paper describes the major aspects of tritium dispersion phenomenology, summarizes deposition attributes of the computer models used in the DOE Complex for tritium dispersion, and recommends an approach to account for deposition in accident analysis.

  1. Site restoration: Estimation of attributable costs from plutonium-dispersal accidents

    SciTech Connect (OSTI)

    Chanin, D.I.; Murfin, W.B.

    1996-05-01

    A nuclear weapons accident is an extremely unlikely event due to the extensive care taken in operations. However, under some hypothetical accident conditions, plutonium might be dispersed to the environment. This would result in costs being incurred by the government to remediate the site and compensate for losses. This study is a multi-disciplinary evaluation of the potential scope of the post-accident response that includes technical factors, current and proposed legal requirements and constraints, as well as social/political factors that could influence decision making. The study provides parameters that can be used to assess economic costs for accidents postulated to occur in urban areas, Midwest farmland, Western rangeland, and forest. Per-area remediation costs have been estimated, using industry-standard methods, for both expedited and extended remediation. Expedited remediation costs have been evaluated for highways, airports, and urban areas. Extended remediation costs have been evaluated for all land uses except highways and airports. The inclusion of cost estimates in risk assessments, together with the conventional estimation of doses and health effects, allows a fuller understanding of the post-accident environment. The insights obtained can be used to minimize economic risks by evaluation of operational and design alternatives, and through development of improved capabilities for accident response.

  2. DOE Accident Prevention and Investigation Program | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    DOE Accident Prevention and Investigation Program DOE Accident Prevention and Investigation Program The Department of Energy (DOE) Accident Prevention and Investigation Program serves as a key DOE corporate safety resource for promoting accident PREVENTION through exchange of lessons learned and information for improvement of our integrated safety management system. The techniques and tools utilized in the investigation of "accidents" can be valuable in looking at leading indicators

  3. Large Break LOCA Accident Management Strategies for Accidents With Large Containment Leaks

    SciTech Connect (OSTI)

    Sdouz, Gert

    2006-07-01

    The goal of this work is the investigation of the influence of different accident management strategies on the thermal-hydraulics in the containment during a Large Break Loss of Coolant Accident with a large containment leak from the beginning of the accident. The increasing relevance of terrorism suggests a closer look at this kind of severe accidents. Normally the course of severe accidents and their associated phenomena are investigated with the assumption of an intact containment from the beginning of the accident. This intact containment has the ability to retain a large part of the radioactive inventory. In these cases there is only a release via a very small leakage due to the un-tightness of the containment up to cavity bottom melt through. This paper represents the last part of a comprehensive study on the influence of accident management strategies on the source term of VVER-1000 reactors. Basically two different accident sequences were investigated: the 'Station Blackout'- sequence and the 'Large Break LOCA'. In a first step the source term calculations were performed assuming an intact containment from the beginning of the accident and no accident management action. In a further step the influence of different accident management strategies was studied. The last part of the project was a repetition of the calculations with the assumption of a damaged containment from the beginning of the accident. This paper concentrates on the last step in the case of a Large Break LOCA. To be able to compare the results with calculations performed years ago the calculations were performed using the Source Term Code Package (STCP), hydrogen explosions are not considered. In this study four different scenarios have been investigated. The main parameter was the switch on time of the spray systems. One of the results is the influence of different accident management strategies on the source term. In the comparison with the sequence with intact containment it was

  4. TMI-2 - A Case Study for PWR Instrumentation Performance during a Severe Accident

    SciTech Connect (OSTI)

    Joy L. Rempe; Darrell L. Knudson

    2014-05-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focussed upon a set of sensors that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this report. For each sensor, a description is provided with the measured data and conclusions related to the sensor’s survivability, and the basis for conclusions about its survivability. As noted within this document, several techniques were invoked in the TMI-2 post-accident evaluation program to assess sensor status, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this document provides recommendations related to the sensor survivability and data evaluation

  5. TMI-2 - A Case Study for PWR Instrumentation Performance during a Severe Accident

    SciTech Connect (OSTI)

    Joy L. Rempe; Darrell L. Knudson

    2013-03-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focussed upon a set of sensors that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this report. For each sensor, a description is provided with the measured data and conclusions related to the sensor’s survivability, and the basis for conclusions about its survivability. As noted within this document, several techniques were invoked in the TMI-2 post-accident evaluation program to assess sensor status, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this document provides recommendations related to the sensor survivability and data evaluation

  6. NIF: Impacts of chemical accidents and comparison of chemical/radiological accident approaches

    SciTech Connect (OSTI)

    Lazaro, M.A.; Policastro, A.J.; Rhodes, M.

    1996-01-12

    The US Department of Energy (DOE) proposes to construct and operate the National Ignition Facility (NIF). The goals of the NIF are to (1) achieve fusion ignition in the laboratory for the first time by using inertial confinement fusion (ICF) technology based on an advanced-design neodymium glass solid-state laser, and (2) conduct high-energy-density experiments in support of national security and civilian applications. The primary focus of this paper is worker-public health and safety issues associated with postulated chemical accidents during the operation of NIF. The key findings from the accident analysis will be presented. Although NIF chemical accidents will be emphasized, the important differences between chemical and radiological accident analysis approaches and the metrics for reporting results will be highlighted. These differences are common EIS facility and transportation accident assessments.

  7. Reactor Safety Gap Evaluation of Accident Tolerant Components and Severe Accident Analysis

    SciTech Connect (OSTI)

    Farmer, Mitchell T.; Bunt, R.; Corradini, M.; Ellison, Paul B.; Francis, M.; Gabor, John D.; Gauntt, R.; Henry, C.; Linthicum, R.; Luangdilok, W.; Lutz, R.; Paik, C.; Plys, M.; Rabiti, Cristian; Rempe, J.; Robb, K.; Wachowiak, R.

    2015-01-31

    The overall objective of this study was to conduct a technology gap evaluation on accident tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist, given the current state of light water reactor (LWR) severe accident research, and additionally augmented by insights obtained from the Fukushima accident. The ultimate benefit of this activity is that the results can be used to refine the Department of Energy’s (DOE) Reactor Safety Technology (RST) research and development (R&D) program plan to address key knowledge gaps in severe accident phenomena and analyses that affect reactor safety and that are not currently being addressed by the industry or the Nuclear Regulatory Commission (NRC).

  8. Scoping Study Investigating PWR Instrumentation during a Severe Accident Scenario

    SciTech Connect (OSTI)

    Rempe, J. L.; Knudson, D. L.; Lutz, R. J.

    2015-09-01

    The accidents at the Three Mile Island Unit 2 (TMI-2) and Fukushima Daiichi Units 1, 2, and 3 nuclear power plants demonstrate the critical importance of accurate, relevant, and timely information on the status of reactor systems during a severe accident. These events also highlight the critical importance of understanding and focusing on the key elements of system status information in an environment where operators may be overwhelmed with superfluous and sometimes conflicting data. While progress in these areas has been made since TMI-2, the events at Fukushima suggests that there may still be a potential need to ensure that critical plant information is available to plant operators. Recognizing the significant technical and economic challenges associated with plant modifications, it is important to focus on instrumentation that can address these information critical needs. As part of a program initiated by the Department of Energy, Office of Nuclear Energy (DOE-NE), a scoping effort was initiated to assess critical information needs identified for severe accident management and mitigation in commercial Light Water Reactors (LWRs), to quantify the environment instruments monitoring this data would have to survive, and to identify gaps where predicted environments exceed instrumentation qualification envelop (QE) limits. Results from the Pressurized Water Reactor (PWR) scoping evaluations are documented in this report. The PWR evaluations were limited in this scoping evaluation to quantifying the environmental conditions for an unmitigated Short-Term Station BlackOut (STSBO) sequence in one unit at the Surry nuclear power station. Results were obtained using the MELCOR models developed for the US Nuclear Regulatory Commission (NRC)-sponsored State of the Art Consequence Assessment (SOARCA) program project. Results from this scoping evaluation indicate that some instrumentation identified to provide critical information would be exposed to conditions that

  9. Type B Accident Investigation Board Report of the April 23, 1997...

    Office of Environmental Management (EM)

    April 23, 1997, Helicopter Accident at Raton Pass, Raton Pass, Colorado Type B Accident Investigation Board Report of the April 23, 1997, Helicopter Accident at Raton Pass, Raton ...

  10. Type B Accident Investigation on the August 5, 2003, Pu-238 Multiple...

    Energy Savers

    Los Alamos National Laboratory Type B Accident Investigation on the August 5, 2003, ... The Accident Investigation Board concluded that the direct cause of the accident was the ...

  11. A Review of Criticality Accidents 2000 Revision

    SciTech Connect (OSTI)

    Thomas P. McLaughlin; Shean P. Monahan; Norman L. Pruvost; Vladimir V. Frolov; Boris G. Ryazanov; Victor I. Sviridov

    2000-05-01

    Criticality accidents and the characteristics of prompt power excursions are discussed. Sixty accidental power excursions are reviewed. Sufficient detail is provided to enable the reader to understand the physical situation, the chemistry and material flow, and when available the administrative setting leading up to the time of the accident. Information on the power history, energy release, consequences, and causes are also included when available. For those accidents that occurred in process plants, two new sections have been included in this revision. The first is an analysis and summary of the physical and neutronic features of the chain reacting systems. The second is a compilation of observations and lessons learned. Excursions associated with large power reactors are not included in this report.

  12. Fuel performance during severe accidents. [PWR

    SciTech Connect (OSTI)

    Buescher, B.J.; Gruen, G.E.; MacDonald, P.E.

    1982-01-01

    As a result of the Three Mile Island Unit-2 (TMI-2) accident, the Nuclear Regulatory Commission has initiated a severe fuel damage test program to evaluate fuel rod and core response during severe accidents similar to TMI-2. This program is underway in the Power Burst Facility at the Idaho National Engineering Laboratory. In preparation for the first test, predictions have been performed using the TRAC-BD1 computer. This paper presents the calculated results showing a slow heatup to 2400 K over 5 hours, and the analysis includes accelerated oxidation of the zirconium cladding at temperatures above 1850 K.

  13. LESSONS LEARNED FROM A RECENT LASER ACCIDENT

    SciTech Connect (OSTI)

    Woods, Michael; /SLAC

    2011-01-26

    A graduate student received a laser eye injury from a femtosecond Ti:sapphire laser beam while adjusting a polarizing beam splitter optic. The direct causes for the accident included failure to follow safe alignment practices and failure to wear the required laser eyewear protection. Underlying root causes included inadequate on-the-job training and supervision, inadequate adherence to requirements, and inadequate appreciation for dimly visible beams outside the range of 400-700nm. This paper describes how the accident occurred, discusses causes and lessons learned, and describes corrective actions being taken.

  14. Qualification of data obtained during a severe accident. Illustrative examples from TMI-2 evaluations

    SciTech Connect (OSTI)

    Rempe, Joy L.; Knudson, Darrell L.

    2015-02-01

    The accidents at the Three Mile Island Unit 2 (TMI-2) Pressurized Water Reactor (PWR) and the Daiichi Units 1, 2, and 3 Boiling Water Reactors (BWRs) provide unique opportunities to evaluate instrumentation exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during the TMI-2 accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. Post-TMI-2 instrumentation evaluation programs focused on data required by TMI-2 operators to assess the condition of the reactor and containment and the effect of mitigating actions taken by these operators. Prior efforts also focused on sensors providing data required for subsequent forensic evaluations and accident simulations. This paper provides additional details related to the formal process used to develop a qualified TMI-2 data base and presents data qualification details for three parameters: reactor coolant system (RCS) pressure; containment building temperature; and containment pressure. These selected examples illustrate the types of activities completed in the TMI-2 data qualification process and the importance of such a qualification effort. These details are described to facilitate implementation of a similar process using data and examinations at the Daiichi Units 1, 2, and 3 reactors so that BWR-specific benefits can be obtained.

  15. Post-accident examination of platinum resistance thermometers installed in the TMI-2 reactor

    SciTech Connect (OSTI)

    Carroll, R.M.; Shepard, R.L.

    1985-09-01

    Laboratory tests conducted on one resistance thermometer and thermowell removed from TMI-2 showed that neither its calibration nor its time response was adversely affected by the accident or post-accident conditions to which it had been exposed. No Never-Seez was used in its thermowell. A broken conduit fitting allowed moisture to enter the extension cables, which affected their insulation resistance. Tests on similar thermometers installed in TMI-2 and Crystal River Unit 3 at shutdown and at full power showed that the time response of the TMI-2 thermometer met the 5-second limit required by the plant technical specifications.

  16. Accident Investigation Board (AIB) findings about the drum breach...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Accident Investigation Board findings Accident Investigation Board (AIB) findings about the drum breach at WIPP WHEN: Apr 23, 2015 5:30 PM - 7:00 PM WHERE: Fuller Lodge 2132 ...

  17. PNNL Results from 2009 Silene Criticality Accident Dosimeter Intercomparison Exercise

    SciTech Connect (OSTI)

    Hill, Robin L.; Conrady, Matthew M.

    2010-06-30

    This document reports the results of testing of the Hanford Personnel Nuclear Accident Dosimeter (PNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on October 13, 14, and 15, 2009.

  18. Y-12's 1958 nuclear criticality accident and increased safety...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    accident and increased safety - 1958 brought accidents, more safety The first X-ray machine was brought to Y-12 in February, 1949. It was a 1,000 KV system installed in Building...

  19. Markov Model of Accident Progression at Fukushima Daiichi

    SciTech Connect (OSTI)

    Cuadra A.; Bari R.; Cheng, L-Y; Ginsberg, T.; Lehner, J.; Martinez-Guridi, G.; Mubayi, V.; Pratt, T.; Yue, M.

    2012-11-11

    On March 11, 2011, a magnitude 9.0 earthquake followed by a tsunami caused loss of offsite power and disabled the emergency diesel generators, leading to a prolonged station blackout at the Fukushima Daiichi site. After successful reactor trip for all operating reactors, the inability to remove decay heat over an extended period led to boil-off of the water inventory and fuel uncovery in Units 1-3. A significant amount of metal-water reaction occurred, as evidenced by the quantities of hydrogen generated that led to hydrogen explosions in the auxiliary buildings of the Units 1 & 3, and in the de-fuelled Unit 4. Although it was assumed that extensive fuel damage, including fuel melting, slumping, and relocation was likely to have occurred in the core of the affected reactors, the status of the fuel, vessel, and drywell was uncertain. To understand the possible evolution of the accident conditions at Fukushima Daiichi, a Markov model of the likely state of one of the reactors was constructed and executed under different assumptions regarding system performance and reliability. The Markov approach was selected for several reasons: It is a probabilistic model that provides flexibility in scenario construction and incorporates time dependence of different model states. It also readily allows for sensitivity and uncertainty analyses of different failure and repair rates of cooling systems. While the analysis was motivated by a need to gain insight on the course of events for the damaged units at Fukushima Daiichi, the work reported here provides a more general analytical basis for studying and evaluating severe accident evolution over extended periods of time. This work was performed at the request of the U.S. Department of Energy to explore 'what-if' scenarios in the immediate aftermath of the accidents.

  20. Superheated-steam test of ethylene propylene rubber cables using a simultaneous aging and accident environment

    SciTech Connect (OSTI)

    Bennett, P.R.; St. Clair, S.D.; Gilmore, T.W.

    1986-06-01

    The superheated-steam test exposed different ethylene propylene rubber (EPR) cables and insulation specimens to simultaneous aging and a 21-day simultaneous accident environment. In addition, some insulation specimens were exposed to five different aging conditions prior to the 21-day simultaneous accident simulation. The purpose of this superheated-steam test (a follow-on to the saturated-steam tests (NUREG/CR-3538)) was to: (1) examine electrical degradation of different configurations of EPR cables; (2) investigate differences between using superheated-steam or saturated-steam at the start of an accident simulation; (3) determine whether the aging technique used in the saturated-steam test induced artificial degradation; and (4) identify the constituents in EPR that affect moisture absorption.

  1. Trends in state-level freight accident rates: An enhancement of risk factor development for RADTRAN

    SciTech Connect (OSTI)

    Saricks, C.; Kvitek, T.

    1991-01-01

    Under the Nuclear Waste Policy Act, the Department of Energy's Office of Civilian Radioactive Waste Management (OCRWM) is concerned with understanding and managing risk as it applies to the shipment of spent commercial nuclear reactor fuel. Understanding risk in relation to mode and geography may provide opportunities to minimize radiological and non-radiological risks of transportation. To enhance such an understanding, a set of state-or waterway-specific accident, fatality, and injury rates (expressed as rates per shipment kilometer) by transportation mode and highway administrative class was developed, using publicly-available data bases. Adjustments made to accommodate miscoded or incomplete information in accident data are described, as well as the procedures for estimating state-level flow data. Results indicate that the shipping conditions under which spent fuel is likely to be transported should be less subject to accidents than the average'' shipment within mode. 10 refs., 3 tabs.

  2. Final safety analysis report for the Galileo Mission: Volume 2, Book 2: Accident model document: Appendices

    SciTech Connect (OSTI)

    Not Available

    1988-12-15

    This section of the Accident Model Document (AMD) presents the appendices which describe the various analyses that have been conducted for use in the Galileo Final Safety Analysis Report II, Volume II. Included in these appendices are the approaches, techniques, conditions and assumptions used in the development of the analytical models plus the detailed results of the analyses. Also included in these appendices are summaries of the accidents and their associated probabilities and environment models taken from the Shuttle Data Book (NSTS-08116), plus summaries of the several segments of the recent GPHS safety test program. The information presented in these appendices is used in Section 3.0 of the AMD to develop the Failure/Abort Sequence Trees (FASTs) and to determine the fuel releases (source terms) resulting from the potential Space Shuttle/IUS accidents throughout the missions.

  3. Severe Accident Test Station Activity Report

    SciTech Connect (OSTI)

    Pint, Bruce A.; Terrani, Kurt A.

    2015-06-01

    Enhancing safety margins in light water reactor (LWR) severe accidents is currently the focus of a number of international R&D programs. The current UO2/Zr-based alloy fuel system is particularly susceptible since the Zr-based cladding experiences rapid oxidation kinetics in steam at elevated temperatures. Therefore, alternative cladding materials that offer slower oxidation kinetics and a smaller enthalpy of oxidation can significantly reduce the rate of heat and hydrogen generation in the core during a coolant-limited severe accident. In the U.S. program, the high temperature steam oxidation performance of accident tolerant fuel (ATF) cladding solutions has been evaluated in the Severe Accident Test Station (SATS) at Oak Ridge National Laboratory (ORNL) since 2012. This report summarizes the capabilities of the SATS and provides an overview of the oxidation kinetics of several candidate cladding materials. A suggested baseline for evaluating ATF candidates is a two order of magnitude reduction in the steam oxidation resistance above 1000ºC compared to Zr-based alloys. The ATF candidates are categorized based on the protective external oxide or scale that forms during exposure to steam at high temperature: chromia, alumina, and silica. Comparisons are made to literature and SATS data for Zr-based alloys and other less-protective materials.

  4. ANS severe accident program overview & planning document

    SciTech Connect (OSTI)

    Taleyarkhan, R.P.

    1995-09-01

    The Advanced Neutron Source (ANS) severe accident document was developed to provide a concise and coherent mechanism for presenting the ANS SAP goals, a strategy satisfying these goals, a succinct summary of the work done to date, and what needs to be done in the future to ensure timely licensability. Guidance was received from various bodies [viz., panel members of the ANS severe accident workshop and safety review committee, Department of Energy (DOE) orders, Nuclear Regulatory Commission (NRC) requirements for ALWRs and advanced reactors, ACRS comments, world-wide trends] were utilized to set up the ANS-relevant SAS goals and strategy. An in-containment worker protection goal was also set up to account for the routine experimenters and other workers within containment. The strategy for achieving the goals is centered upon closing the severe accident issues that have the potential for becoming certification issues when assessed against realistic bounding events. Realistic bounding events are defined as events with an occurrency frequency greater than 10{sup {minus}6}/y. Currently, based upon the level-1 probabilistic risk assessment studies, the realistic bounding events for application for issue closure are flow blockage of fuel element coolant channels, and rapid depressurization-related accidents.

  5. Computerized Accident Incident Reporting System | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Computerized Accident Incident Reporting System Computerized Accident Incident Reporting System CAIRS Database The Computerized Accident/Incident Reporting System is a database used to collect and analyze DOE and DOE contractor reports of injuries, illnesses, and other accidents that occur during DOE operations. CAIRS is a Government computer system and, as such, has security requirements that must be followed. Access to the database is open to DOE and DOE contractors. Additional information

  6. Calculation notes that support accident scenario and consequence development for the steam intrusion from interfacing systems accident

    SciTech Connect (OSTI)

    Ryan, G.W., Westinghouse Hanford

    1996-07-25

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Steam Intrusion from Interfacing Systems. The calculations needed to quantify the risk associated with this accident scenario are included within.

  7. Technical evaluation: 300 Area steam line valve accident

    SciTech Connect (OSTI)

    Not Available

    1993-08-01

    On June 7, 1993, a journeyman power operator (JPO) was severely burned and later died as a result of the failure of a 6-in. valve that occurred when he attempted to open main steam supply (MSS) valve MSS-25 in the U-3 valve pit. The pit is located northwest of Building 331 in the 300 Area of the Hanford Site. Figure 1-1 shows a layout of the 300 Area steam piping system including the U-3 steam valve pit. Figure 1-2 shows a cutaway view of the approximately 10- by 13- by 16-ft-high valve pit with its various steam valves and connecting piping. Valve MSS-25, an 8-in. valve, is located at the bottom of the pit. The failed 6-in. valve was located at the top of the pit where it branched from the upper portion of the 8-in. line at the 8- by 8- by 6-in. tee and was then ``blanked off`` with a blind flange. The purpose of this technical evaluation was to determine the cause of the accident that led to the failure of the 6-in. valve. The probable cause for the 6-in. valve failure was determined by visual, nondestructive, and destructive examination of the failed valve and by metallurgical analysis of the fractured region of the valve. The cause of the accident was ultimately identified by correlating the observed failure mode to the most probable physical phenomenon. Thermal-hydraulic analyses, component stress analyses, and tests were performed to verify that the probable physical phenomenon could be reasonably expected to produce the failure in the valve that was observed.

  8. Advanced sodium fast reactor accident source terms : research needs.

    SciTech Connect (OSTI)

    Powers, Dana Auburn; Clement, Bernard; Ohno, Shuji; Zeyen, Roland

    2010-09-01

    An expert opinion elicitation has been used to evaluate phenomena that could affect releases of radionuclides during accidents at sodium-cooled fast reactors. The intent was to identify research needed to develop a mechanistic model of radionuclide release for licensing and risk assessment purposes. Experts from the USA, France, the European Union, and Japan identified phenomena that could affect the release of radionuclides under hypothesized accident conditions. They qualitatively evaluated the importance of these phenomena and the need for additional experimental research. The experts identified seven phenomena that are of high importance and have a high need for additional experimental research: High temperature release of radionuclides from fuel during an energetic eventEnergetic interactions between molten reactor fuel and sodium coolant and associated transfer of radionuclides from the fuel to the coolantEntrainment of fuel and sodium bond material during the depressurization of a fuel rod with breached claddingRates of radionuclide leaching from fuel by liquid sodiumSurface enrichment of sodium pools by dissolved and suspended radionuclidesThermal decomposition of sodium iodide in the containment atmosphereReactions of iodine species in the containment to form volatile organic iodides. Other issues of high importance were identified that might merit further research as development of the mechanistic model of radionuclide release progressed.

  9. Thermohydraulic and Safety Analysis for CARR Under Station Blackout Accident

    SciTech Connect (OSTI)

    Wenxi Tian; Suizheng Qiu; Guanghui Su; Dounan Jia [Xi'an Jiaotong University, 28 Xianning Road, Xi'an 710049 (China); Xingmin Liu - China Institute of Atomic Energy

    2006-07-01

    A thermohydraulic and safety analysis code (TSACC) has been developed using Fortran 90 language to evaluate the transient thermohydraulic behaviors and safety characteristics of the China Advanced Research Reactor(CARR) under Station Blackout Accident(SBA). For the development of TSACC, a series of corresponding mathematical and physical models were considered. Point reactor neutron kinetics model was adopted for solving reactor power. All possible flow and heat transfer conditions under station blackout accident were considered and the optional models were supplied. The usual Finite Difference Method (FDM) was abandoned and a new model was adopted to evaluate the temperature field of core plate type fuel element. A new simple and convenient equation was proposed for the resolution of the transient behaviors of the main pump instead of the complicated four-quadrant model. Gear method and Adams method were adopted alternately for a better solution to the stiff differential equations describing the dynamic behaviors of the CARR. The computational result of TSACC showed the enough safety margin of CARR under SBA. For the purpose of Verification and Validation (V and V), the simulated results of TSACC were compared with those of Relap5/Mdo3. The V and V result indicated a good agreement between the results by the two codes. Because of the adoption of modular programming techniques, this analysis code is expected to be applied to other reactors by easily modifying the corresponding function modules. (authors)

  10. Novel Accident-Tolerant Fuel Meat and Cladding

    SciTech Connect (OSTI)

    Robert D. Mariani; Pavel G Medvedev; Douglas L Porter; Steven L Hayes; James I. Cole; Xian-Ming Bai

    2013-09-01

    A novel accident-tolerant fuel meat and cladding are here proposed. The fuel meat design incorporates annular fuel with inserts and discs that are fabricated from a material having high thermal conductivity, for example niobium. The inserts are rods or tubes. Discs separate the fuel pellets. Using the BISON fuel performance code it was found that the peak fuel temperature can be lowered by more than 600 degrees C for one set of conditions with niobium metal as the thermal conductor. In addition to improved safety margin, several advantages are expected from the lower temperature such as decreased fission gas release and fuel cracking. Advantages and disadvantages are discussed. An enrichment of only 7.5% fully compensates the lost reactivity of the displaced UO2. Slightly higher enrichments, such as 9%, allow uprates and increased burnups to offset the initial costs for retooling. The design has applications for fast reactors and transuranic burning, which may accelerate its development. A zirconium silicide coating is also described for accident tolerant applications. A self-limiting degradation behavior for this coating is expected to produce a glassy, self-healing layer that becomes more protective at elevated temperature, with some similarities to MoSi2 and other silicides. Both the fuel and coating may benefit from the existing technology infrastructure and the associated wide expertise for a more rapid development in comparison to other, more novel fuels and cladding.

  11. ATMOSPHERIC MODELING IN SUPPORT OF A ROADWAY ACCIDENT

    SciTech Connect (OSTI)

    Buckley, R.; Hunter, C.

    2010-10-21

    The United States Forest Service-Savannah River (USFS) routinely performs prescribed fires at the Savannah River Site (SRS), a Department of Energy (DOE) facility located in southwest South Carolina. This facility covers {approx}800 square kilometers and is mainly wooded except for scattered industrial areas containing facilities used in managing nuclear materials for national defense and waste processing. Prescribed fires of forest undergrowth are necessary to reduce the risk of inadvertent wild fires which have the potential to destroy large areas and threaten nuclear facility operations. This paper discusses meteorological observations and numerical model simulations from a period in early 2002 of an incident involving an early-morning multicar accident caused by poor visibility along a major roadway on the northern border of the SRS. At the time of the accident, it was not clear if the limited visibility was due solely to fog or whether smoke from a prescribed burn conducted the previous day just to the northwest of the crash site had contributed to the visibility. Through use of available meteorological information and detailed modeling, it was determined that the primary reason for the low visibility on this night was fog induced by meteorological conditions.

  12. JOBAID-VIEWING USER RECORDS

    Energy.gov [DOE]

    In this job aid you will View To-Do List using Filter and View options, View Completed Work, and View Curriculum Status and Detials areas. 

  13. US Department of Energy Chernobyl accident bibliography

    SciTech Connect (OSTI)

    Kennedy, R A; Mahaffey, J A; Carr, F Jr

    1992-04-01

    This bibliography has been prepared by Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE) Office of Health and Environmental Research to provide bibliographic information in a usable format for research studies relating to the Chernobyl nuclear accident that occurred in the Ukrainian Republic, USSR in 1986. This report is a product of the Chernobyl Database Management project. The purpose of this project is to produce and maintain an information system that is the official United States repository for information related to the accident. Two related products prepared for this project are the Chernobyl Bibliographic Search System (ChernoLit{trademark}) and the Chernobyl Radiological Measurements Information System (ChernoDat). This report supersedes the original release of Chernobyl Bibliography (Carr and Mahaffey, 1989). The original report included about 2200 references. Over 4500 references and an index of authors and editors are included in this report.

  14. Hanford waste tank bump accident analysis

    SciTech Connect (OSTI)

    MALINOVIC, B.

    2003-03-21

    This report provides a new evaluation of the Hanford tank bump accident analysis (HNF-SD-Wh4-SAR-067 2001). The purpose of the new evaluation is to consider new information and to support new recommendations for final safety controls. This evaluation considers historical data, industrial failure modes, plausible accident scenarios, and system responses. A tank bump is a postulated event in which gases, consisting mostly of water vapor, are suddenly emitted from the waste and cause tank headspace pressurization. A tank bump is distinguished from a gas release event in two respects: First, the physical mechanism for release involves vaporization of locally superheated liquid, and second, gases emitted to the head space are not flammable. For this reason, a tank bump is often called a steam bump. In this report, even though non-condensible gases may be considered in bump models, flammability and combustion of emitted gases are not. The analysis scope is safe storage of waste in its current configuration in single-shell tanks (SSTs) and double-shell tanks (DSTs). The analysis considers physical mechanisms for tank bump to formulate criteria for bump potential, application of the criteria to the tanks, and accident analysis of bump scenarios. The result of consequence analysis is the mass of waste released from tanks for specific scenarios where bumps are credible; conversion to health consequences is performed elsewhere using standard Hanford methods (Cowley et al. 2000). The analysis forms a baseline for future extension to consider waste retrieval.

  15. Risk Estimation Methodology for Launch Accidents.

    SciTech Connect (OSTI)

    Clayton, Daniel James; Lipinski, Ronald J.; Bechtel, Ryan D.

    2014-02-01

    As compact and light weight power sources with reliable, long lives, Radioisotope Power Systems (RPSs) have made space missions to explore the solar system possible. Due to the hazardous material that can be released during a launch accident, the potential health risk of an accident must be quantified, so that appropriate launch approval decisions can be made. One part of the risk estimation involves modeling the response of the RPS to potential accident environments. Due to the complexity of modeling the full RPS response deterministically on dynamic variables, the evaluation is performed in a stochastic manner with a Monte Carlo simulation. The potential consequences can be determined by modeling the transport of the hazardous material in the environment and in human biological pathways. The consequence analysis results are summed and weighted by appropriate likelihood values to give a collection of probabilistic results for the estimation of the potential health risk. This information is used to guide RPS designs, spacecraft designs, mission architecture, or launch procedures to potentially reduce the risk, as well as to inform decision makers of the potential health risks resulting from the use of RPSs for space missions.

  16. Investigations on optimization of accident management measures following a station blackout accident in a VVER-1000 pressurized water reactor

    SciTech Connect (OSTI)

    Tusheva, P.; Schaefer, F.; Kliem, S.

    2012-07-01

    The reactor safety issues are of primary importance for preserving the health of the population and ensuring no release of radioactivity and fission products into the environment. A part of the nuclear research focuses on improvement of the safety of existing nuclear power plants. Studies, research and efforts are a continuing process at improving the safety and reliability of existing and newly developed nuclear power plants at prevention of a core melt accident. Station blackout (loss of AC power supply) is one of the dominant accidents taken into consideration at performing accident analysis. In case of multiple failures of safety systems it leads to a severe accident. To prevent an accident to turn into a severe one or to mitigate the consequences, accident management measures must be performed. The present paper outlines possibilities for application and optimization of accident management measures following a station blackout accident. Assessed is the behaviour of the nuclear power plant during a station blackout accident without accident management measures and with application of primary/secondary side oriented accident management measures. Discussed are the possibilities for operators ' intervention and the influence of the performed accident management measures on the course of the accident. Special attention has been paid to the effectiveness of the passive feeding and physical phenomena having an influence on the system behaviour. The performed simulations show that the effectiveness of the secondary side feeding procedure can be limited due to an early evaporation or flashing effects in the feed water system. The analyzed cases show that the effectiveness of the accident management measures strongly depends on the initiation criteria applied for depressurization of the reactor coolant system. (authors)

  17. Precursors to potential severe core damage accidents, 1986: A status report: Main report and Appendixes A,B, and C

    SciTech Connect (OSTI)

    Minarick, J W; Harris, J D; Austin, P N; Cletcher, J W; Hagen, E W

    1988-05-01

    The Accident Sequence Precursor Program reviews licensee event reports of operational events that have occurred at LWRs to identify and categorize precursors to potential severe core-damage accidents. Accident sequences considered in the study are those associated with inadequate core cooling. Accident sequence precursors are events that are important elements in such sequences. Such precursors could be infrequent initiating events or equipment failures that, when coupled with one or more postulated events, could result in a plant condition with inadequate core cooling. Originally proposed in the Risk Assessment Review Group Report (Lewis Committee report) in 1978, the study - subsequently named the Accident Sequence Precursor Program - was initiated at the Nuclear Operations Analysis Center in 1979. Earlier reports by the program involved assessment of events that occurred in 1969-1981 and 1984-1985. The present report involves the assessment of events that occurred during 1986. A nuclear plant has safety systems for mitigating the consequences of accidents or off-normal initiating events that may occur during the course of plant operation. These systems are built to high-quality standards and are redundant; nonetheless, they have a nonzero probability of failing or being in a failed state when required to operate. This report uses LERs and other plant data, estimated system unavailabilities, the expected average frequency of initiating events (LOFWs, LOOPs, LOCAs), and event details to evaluate the potential impact of the following two situations.

  18. Development of Advanced Accident Tolerant Fuels for Commercial Light Water Reactors

    DOE PAGES-Beta [OSTI]

    Bragg-Sitton, Shannon M.

    2014-03-01

    The safe, reliable and economic operation of the nations nuclear power reactor fleet has always been a top priority for the United States nuclear industry. Continual improvement of technology, including advanced materials and nuclear fuels remains central to industrys success. Decades of research combined with continual operation have produced steady advancements in technology and yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. Thanks to efforts by both the U.S. government and private companies, nuclear technologies have advanced over time to optimize economic operations in nuclear utilitiesmorewhile ensuring safety. One of the missions of the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) is to develop nuclear fuels and claddings with enhanced accident tolerance. In 2011, following the Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex, enhancing the accident tolerance of LWRs became a topic of serious discussion. As a result of direction from the U.S. Congress, DOE-NE initiated Accident Tolerant Fuel (ATF) development as a primary component of the Fuel Cycle Research & Development (FCRD) Advanced Fuels Campaign (AFC). Prior to the unfortunate events at Fukushima, the emphasis for advanced LWR fuel development was on improving nuclear fuel performance in terms of increased burnup for waste minimization, increased power density for power upgrades, and increased fuel reliability. Fukushima highlighted some undesirable performance characteristics of the standard fuel system during severe accidents, including accelerated hydrogen production under certain circumstances. Thus, fuel system behavior under design basis accident and severe accident conditions became the primary focus for advanced fuels while still striving for improved performance under normal operating conditions to

  19. Development of Advanced Accident Tolerant Fuels for Commercial Light Water Reactors

    SciTech Connect (OSTI)

    Bragg-Sitton, Shannon M.

    2014-03-01

    The safe, reliable and economic operation of the nations nuclear power reactor fleet has always been a top priority for the United States nuclear industry. Continual improvement of technology, including advanced materials and nuclear fuels remains central to industrys success. Decades of research combined with continual operation have produced steady advancements in technology and yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. Thanks to efforts by both the U.S. government and private companies, nuclear technologies have advanced over time to optimize economic operations in nuclear utilities while ensuring safety. One of the missions of the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) is to develop nuclear fuels and claddings with enhanced accident tolerance. In 2011, following the Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex, enhancing the accident tolerance of LWRs became a topic of serious discussion. As a result of direction from the U.S. Congress, DOE-NE initiated Accident Tolerant Fuel (ATF) development as a primary component of the Fuel Cycle Research & Development (FCRD) Advanced Fuels Campaign (AFC). Prior to the unfortunate events at Fukushima, the emphasis for advanced LWR fuel development was on improving nuclear fuel performance in terms of increased burnup for waste minimization, increased power density for power upgrades, and increased fuel reliability. Fukushima highlighted some undesirable performance characteristics of the standard fuel system during severe accidents, including accelerated hydrogen production under certain circumstances. Thus, fuel system behavior under design basis accident and severe accident conditions became the primary focus for advanced fuels while still striving for improved performance under normal operating conditions to ensure

  20. ThreatView

    Energy Science and Technology Software Center (OSTI)

    2007-09-25

    The ThreatView project is based on our prior work with the existing ParaView open-source scientific visualization application. Where ParaView provides a grapical client optimized scientific visualization over the VTK parallel client server architecture, ThreatView provides a client optimized for more generic visual analytics over the same architecture. Because ThreatView is based on the VTK parallel client-server architecture, data sources can reside on remote hosts, and processing and rendering can be performed in parallel. As seenmore » in Fig. 1, ThreatView provides four main methods for visualizing data: Landscape View, which displays a graph using a landscape metaphor where clusters of graph nodes produce "hills" in the landscape; Graph View, which displays a graph using a traditional "ball-and-stick" style; Table View, which displays tabular data in a standard spreadsheet; and Attribute View, which displays a tabular "histogram" of input data - for a selected table column, the Attribute View displays each unique value within the column, and the number of times that value appears in the data. There are two supplemental view types: Text View, which displays tabular data one-record-at-a-time; and the Statistics View, which displays input metadata, such as the number of vertices and edges in a graph, the number of rows in a table, etc.« less

  1. Severe Accident Scoping Simulations of Accident Tolerant Fuel Concepts for BWRs

    SciTech Connect (OSTI)

    Robb, Kevin R.

    2015-08-01

    Accident-tolerant fuels (ATFs) are fuels and/or cladding that, in comparison with the standard uranium dioxide Zircaloy system, can tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operations [1]. It is important to note that the currently used uranium dioxide Zircaloy fuel system tolerates design basis accidents (and anticipated operational occurrences and normal operation) as prescribed by the US Nuclear Regulatory Commission. Previously, preliminary simulations of the plant response have been performed under a range of accident scenarios using various ATF cladding concepts and fully ceramic microencapsulated fuel. Design basis loss of coolant accidents (LOCAs) and station blackout (SBO) severe accidents were analyzed at Oak Ridge National Laboratory (ORNL) for boiling water reactors (BWRs) [2]. Researchers have investigated the effects of thermal conductivity on design basis accidents [3], investigated silicon carbide (SiC) cladding [4], as well as the effects of ATF concepts on the late stage accident progression [5]. These preliminary analyses were performed to provide initial insight into the possible improvements that ATF concepts could provide and to identify issues with respect to modeling ATF concepts. More recently, preliminary analyses for a range of ATF concepts have been evaluated internationally for LOCA and severe accident scenarios for the Chinese CPR1000 [6] and the South Korean OPR-1000 [7] pressurized water reactors (PWRs). In addition to these scoping studies, a common methodology and set of performance metrics were developed to compare and support prioritizing ATF concepts [8]. A proposed ATF concept is based on iron-chromium-aluminum alloys (FeCrAl) [9]. With respect to enhancing accident tolerance, FeCrAl alloys have substantially slower oxidation kinetics compared to the zirconium alloys typically employed. During a severe accident, Fe

  2. Assessment of light water reactor accident management programs and experience

    SciTech Connect (OSTI)

    Hammersley, R.J.

    1992-03-01

    The objective of this report is to provide an assessment of the current light water reactor experience regarding accident management programs and associated technology developments. This assessment for light water reactor (LWR) designs is provided as a resource and reference for the development of accident management capabilities for the production reactors at the Savannah River Site. The specific objectives of this assessment are as follows: 1. Perform a review of the NRC, utility, and industry (NUMARC, EPRI) accident management programs and implementation experience. 2. Provide an assessment of the problems and opportunities in developing an accident management program in conjunction or following the Individual Plant Examination process. 3. Review current NRC, utility, and industry technological developments in the areas of computational tools, severe accident predictive tools, diagnostic aids, and severe accident training and simulation.

  3. A framework for the assessment of severe accident management strategies

    SciTech Connect (OSTI)

    Kastenberg, W.E.; Apostolakis, G.; Dhir, V.K.

    1993-09-01

    Severe accident management can be defined as the use of existing and/or altemative resources, systems and actors to prevent or mitigate a core-melt accident. For each accident sequence and each combination of severe accident management strategies, there may be several options available to the operator, and each involves phenomenological and operational considerations regarding uncertainty. Operational uncertainties include operator, system and instrumentation behavior during an accident. A framework based on decision trees and influence diagrams has been developed which incorporates such criteria as feasibility, effectiveness, and adverse effects, for evaluating potential severe accident management strategies. The framework is also capable of propagating both data and model uncertainty. It is applied to several potential strategies including PWR cavity flooding, BWR drywell flooding, PWR depressurization and PWR feed and bleed.

  4. Los Alamos National Laboratory Accident Investigation Board Corrective

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Action Plan Update | Department of Energy Accident Investigation Board Corrective Action Plan Update Los Alamos National Laboratory Accident Investigation Board Corrective Action Plan Update Topic: Status of the Corrective Actions that were identified by the Accident Investigation Board. It was noted that there are 22 Judgments of Need that were assessed against the Los Alamos Site. AIB-CAP-Update - January 13, 2016 (1.95

  5. Accident Response Group | National Nuclear Security Administration | (NNSA)

    National Nuclear Security Administration (NNSA)

    Accident Response Group NNSA's Accident Response Group (ARG) provides technical guidance and responds to U.S. nuclear weapons accidents. ARG_Logo The team assists in assessing weapons damage and risk, and in developing and implementing procedures for safe weapon recovery, packaging, transportation, and disposal of damaged weapons. The ARG headquarters is located in Albuquerque, New Mexico and is supported by Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Sandia National

  6. ORISE: The Medical Basis for Radiation-Accident Preparedness: Medical

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Management (Published by REAC/TS) The Medical Basis for Radiation-Accident Preparedness: Medical Management Proceedings of the Fifth International REAC/TS Symposium on the Medical Basis for Radiation-Accident Preparedness and the Biodosimetry Workshop As part of its mission to provide continuing education for personnel responsible for treating radiation injuries, REAC/TS hosted the Fifth International REAC/TS Symposium on the Medical Basis for Radiation-Accident Preparedness symposium and

  7. Preliminary dose assessment of the Chernobyl accident

    SciTech Connect (OSTI)

    Hull, A.P.

    1987-01-01

    From the major accident at Unit 4 of the Chernobyl nuclear power station, a plume of airborne radioactive fission products was initially carried northwesterly toward Poland, thence toward Scandinavia and into Central Europe. Reports of the levels of radioactivity in a variety of media and of external radiation levels were collected in the Department of Energy's Emergency Operations Center and compiled into a data bank. Portions of these and other data which were obtained directly from published and official reports were utilized to make a preliminary assessment of the extent and magnitude of the external dose to individuals downwind from Chernobyl. Radioactive /sup 131/I was the predominant fission product. The time of arrival of the plume and the maximum concentrations of /sup 131/I in air, vegetation and milk and the maximum reported depositions and external radiation levels have been tabulated country by country. A large amount of the total activity in the release was apparently carried to a significant elevation. The data suggest that in areas where rainfall occurred, deposition levels were from ten to one-hundred times those observed in nearby ''dry'' locations. Sufficient spectral data were obtained to establish average release fractions and to establish a reference spectra of the other nuclides in the release. Preliminary calculations indicated that the collective dose equivalent to the population in Scandinavia and Central Europe during the first year after the Chernobyl accident would be about 8 x 10/sup 6/ person-rem. From the Soviet report, it appears that a first year population dose of about 2 x 10/sup 7/ person-rem (2 x 10/sup 5/ Sv) will be received by the population who were downwind of Chernobyl within the U.S.S.R. during the accident and its subsequent releases over the following week. 32 refs., 14 figs., 20 tabs.

  8. Postulated accident scenarios in weapons disassembly

    SciTech Connect (OSTI)

    Payne, S.S.

    1997-06-01

    A very brief summary of three postulated accident scenarios for weapons disassembly is provided in the paper. The first deals with a tetrahedral configuration of four generic pits; the second, an infinite planar array of generic pits with varying interstitial water density; and the third, a spherical shell with internal mass suspension in water varying the size and mass of the shell. Calculations were performed using the Monte Carlo Neutron Photon transport code MCNP4A. Preliminary calculations pointed to a need for higher resolution of small pit separation regimes and snapshots of hydrodynamic processes of water/plutonium mixtures.

  9. Accident Investigation Reports - Type B | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    is an independent product of the Type B Accident Investigation Board appointed by John Kennedy, Acting Manager, Chicago Operations Office, U.S. Department of Energy (DOE). October...

  10. Improvement of Design Codes to Account for Accident Thermal Effects...

    Energy Savers

    IMPROVEMENT OF DESIGN CODES TO ACCOUNT FOR ACCIDENT THERMAL EFFECTS ON SEISMIC PERFORMANCE ... PROJECT OBJECTIVES (CONT'D) Develop design guidelines and recommendations for ...

  11. Accident Investigation of the August 21, 2012, Contamination...

    Energy.gov (indexed) [DOE]

    PDF icon Accident Investigation of the August 21, 2012, Contamination Incident at the Los Alamos Neutron Science Center at the Los Alamos National Laboratory More Documents & ...

  12. Type B Accident Investigation Board Report, May 8, 2004, Exothermic...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Report, May 8, 2004, Exothermic Metal Reactor Event During Sodium Transfer Activities, ... Type B Accident Investigation Board Report, May 8, 2004, Exothermic Metal Reactor Event ...

  13. Code System to Model LWR Meltdown Accident Response.

    Energy Science and Technology Software Center (OSTI)

    2001-04-25

    MARCH2 describes the response of water cooled reactors to severe accidents, including consideration of the primary coolant system as well as the containment.

  14. Type B Accident Investigation of the August 22, 2000, Injury...

    Office of Environmental Management (EM)

    Chemical Reaction at the Portsmouth Gaseous Diffusion Plant, X-701B Site Type B Accident Investigation of the August 22, 2000, Injury Resulting From Violent Exothermic Chemical ...

  15. Accident Investigation Report - Fire Report | Department of Energy

    Office of Environmental Management (EM)

    an Accident Investigation Board to investigate an underground mine fire involving a salt haul truck occurred at DOE's WIPP near Carlsbad, New Mexico. The Board began the...

  16. Sandia Energy - Waste Isolation Pilot Plant Accident Investigation...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Home Energy Nuclear Energy News News & Events Research & Capabilities Systems Analysis Materials Science Computational Modeling & Simulation Waste Isolation Pilot Plant Accident...

  17. Hazard Categorization and Accident Analysis Techniques for Compliance...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports by Diane Johnson he purpose of this DOE Standard is to...

  18. Type B Accident Investigation Board Report for the January 11...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    barrier analysis, change analysis, and event and causal factor analysis. PDF icon Type B Accident Investigation Board Report for the January 11, 2006, Personal Injury During ...

  19. Type B Accident Investigation Board Report BNFL, Inc. Employee...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Employee Foot Injury on December 17, 2003, at the East Tennessee Technology Park Building K-31 Type B Accident Investigation Board Report BNFL, Inc. Employee Foot Injury on ...

  20. Type B Accident Investigation At Washington Closure Hanford,...

    Energy Savers

    LLC, Employee Fall Injury on July 1, 2009, At The 336 Building, Hanford Site, Washington Type B Accident Investigation At Washington Closure Hanford, LLC, Employee Fall Injury ...

  1. Accident Investigation of the October 1, 2013, Tice Electric...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Company Employee Fatality near Patrick's Knob Radio Station, Bonneville Power Administration Accident Investigation of the October 1, 2013, Tice Electric Company Employee Fatality ...

  2. Type B Accident Investigation Board Report Employee Puncture...

    Energy.gov (indexed) [DOE]

    investigation of the June 14, 2010, employee puncture wound at the Department of ... TYPE B ACCIDENT INVESTIGATION BOARD REPORT EMPLOYEE PUNCTURE WOUND AT THE F-TRU WASTE ...

  3. Type B Accident Investigation Board Report of the Brookhaven...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Laboratory Employee Injury at Building 1005H on October 9, 2009 Type B Accident Investigation Board Report of the Brookhaven National Laboratory Employee Injury at Building ...

  4. Accident Investigation of the June 1, 2013, Stairway Fall Resulting...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    in a Federal Employee Fatality at DOE Headquarters Germantown, Maryland Accident Investigation of the June 1, 2013, Stairway Fall Resulting in a Federal Employee Fatality at DOE ...

  5. Improvement of Design Codes to Account for Accident Thermal Effects...

    Office of Environmental Management (EM)

    IMPROVEMENT OF DESIGN CODES TO ACCOUNT FOR ACCIDENT THERMAL EFFECTS ON SEISMIC PERFORMANCE Amit H. Varma, Kadir Sener, Saahas Bhardwaj Purdue University Andrew Whittaker: Univ. of...

  6. Type B Accident Investigation Report of the October 28, 2004...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    of the October 28, 2004, Burn Injuries Sustained During an Office of Secure Transportation Joint Training Exercise at Fort Hunter-Liggett, CA Type B Accident Investigation Report ...

  7. Neutronic Analysis of Candidate Accident-tolerant Cladding Concepts...

    Office of Scientific and Technical Information (OSTI)

    Concepts in Light Water Reactors Citation Details In-Document Search Title: Neutronic Analysis of Candidate Accident-tolerant Cladding Concepts in Light Water Reactors Authors: ...

  8. Neutronic Analysis of Candidate Accident-Tolerant Cladding Concepts...

    Office of Scientific and Technical Information (OSTI)

    in Pressurized Water Reactors Citation Details In-Document Search Title: Neutronic Analysis of Candidate Accident-Tolerant Cladding Concepts in Pressurized Water Reactors ...

  9. Sandia Assists NASA in Understanding Launch-Area Accidents

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... Launch-Area Accidents Curiosity's multi-mission radioisotope thermoelectric generator on Mars. Curiosity's multi-mission radioisotope thermoelectric generator on Mars. ...

  10. Accident Investigation of the September 20, 2012 Fatal Fall from...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Power Marketing Administration Accident Investigation of the September 20, 2012 Fatal Fall from the Dworshak-Taft 1 Transmission Tower, at the Bonneville Power Marketing ...

  11. Type B Accident Investigation of the January 10, 2006, Flash...

    Energy.gov (indexed) [DOE]

    Independent Oversight Follow-up Review, Savannah River National Laboratory - January 2012 Type B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April ...

  12. Type B Accident Investigation of the Arc Flash at Brookhaven...

    Energy Savers

    Arc Flash at Brookhaven National Laboratory, April 14, 2006 Type B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April 14, 2006 February 10, 2006 An ...

  13. Type A Accident Investigation of the March 16, 2000, Plutonium...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    New Mexico Type A Accident Investigation of the March 16, 2000, Plutonium-238 Multiple Intake Event at the Plutonium Facility, Los Alamos National Laboratory, New Mexico July ...

  14. Type B Accident Investigation Report on the Exertional Heat Illnesses...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    New Mexico, July 13, 2006 Type B Accident Investigation Report on the Exertional Heat Illnesses during SPOTC 2006 at the National Training Center in Albuquerque, New Mexico, July ...

  15. Type A Accident Investigation of the June 21, 2001, Drilling...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    June 21, 2001, Drilling Rig Operator Injury at the Fermi National Accelerator Laboratory, August 2001 Type A Accident Investigation of the June 21, 2001, Drilling Rig Operator ...

  16. The Nuclear Accident at Three Mile Island a Practical Lesson in the Fundamental Importance of Effective Communications

    SciTech Connect (OSTI)

    DeVine Jr, J.C.

    2008-07-01

    The Three Mile Island Unit 2 (TMI-2) accident in March 1979 had a profound effect on the course of commercial nuclear generation in the United States and around the world. And while the central elements of the accident were matters of nuclear engineering, design and operations, its consequences were compounded, and in some respects superseded, by extraordinarily ineffective communications by all parties at all levels. Communications failures during the accident and its aftermath caused misunderstanding, distrust, and incorrect emergency response - and seeded or reinforced public opposition to nuclear power that persists to this day. There are communications lessons from TMI that have not yet been fully learned, and some that once were learned but are now gradually being forgotten. The more glaring TMI communications problems were in the arena of external interactions and communications among the plant owner, the Nuclear Regulatory Commission (NRC), the media, and the public. Confusing, fragmented, and contradictory public statements early in the accident, regardless of cause, undermined all possibility for reasonable discourse thereafter. And because the TMI accident was playing out on a world stage, the breakdown in public trust had long term and widespread implications. At the plant site, both TMI-2 cleanup and restart of the undamaged TMI-1 unit met with years of public and political criticism, and attendant regulatory pressure. Across the nation, public trust in nuclear power and those who operate it plummeted, unquestionably contributing to the 25+ year hiatus in new plant orders. There were other, less visible but equally important, consequences of ineffective communications at TMI. The unplanned 'precautionary' evacuation urged by the governor two days after the accident - a life changing, traumatic event for thousands of residents - was prompted primarily by misunderstandings and miscommunications regarding the condition of the plant. And today, nearly 30

  17. Type B Accident Investigation of the March 20, 2003, Stair Installation Accident at Building 752, Sandia National Laboratories

    Energy.gov [DOE]

    This report is an independent product of the Type B Accident Investigation Board appointed by Karen L. Boardman, Manager, Sandia Site Office (SSO), National Nuclear Security Administration (NNSA).

  18. Calculation notes that support accident scenario and consequence development for the steam intrusion from interfacing systems accident

    SciTech Connect (OSTI)

    Van Vleet, R.J.; Ryan, G.W.; Crowe, R.D.; Lindberg, S.E., Fluor Daniel Hanford

    1997-03-04

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report (FSAR): Steam Intrusion From Interfacing Systems. The calculations needed to quantify the risk associated with this accident scenario are included in the following sections to aid in the understanding of this accident scenario. Information validation forms citing assumptions that were approved for use specifically in this analysis are included in Appendix A. Copies of these forms are also on file with TWRS Project Files. Calculations performed in this document, in general, are expressed in traditional (English) units to aid understanding of the accident scenario and related parameters.

  19. Type B Accident Investigation Board Report of the April 23, 1997, Helicopter Accident at Raton Pass, Raton Pass, Colorado

    Energy.gov [DOE]

    This report is an independent product of the Type B Accident Investigation Board appointed by Michael S. Cowan, Chief Program Officer, Western Area Power Administration.

  20. Advanced Fuels Campaign Light Water Reactor Accident Tolerant Fuel Performance Metrics

    SciTech Connect (OSTI)

    Brad Merrill; Melissa Teague; Robert Youngblood; Larry Ott; Kevin Robb; Michael Todosow; Chris Stanek; Mitchell Farmer; Michael Billone; Robert Montgomery; Nicholas Brown; Shannon Bragg-Sitton

    2014-02-01

    The safe, reliable and economic operation of the nation’s nuclear power reactor fleet has always been a top priority for the United States’ nuclear industry. As a result, continual improvement of technology, including advanced materials and nuclear fuels, remains central to industry’s success. Decades of research combined with continual operation have produced steady advancements in technology and yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. In 2011, following the Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex, enhancing the accident tolerance of LWRs became a topic of serious discussion. As a result of direction from the U.S. Congress, the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) initiated an Accident Tolerant Fuel (ATF) Development program. The complex multiphysics behavior of LWR nuclear fuel makes defining specific material or design improvements difficult; as such, establishing qualitative attributes is critical to guide the design and development of fuels and cladding with enhanced accident tolerance. This report summarizes a common set of technical evaluation metrics to aid in the optimization and down selection of candidate designs. As used herein, “metrics” describe a set of technical bases by which multiple concepts can be fairly evaluated against a common baseline and against one another. Furthermore, this report describes a proposed technical evaluation methodology that can be applied to assess the ability of each concept to meet performance and safety goals relative to the current UO2 – zirconium alloy system and relative to one another. The resultant ranked evaluation can then inform concept down-selection, such that the most promising accident tolerant fuel design option(s) can continue to be developed for lead test rod or lead test assembly

  1. SOCRAT: The System of Codes for Realistic Analysis of Severe Accidents

    SciTech Connect (OSTI)

    Bolshov, Leonid; Strizhov, Valery

    2006-07-01

    For a long time in the Russian Federation the computer code for analysis of severe accidents is being developed. The main peculiarity of this code from the known computer codes for analysis of severe accidents at NPP such as MELCOR and ASTEC, is a consequent realization of the mechanistic approach for modeling of the melt progression processes, including beyond design basis accidents with the severe core damage. The motivation of the development is defined by the new design requirements to the safety of nuclear power plants with the improved economic factors, by the modernization of existing NPPs, by the development of instructions to the accident management and emergency planning. The realistic assessments of Nuclear power plants safety require usage of the best estimate codes allowing description of the melt progression processes accompanying severe accident at the nuclear installation and behavior of the containment under abnormal condition (in particular, rates of the steam and hydrogen release, relocation of molten materials to the concrete cavity after failure of the reactor vessel). The developed computer codes were used for the safety justification of NPP with the new generation of VVER type reactor such as Tyanvan NPP in China and Kudamkulam NPP in India. In particular using this code system the justification of the system for hydrogen safety, analysis of core degradation and relocation of the molten core to the core catcher used for the guarantied localization of the melt and prevention of the ex-vessel melt progression. The considered system of codes got recently name SOCRAT provides the self consistent analysis of in-vessel processes and processes, running in the containment, including melt localization device. In the paper the structure of the computer code SOCRAT is presented, functionality of the separate parts of the code is described, results of verification of different models of the code are also considered. (authors)

  2. Accident response group (ARG) containers for recovery of damaged warheads

    SciTech Connect (OSTI)

    York, A.R. II; Hoffman, J.P.

    1993-09-01

    This report provides an overview of the containers that are currently stored at Pantex and available for use in response to an accident or for use in any other application where a sealed containment vessel and accident resistant overpack may be needed.

  3. Canister Storage Building (CSB) Design Basis Accident Analysis Documentation

    SciTech Connect (OSTI)

    CROWE, R.D.

    1999-09-09

    This document provides the detailed accident analysis to support ''HNF-3553, Spent Nuclear Fuel Project Final Safety, Analysis Report, Annex A,'' ''Canister Storage Building Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the Canister Storage Building Final Safety Analysis Report.

  4. Cold Vacuum Drying (CVD) Facility Design Basis Accident Analysis Documentation

    SciTech Connect (OSTI)

    PIEPHO, M.G.

    1999-10-20

    This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report, ''Cold Vacuum Drying Facility Final Safety Analysis Report (FSAR).'' All assumptions, parameters and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR.

  5. Canister Storage Building (CSB) Design Basis Accident Analysis Documentation

    SciTech Connect (OSTI)

    CROWE, R.D.; PIEPHO, M.G.

    2000-03-23

    This document provided the detailed accident analysis to support HNF-3553, Spent Nuclear Fuel Project Final Safety Analysis Report, Annex A, ''Canister Storage Building Final Safety Analysis Report''. All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the Canister Storage Building Final Safety Analysis Report.

  6. Canister storage building design basis accident analysis documentation

    SciTech Connect (OSTI)

    KOPELIC, S.D.

    1999-02-25

    This document provides the detailed accident analysis to support HNF-3553, Spent Nuclear Fuel Project Final Safety Analysis Report, Annex A, ''Canister Storage Building Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the Canister Storage Building Final Safety Analysis Report.

  7. BWR containment failure analysis during degraded-core accidents

    SciTech Connect (OSTI)

    Yue, D.D.

    1982-06-06

    This paper presents a containment failure mode analysis during a spectrum of postulated degraded core accident sequences in a typical 1000-MW(e) boiling water reactor (BWR) with a Mark-I wetwell containment. Overtemperature failure of containment electric penetration assemblies (CEPAs) has been found to be the major failure mode during such accidents.

  8. Web Based Course: SAF-230DE, Accident Investigation Overview Promotional Video

    Energy.gov [DOE]

    This course that provides an overview of the fundamentals of accident investigation. The course is intended to meet the every five year refresher training requirement for DOE Federal Accident Investigators under DOE O 225.1B, Accident Investigations.

  9. Uncertainty quantification for accident management using ACE surrogates

    SciTech Connect (OSTI)

    Varuttamaseni, A.; Lee, J. C.; Youngblood, R. W.

    2012-07-01

    The alternating conditional expectation (ACE) regression method is used to generate RELAP5 surrogates which are then used to determine the distribution of the peak clad temperature (PCT) during the loss of feedwater accident coupled with a subsequent initiation of the feed and bleed (F and B) operation in the Zion-1 nuclear power plant. The construction of the surrogates assumes conditional independence relations among key reactor parameters. The choice of parameters to model is based on the macroscopic balance statements governing the behavior of the reactor. The peak clad temperature is calculated based on the independent variables that are known to be important in determining the success of the F and B operation. The relationship between these independent variables and the plant parameters such as coolant pressure and temperature is represented by surrogates that are constructed based on 45 RELAP5 cases. The time-dependent PCT for different values of F and B parameters is calculated by sampling the independent variables from their probability distributions and propagating the information through two layers of surrogates. The results of our analysis show that the ACE surrogates are able to satisfactorily reproduce the behavior of the plant parameters even though a quasi-static assumption is primarily used in their construction. The PCT is found to be lower in cases where the F and B operation is initiated, compared to the case without F and B, regardless of the F and B parameters used. (authors)

  10. GPHS-RTG launch accident analysis for Galileo and Ulysses

    SciTech Connect (OSTI)

    Bradshaw, C.T. )

    1991-01-01

    This paper presents the safety program conducted to determine the response of the General Purpose Heat Source (GPHS) Radioisotope Thermoelectric Generator (RTG) to potential launch accidents of the Space Shuttle for the Galileo and Ulysses missions. The National Aeronautics and Space Administration (NASA) provided definition of the Shuttle potential accidents and characterized the environments. The Launch Accident Scenario Evaluation Program (LASEP) was developed by GE to analyze the RTG response to these accidents. RTG detailed response to Solid Rocket Booster (SRB) fragment impacts, as well as to other types of impact, was obtained from an extensive series of hydrocode analyses. A comprehensive test program was conducted also to determine RTG response to the accident environments. The hydrocode response analyses coupled with the test data base provided the broad range response capability which was implemented in LASEP.

  11. MELCOR accident analysis for ARIES-ACT

    SciTech Connect (OSTI)

    Paul W. Humrickhouse; Brad J. Merrill

    2012-08-01

    We model a loss of flow accident (LOFA) in the ARIES-ACT1 tokamak design. ARIES-ACT1 features an advanced SiC blanket with LiPb as coolant and breeder, a helium cooled steel structural ring and tungsten divertors, a thin-walled, helium cooled vacuum vessel, and a room temperature water-cooled shield outside the vacuum vessel. The water heat transfer system is designed to remove heat by natural circulation during a LOFA. The MELCOR model uses time-dependent decay heats for each component determined by 1-D modeling. The MELCOR model shows that, despite periodic boiling of the water coolant, that structures are kept adequately cool by the passive safety system.

  12. Preliminary Investigation of Candidate Materials for Use in Accident Resistant Fuel

    SciTech Connect (OSTI)

    Jason M. Harp; Paul A. Lessing; Blair H. Park; Jakeob Maupin

    2013-09-01

    As part of a Collaborative Research and Development Agreement (CRADA) with industry, Idaho National Laboratory (INL) is investigating several options for accident resistant uranium compounds including silicides, and nitrides for use in future light water reactor (LWR) fuels. This work is part of a larger effort to create accident tolerant fuel forms where changes to the fuel pellets, cladding, and cladding treatment are considered. The goal fuel form should have a resistance to water corrosion comparable to UO2, have an equal to or larger thermal conductivity than uranium dioxide, a melting temperature that allows the material to stay solid under power reactor conditions, and a uranium loading that maintains or improves current LWR power densities. During the course of this research, fuel fabricated at INL will be characterized, irradiated at the INL Advanced Test Reactor, and examined after irradiation at INL facilities to help inform industrial partners on candidate technologies.

  13. Accident source terms for boiling water reactors with high burnup cores.

    SciTech Connect (OSTI)

    Gauntt, Randall O.; Powers, Dana Auburn; Leonard, Mark Thomas

    2007-11-01

    The primary objective of this report is to provide the technical basis for development of recommendations for updates to the NUREG-1465 Source Term for BWRs that will extend its applicability to accidents involving high burnup (HBU) cores. However, a secondary objective is to re-examine the fundamental characteristics of the prescription for fission product release to containment described by NUREG-1465. This secondary objective is motivated by an interest to understand the extent to which research into the release and behaviors of radionuclides under accident conditions has altered best-estimate calculations of the integral response of BWRs to severe core damage sequences and the resulting radiological source terms to containment. This report, therefore, documents specific results of fission product source term analyses that will form the basis for the HBU supplement to NUREG-1465. However, commentary is also provided on observed differences between the composite results of the source term calculations performed here and those reflected NUREG-1465 itself.

  14. Type A Accident Investigation Board Report on the April 19, 1999...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Type A Accident Investigation Board Report on the April 19, 1999, Special Agent Fatality ... responsibility for conducting a Type A accident investigation to the AL Manager on April ...

  15. Type B Accident Investigation of the July 31, 2006, Fall from...

    Office of Environmental Management (EM)

    31, 2006, Fall from Ladder Accident at the Lawrence Livermore National Laboratory, Livermore, California Type B Accident Investigation of the July 31, 2006, Fall from Ladder ...

  16. Reactor safety study. An assessment of accident risks in U. S...

    Office of Scientific and Technical Information (OSTI)

    An assessment of accident risks in U. S. commercial nuclear power plants. Executive ... An assessment of accident risks in U. S. commercial nuclear power plants. Executive ...

  17. The Accident at Fukushima: What Happened?

    SciTech Connect (OSTI)

    Fujie, Takao

    2012-07-01

    At 2:46 PM, on the coast of the Pacific Ocean in eastern Japan, people were spending an ordinary afternoon. The earthquake had a magnitude of 9.0, the fourth largest ever recorded in the world. Avery large number of aftershocks were felt after the initial earthquake. More than 100 of them had a magnitude of over 6.0. There were very few injured or dead at this point. The large earthquake caused by this enormous crustal deformation spawned a rare and enormous tsunami that crashed down 30-40 minutes later. It easily cleared the high levees, washing away cars and houses and swallowing buildings of up to three stories in height. The largest tsunami reading taken from all regions was 40 meters in height. This tsunami reached the West Coast of the United States and the Pacific coast of South America, with wave heights of over two meters. It was due to this tsunami that the disaster became one of a not imaginable scale, which saw the number of dead or missing reach about 20,000 persons. The enormous tsunami headed for 15 nuclear power plants on the Pacific coast, but 11 power plants withstood the tsunami and attained cold shutdown. The flood height of the tsunami that struck each power station ranged to a maximum of 15 meters. The Fukushima Daiichi Nuclear Power Plant Units experienced the largest and the cores of three reactors suffered meltdown. As a result, more than 160,000 residents were forced to evacuate, and are still living in temporary accommodation. The main focus of this presentation is on what happened at the Fukushima Daiichi, and how station personnel responded to the accident, with considerable international support. A year after the Fukushima Daiichi accident, Japan is in the process of leveraging the lessons learned from the accident to further improve the safety of nuclear power facilities and regain the trust of society. In this connection, not only international organizations, including IAEA, and WANO, but also governmental organizations and nuclear

  18. Accident Performance of Light Water Reactor Cladding Materials

    SciTech Connect (OSTI)

    Nelson, Andrew T.

    2012-07-24

    During a loss of coolant accident as experienced at Fukushima, inadequate cooling of the reactor core forces component temperatures ever higher where they must withstand aggressive chemical environments. Conventional zirconium cladding alloys will readily oxidize in the presence of water vapor at elevated temperatures, rapidly degrading and likely failing. A cladding breach removes the critical barrier between actinides and fission products and the coolant, greatly increasing the probability of the release of radioactivity in the event of a containment failure. These factors have driven renewed international interest in both study and improvement of the materials used in commercial light water reactors. Characterization of a candidate cladding alloy or oxidation mitigation technique requires understanding of both the oxidation kinetics and hydrogen production as a function of temperature and atmosphere conditions. Researchers in the MST division supported by the DOE-NE Fuel Cycle Research and Development program are working to evaluate and quantify these parameters across a wide range of proposed cladding materials. The primary instrument employed is a simultaneous thermal analyzer (STA) equipped with a specialized water vapor furnace capable of maintaining temperatures above 1200 C in a range of atmospheres and water vapor contents. The STA utilizes thermogravimetric analysis and a coupled mass spectrometer to measure in situ oxidation and hydrogen production of candidate materials. This capability is unprecedented in study of materials under consideration for reactor cladding use, and is currently being expanded to investigate proposed coating techniques as well as the effect of coating defects on corrosion resistance.

  19. Taking the long view

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Taking the long view Taking the long view on environmental stewardship A newly articulated mission for environmental stewardship at the Laboratory can be summed up in a simple phrase: clean up the past, control current operations, and create a sustainable future. March 20, 2012 Los Alamos Aerial Aerial view of a canyon in Los Alamos, New Mexico. Contact Environmental Communication & Public Outreach P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505) 667-0216 Email "The future viability of

  20. Aging, Loss-of-Coolant Accident (LOCA), and high potential testing of damaged cables

    SciTech Connect (OSTI)

    Vigil, R.A.; Jacobus, M.J.

    1994-04-01

    Experiments were conducted to assess the effects of high potential testing of cables and to assess the survivability of aged and damaged cables under Loss-of-Coolant Accident (LOCA) conditions. High potential testing at 240 Vdc/mil on undamaged cables suggested that no damage was incurred on the selected virgin cables. During aging and LOCA testing, Okonite ethylene propylene rubber (EPR) cables with a bonded jacket experienced unexpected failures. The failures appear to be primarily related to the level of thermal aging and the presence of a bonded jacket that ages more rapidly than the insulation. For Brand Rex crosslinked polyolefin (XLPO) cables, the results suggest that 7 mils of insulation remaining should give the cables a high probability of surviving accident exposure following aging. The voltage necessary to detect when 7 mils of insulation remain on unaged Brand Rex cables is approximately 35 kVdc. This voltage level would almost certainly be unacceptable to a utility for use as a damage assessment tool. However, additional tests indicated that a 35 kvdc voltage application would not damage virgin Brand Rex cables when tested in water. Although two damaged Rockbestos silicone rubber cables also failed during the accident test, no correlation between failures and level of damage was apparent.

  1. Material selection for accident tolerant fuel cladding

    SciTech Connect (OSTI)

    Pint, B. A.; Terrani, K. A.; Yamamoto, Y.; Snead, L. L.

    2015-09-14

    Alternative cladding materials are being investigated for accident tolerance, which can be defined as >100X improvement (compared to current Zr-based alloys) in oxidation resistance in steam environments at ?1200C for short (?4 h) times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. Therefore, commercial Ti2AlC that is not single phase, formed a much thicker oxide at 1200C in steam and significant TiO2, and therefore may be challenging to use as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475C, while reducing its Cr content to minimize susceptibility to irradiation assisted Cr-rich ? formation. The composition effects and critical limits to retaining protective scale formation at >1400C are still being evaluated.

  2. Material selection for accident tolerant fuel cladding

    DOE PAGES-Beta [OSTI]

    Pint, B. A.; Terrani, K. A.; Yamamoto, Y.; Snead, L. L.

    2015-09-14

    Alternative cladding materials are being investigated for accident tolerance, which can be defined as >100X improvement (compared to current Zr-based alloys) in oxidation resistance in steam environments at ≥1200°C for short (≤4 h) times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. Therefore, commercial Ti2AlC that is not single phase, formed a much thicker oxide at 1200°C in steammore » and significant TiO2, and therefore may be challenging to use as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation assisted Cr-rich α’ formation. The composition effects and critical limits to retaining protective scale formation at >1400°C are still being evaluated.« less

  3. Material selection for accident tolerant fuel cladding

    SciTech Connect (OSTI)

    Pint, B. A.; Terrani, K. A.; Yamamoto, Y.; Snead, L. L.

    2015-09-14

    Alternative cladding materials are being investigated for accident tolerance, which can be defined as >100X improvement (compared to current Zr-based alloys) in oxidation resistance in steam environments at ≥1200°C for short (≤4 h) times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. Therefore, commercial Ti2AlC that is not single phase, formed a much thicker oxide at 1200°C in steam and significant TiO2, and therefore may be challenging to use as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation assisted Cr-rich α’ formation. The composition effects and critical limits to retaining protective scale formation at >1400°C are still being evaluated.

  4. Material Selection for Accident Tolerant Fuel Cladding

    SciTech Connect (OSTI)

    Pint, Bruce A.; Terrani, Kurt A.; Yamamoto, Yukinori; Snead, Lance Lewis

    2015-01-01

    Alternative cladding materials to Zr-based alloys are being investigated for accident tolerance, which can be defined as > 100X improvement (compared to Zr-based alloys) in oxidation resistance to steam or steam-H2 environments at ≥ 1200°C for short times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. However, commercial Ti2AlC that was not single phase, formed a much thicker oxide at 1200°C in steam and significant TiO2, and therefore Ti2AlC may be challenging to form as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation-assisted α´ formation. The composition effects and critical limits to retaining protective scale formation at > 1400°C are still being evaluated.

  5. MELCOR Accident Consequence Code System (MACCS)

    SciTech Connect (OSTI)

    Chanin, D.I. ); Sprung, J.L.; Ritchie, L.T.; Jow, Hong-Nian )

    1990-02-01

    This report describes the MACCS computer code. The purpose of this code is to simulate the impact of severe accidents at nuclear power plants on the surrounding environment. MACCS has been developed for the US Nuclear Regulatory Commission to replace the previous CRAC2 code, and it incorporates many improvements in modeling flexibility in comparison to CRAC2. The principal phenomena considered in MACCS are atmospheric transport, mitigative actions based on dose projection, dose accumulation by a number of pathways including food and water ingestion, early and latent health effects, and economic costs. The MACCS code can be used for a variety of applications. These include (1) probabilistic risk assessment (PRA) of nuclear power plants and other nuclear facilities, (2) sensitivity studies to gain a better understanding of the parameters important to PRA, and (3) cost-benefit analysis. This report is composed of three volumes. This document, Volume 1, the Users's Guide, describes the input data requirements of the MACCS code and provides directions for its use as illustrated by three sample problems.

  6. ParaView

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... program in step 4 above. 1. Open ParaView and select File->Connect from the menu. 5. The server config script will start an xterm allowing you to login to the selected system. ...

  7. Taking the long view

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    2012 Los Alamos Aerial Aerial view of a canyon in Los Alamos, New Mexico. Contact Environmental Communication & Public Outreach P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505)...

  8. Type B Accident Investigation of the Savannah River Site Arc...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    of the Savannah River Site Arc Flash Burn Injury on September 23, 2009, in the D Area Powerhouse Type B Accident Investigation of the Savannah River Site Arc Flash Burn Injury on ...

  9. Accident Investigation of the July 30, 2013, Electrical Fatality...

    Energy Savers

    July 30, 2013, Electrical Fatality on the Bandon-Rogue No. 1 115kV Line at the Bonneville Power Administration Accident Investigation of the July 30, 2013, Electrical Fatality on ...

  10. Type B Accident Investigation Board Report Grout Injection Operator...

    Energy Savers

    and no damage to any structures inside the calvareum (i.e., no evidence of brain injury). Page 16 2.4. Investigation Readiness and Accident Scene Preservation The...

  11. Core coolability following loss-of-heat sink accidents. [LMFBR

    SciTech Connect (OSTI)

    Khatib-Rahbar, M.

    1983-01-01

    Most investigations of core meltdown scenarios in liquid metal fast breeder reactors (LMFBRs) have focused on accidents resulting from unprotected transients. In comparison, protected accidents which may lead to loss of core coolability and subsequent meltdown have received considerably less attention until recently. The sequence of events leading to the protected loss-of-heat sink (LOHS) accident is among other things dependent on plant type and design. The situation is vastly different in pool-type LMFBRs as compared to the loop-type design; this is as a result of major differences in the primary system configuration, coolant inventory and the structural design. The principal aim of the present paper is to address LOHS accidents in a loop-type LMFBR in regard to physical sequences of events which could lead to loss-of-core coolability and subsequent meltdown.

  12. Type B Accident Investigation Board Report of the Bechtel Jacobs...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Bechtel Jacobs Company, LLC Employee Fall Injury on January 3, 2006, at the K-25 Building, ... Type B Accident Investigation Board Report of the Bechtel Jacobs Company, LLC Employee ...

  13. Level 1 Accident Investigation Report of August 17, 2004, Fatal...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    wire on the Grand Coulee-Bell 6 500-kV line between tower 842 and BPA's Bell Substation in Mead, Washington. (See Appendix 7, Site Map.) Level 1 Accident Investigation ...

  14. Accidents and Intentional Destructive Acts Guidance and Requirements

    Energy.gov [DOE]

    Accidents, as they relate to public and occupational health issues, include the determination of potential adverse effects on human health. The effects of Intentional Destructive Acts (IDAs), more...

  15. Accident Investigation Reports - Type B | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    independent product of the Type B Accident Investigation Board appointed by James M. Turner, Ph.D., Manager of the U.S. Department of Energy, Oakland Operations Office. July 7,...

  16. Corrective Action Plan Addressing the Accident Investigation Report

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Corrective Action Plan Addressing the Accident Investigation Report of the February 5, 2014 Fire Event and the February 14, 2014 Radiological Release Event, Rev 1 Page 2 of 89 Table of Contents 1 Purpose ................................................................................................................................................................................................ 7 2 Summary of the

  17. Type B Accident Investigation Of The February 25, 2009 Injury...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    New Mexico Type B Accident Investigation Of The February 25, 2009 Injury To A Passenger In An Electric Cart At The Waste Isolation Pilot Plant, Carlsbad, New Mexico April 1, ...

  18. Type B Accident Investigation Board Report on the Head Injury...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    New Mexico - August 25, 2004 Type B Accident Investigation Board Report on the Head Injury to a Miner at the Waste Isolation Pilot Plant, Carlsbad, New Mexico - August 25, ...

  19. Full-Scale Accident Testing in Support of Used Nuclear Fuel Transportation.

    SciTech Connect (OSTI)

    Durbin, Samuel G.; Lindgren, Eric R.; Rechard, Rob P.; Sorenson, Ken B.

    2014-09-01

    The safe transport of spent nuclear fuel and high-level radioactive waste is an important aspect of the waste management system of the United States. The Nuclear Regulatory Commission (NRC) currently certifies spent nuclear fuel rail cask designs based primarily on numerical modeling of hypothetical accident conditions augmented with some small scale testing. However, NRC initiated a Package Performance Study (PPS) in 2001 to examine the response of full-scale rail casks in extreme transportation accidents. The objectives of PPS were to demonstrate the safety of transportation casks and to provide high-fidelity data for validating the modeling. Although work on the PPS eventually stopped, the Blue Ribbon Commission on America’s Nuclear Future recommended in 2012 that the test plans be re-examined. This recommendation was in recognition of substantial public feedback calling for a full-scale severe accident test of a rail cask to verify evaluations by NRC, which find that risk from the transport of spent fuel in certified casks is extremely low. This report, which serves as the re-assessment, provides a summary of the history of the PPS planning, identifies the objectives and technical issues that drove the scope of the PPS, and presents a possible path for moving forward in planning to conduct a full-scale cask test. Because full-scale testing is expensive, the value of such testing on public perceptions and public acceptance is important. Consequently, the path forward starts with a public perception component followed by two additional components: accident simulation and first responder training. The proposed path forward presents a series of study options with several points where the package performance study could be redirected if warranted.

  20. Revised accident source terms for light-water reactors

    SciTech Connect (OSTI)

    Soffer, L.

    1995-02-01

    This paper presents revised accident source terms for light-water reactors incorporating the severe accident research insights gained in this area over the last 15 years. Current LWR reactor accident source terms used for licensing date from 1962 and are contained in Regulatory Guides 1.3 and 1.4. These specify that 100% of the core inventory of noble gases and 25% of the iodine fission products are assumed to be instantaneously available for release from the containment. The chemical form of the iodine fission products is also assumed to be predominantly elemental iodine. These assumptions have strongly affected present nuclear air cleaning requirements by emphasizing rapid actuation of spray systems and filtration systems optimized to retain elemental iodine. A proposed revision of reactor accident source terms and some im implications for nuclear air cleaning requirements was presented at the 22nd DOE/NRC Nuclear Air Cleaning Conference. A draft report was issued by the NRC for comment in July 1992. Extensive comments were received, with the most significant comments involving (a) release fractions for both volatile and non-volatile species in the early in-vessel release phase, (b) gap release fractions of the noble gases, iodine and cesium, and (c) the timing and duration for the release phases. The final source term report is expected to be issued in late 1994. Although the revised source terms are intended primarily for future plants, current nuclear power plants may request use of revised accident source term insights as well in licensing. This paper emphasizes additional information obtained since the 22nd Conference, including studies on fission product removal mechanisms, results obtained from improved severe accident code calculations and resolution of major comments, and their impact upon the revised accident source terms. Revised accident source terms for both BWRS and PWRS are presented.

  1. Type B Accident Investigation Report on the Exertional Heat Illnesses

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    during SPOTC 2006 at the National Training Center in Albuquerque, New Mexico, July 13, 2006 | Department of Energy Type B Accident Investigation Report on the Exertional Heat Illnesses during SPOTC 2006 at the National Training Center in Albuquerque, New Mexico, July 13, 2006 Type B Accident Investigation Report on the Exertional Heat Illnesses during SPOTC 2006 at the National Training Center in Albuquerque, New Mexico, July 13, 2006 July 13, 2006 This Report addresses three injuries that

  2. Severe accident progression perspectives based on IPE results

    SciTech Connect (OSTI)

    Lehner, J.R.; Lin, C.C.; Pratt, W.T.; Drouin, M.

    1996-08-01

    Accident progression perspectives were gathered from the level 2 PRA analyses (the analysis of the accident after core damage has occurred involving the containment performance and the radionuclide release from the containment) described in the IPE submittals. Insights related to the containment failure modes, the releases associated with those failure modes, and the factors responsible for the types of containment failures and release sizes reported were obtained. Complete results are discussed in NUREG-1560 and summarized here.

  3. Volume II - Accident and Operational Safety Analysis Handbook

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    208-2012 July 2012 DOE HANDBOOK Accident and Operational Safety Analysis Volume II: Operational Safety Analysis Techniques U.S. Department of Energy Washington, D.C. 20585 NOT MEASUREMENT SENSITIVE DOE-HDBK-1208-2012 i ACKNOWLEDGEMENTS This Department of Energy (DOE) Accident and Operational Safety Analysis Handbook was prepared under the sponsorship of the DOE Office of Health Safety and Security (HSS), Office of Corporate Safety Programs, and the Energy Facility Contractors Operating Group

  4. The potential impact of enhanced accident tolerant cladding materials on reactivity initiated accidents in light water reactors

    DOE PAGES-Beta [OSTI]

    Brown, Nicholas R.; Wysocki, Aaron J.; Terrani, Kurt A.; Xu, Kevin G.; Wachs, Daniel M.

    2016-09-28

    Here, advanced cladding materials with potentially enhanced accident tolerance will yield different light-water-reactor performance and safety characteristics than the present zirconium-based cladding alloys. These differences are due to cladding material properties, reactor physics, thermal, and hydraulic characteristics. Differences in reactors physics characteristics are driven by the fundamental properties (e.g., absorption in iron for an iron-based cladding) and also by design modifications necessitated by the candidate cladding materials (e.g., a larger fuel pellet to compensate for parasitic absorption). Potential changes in thermal hydraulic limits after transition from the current zirconium alloy cladding to the advanced materials will also affect the transientmore » response of the integral fuel. This paper describes three-dimensional nodal kinetics simulations of a reactivity-initiated accident (RIA) in a representative state-of-the-art pressurized water reactor with both nuclear-grade iron-chromium-aluminum (FeCrAl) and silicon-carbide (SiC-SiC)-based cladding materials. The impact of candidate cladding materials on the reactor kinetics behavior of RIA progression versus that of reference Zr cladding is predominantly due to differences in (1) fuel mass/volume/specific power density, (2) spectral effects due to parasitic neutron absorption, (3) control rod worth due to hardened (or softened) spectrum, and (4) initial conditions due to power peaking and neutron transport cross sections in the equilibrium cycle cores resulting from hardened (or softened) spectrum. This study shows similar behavior for SiC-SiC-based cladding configurations on the transient response versus reference Zircaloy cladding. However, the FeCrAl cladding response indicates similar energy deposition, but with significantly shorter pulses of higher magnitude. This is due to the shorter neutron generation time of the models with FeCrAl cladding. Therefore, the FeCrAl-based cases have

  5. Cladding embrittlement during postulated loss-of-coolant accidents.

    SciTech Connect (OSTI)

    Billone, M.; Yan, Y.; Burtseva, T.; Daum, R.; Nuclear Engineering Division

    2008-07-31

    The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating and cooling rates. Recommendations are given for types of tests that would identify LOCA conditions under which embrittlement would occur.

  6. Ferritic Alloys as Accident Tolerant Fuel Cladding Material for Light Water Reactors

    SciTech Connect (OSTI)

    Rebak, Raul B.

    2014-12-30

    The objective of the GE project is to demonstrate that advanced steels such as iron-chromium-aluminum (FeCrAl) alloys could be used as accident tolerant fuel cladding material in commercial light water reactors. The GE project does not include fuel development. Current findings support the concept that a FeCrAl alloy could be used for the cladding of commercial nuclear fuel. The use of this alloy will benefit the public since it is going to make the power generating light water reactors safer. In the Phase 1A of this cost shared project, GE (GRC + GNF) teamed with the University of Michigan, Los Alamos National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory to study the environmental and mechanical behavior of more than eight candidate cladding materials both under normal operation conditions of commercial nuclear reactors and under accident conditions in superheated steam (loss of coolant condition). The main findings are as follows: (1) Under normal operation conditions the candidate alloys (e.g. APMT, Alloy 33) showed excellent resistance to general corrosion, shadow corrosion and to environmentally assisted cracking. APMT also showed resistance to proton irradiation up to 5 dpa. (2) Under accident conditions the selected candidate materials showed several orders of magnitude improvement in the reaction with superheated steam as compared with the current zirconium based alloys. (3) Tube fabrication feasibility studies of FeCrAl alloys are underway. The aim is to obtain a wall thickness that is below 400 µm. (4) A strategy is outlined for the regulatory path approval and for the insertion of a lead fuel assembly in a commercial reactor by 2022. (5) The GE team worked closely with INL to have four rodlets tested in the ATR. GE provided the raw stock for the alloys, the fuel for the rodlets and the cost for fabrication/welding of the rodlets. INL fabricated the rodlets and the caps and welded them to

  7. Type B Accident Investigation Board Report on the March 27, 1998, Rotating Shaft Accident at the Ames Laboratory, Ames, Iowa

    Energy.gov [DOE]

    This report is an independent product of the Type B Accident Investigation Board appointed by John Kennedy, Acting Manager, Chicago Operations Office, U.S. Department of Energy (DOE).

  8. Type B Accident Investigation of the July 14, 2005, Americium Contamination Accident at the Sigma Facility, Los Alamos National Laboratory

    Energy.gov [DOE]

    This report is an independent product of the Type B Accident Investigation Board appointed by Edwin L. Wilmot, Manager of the Los Alamos Site Office of the National Nuclear Security Administration, U.S. Department of Energy.

  9. Criteria for calculating the efficiency of HEPA filters during and after design basis accidents

    SciTech Connect (OSTI)

    Bergman, W.; First, M.W.; Anderson, W.L.; Gilbert, H.; Jacox, J.W.

    1994-12-01

    We have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data.

  10. Alternative Fuels Data Center: Natural Gas Safety after a Traffic Accident

    Alternative Fuels and Advanced Vehicles Data Center

    Natural Gas Safety after a Traffic Accident to someone by E-mail Share Alternative Fuels Data Center: Natural Gas Safety after a Traffic Accident on Facebook Tweet about Alternative Fuels Data Center: Natural Gas Safety after a Traffic Accident on Twitter Bookmark Alternative Fuels Data Center: Natural Gas Safety after a Traffic Accident on Google Bookmark Alternative Fuels Data Center: Natural Gas Safety after a Traffic Accident on Delicious Rank Alternative Fuels Data Center: Natural Gas

  11. Risk communication with Fukushima residents affected by the Fukushima Daiichi accident at whole-body counting

    SciTech Connect (OSTI)

    Gunji, I.; Furuno, A.; Yonezawa, R.; Sugiyama, K.

    2013-07-01

    After the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi nuclear power plant accident, the Tokai Research and Development Center of the Japan Atomic Energy Agency (JAEA) have had direct dialogue as risk communication with Fukushima residents who underwent whole-body counting examination (WBC). The purpose of the risk communication was to exchange information and opinions about radiation in order to mitigate Fukushima residents' anxiety and stress. Two kinds of opinion surveys were performed: one survey evaluated residents' views of the nuclear accident itself and the second survey evaluated the management of WBC examination as well as the quality of JAEA's communication skills on risks. It appears that most Fukushima residents seem to have reduced their anxiety level after the direct dialogue. The results of the surveys show that Fukushima residents have the deepest anxiety and concern about their long-term health issues and that they harbor anger toward the government and TEPCO. On the other hand, many WBC patients and patients' relatives have expressed gratitude for help in reducing their feelings of anxiety.

  12. Nuclear Facility Accident (NFAC) Unit Test Report For HPAC Version 6.3

    SciTech Connect (OSTI)

    Lee, Ronald W.; Morris, Robert W.; Sulfredge, Charles David

    2015-12-01

    This is a unit test report for the Nuclear Facility Accident (NFAC) model for the Hazard Prediction and Assessment Capability (HPAC) version 6.3. NFAC’s responsibility as an HPAC component is three-fold. First, it must present an interactive graphical user interface (GUI) by which users can view and edit the definition of an NFAC incident. Second, for each incident defined, NFAC must interact with RTH to create activity table inputs and associate them with pseudo materials to be transported via SCIPUFF. Third, NFAC must create SCIPUFF releases with the associated pseudo materials for transport and dispersion. The goal of NFAC unit testing is to verify that the inputs it produces are correct for the source term or model definition as specified by the user via the GUI.

  13. Decontamination Dressdown at a Transportation Accident Involving

    Office of Environmental Management (EM)

    Decommissioning Plan Review Module March 2010 CD-0 O 0 C OFFICE OF D C CD-1 F ENVIRO Standard R Decomm Rev Critical Decisi CD-2 M ONMENTAL Review Plan missioning view Module ion (CD) Ap CD March 2010 L MANAGE n (SRP) g Plan e plicability D-3 EMENT CD-4 Post Oper ration Standard Review Plan, 2 nd Edition, March 2010 i FOREWORD The Standard Review Plan (SRP) 1 provides a consistent, predictable corporate review framework to ensure that issues and risks that could challenge the success of Office of

  14. Radiological Impact Assessment (RIA) following a postulated accident in PHWRS

    SciTech Connect (OSTI)

    Soni, N.; Kansal, M.; Rammohan, H. P.; Malhotra, P. K.

    2012-07-01

    Radiological Impact Assessment (RIA) following postulated accident i.e Loss of Coolant Accident (LOCA) with failed Emergency Core Cooling System (ECCS), performed as part of the reactor safety analysis of a typical 700 MWe Indian Pressurized Heavy Water Reactor(PHWR). The rationale behind the assessment is that the public needs to be protected in the event that the postulated accident results in radionuclide release outside containment. Radionuclides deliver dose to the human body through various pathways namely, plume submersion, exposure due to ground deposition, inhalation and ingestion. The total exposure dose measured in terms of total effective dose equivalent (TEDE) is the sum of doses to a hypothetical adult human at exclusion zone boundary by all the exposure pathways. The analysis provides the important inputs to decide upon the type of emergency counter measures to be adopted during the postulated accident. The importance of the various pathways in terms of contribution to the total effective dose equivalent(TEDE) is also assessed with respect to time of exposure. Inhalation and plume gamma dose are the major contributors towards TEDE during initial period of accident whereas ingestion and ground shine dose start dominating in TEDE in the extended period of exposure. Moreover, TEDE is initially dominated by I-131, Kr-88, Te-132, I-133 and Sr-89, whereas, as time progresses, Xe-133,I-131 and Te-132 become the main contributors. (authors)

  15. PNNL Results from 2010 CALIBAN Criticality Accident Dosimeter Intercomparison Exercise

    SciTech Connect (OSTI)

    Hill, Robin L.; Conrady, Matthew M.

    2011-10-28

    This document reports the results of the Hanford personnel nuclear accident dosimeter (PNAD) and fixed nuclear accident dosimeter (FNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on September 20-23, 2010. Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimeter intercomparison exercise at the Commissariat a Energie Atomique (CEA) Valduc Center near Dijon, France on September 20-23, 2010. The intercomparison exercise was funded by the U.S. Department of Energy, Nuclear Criticality Safety Program, with Lawrence Livermore National Laboratory as the lead Laboratory. PNNL was one of six invited DOE Laboratory participants. The other participating Laboratories were: Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Savannah River Site (SRS), the Y-12 National Security Complex at Oak Ridge, and Sandia National Laboratory (SNL). The goals of PNNL's participation in the intercomparison exercise were to test and validate the procedures and algorithm currently used for the Hanford personnel nuclear accident dosimeters (PNADs) on the metallic reactor, CALIBAN, to test exposures to PNADs from the side and from behind a phantom, and to test PNADs that were taken from a historical batch of Hanford PNADs that had varying degrees of degradation of the bare indium foil. Similar testing of the PNADs was done on the Valduc SILENE test reactor in 2009 (Hill and Conrady, 2010). The CALIBAN results are reported here.

  16. ATWS at Browns Ferry Unit One - accident sequence analysis

    SciTech Connect (OSTI)

    Harrington, R.M.; Hodge, S.A.

    1984-07-01

    This study describes the predicted response of Unit One at the Browns Ferry Nuclear Plant to a postulated complete failure to scram following a transient occurrence that has caused closure of all Main Steam Isolation Valves (MSIVs). This hypothetical event constitutes the most severe example of the type of accident classified as Anticipated Transient Without Scram (ATWS). Without the automatic control rod insertion provided by scram, the void coefficient of reactivity and the mechanisms by which voids are formed in the moderator/coolant play a dominant role in the progression of the accident. Actions taken by the operator greatly influence the quantity of voids in the coolant and the effect is analyzed in this report. The progression of the accident sequence under existing and under recommended procedures is discussed. For the extremely unlikely cases in which equipment failure and wrongful operator actions might lead to severe core damage, the sequence of emergency action levels and the associated timing of events are presented.

  17. REACTOR VIEWING APPARATUS

    DOE Patents [OSTI]

    Monk, G.S.

    1959-01-13

    An optical system is presented that is suitable for viewing objects in a region of relatively high radioactivity, or high neutron activity, such as a neutronic reactor. This optical system will absorb neutrons and gamma rays thereby protecting personnel fronm the harmful biological effects of such penetrating radiations. The optical system is comprised of a viewing tube having a lens at one end, a transparent solid member at the other end and a transparent aqueous liquid completely filling the tube between the ends. The lens is made of a polymerized organic material and the transparent solid member is made of a radiation absorbent material. A shield surrounds the tube betwcen the flanges and is made of a gamma ray absorbing material.

  18. Stereoscopic optical viewing system

    DOE Patents [OSTI]

    Tallman, C.S.

    1986-05-02

    An improved optical system which provides the operator with a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  19. Stereoscopic optical viewing system

    DOE Patents [OSTI]

    Tallman, Clifford S.

    1987-01-01

    An improved optical system which provides the operator a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  20. Improvement design study on steam generator of MHR-50/100 aiming higher safety level after water ingress accident

    SciTech Connect (OSTI)

    Oyama, S.; Minatsuki, I.; Shimizu, K.

    2012-07-01

    Mitsubishi Heavy Industries, Ltd. (MHI) has been studying on MHI original High Temperature Gas cooled Reactor (HTGR), namely MHR-50/100, for commercialization with supported by JAEA. In the heat transfer system, steam generator (SG) is one of the most important components because it should be imposed a function of heat transfer from reactor power to steam turbine system and maintaining a nuclear grade boundary. Then we especially focused an effort of a design study on the SG having robustness against water ingress accident based on our design experience of PWR, FBR and HTGR. In this study, we carried out a sensitivity analysis from the view point of economic and plant efficiency. As a result, the SG design parameter of helium inlet/outlet temperature of 750 deg. C/300 deg. C, a side-by-side layout and one unit of SG attached to a reactor were selected. In the next, a design improvement of SG was carried out from the view point of securing the level of inherent safety without reliance on active steam dump system during water ingress accident considering the situation of the Fukushima nuclear power plant disaster on March 11, 2011. Finally, according to above basic design requirement to SG, we performed a conceptual design on adapting themes of SG structure improvement. (authors)

  1. Type A Accident Investigation Board Report on the April 3, 1995...

    Energy.gov (indexed) [DOE]

    1, 1995 The accident under investigation occurred on April 3, 1995, at approximately 10:46 a.m. As a result of the accident, a Wackenhut Services, Incorporated-Savannah River Site ...

  2. DOE-ID FOIA Type A Accident Investigation Board Report - July...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Research Library You are here: DOE-ID Home > FOIA > Type A Accident Investigation Board Report - July 28, 1998 Type A Accident Investigation Board Report - July 28, 1998 Fatality ...

  3. Calculation notes for surface leak resulting in pool, TWRS FSAR accident analysis

    SciTech Connect (OSTI)

    Hall, B.W.

    1996-09-25

    This document includes the calculations performed to quantify the risk associated with the unmitigated and mitigated accident scenarios described in the TWRS FSAR for the accident analysis titled: Surface Leaks Resulting in Pool.

  4. Calculation Notes for Subsurface Leak Resulting in Pool, TWRS FSAR Accident Analysis

    SciTech Connect (OSTI)

    Hall, B.W.

    1996-09-25

    This document includes the calculations performed to quantify the risk associated with the unmitigated and mitigated accident scenarios described in the TWRS FSAR for the accident analysis titled: Subsurface Leaks Resulting in Pool.

  5. Environmental radionuclide distribution in Georgia after the Chernobyl accident

    SciTech Connect (OSTI)

    Mosulishvili, L.M.; Shoniya, N.I.; Katamadze, N.M.

    1994-01-01

    Atmospheric Chernobyl-released radioactivity, assessed at about 2 x 10{sup 18} Bq, caused global environmental contamination. Contaminated air masses appeared in the Transcaucasian region in early May, 1986. Rains that month promoted intense radionuclide deposition all over Georgia. The contamination level of western Georgia considerably exceeded the contamination level of eastern Georgia. The Black Sea coast of Georgia suffered from the Chernobyl accident as much as did strongly contaminated areas of the Ukraine and Belarus`. Unfortunately, governmental decrees on countermeasures against the consequences of the Chernobyl accident at that time did not even refer to the coast of Georgia. The authors observed the first increase in radioactivity background in rainfall samples collected on May 2, 1986, in Tbilisi. {gamma}-Spectrometric measurements of aerosol filters, vegetation, food stuffs, and other objects, in addition to rainfall, persistently confirmed the occurrence of short-lived radionuclides, including {sup 131}I. At first, this fact seemed unbelievable, because the Chernobyl accident had occurred only 4-5 days earlier and far from Georgia. However, these arguments proved to be faulty. Soon, environmental monitoring of radiation in Georgia became urgent. Environmental radionuclide distribution in Georgia shortly after the Chernobyl accident, as well as the methods of analysis, are reported in this paper.

  6. Test Data for USEPR Severe Accident Code Validation

    SciTech Connect (OSTI)

    J. L. Rempe

    2007-05-01

    This document identifies data that can be used for assessing various models embodied in severe accident analysis codes. Phenomena considered in this document, which were limited to those anticipated to be of interest in assessing severe accidents in the USEPR developed by AREVA, include: • Fuel Heatup and Melt Progression • Reactor Coolant System (RCS) Thermal Hydraulics • In-Vessel Molten Pool Formation and Heat Transfer • Fuel/Coolant Interactions during Relocation • Debris Heat Loads to the Vessel • Vessel Failure • Molten Core Concrete Interaction (MCCI) and Reactor Cavity Plug Failure • Melt Spreading and Coolability • Hydrogen Control Each section of this report discusses one phenomenon of interest to the USEPR. Within each section, an effort is made to describe the phenomenon and identify what data are available modeling it. As noted in this document, models in US accident analysis codes (MAAP, MELCOR, and SCDAP/RELAP5) differ. Where possible, this report identifies previous assessments that illustrate the impact of modeling differences on predicting various phenomena. Finally, recommendations regarding the status of data available for modeling USEPR severe accident phenomena are summarized.

  7. Evaluation of severe accident risks: Surry Unit 1

    SciTech Connect (OSTI)

    Breeding, R.J. ); Helton, J.C. ); Murfin, W.B. ); Smith, L.N. )

    1990-10-01

    In support of the Nuclear Regulatory Commission's (NRC's) assessment of the risk from severe accidents at commercial nuclear power plants in the US reported in NUREG-1150, the Severe Accident Risk Reduction Program (SARRP) has completed a revised calculation of the risk to the general public from severe accidents at the Surry Power Station, Unit 1. This power plant, located in southeastern Virginia, is operated by the Virginia Electric Power Corp. The emphasis in this risk analysis was not on determining a so-called'' point estimate of risk. Rather, it was to determine the distribution of risk, and to discover the uncertainties that account for the breadth of this distribution. Off-site risk initiation by events, both internal to the power station and external to the power station were assessed. This document, Volume 3, Revision 1, Part 2, provides Appendices A through E to this report. These appendices contain: supporting information for the accident progression analysis; the source term analysis; the consequence analysis; risk results; and sampling information.

  8. Source terms for plutonium aerosolization from nuclear weapon accidents

    SciTech Connect (OSTI)

    Stephens, D.R.

    1995-07-01

    The source term literature was reviewed to estimate aerosolized and respirable release fractions for accidents involving plutonium in high-explosive (HE) detonation and in fuel fires. For HE detonation, all estimates are based on the total amount of Pu. For fuel fires, all estimates are based on the amount of Pu oxidized. I based my estimates for HE detonation primarily upon the results from the Roller Coaster experiment. For hydrocarbon fuel fire oxidation of plutonium, I based lower bound values on laboratory experiments which represent accident scenarios with very little turbulence and updraft of a fire. Expected values for aerosolization were obtained from the Vixen A field tests, which represent a realistic case for modest turbulence and updraft, and for respirable fractions from some laboratory experiments involving large samples of Pu. Upper bound estimates for credible accidents are based on experiments involving combustion of molten plutonium droplets. In May of 1991 the DOE Pilot Safety Study Program established a group of experts to estimate the fractions of plutonium which would be aerosolized and respirable for certain nuclear weapon accident scenarios.

  9. Modeling & analysis of core debris recriticality during hypothetical severe accidents in the Advanced Neutron Source Reactor

    SciTech Connect (OSTI)

    Kim, S.H.; Georgevich, V.; Simpson, D.B.; Slater, C.O.; Taleyarkhan, R.P.

    1992-10-01

    This paper discusses salient aspects of severe-accident-related recriticality modeling and analysis in the Advanced Neutron Source (ANS) reactor. The development of an analytical capability using the KEN05A-SCALE system is described including evaluation of suitable nuclear cross-section sets to account for the effects of system geometry, mixture temperature, material dispersion and other thermal-hydraulic conditions. Benchmarking and validation efforts conducted with KEN05-SCALE and other neutronic codes against critical experiment data are described. Potential deviations and biases resulting from use of the 16-group Hansen-Roach library are shown. A comprehensive test matrix of calculations to evaluate the threat of a criticality event in the ANS is described. Strong dependencies on geometry, material constituents, and thermal-hydraulic conditions are described. The introduction of designed mitigative features are described.

  10. Level 1 Accident Report of the March 1, 2010 Bobcat Fatality at BPA's White

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Bluffs Substation | Department of Energy Report of the March 1, 2010 Bobcat Fatality at BPA's White Bluffs Substation Level 1 Accident Report of the March 1, 2010 Bobcat Fatality at BPA's White Bluffs Substation March 31, 2010 On March 2, 2010 at the request of the Bonneville Power Administration (BPA) Chief Safety Officer, a Level I Accident Investigation was convened to investigate an accident in which a supplemental labor contractor was fatally injured in a Bobcat/backhoe accident at the

  11. Identification and evaluation of PWR in-vessel severe accident management strategies

    SciTech Connect (OSTI)

    Dukelow, J S [Pacific Northwest Lab., Richland, WA (United States); Harrison, D G [Jason Associates, Idaho Falls, ID (United States); Morgenstern, M [Battelle Human Affairs Research Center, Seattle, WA (United States)

    1992-03-01

    This reports documents work performed the NRC/RES Accident Management Guidance Program to evaluate possible strategies for mitigating the consequences of PWR severe accidents. The selection and evaluation of strategies was limited to the in-vessel phase of the severe accident, i.e., after the initiation of core degradation and prior to RPV failure. A parallel project at BNL has been considering strategies applicable to the ex-vessel phase of PWR severe accidents.

  12. The View from HQ

    National Nuclear Security Administration (NNSA)

    A publication of the Office of Advanced Simulation & Computing, NNSA Defense Programs NA-ASC-500-07-Issue 3 May 2007 The View from HQ by Dimitri Kusnezov I have been spending much of my time these days thinking about science, technology and engineering and the role of the laboratories and how that will be reflected in the Complex of the future. This is on my mind for two reasons: one is my responsibility to produce a science and technology roadmap for Complex 2030-Defense Program's vision

  13. Radionuclide release calculations for selected severe accident scenarios

    SciTech Connect (OSTI)

    Denning, R.S.; Leonard, M.T.; Cybulskis, P.; Lee, K.W.; Kelly, R.F.; Jordan, H.; Schumacher, P.M.; Curtis, L.A. )

    1990-08-01

    This report provides the results of source term calculations that were performed in support of the NUREG-1150 study. Severe Accident Risks: An Assessment for Five US Nuclear Power Plants.'' This is the sixth volume of a series of reports. It supplements results presented in the earlier volumes. Analyses were performed for three of the NUREG-1150 plants: Peach Bottom, a Mark I, boiling water reactor; Surry, a subatmospheric containment, pressurized water reactor; and Sequoyah, an ice condenser containment, pressurized water reactor. Complete source term results are presented for the following sequences: short term station blackout with failure of the ADS system in the Peach Bottom plant; station blackout with a pump seal LOCA for the Surry plant; station blackout with a pump seal LOCA in the Sequoyah plant; and a very small break with loss of ECC and spray recirculation in the Sequoyah plant. In addition, some partial analyses were performed which did not require running all of the modules of the Source Term Code Package. A series of MARCH3 analyses were performed for the Surry and Sequoyah plants to evaluate the effects of alternative emergency operating procedures involving primary and secondary depressurization on the progress of the accident. Only thermal-hydraulic results are provided for these analyses. In addition, three accident sequences were analyzed for the Surry plant for accident-induced failure of steam generator tubes. In these analyses, only the transport of radionuclides within the primary system and failed steam generator were examined. The release of radionuclides to the environment is presented for the phase of the accident preceding vessel meltthrough. 17 refs., 176 figs., 113 tabs.

  14. Proposed revision 2 to Regulatory Guide 8. 12: Criticality accident alarm systems: Draft Regulatory Guide

    SciTech Connect (OSTI)

    Not Available

    1988-05-01

    Section 70.24, ''Criticality Accident Requirements,'' of 10 CFR Part 70, ''Domestic Licensing of Special Nuclear Material,'' requires licensees who are authorized to possess special nuclear material in excess of certain amounts to maintain a criticality accident alarm system. This guide describes a system acceptable to the NRC staff for meeting the Commission's requirements for a criticality accident alarm system.

  15. Microsoft Word - 2015.06.22 - Report to Congress - Accident Tolerant Fuels

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ROADMAP: DEVELOPMENT OF LWR FUELS WITH ENHANCED ACCIDENT TOLERANCE Page i Development of Light Water Reactor Fuels with Enhanced Accident Tolerance Report to Congress April 2015 United States Department of Energy Washington, DC 20585 _____________________________________________________________________________ ROADMAP: DEVELOPMENT OF LWR FUELS WITH ENHANCED ACCIDENT TOLERANCE Page i Message from the Assistant Secretary for Nuclear Energy In the Senate Appropriations Committee Report (Senate

  16. K West Basin Integrated Water Treatment System (IWTS) E-F Annular Filter Vessel Accident Calculations

    SciTech Connect (OSTI)

    RITTMANN, P.D.

    1999-10-07

    Three bounding accidents postdated for the K West Basin integrated water treatment system are evaluated against applicable risk evaluation guidelines. The accidents are a spray leak during fuel retrieval, spray leak during backflushing, and a hydrogen explosion. Event trees and accident probabilities are estimated. In all cases, the unmitigated dose consequences are below the risk evaluation guidelines.

  17. K West Basin Integrated Water Treatment System (IWTS) E-F Annular Filter Vessel Accident Calculations

    SciTech Connect (OSTI)

    PIEPHO, M.G.

    2000-01-10

    Four bounding accidents postulated for the K West Basin integrated water treatment system are evaluated against applicable risk evaluation guidelines. The accidents are a spray leak during fuel retrieval, spray leak during backflushing a hydrogen explosion, and a fire breaching filter vessel and enclosure. Event trees and accident probabilities are estimated. In all cases, the unmitigated dose consequences are below the risk evaluation guidelines.

  18. Structural response of reactor-core hexcan subassemblies subjected to dynamic overpressurization under accident conditions

    SciTech Connect (OSTI)

    Pfeiffer, P.A.; Kulak, R.F.

    1993-06-01

    This paper presents a two-dimensional structural analysis for the evaluation of a single core subassembly due to internal overpressure associated with possible failure of fuel pins having high fission gas plenum pressure. Structural models are developed for the subassemblies and their surroundings with emphasis on the critical physical aspects of the problem. With these models the strains, deformations and the extent of permanent damage (plastic strain) to the subassemblies can be assessed. The nonlinear structural analyses was performed with a finite element program called STRAW (Structural Transient Response of Assembly Wrappers). This finite element program is applicable to nonlinear large displacement problems. The results of this study indicate that the permanent deformation (damage) is strongly influenced by the rise time (time to reach peak pressure) of the pressure pulse and the pressure in the fuel pin. The rise time is influenced by the opening time of the flow path for release of gas from the fuel pin plenum. Several examples are illustrated with various rise times and pressure magnitudes and the resulting permanent deformation of the hexcan wall.

  19. Structural response of reactor-core hexcan subassemblies subjected to dynamic overpressurization under accident conditions

    SciTech Connect (OSTI)

    Pfeiffer, P.A.; Kulak, R.F.

    1993-01-01

    This paper presents a two-dimensional structural analysis for the evaluation of a single core subassembly due to internal overpressure associated with possible failure of fuel pins having high fission gas plenum pressure. Structural models are developed for the subassemblies and their surroundings with emphasis on the critical physical aspects of the problem. With these models the strains, deformations and the extent of permanent damage (plastic strain) to the subassemblies can be assessed. The nonlinear structural analyses was performed with a finite element program called STRAW (Structural Transient Response of Assembly Wrappers). This finite element program is applicable to nonlinear large displacement problems. The results of this study indicate that the permanent deformation (damage) is strongly influenced by the rise time (time to reach peak pressure) of the pressure pulse and the pressure in the fuel pin. The rise time is influenced by the opening time of the flow path for release of gas from the fuel pin plenum. Several examples are illustrated with various rise times and pressure magnitudes and the resulting permanent deformation of the hexcan wall.

  20. Analysis of the FeCrAl Accident Tolerant Fuel Concept Benefits during BWR Station Blackout Accidents

    SciTech Connect (OSTI)

    Robb, Kevin R

    2015-01-01

    Iron-chromium-aluminum (FeCrAl) alloys are being considered for fuel concepts with enhanced accident tolerance. FeCrAl alloys have very slow oxidation kinetics and good strength at high temperatures. FeCrAl could be used for fuel cladding in light water reactors and/or as channel box material in boiling water reactors (BWRs). To estimate the potential safety gains afforded by the FeCrAl concept, the MELCOR code was used to analyze a range of postulated station blackout severe accident scenarios in a BWR/4 reactor employing FeCrAl. The simulations utilize the most recently known thermophysical properties and oxidation kinetics for FeCrAl. Overall, when compared to the traditional Zircaloy-based cladding and channel box, the FeCrAl concept provides a few extra hours of time for operators to take mitigating actions and/or for evacuations to take place. A coolable core geometry is retained longer, enhancing the ability to stabilize an accident. Finally, due to the slower oxidation kinetics, substantially less hydrogen is generated, and the generation is delayed in time. This decreases the amount of non-condensable gases in containment and the potential for deflagrations to inhibit the accident response.

  1. Economic consequences of the Chernobyl accident in Norway in 1986 and 1987

    SciTech Connect (OSTI)

    Tveten, U.

    1988-01-01

    In the accident consequence assessment (ACA) area there is extensive cooperation between the Nordic countries (Denmark, Finland, Norway, and Sweden), performed within the Nordic Safety Program, and partially funded by the Nordic Council of Ministers, via the Nordic Liaison Committee for Atomic Energy. One of the 17 projects in the ACA-related program area is concerned with the economic consequences of the Chernobyl accident in Finland, Norway, and Sweden. This paper is limited to describing conditions in Norway. There are areas in Norway where the Chernobyl fallout is >100 kBq/m{sup 2}, and the total amount of radiocesium deposited over Norway is estimated by the National Institute for Radiation Hygiene to be 6% of the radiocesium released from the reactor. The areas where ground concentrations are highest are mostly in sparsely populated mountain areas. These areas are, however, important in connection with several nutritional pathways, notably, sheep, goats, reindeer, and freshwater fish. The purpose of this paper is to summarize information on mitigating actions and economic consequences of the deposited radioactive materials to Norwegian agriculture in the 1986-87 and 1987-88 slaughtering periods.

  2. Protective laser beam viewing device

    DOE Patents [OSTI]

    Neil, George R.; Jordan, Kevin Carl

    2012-12-18

    A protective laser beam viewing system or device including a camera selectively sensitive to laser light wavelengths and a viewing screen receiving images from the laser sensitive camera. According to a preferred embodiment of the invention, the camera is worn on the head of the user or incorporated into a goggle-type viewing display so that it is always aimed at the area of viewing interest to the user and the viewing screen is incorporated into a video display worn as goggles over the eyes of the user.

  3. Type B Accident Investigation Board Report of the January 20, 1998, Electrical Accident at the Casa Grande Substation,South of Phoenix, Arizona

    Energy.gov [DOE]

    This report is an independent product of the Type-B Accident Investigation Board appointed by Michael S.Cowan, Chief Program Officer, Western Area Power Administration.

  4. The view from Kiev

    SciTech Connect (OSTI)

    Kiselyov, S.

    1993-11-01

    This article reports the observations of correspondents for the Bulletin (two Russian journalists, one based in Moscow, the other in Kiev) who investigated the status of the Soviet Union's Black Sea Fleet and Ukraine's status as a non-nuclear-weapons state. After two years of wrangling and two earlier failed settlements, Russian President Boris Yeltsin met with Ukrainian President Leonid Kravchuk at Massandra in Crimea. On September 3, the leaders announced that Russia would buy out Ukraine's interest in the fleet and lease the port at Sevastopol. The Massandra summit was also supposed to settle Ukraine's status as a non-nuclear-weapons state. Described here are the Kiev-based correspondent's views on the Massandra summit (and its major topics), which was to have been called off by the Russian foreign ministry when Ukrainian Prime Minister Leonid Kuchma resigned.

  5. False color viewing device

    DOE Patents [OSTI]

    Kronberg, J.W.

    1991-05-08

    This invention consists of a viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching, the user`s eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

  6. False color viewing device

    DOE Patents [OSTI]

    Kronberg, James W.

    1992-01-01

    A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

  7. False color viewing device

    DOE Patents [OSTI]

    Kronberg, J.W.

    1992-10-20

    A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage. 7 figs.

  8. Mountain View Grand | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    Mountain View Grand Jump to: navigation, search Name Mountain View Grand Facility Mountain View Grand Sector Wind energy Facility Type Small Scale Wind Facility Status In Service...

  9. INDUSTRIAL/MILITARY ACTIVITY-INITIATED ACCIDENT SCREENING ANALYSIS

    SciTech Connect (OSTI)

    D.A. Kalinich

    1999-09-27

    Impacts due to nearby installations and operations were determined in the Preliminary MGDS Hazards Analysis (CRWMS M&O 1996) to be potentially applicable to the proposed repository at Yucca Mountain. This determination was conservatively based on limited knowledge of the potential activities ongoing on or off the Nevada Test Site (NTS). It is intended that the Industrial/Military Activity-Initiated Accident Screening Analysis provided herein will meet the requirements of the ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987) in establishing whether this external event can be screened from further consideration or must be included as a design basis event (DBE) in the development of accident scenarios for the Monitored Geologic Repository (MGR). This analysis only considers issues related to preclosure radiological safety. Issues important to waste isolation as related to impact from nearby installations will be covered in the MGR performance assessment.

  10. Enhanced Accident Tolerant LWR Fuels National Metrics Workshop Report

    SciTech Connect (OSTI)

    Lori Braase

    2013-01-01

    The U.S. Department of Energy Office of Nuclear Energy (DOE-NE), in collaboration with the nuclear industry, has been conducting research and development (R&D) activities on advanced Light Water Reactor (LWR) fuels for the last few years. The emphasis for these activities was on improving the fuel performance in terms of increased burnup for waste minimization and increased power density for power upgrades, as well as collaborating with industry on fuel reliability. After the events at the Fukushima Nuclear Power Plant in Japan in March 2011, enhancing the accident tolerance of LWRs became a topic of serious discussion. In the Consolidated Appropriations Act, 2012, Conference Report 112-75, the U.S. Congress directed DOE-NE to: • Give “priority to developing enhanced fuels and cladding for light water reactors to improve safety in the event of accidents in the reactor or spent fuel pools.” • Give “special technical emphasis and funding priority…to activities aimed at the development and near-term qualification of meltdown-resistant, accident-tolerant nuclear fuels that would enhance the safety of present and future generations of light water reactors.” • Report “to the Committee, within 90 days of enactment of this act, on its plan for development of meltdown-resistant fuels leading to reactor testing and utilization by 2020.” Fuels with enhanced accident tolerance are those that, in comparison with the standard UO2-zirconium alloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, and operational transients, as well as design-basis and beyond design-basis events. The overall draft strategy for development and demonstration is comprised of three phases: Feasibility Assessment and Down-selection; Development and Qualification; and

  11. Ion irradiation testing of Improved Accident Tolerant Cladding Materials

    SciTech Connect (OSTI)

    Anderoglu, Osman; Tesmer, Joseph R.; Maloy, Stuart A.

    2014-01-14

    This report summarizes the results of ion irradiations conducted on two FeCrAl alloys (named as ORNL A&B) for improving the accident tolerance of LWR nuclear fuel cladding. After irradiation with 1.5 MeV protons to ~0.5 to ~1 dpa and 300°C nanoindentations were performed on the cross-sections along the ion range. An increase in hardness was observed in both alloys. Microstructural analysis shows radiation induced defects.

  12. Estimated long term health effects of the Chernobyl accident

    SciTech Connect (OSTI)

    Cardis, E.

    1996-07-01

    Apart from the dramatic increase in thyroid cancer in those exposed as children, there is no evidence to date of a major public health impact as a result of radiation exposure due to the Chernobyl accident in the three most affected countries (Belarus, Russia, and Ukraine). Although some increases in the frequency of cancer in exposed populations have been reported ,these results are difficult to interpret, mainly because of differences in the intensity and method of follow-up between exposed populations and the general population with which they are compared. If the experience of the survivors of the atomic bombing of Japan and of other exposed populations is applicable, the major radiological impact of the accident will be cases of cancer. The total lifetime numbers of excess cancers will be greatest among the `liquidators` (emergency and recovery workers) and among the residents of `contaminated` territories, of the order of 2000 to 2500 among each group (the size of the exposed populations is 200,000 liquidators and 3,700,000 residents of `contaminated` areas). These increases would be difficult to detect epidemiologically against an expected background number of 41500 and 433000 cases of cancer respectively among the two groups. The exposures for populations due to the Chernobyl accident are different in type and pattern from those of the survivors of the atomic bombing of Japan. Thus predictions derived from studies of these populations are uncertain. The extent of the incidence of thyroid cancer was not envisaged. Since only ten years have lapsed since the accident, continued monitoring of the health of the population is essential to assess the public health impact.

  13. Scaling and design analyses of a scaled-down, high-temperature test facility for experimental investigation of the initial stages of a VHTR air-ingress accident

    SciTech Connect (OSTI)

    Arcilesi, David J.; Ham, Tae Kyu; Kim, In Hun; Sun, Xiaodong; Christensen, Richard N.; Oh, Chang H.

    2015-07-01

    A critical event in the safety analysis of the very high-temperature gas-cooled reactor (VHTR) is an air-ingress accident. This accident is initiated, in its worst case scenario, by a double-ended guillotine break of the coaxial cross vessel, which leads to a rapid reactor vessel depressurization. In a VHTR, the reactor vessel is located within a reactor cavity that is filled with air during normal operating conditions. Following the vessel depressurization, the dominant mode of ingress of an air–helium mixture into the reactor vessel will either be molecular diffusion or density-driven stratified flow. The mode of ingress is hypothesized to depend largely on the break conditions of the cross vessel. Since the time scales of these two ingress phenomena differ by orders of magnitude, it is imperative to understand under which conditions each of these mechanisms will dominate in the air ingress process. Computer models have been developed to analyze this type of accident scenario. There are, however, limited experimental data available to understand the phenomenology of the air-ingress accident and to validate these models. Therefore, there is a need to design and construct a scaled-down experimental test facility to simulate the air-ingress accident scenarios and to collect experimental data. The current paper focuses on the analyses performed for the design and operation of a 1/8th geometric scale (by height and diameter), high-temperature test facility. A geometric scaling analysis for the VHTR, a time scale analysis of the air-ingress phenomenon, a transient depressurization analysis of the reactor vessel, a hydraulic similarity analysis of the test facility, a heat transfer characterization of the hot plenum, a power scaling analysis for the reactor system, and a design analysis of the containment vessel are discussed.

  14. Most Viewed Documents for Fission And Nuclear Technologies: September 2014

    Office of Scientific and Technical Information (OSTI)

    | OSTI, US Dept of Energy Office of Scientific and Technical Information for Fission And Nuclear Technologies: September 2014 Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. (1977) 71 Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (1977) 68 Stress analysis and evaluation of a rectangular pressure vessel. [For equipment for sampling Hanford tank radwaste] Rezvani, M.A.;

  15. Enhanced Accident Tolerant Fuels for LWRS - A Preliminary Systems Analysis

    SciTech Connect (OSTI)

    Gilles Youinou; R. Sonat Sen

    2013-09-01

    The severe accident at Fukushima Daiichi nuclear plants illustrates the need for continuous improvements through developing and implementing technologies that contribute to safe, reliable and cost-effective operation of the nuclear fleet. Development of enhanced accident tolerant fuel contributes to this effort. These fuels, in comparison with the standard zircaloy – UO2 system currently used by the LWR industry, should be designed such that they tolerate loss of active cooling in the core for a longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, operational transients, and design-basis events. This report presents a preliminary systems analysis related to most of these concepts. The potential impacts of these innovative LWR fuels on the front-end of the fuel cycle, on the reactor operation and on the back-end of the fuel cycle are succinctly described without having the pretension of being exhaustive. Since the design of these various concepts is still a work in progress, this analysis can only be preliminary and could be updated as the designs converge on their respective final version.

  16. Cofrentes NPP activities on PSA and severe accident analysis

    SciTech Connect (OSTI)

    Suarez, J.; Borondo, L.; Garcia, P.J.

    1996-07-01

    Cofrentes NPP (CNPP) has developed a Level 1 PSA with the following scope: analysis of internal events, with the reactor initially operating at power, internal and external flooding risk analysis; internal fire risk analysis; reliability analysis of the containment heat removal and containment isolation systems. Level 1 CNPP-PSA results reveal that total core damage frequency in CNPP is less than other similar BWR/6 plants. The CNPP-PSA related activities and applications being carried out currently are: adjusting of MAAP 3.0B, revision 10, on VAX and PC; acquisition of MAAP 4; development of Level1/Level2-PSA interface; seismic site categorization for the IPEEE; prioritization of motor operated valves related to GL-89/10, complementary analysis for exemption to some 10CFR50 App. J requirements; Q-List grading; reliability-centered maintenance; maintenance rule support; on-line maintenance support, off-line risk-monitor development, PSA applicability to the 10CFR50 App. R requirements, analysis of the frequency of mis-oriented fuel bundle event, etc. About severe accident management, CNPP, as part of the Spanish-BWROG, is currently analyzing the generic products of the US-BWROG AMG in order to generate their specific ones. Also, in this group BWR, the development of tools to simulate accident scenarios beyond core damage will be studied and a training process oriented to warrant the optimum use of new EOP/AMG in accident scenarios will be implemented.

  17. Cold Vacuum Drying facility design basis accident analysis documentation

    SciTech Connect (OSTI)

    CROWE, R.D.

    2000-08-08

    This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report (FSAR), ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR. The calculations in this document address the design basis accidents (DBAs) selected for analysis in HNF-3553, ''Spent Nuclear Fuel Project Final Safety Analysis Report'', Annex B, ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' The objective is to determine the quantity of radioactive particulate available for release at any point during processing at the Cold Vacuum Drying Facility (CVDF) and to use that quantity to determine the amount of radioactive material released during the DBAs. The radioactive material released is used to determine dose consequences to receptors at four locations, and the dose consequences are compared with the appropriate evaluation guidelines and release limits to ascertain the need for preventive and mitigative controls.

  18. KERENA safety concept in the context of the Fukushima accident

    SciTech Connect (OSTI)

    Zacharias, T.; Novotny, C.; Bielor, E.

    2012-07-01

    Within the last three years AREVA NP and E.On KK finalized the basic design of KERENA which is a medium sized innovative boiling water reactor, based on the operational experience of German BWR nuclear power plants (NPPs). It is a generation III reactor design with a net electrical output of about 1250 MW. It combines active safety equipment of service-proven designs with new passive safety components, both safety classified. The passive systems utilize basic laws of physics, such as gravity and natural convection, enabling them to function without electric power. Even actuation of these systems is performed thanks to basic physic laws. The degree of diversity in component and system design, achieved by combining active and passive equipment, results in a very low core damage frequency. The Fukushima accident enhanced the world wide discussion about the safety of operating nuclear power plants. World wide stress tests for operating nuclear power plants are being performed embracing both natural and man made hazards. Beside the assessment of existing power plants, also new designs are analyzed regarding the system response to beyond design base accidents. KERENA's optimal combination of diversified cooling systems (active and passive) allows passing efficiently such tests, with a high level of confidence. This paper describes the passive safety components and the KERENA reactor behavior after a Fukushima like accident. (authors)

  19. Radionuclide mass balance for the TMI-2 accident: data-base system and preliminary mass balance. Volume 2

    SciTech Connect (OSTI)

    Goldman, M I; Davis, R J; Strahl, J F; Arcieri, W C; Tonkay, D W

    1983-04-01

    Tables are presented which represent the radionuclide levels following the Three Mile Island-2 reactor accident.

  20. Fermilab | Tritium at Fermilab | Ferry Creek Aerial View

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Ferry Creek Aerial View Ferry Creek Aerial View

  1. Fermilab | Tritium at Fermilab | Kress Creek Aerial View

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Kress Creek Aerial View Kress Creek Aerial View

  2. Another Look at the Relationship Between Accident- and Encroachment-Based Approaches to Run-Off-the-Road Accidents Modeling

    SciTech Connect (OSTI)

    Miaou, Shaw-Pin

    1997-08-01

    The purpose of this study was to look for ways to combine the strengths of both approaches in roadside safety research. The specific objectives were (1) to present the encroachment-based approach in a more systematic and coherent way so that its limitations and strengths can be better understood from both statistical and engineering standpoints, and (2) to apply the analytical and engineering strengths of the encroachment-based thinking to the formulation of mean functions in accident-based models.

  3. Security Conditions

    Directives, Delegations, and Requirements [Office of Management (MA)]

    2004-07-08

    This Notice ensures that DOE uniformly meets the requirements of the Homeland Security Advisory System outlined in Homeland Security Presidential Directive-3, Threat Conditions and Associated Protective Measures, dated 3-11-02, and provides responses specified in Presidential Decision Directive 39, U.S. Policy on Counterterrorism (U), dated 6-21-95. It cancels DOE N 473.8, Security Conditions, dated 8-7-02. Extended until 7-7-06 by DOE N 251.64, dated 7-7-05 Cancels DOE N 473.8

  4. Highland View school | Y-12 National Security Complex

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Highland View school Highland View school Aerial showing Highland View school and surrounding homes

  5. EMERGENCY RESPONSE TO A TRANSPORTATION ACCIDENT INVOLVING RADIOACTIVE...

    Office of Environmental Management (EM)

    DISCLAIMER DISCLAIMER DISCLAIMER DISCLAIMER DISCLAIMER Viewing this video and completing ... Meeting that goal is beyond the scope of this video and requires either additional ...

  6. Radiation View Factor With Shadowing

    Energy Science and Technology Software Center (OSTI)

    1992-02-24

    FACET calculates the radiation geometric view factor (alternatively called shape factor, angle factor, or configuration factor) between surfaces for axisymmetric, two-dimensional planar and three-dimensional geometries with interposed third surface obstructions. FACET was developed to calculate view factors as input data to finite element heat transfer analysis codes.

  7. SCDAP/RELAP5/MOD 3.1 code manual: MATPRO, A library of materials properties for Light-Water-Reactor accident analysis. Volume 4

    SciTech Connect (OSTI)

    Hagrman, D.T.; Allison, C.M.; Berna, G.A.

    1995-06-01

    The SCDAP/RELAP5 code has been developed for best estimate transient simulation of light -- water-reactor coolant systems during a severe accident. The code models the coupled behavior of the reactor coolant system, the core, fission products released during a severe accident transient as well as large and small break loss of coolant accidents, operational transients such as anticipated transient without SCRAM, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater conditioning systems. This volume, Volume IV, describes the material properties correlations and computer subroutines (MATPRO) used by SCDAP/RELAP5. formulation of the materials properties are generally semi-empirical in nature. The materials property subroutines contained in this document are for uranium, uranium dioxide, mixed uranium-plutonium dioxide fuel, zircaloy cladding, zirconium dioxide, stainless steel, stainless steel oxide, silver-indium-cadmium alloy, cadmium, boron carbide, Inconel 718, zirconium-uranium-oxygen melts, fill gas mixtures, carbon steel, and tungsten. This document also contains descriptions of the reaction and solution rate models needed to analyze a reactor accident.

  8. Descriptions of selected accidents that have occurred at nuclear reactor facilities

    SciTech Connect (OSTI)

    Bertini, H.W.

    1980-04-01

    This report was prepared at the request of the President's Commission on the Accident at Three Mile Island to provide the members of the Commission with some insight into the nature and significance of accidents that have occurred at nuclear reactor facilities in the past. Toward that end, this report presents a brief description of 44 accidents which have occurred throughout the world and which meet at least one of the severity criteria that were established.

  9. Interface requirements to couple thermal hydraulics codes to severe accident codes: ICARE/CATHARE

    SciTech Connect (OSTI)

    Camous, F.; Jacq, F.; Chatelard, P.

    1997-07-01

    In order to describe with the same code the whole sequence of severe LWR accidents, up to the vessel failure, the Institute of Protection and Nuclear Safety has performed a coupling of the severe accident code ICARE2 to the thermalhydraulics code CATHARE2. The resulting code, ICARE/CATHARE, is designed to be as pertinent as possible in all the phases of the accident. This paper is mainly devoted to the description of the ICARE2-CATHARE2 coupling.

  10. Temperature of aircraft cargo flame exposure during accidents involving fuel spills

    SciTech Connect (OSTI)

    Mansfield, J.A.

    1993-01-01

    This report describes an evaluation of flame exposure temperatures of weapons contained in alert (parked) bombers due to accidents that involve aircraft fuel fires. The evaluation includes two types of accident, collisions into an alert aircraft by an aircraft that is on landing or take-off, and engine start accidents. Both the B-1B and B-52 alert aircraft are included in the evaluation.

  11. Safety evaluation of MHTGR licensing basis accident scenarios

    SciTech Connect (OSTI)

    Kroeger, P.G.

    1989-04-01

    The safety potential of the Modular High-Temperature Gas Reactor (MHTGR) was evaluated, based on the Preliminary Safety Information Document (PSID), as submitted by the US Department of Energy to the US Nuclear Regulatory Commission. The relevant reactor safety codes were extended for this purpose and applied to this new reactor concept, searching primarily for potential accident scenarios that might lead to fuel failures due to excessive core temperatures and/or to vessel damage, due to excessive vessel temperatures. The design basis accident scenario leading to the highest vessel temperatures is the depressurized core heatup scenario without any forced cooling and with decay heat rejection to the passive Reactor Cavity Cooling System (RCCS). This scenario was evaluated, including numerous parametric variations of input parameters, like material properties and decay heat. It was found that significant safety margins exist, but that high confidence levels in the core effective thermal conductivity, the reactor vessel and RCCS thermal emissivities and the decay heat function are required to maintain this safety margin. Severe accident extensions of this depressurized core heatup scenario included the cases of complete RCCS failure, cases of massive air ingress, core heatup without scram and cases of degraded RCCS performance due to absorbing gases in the reactor cavity. Except for no-scram scenarios extending beyond 100 hr, the fuel never reached the limiting temperature of 1600/degree/C, below which measurable fuel failures are not expected. In some of the scenarios, excessive vessel and concrete temperatures could lead to investment losses but are not expected to lead to any source term beyond that from the circulating inventory. 19 refs., 56 figs., 11 tabs.

  12. Analysis of Three Mile Island-Unit 2 accident

    SciTech Connect (OSTI)

    Not Available

    1980-03-01

    The Nuclear Safety Analysis Center (NSAC) of the Electric Power Research Institute has analyzed the Three Mile Island-2 accident. Early results of this analysis were a brief narrative summary, issued in mid-May 1979 and an initial version of this report issued later in 1979 as noted in the Foreword. The present report is a revised version of the 1979 report, containing summaries, a highly detailed sequence of events, a comparison of that sequence of events with those from other sources, 25 appendices, references and a list of abbreviations and acronyms. A matrix of equipment and system actions is included as a folded insert.

  13. Advance plant severe accident/thermal hydraulic issues for ACRS

    SciTech Connect (OSTI)

    Kress, T.S.

    1994-09-01

    The ACRS has been reviewing various advance plant designs for certification. The most active reviews have been for the ABWR, AP600, and System 80+. We have completed the reviews for ABWR and System 80+ and are presently concentrating on AP600. The ACRS gave essentially unqualified certification approval for the two completed reviews, yet,,during the process of review a number of issues arose and the plant designs changed somewhat to accommodate some of the ACRS concerns. In this talk, I will describe some of the severe accident and thermal hydraulic related issues we discussed in our reviews.

  14. DOE-STD-3014-96; DOE Standard Accident Analysis For Aircraft...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ... and the Expert Panel on Accident Analysis for Aircraft Crash into Hazardous Facilities. ... Immediately Dangerous to Life or Health (IDLH): The maximum concentration of a (chemical) ...

  15. Summary of the SRS Severe Accident Analysis Program, 1987--1992

    SciTech Connect (OSTI)

    Long, T.A.; Hyder, M.L.; Britt, T.E.; Allison, D.K.; Chow, S.; Graves, R.D.; DeWald, A.B. Jr.; Monson, P.R. Jr.; Wooten, L.A.

    1992-11-01

    The Severe Accident Analysis Program (SAAP) is a program of experimental and analytical studies aimed at characterizing severe accidents that might occur in the Savannah River Site Production Reactors. The goals of the Severe Accident Analysis Program are: To develop an understanding of severe accidents in SRS reactors that is adequate to support safety documentation for these reactors, including the Safety Analysis Report (SAR), the Probabilistic Risk Assessment (PRA), and other studies evaluating the safety of reactor operation; To provide tools and bases for the evaluation of existing or proposed safety related equipment in the SRS reactors; To provide bases for the development of accident management procedures for the SRS reactors; To develop and maintain on the site a sufficient body of knowledge, including documents, computer codes, and cognizant engineers and scientists, that can be used to authoritatively resolve questions or issues related to reactor accidents. The Severe Accident Analysis Program was instituted in 1987 and has already produced a substantial amount of information, and specialized calculational tools. Products of the Severe Accident Analysis Program (listed in Section 9 of this report) have been used in the development of the Safety Analysis Report (SAR) and the Probabilistic Risk Assessment (PRA), and in the development of technical specifications for the SRS reactors. A staff of about seven people is currently involved directly in the program and in providing input on severe accidents to other SRS activities.

  16. Type A Accident Report of the June 26, 2009 Vehicle Fatality...

    Office of Environmental Management (EM)

    Report of the June 26, 2009 Vehicle Fatality at Lawrence Livermore National Laboratory Type A Accident Report of the June 26, 2009 Vehicle Fatality at Lawrence Livermore National ...

  17. A comparative analysis of accident risks in fossil, hydro, and nuclear energy chains

    SciTech Connect (OSTI)

    Burgherr, P.; Hirschberg, S.

    2008-07-01

    This study presents a comparative assessment of severe accident risks in the energy sector, based on the historical experience of fossil (coal, oil, natural gas, and LPG (Liquefied Petroleum Gas)) and hydro chains contained in the comprehensive Energy-related Severe Accident Database (ENSAD), as well as Probabilistic Safety Assessment (PSA) for the nuclear chain. Full energy chains were considered because accidents can take place at every stage of the chain. Comparative analyses for the years 1969-2000 included a total of 1870 severe ({>=} 5 fatalities) accidents, amounting to 81,258 fatalities. Although 79.1% of all accidents and 88.9% of associated fatalities occurred in less developed, non-OECD countries, industrialized OECD countries dominated insured losses (78.0%), reflecting their substantially higher insurance density and stricter safety regulations. Aggregated indicators and frequency-consequence (F-N) curves showed that energy-related accident risks in non-OECD countries are distinctly higher than in OECD countries. Hydropower in non-OECD countries and upstream stages within fossil energy chains are most accident-prone. Expected fatality rates are lowest for Western hydropower and nuclear power plants; however, the maximum credible consequences can be very large. Total economic damages due to severe accidents are substantial, but small when compared with natural disasters. Similarly, external costs associated with severe accidents are generally much smaller than monetized damages caused by air pollution.

  18. Type B Accident Investigation Board Report on the March 27, 1998...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    More Documents & Publications Type A Accident Investigation Board Report on the August 13, 1996, Electrical Shock at TRA-609, Test Reactor Area, Idaho National Engineering ...

  19. Type B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April 14, 2006

    Office of Energy Efficiency and Renewable Energy (EERE)

    This report is an independent product of the Type B Accident Investigation Board appointed by Elizabeth D. Sellers, Manager, Idaho Operations Office, U.S. Department of Energy.

  20. Order Module--DOE Order 225.1B, ACCIDENT INVESTIGATIONS

    Energy.gov [DOE]

    DOE O 225.1B prescribes organizational responsibilities, authorities, and requirements for conducting investigations of certain accidents occurring at DOE sites, facilities, areas, operations, and...

  1. TotalView Training 2015

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    TotalView Training 2015 TotalView Training 2015 NERSC will host an in-depth training course on TotalView, a graphical parallel debugger developed by Rogue Wave Software, on Thursday, March 26, 2015. This will be provided by Rogue Wave Software staff members. The training will include a lecture and demo sessions in the morning, followed by a hands-on parallel debugging session in the afternoon. Location This event will be presented online using WebEx technology and in person at NERSC Oakland

  2. Analysis of main steam isolation valve leakage in design basis accidents using MELCOR 1.8.6 and RADTRAD.

    SciTech Connect (OSTI)

    Salay, Michael; Kalinich, Donald A.; Gauntt, Randall O.; Radel, Tracy E.

    2008-10-01

    Analyses were performed using MELCOR and RADTRAD to investigate main steam isolation valve (MSIV) leakage behavior under design basis accident (DBA) loss-of-coolant (LOCA) conditions that are presumed to have led to a significant core melt accident. Dose to the control room, site boundary and LPZ are examined using both approaches described in current regulatory guidelines as well as analyses based on best estimate source term and system response. At issue is the current practice of using containment airborne aerosol concentrations as a surrogate for the in-vessel aerosol concentration that exists in the near vicinity of the MSIVs. This study finds current practice using the AST-based containment aerosol concentrations for assessing MSIV leakage is non-conservative and conceptually in error. A methodology is proposed that scales the containment aerosol concentration to the expected vessel concentration in order to preserve the simplified use of the AST in assessing containment performance under assumed DBA conditions. This correction is required during the first two hours of the accident while the gap and early in-vessel source terms are present. It is general practice to assume that at {approx}2hrs, recovery actions to reflood the core will have been successful and that further core damage can be avoided. The analyses performed in this study determine that, after two hours, assuming vessel reflooding has taken place, the containment aerosol concentration can then conservatively be used as the effective source to the leaking MSIV's. Recommendations are provided concerning typical aerosol removal coefficients that can be used in the RADTRAD code to predict source attenuation in the steam lines, and on robust methods of predicting MSIV leakage flows based on measured MSIV leakage performance.

  3. Accident Investigation of the February 7, 2013, Scissor Lift Accident in the West Hackberry Brine Tank-14 Resulting in Injury, Strategic Petroleum Reserve West Hackberry, LA

    Energy.gov [DOE]

    On February 15, 2013, an Accident Investigation Board (the Board) was appointed to investigate an accident that resulted in serious injuries caused when a scissor lift tipped over in Brine Tank-14 (WHT-14) at the Strategic Petroleum Reserve, West Hackberry, Louisiana, site on February 7, 2013. The Board’s responsibilities have been completed with respect to this investigation. The analysis and the identification of the direct cause, root causes, contributing causes, and judgments of need resulting from this investigation were performed in accordance with the Department of Energy (DOE) Order 225.1B, Accident Investigations.

  4. DOE - NNSA/NFO -- News & Views Emergency Joint Exercise

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    part in a 1981 weapons accident training exercise, in Area 25 of the Nevada Test Site. The purpose of the exercise was to put into action a planned response to a nuclear accident. ...

  5. Accident consequence calculations for project W-058 safetyanalysis

    SciTech Connect (OSTI)

    Van Keuren, J.C.

    1997-06-10

    Accident consequence analyses have been performed for Project W-058, the Replacement Cross Site Transfer System. using the assumption and analysis techniques developed for the Tank Remediation Waste system Basis for Interim Operation. most potential accident involving the FISTS are bounded by the TWRS BIO analysis. However, the spray leak and pool leak scenarios require revised analyses since the RCSTS design utilizes larger diameter pipe and higher pressures than those analyzed in the TWRS BIO. Also the volume of diversion box and vent station are larger than that assumed for the valve pits in the TWRS BIO, which effects results of sprays or spills into the pits. the revised analysis for the spray leak is presented in Section 2, for the above ground spill in Section 3, for the presented in Section 2, for the above ground spill in Section 3, for the subsurface spill forming a pool in Section 4, and for the subsurface pool remaining subsurface in Section 5. The conclusion from these sections are summarized below.

  6. PERSPECTIVES ON A DOE CONSEQUENCE INPUTS FOR ACCIDENT ANALYSIS APPLICATIONS

    SciTech Connect (OSTI)

    , K; Jonathan Lowrie, J; David Thoman , D; Austin Keller , A

    2008-07-30

    Department of Energy (DOE) accident analysis for establishing the required control sets for nuclear facility safety applies a series of simplifying, reasonably conservative assumptions regarding inputs and methodologies for quantifying dose consequences. Most of the analytical practices are conservative, have a technical basis, and are based on regulatory precedent. However, others are judgmental and based on older understanding of phenomenology. The latter type of practices can be found in modeling hypothetical releases into the atmosphere and the subsequent exposure. Often the judgments applied are not based on current technical understanding but on work that has been superseded. The objective of this paper is to review the technical basis for the major inputs and assumptions in the quantification of consequence estimates supporting DOE accident analysis, and to identify those that could be reassessed in light of current understanding of atmospheric dispersion and radiological exposure. Inputs and assumptions of interest include: Meteorological data basis; Breathing rate; and Inhalation dose conversion factor. A simple dose calculation is provided to show the relative difference achieved by improving the technical bases.

  7. Accident Fault Trees for Defense Waste Processing Facility

    SciTech Connect (OSTI)

    Sarrack, A.G.

    1999-06-22

    The purpose of this report is to document fault tree analyses which have been completed for the Defense Waste Processing Facility (DWPF) safety analysis. Logic models for equipment failures and human error combinations that could lead to flammable gas explosions in various process tanks, or failure of critical support systems were developed for internal initiating events and for earthquakes. These fault trees provide frequency estimates for support systems failures and accidents that could lead to radioactive and hazardous chemical releases both on-site and off-site. Top event frequency results from these fault trees will be used in further APET analyses to calculate accident risk associated with DWPF facility operations. This report lists and explains important underlying assumptions, provides references for failure data sources, and briefly describes the fault tree method used. Specific commitments from DWPF to provide new procedural/administrative controls or system design changes are listed in the ''Facility Commitments'' section. The purpose of the ''Assumptions'' section is to clarify the basis for fault tree modeling, and is not necessarily a list of items required to be protected by Technical Safety Requirements (TSRs).

  8. Estimating vehicle roadside encroachment frequency using accident prediction models

    SciTech Connect (OSTI)

    Miaou, S.-P.

    1996-07-01

    The existing data to support the development of roadside encroachment- based accident models are extremely limited and largely outdated. Under the sponsorship of the Federal Highway Administration and Transportation Research Board, several roadside safety projects have attempted to address this issue by providing rather comprehensive data collection plans and conducting pilot data collection efforts. It is clear from the results of these studies that the required field data collection efforts will be expensive. Furthermore, the validity of any field collected encroachment data may be questionable because of the technical difficulty to distinguish intentional from unintentional encroachments. This paper proposes an alternative method for estimating the basic roadside encroachment data without actually field collecting them. The method is developed by exploring the probabilistic relationships between a roadside encroachment event and a run-off-the-road event With some mild assumptions, the method is capable of providing a wide range of basic encroachment data from conventional accident prediction models. To illustrate the concept and use of such a method, some basic encroachment data are estimated for rural two-lane undivided roads. In addition, the estimated encroachment data are compared with the existing collected data. The illustration shows that the method described in this paper can be a viable approach to estimating basic encroachment data without actually collecting them which can be very costly.

  9. A SCOPING STUDY: Development of Probabilistic Risk Assessment Models for Reactivity Insertion Accidents During Shutdown In U.S. Commercial Light Water Reactors

    SciTech Connect (OSTI)

    S. Khericha

    2011-06-01

    This report documents the scoping study of developing generic simplified fuel damage risk models for quantitative analysis from inadvertent reactivity insertion events during shutdown (SD) in light water pressurized and boiling water reactors. In the past, nuclear fuel reactivity accidents have been analyzed both mainly deterministically and probabilistically for at-power and SD operations of nuclear power plants (NPPs). Since then, many NPPs had power up-rates and longer refueling intervals, which resulted in fuel configurations that may potentially respond differently (in an undesirable way) to reactivity accidents. Also, as shown in a recent event, several inadvertent operator actions caused potential nuclear fuel reactivity insertion accident during SD operations. The set inadvertent operator actions are likely to be plant- and operation-state specific and could lead to accident sequences. This study is an outcome of the concern which arose after the inadvertent withdrawal of control rods at Dresden Unit 3 in 2008 due to operator actions in the plant inadvertently three control rods were withdrawn from the reactor without knowledge of the main control room operator. The purpose of this Standardized Plant Analysis Risk (SPAR) Model development project is to develop simplified SPAR Models that can be used by staff analysts to perform risk analyses of operating events and/or conditions occurring during SD operation. These types of accident scenarios are dominated by the operator actions, (e.g., misalignment of valves, failure to follow procedures and errors of commissions). Human error probabilities specific to this model were assessed using the methodology developed for SPAR model human error evaluations. The event trees, fault trees, basic event data and data sources for the model are provided in the report. The end state is defined as the reactor becomes critical. The scoping study includes a brief literature search/review of historical events, developments of

  10. Type B Accident Investigation of the July 31, 2006, Fall from Ladder Accident at the Lawrence Livermore National Laboratory, Livermore, California

    Energy.gov [DOE]

    This report is an independent product of the Type B Accident Investigation Board appointed by Camille Yuan-Soo Hoo, Manager of the Livermore Site Office of the National Nuclear Security Administration, U.S. Department of Energy.

  11. Type B Accident Investigation Board Report on the August 5, 1998, Load Haul Dump Accident at U16b Tunnel, Nevada Test Site

    Energy.gov [DOE]

    Thisis theType B Accident Investigation Board report of an industrial accident at the Nevada Test site (NTS), U16b tunnel in which a Bechtel Nevada (BN) employee suffered a compressed skull fracture as a result of being struck onthe head by a valve and fitting assembly on the end of a hose whichhad been broken from a water pipe by a moving piece of construction equipment.

  12. ASN Aircraft accident Beechcraft 1900C N27RA Tonopah-Test Range...

    National Nuclear Security Administration (NNSA)

    Accident description languages: Share 0 Statd,LB:5E)(WEWkNF75WLEW)w(Ni7wkE.(wnNa75WLEW)w(... According to the Air Force Materiel Command Accident Investigation Board report, the pilot ...

  13. Recovery sequences for a station blackout accident at the Grand Gulf Nuclear Station

    SciTech Connect (OSTI)

    Carbajo, J.J. [Martin Marietta Energy Systems, Oak Ridge, TN (United States)

    1995-12-31

    Recovery sequences for a low-pressure, short term, station blackout severe accident at the Grand Gulf power plant have been investigated using the computer code MELCOR, version 1.8.3 PN. This paper investigates the effect of reflood timing and mass flow rate on accident recovery.

  14. Precursors to potential severe core damage accidents: 1997 -- A status report. Volume 26

    SciTech Connect (OSTI)

    Belles, R.J.; Cletcher, J.W.; Copinger, D.A.; Muhlheim, M.D.; Dolan, B.W.; Minarick, J.W.

    1998-11-01

    This report describes the five operational events in 1997 that affected five commercial light-water reactors (LWRs) and that are considered to be precursors to potential severe core damage accidents. All these events had conditional probabilities of subsequent severe core damage greater than or equal to 1.0 {times} 10{sup {minus}6}. These events were identified by first computer-screening the 1997 licensee event reports from commercial LWRs to identify those events that could be precursors. Candidate precursors were selected and evaluated in a process similar to that used in previous assessments. Selected events underwent engineering evaluation that identified, analyzed, and documented the precursors. Other events designated by the Nuclear Regulatory Commission (NRC) also underwent a similar evaluation. Finally, documented precursors were submitted for review by licensees and NRC headquarters to ensure that the plant design and its response to the precursor were correctly characterized. This study is a continuation of earlier work, which evaluated 1969--1996 events. The report discusses the general rationale for this study, the selection and documentation of events as precursors, and the estimation of conditional probabilities of subsequent severe core damage for the events.

  15. On the issue of Zircaloy ductility during a reactivity-initiated accident

    SciTech Connect (OSTI)

    Link, T.M.; Motta, A.T.; Koss, D.A.

    1997-01-01

    During reactor exposure, Zircaloy cladding undergoes various microstructural changes including irradiation damage, oxidation, and hydrogen pick-up. There is a concern that the combination of these changes in high burnup cladding will cause failure during a reactivity-initiated accident (RIA) at an energy deposition level significantly lower than that of fresh cladding. In RIA conditions, the cladding must withstand loading at high strain rates and under deformation paths close to transverse plane-strain extension. Thus to assess cladding failure it is necessary to examine the failure mechanism of unirradiated Zircaloy cladding under RIA-like loading conditions. The authors present here a theoretical analysis of a possible failure mode of Zircaloy cladding due to localized necking. The results of the analysis suggest that high-burnup cladding is susceptible to pronounced losses of ductility under a combination of plane strain loading deformation and the presence of thickness imperfections. Such imperfections may be caused by hydride embrittlement of the cladding or non-uniform oxidation such that an axial thickness change is created.

  16. A statistical description of the types and severities of accidents involving tractor semi-trailers

    SciTech Connect (OSTI)

    Clauss, D.B.; Wilson, R.K.; Blower, D.F.; Campbell, K.L.

    1994-06-01

    This report provides a statistical description of the types and severities of tractor semi-trailer accidents involving at least one fatality. The data were developed for use in risk assessments of hazardous materials transportation. Several accident databases were reviewed to determine their suitability to the task. The TIFA (Trucks Involved in Fatal Accidents) database created at the University of Michigan Transportation Research Institute was extensively utilized. Supplementary data on collision and fire severity, which was not available in the TIFA database, were obtained by reviewing police reports for selected TIFA accidents. The results are described in terms of frequencies of different accident types and cumulative distribution functions for the peak contact velocity, rollover skid distance, fire temperature, fire size, fire separation, and fire duration.

  17. Qualification of Daiichi Units 1, 2, and 3 Data for Severe Accident Evaluations - Process and Illustrative Examples from Prior TMI-2 Evaluations

    SciTech Connect (OSTI)

    Rempe, Joy Lynn; Knudson, Darrell Lee

    2014-09-01

    The accidents at the Three Mile Island Unit 2 (TMI-2) Pressurized Water Reactor (PWR) and the Daiichi Units 1, 2, and 3 Boiling Water Reactors (BWRs) provide unique opportunities to evaluate instrumentation exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during the TMI-2 accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This initial review focused on the set of sensors deemed most important by post-TMI-2 instrumentation evaluation programs. Instrumentation evaluation programs focused on data required by TMI-2 operators to assess the condition of the reactor and containment and the effect of mitigating actions taken by these operators. In addition, prior efforts focused on sensors providing data required for subsequent forensic evaluations and accident simulations. To encourage the potential for similar activities to be completed for qualifying data from Daiichi Units 1, 2, and 3, this report provides additional details related to the formal process used to develop a qualified TMI-2 data base and presents data qualification details for three parameters: primary system pressure; containment building temperature; and containment pressure. As described within this report, sensor evaluations and data qualification required implementation of various processes, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design to instruments easily removed from the TMI-2 plant for evaluations. As documented

  18. Accident Investigation of the June 1, 2013, Stairway Fall Resulting in a Federal Employee Fatality at DOE Headquarters Germantown, Maryland

    Energy.gov [DOE]

    On June 28, 2013, an Accident Investigation Board was appointed to investigate an accident at the Department of Energy Germantown Headquarters facility, on June 1, 2013 that resulted in a fatality on June 24, 2013.

  19. Regulatory analyses for severe accident issues: an example

    SciTech Connect (OSTI)

    Burke, R.P.

    1985-01-01

    A study has been performed as part of a program to establish methods for incorporation of information from a broad range of research programs, particularly those which generate probabilistic risk information, and to develop suitable presentation formats for providing guidance to decisionmakers on issues related to severe accidents. The study addresses issues related to information availability, content, and presentation formats for use in the regulatory decisionmaking process. The approach employed to address these issues was to perform an example regulatory analysis on representative topics of interest using available technical information. The issue examined in the example analysis is the implementation of either a vented containment system or an alternative decay heat removal system at the Peach Bottom No. 2 plant. The example demonstrates many of the problems which will be encountered as probabilistic information from ongoing programs is incorporated into the regulatory decisionmaking process.

  20. Probabilistic Accident Consequence Uncertainty - A Joint CEC/USNRC Study

    SciTech Connect (OSTI)

    Gregory, Julie J.; Harper, Frederick T.

    1999-07-28

    The joint USNRC/CEC consequence uncertainty study was chartered after the development of two new probabilistic accident consequence codes, MACCS in the U.S. and COSYMA in Europe. Both the USNRC and CEC had a vested interest in expanding the knowledge base of the uncertainty associated with consequence modeling, and teamed up to co-sponsor a consequence uncertainty study. The information acquired from the study was expected to provide understanding of the strengths and weaknesses of current models as well as a basis for direction of future research. This paper looks at the elicitation process implemented in the joint study and discusses some of the uncertainty distributions provided by eight panels of experts from the U.S. and Europe that were convened to provide responses to the elicitation. The phenomenological areas addressed by the expert panels include atmospheric dispersion and deposition, deposited material and external doses, food chain, early health effects, late health effects and internal dosimetry.

  1. Shipping container response to three severe railway accident scenarios

    SciTech Connect (OSTI)

    Mok, G.C.; Fischer, L.E.; Murty, S.S.; Witte, M.C.

    1998-04-01

    The probability of damage and the potential resulting hazards are analyzed for a representative rail shipping container for three severe rail accident scenarios. The scenarios are: (1) the rupture of closure bolts and resulting opening of closure lid due to a severe impact, (2) the puncture of container by an impacting rail-car coupler, and (3) the yielding of container due to side impact on a rigid uneven surface. The analysis results indicate that scenario 2 is a physically unreasonable event while the probabilities of a significant loss of containment in scenarios 1 and 3 are extremely small. Before assessing the potential risk for the last two scenarios, the uncertainties in predicting complex phenomena for rare, high- consequence hazards needs to be addressed using a rigorous methodology.

  2. Decontamination analysis of the NUWAX-83 accident site using DECON

    SciTech Connect (OSTI)

    Tawil, J.J.

    1983-11-01

    This report presents an analysis of the site restoration options for the NUWAX-83 site, at which an exercise was conducted involving a simulated nuclear weapons accident. This analysis was performed using a computer program deveoped by Pacific Northwest Laboratory. The computer program, called DECON, was designed to assist personnel engaged in the planning of decontamination activities. The many features of DECON that are used in this report demonstrate its potential usefulness as a site restoration planning tool. Strategies that are analyzed with DECON include: (1) employing a Quick-Vac option, under which selected surfaces are vacuumed before they can be rained on; (2) protecting surfaces against precipitation; (3) prohibiting specific operations on selected surfaces; (4) requiring specific methods to be used on selected surfaces; (5) evaluating the trade-off between cleanup standards and decontamination costs; and (6) varying of the cleanup standards according to expected exposure to surface.

  3. Phase 1A Final Report for the AREVA Team Enhanced Accident Tolerant Fuels Concepts

    SciTech Connect (OSTI)

    Morrell, Mike E.

    2015-03-19

    plants large scale investment by the fuel vendors is difficult to justify. Specific EATF enhancements considered by the AREVA team were; Improved performance in DB and BDB conditions; Reduced release to the environment in a catastrophic accident; Improved performance during normal operating conditions; Improved performance if US reactors start to load follow; Equal or improved economics of the fuel; and Improvements to the fuel behavior to support future transportation and storage of the used nuclear fuel (UNF). In pursuit of the above enhancements, EATF technology concepts that our team considered were; Additives to the fuel pellets which included; Chromia doping to increase fission gas retention. Chromia doping has the potential to improve load following characteristics, improve performance of the fuel pellet during clad failure, and potentially lock up cesium into the fuel matrix; Silicon Carbide (SiC) Fibers to improve thermal heat transfer in normal operating conditions which also improves margin in accident conditions and the potential to lock up iodine into the fuel matrix; Nano-diamond particles to enhance thermal conductivity; Coatings on the fuel cladding; and Nine coatings on the existing Zircaloy cladding to increase coping time and reduce clad oxidation and hydrogen generation during accident conditions, as well as reduce hydrogen pickup and mitigate hydride reorientation in the cladding. To facilitate the development process AREVA adopted a formal “Gate Review Process” (GR) that was used to review results and focus resources onto promising technologies to reduce costs and identify the technologies that would potentially be carried forward to LFAs within a 10 year period. During the initial discovery phase of the project AREVA took the decision to be relatively hands off and allow our university and National Laboratory partners to be free thinking and consider options that would not be constrained by preconceived ideas from the fuel vendor. To counter

  4. Modeling and analysis of core debris recriticality during hypothetical severe accidents in the Advanced Neutron Source Reactor

    SciTech Connect (OSTI)

    Taleyarkhan, R.P.; Kim, S.H.; Slater, C.O.; Moses, D.L.; Simpson, D.B.; Georgevich, V.

    1993-05-01

    This paper discusses salient aspects of severe-accident-related recriticality modeling and analysis in the Advanced Neutron Source (ANS) reactor. The development of an analytical capability using the KENO V.A-SCALE system is described including evaluation of suitable nuclear cross-section sets to account for the effects of system geometry, mixture temperature, material dispersion and other thermal-hydraulic conditions. Benchmarking and validation efforts conducted with KENO V.A-SCALE and other neutronic codes against critical experiment data are described. Potential deviations and biases resulting from use of the 16-group Hansen-Roach library are shown. A comprehensive test matrix of calculations to evaluate the threat of a recriticality event in the ANS is described. Strong dependencies on geometry, material constituents, and thermal-hydraulic conditions are described. The introduction of designed mitigative features is described.

  5. Type A Accident Investigation Board Report on the April 3, 1995, Security Rappel Tower Fatality at the DOE Savannah River Site

    Office of Energy Efficiency and Renewable Energy (EERE)

    The objectives of this investigation are twofold: to determine the cause and surrounding circumstances of this accident and to prevent the occurrence of similar accidents.

  6. Wide field of view telescope

    DOE Patents [OSTI]

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  7. Hydrogen Mitigation Strategy of the APR1400 Nuclear Power Plant for a Hypothetical Station Blackout Accident

    SciTech Connect (OSTI)

    Kim, Jongtae; Hong, Seong-Wan; Kim, Sang-Baik; Kim, Hee-Dong [Korea Atomic Energy Research Institute (Korea, Republic of)

    2005-06-15

    In order to analyze the hydrogen distribution during a hypothetical station blackout accident in the Korean next-generation Advanced Power Reactor 1400 (APR1400) containment, the three-dimensional computational fluid dynamics code GASFLOW was used. The source of the hydrogen and steam for the GASFLOW analysis was obtained from a MAAP calculation. The discharged water, steam, and hydrogen from the pressurizer are released into the water of the in-containment refueling water storage tank (IRWST). Most of the discharged steam is condensed in the IRWST water because of its subcooling, and dry hydrogen is released into the free volume of the IRWST; finally, it goes out to the annular compartment above the IRWST through the vent holes. From the GASFLOW analysis, it was found that the gas mixture in the IRWST becomes quickly nonflammable by oxygen starvation but the hydrogen is accumulated in the annular compartment because of the narrow ventilation gap between the operating deck and containment wall when the igniters installed in the IRWST are not operated. When the igniters installed in the APR1400 were turned on, a short period of burning occurred in the IRWST, and then the flame was extinguished by the oxygen starvation in the IRWST. The unburned hydrogen was released into the annular compartment and went up to the dome because no igniters are installed around the annular compartment in the base design of the APR1400. From this result, it could be concluded that the control of the hydrogen concentration is difficult for the base design. In this study design modifications are proposed and evaluated with GASFLOW in view of the hydrogen mitigation strategy.

  8. WHEN MODEL MEETS REALITY – A REVIEW OF SPAR LEVEL 2 MODEL AGAINST FUKUSHIMA ACCIDENT

    SciTech Connect (OSTI)

    Zhegang Ma

    2013-09-01

    The Standardized Plant Analysis Risk (SPAR) models are a set of probabilistic risk assessment (PRA) models used by the Nuclear Regulatory Commission (NRC) to evaluate the risk of operations at U.S. nuclear power plants and provide inputs to risk informed regulatory process. A small number of SPAR Level 2 models have been developed mostly for feasibility study purpose. They extend the Level 1 models to include containment systems, group plant damage states, and model containment phenomenology and accident progression in containment event trees. A severe earthquake and tsunami hit the eastern coast of Japan in March 2011 and caused significant damages on the reactors in Fukushima Daiichi site. Station blackout (SBO), core damage, containment damage, hydrogen explosion, and intensive radioactivity release, which have been previous analyzed and assumed as postulated accident progression in PRA models, now occurred with various degrees in the multi-units Fukushima Daiichi site. This paper reviews and compares a typical BWR SPAR Level 2 model with the “real” accident progressions and sequences occurred in Fukushima Daiichi Units 1, 2, and 3. It shows that the SPAR Level 2 model is a robust PRA model that could very reasonably describe the accident progression for a real and complicated nuclear accident in the world. On the other hand, the comparison shows that the SPAR model could be enhanced by incorporating some accident characteristics for better representation of severe accident progression.

  9. Community emergency response to nuclear power plant accidents: A selected and partially annotated bibliography

    SciTech Connect (OSTI)

    Youngen, G.

    1988-10-01

    The role of responding to emergencies at nuclear power plants is often considered the responsibility of the personnel onsite. This is true for most, if not all, of the incidents that may happen during the course of the plant`s operating lifetime. There is however, the possibility of a major accident occurring at anytime. Major nuclear accidents at Chernobyl and Three Mile Island have taught their respective countries and communities a significant lesson in local emergency preparedness and response. Through these accidents, the rest of the world can also learn a great deal about planning, preparing and responding to the emergencies unique to nuclear power. This bibliography contains books, journal articles, conference papers and government reports on emergency response to nuclear power plant accidents. It does not contain citations for ``onsite`` response or planning, nor does it cover the areas of radiation releases from transportation accidents. The compiler has attempted to bring together a sampling of the world`s collective written experience on dealing with nuclear reactor accidents on the sate, local and community levels. Since the accidents at Three Mile Island and Chernobyl, that written experience has grown enormously.

  10. Thermal hydraulic-severe accident code interfaces for SCDAP/RELAP5/MOD3.2

    SciTech Connect (OSTI)

    Coryell, E.W.; Siefken, L.J.; Harvego, E.A.

    1997-07-01

    The SCDAP/RELAP5 computer code is designed to describe the overall reactor coolant system thermal-hydraulic response, core damage progression, and fission product release during severe accidents. The code is being developed at the Idaho National Engineering Laboratory under the primary sponsorship of the Office of Nuclear Regulatory Research of the U.S. Nuclear Regulatory Commission. The code is the result of merging the RELAP5, SCDAP, and COUPLE codes. The RELAP5 portion of the code calculates the overall reactor coolant system, thermal-hydraulics, and associated reactor system responses. The SCDAP portion of the code describes the response of the core and associated vessel structures. The COUPLE portion of the code describes response of lower plenum structures and debris and the failure of the lower head. The code uses a modular approach with the overall structure, input/output processing, and data structures following the pattern established for RELAP5. The code uses a building block approach to allow the code user to easily represent a wide variety of systems and conditions through a powerful input processor. The user can represent a wide variety of experiments or reactor designs by selecting fuel rods and other assembly structures from a range of representative core component models, and arrange them in a variety of patterns within the thermalhydraulic network. The COUPLE portion of the code uses two-dimensional representations of the lower plenum structures and debris beds. The flow of information between the different portions of the code occurs at each system level time step advancement. The RELAP5 portion of the code describes the fluid transport around the system. These fluid conditions are used as thermal and mass transport boundary conditions for the SCDAP and COUPLE structures and debris beds.

  11. The response of BWR Mark II containments to station blackout severe accident sequences

    SciTech Connect (OSTI)

    Greene, S.R.; Hodge, S.A.; Hyman, C.R.; Tobias, M.L. (Oak Ridge National Lab., TN (USA))

    1991-05-01

    This report describes the results of a series of calculations conducted to investigate the response of BWR Mark 2 containments to short-term and long-term station blackout severe accident sequences. The BWR-LTAS, BWRSAR, and MELCOR codes were employed to conduct quantitative accident sequence progression and containment response analyses for several station blackout scenarios. The accident mitigation effectiveness of automatic depressurization system actuation, drywell flooding via containment spray operation, and debris quenching in Mark 2 suppression pools is assessed. 27 refs., 16 figs., 21 tabs.

  12. Study on the Accidental Rupture of Hot Leg or Surge Line in SBO Accident

    SciTech Connect (OSTI)

    Kun Zhang; Xuewu Cao [Shanghai Jiaotong University, Shanghai (China)

    2006-07-01

    The postulated total station blackout accident (SBO) of PWR NPP with 600 MWe in China is analyzed as the base case using SCDAP/RELAP5 code. Then the hot leg or surge line are assumed to rupture before the lower head of Reactor Pressure Vessel (RPV) ruptures, and the progressions are analyzed in detail comparing with the base case. The results show that the accidental rupture of hot leg or surge line will greatly influence the progression of accident. The probability of hot leg or surge line rupture in intentional depressurization is also studied in this paper, which provides a suggestion to the development of Severe Accident Management Guidelines (SAMG). (authors)

  13. Application of MELCOR Code to a French PWR 900 MWe Severe Accident Sequence and Evaluation of Models Performance Focusing on In-Vessel Thermal Hydraulic Results

    SciTech Connect (OSTI)

    De Rosa, Felice [ENEA, Italian National Agency for New Technologies, Energy and the Environment (Italy)

    2006-07-01

    In the ambit of the Severe Accident Network of Excellence Project (SARNET), funded by the European Union, 6. FISA (Fission Safety) Programme, one of the main tasks is the development and validation of the European Accident Source Term Evaluation Code (ASTEC Code). One of the reference codes used to compare ASTEC results, coming from experimental and Reactor Plant applications, is MELCOR. ENEA is a SARNET member and also an ASTEC and MELCOR user. During the first 18 months of this project, we performed a series of MELCOR and ASTEC calculations referring to a French PWR 900 MWe and to the accident sequence of 'Loss of Steam Generator (SG) Feedwater' (known as H2 sequence in the French classification). H2 is an accident sequence substantially equivalent to a Station Blackout scenario, like a TMLB accident, with the only difference that in H2 sequence the scram is forced to occur with a delay of 28 seconds. The main events during the accident sequence are a loss of normal and auxiliary SG feedwater (0 s), followed by a scram when the water level in SG is equal or less than 0.7 m (after 28 seconds). There is also a main coolant pumps trip when {delta}Tsat < 10 deg. C, a total opening of the three relief valves when Tric (core maximal outlet temperature) is above 603 K (330 deg. C) and accumulators isolation when primary pressure goes below 1.5 MPa (15 bar). Among many other points, it is worth noting that this was the first time that a MELCOR 1.8.5 input deck was available for a French PWR 900. The main ENEA effort in this period was devoted to prepare the MELCOR input deck using the code version v.1.8.5 (build QZ Oct 2000 with the latest patch 185003 Oct 2001). The input deck, completely new, was prepared taking into account structure, data and same conditions as those found inside ASTEC input decks. The main goal of the work presented in this paper is to put in evidence where and when MELCOR provides good enough results and why, in some cases mainly referring to its

  14. Health Physics Code System for Evaluating Accidents Involving Radioactive Materials.

    Energy Science and Technology Software Center (OSTI)

    2014-10-01

    Version 03 The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculational tool for evaluating accidents involving radioactive materials. HOTSPOT codes provide a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. The developer's website is: http://www.llnl.gov/nhi/hotspot/. Four general programs, PLUME, EXPLOSION, FIRE, and RESUSPENSION, calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosivemore » release, fuel fire, or an area contamination event. Additional programs deal specifically with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. The FIDLER program can calibrate radiation survey instruments for ground survey measurements and initial screening of personnel for possible plutonium uptake in the lung. The HOTSPOT codes are fast, portable, easy to use, and fully documented in electronic help files. HOTSPOT supports color high resolution monitors and printers for concentration plots and contours. The codes have been extensively used by the DOS community since 1985. Tables and graphical output can be directed to the computer screen, printer, or a disk file. The graphical output consists of dose and ground contamination as a function of plume centerline downwind distance, and radiation dose and ground contamination contours. Users have the option of displaying scenario text on the plots. HOTSPOT 3.0.1 fixes three significant Windows 7 issues: � Executable installed properly under "Program Files/HotSpot 3.0". Installation package now smaller: removed dependency on older Windows DLL files which previously needed to \\ � Forms now properly scale based on DPI instead of font for users who change their screen resolution to something other than 100%. This is a more common feature in Windows 7

  15. AP1000{sup R} severe accident features and post-Fukushima considerations

    SciTech Connect (OSTI)

    Scobel, J. H.; Schulz, T. L.; Williams, M. G.

    2012-07-01

    The AP1000{sup R} passive nuclear power plant is uniquely equipped to withstand an extended station blackout scenario such as the events following the earthquake and tsunami at Fukushima without compromising core and containment integrity. The AP1000 plant shuts down the reactor, cools the core, containment and spent fuel pool for more than 3 days using passive systems that do not require AC or DC power or operator actions. Following this passive coping period, minimal operator actions are needed to extend the operation of the passive features to 7 days using installed equipment. To provide defense-in-depth for design extension conditions, the AP1000 plant has engineered features that mitigate the effects of core damage. Engineered features retain damaged core debris within the reactor vessel as a key feature. Other aspects of the design protect containment integrity during severe accidents, including unique features of the AP1000 design relative to passive containment cooling with water and air, and hydrogen management. (authors)

  16. TRACE/PARCS Core Modeling of a BWR/5 for Accident Analysis of ATWS Events

    SciTech Connect (OSTI)

    Cuadra A.; Baek J.; Cheng, L.; Aronson, A.; Diamond, D.; Yarsky, P.

    2013-11-10

    The TRACE/PARCS computational package [1, 2] isdesigned to be applicable to the analysis of light water reactor operational transients and accidents where the coupling between the neutron kinetics (PARCS) and the thermal-hydraulics and thermal-mechanics (TRACE) is important. TRACE/PARCS has been assessed for itsapplicability to anticipated transients without scram(ATWS) [3]. The challenge, addressed in this study, is to develop a sufficiently rigorous input model that would be acceptable for use in ATWS analysis. Two types of ATWS events were of interest, a turbine trip and a closure of main steam isolation valves (MSIVs). In the first type, initiated by turbine trip, the concern is that the core will become unstable and large power oscillations will occur. In the second type,initiated by MSIV closure,, the concern is the amount of energy being placed into containment and the resulting emergency depressurization. Two separate TRACE/PARCS models of a BWR/5 were developed to analyze these ATWS events at MELLLA+ (maximum extended load line limit plus)operating conditions. One model [4] was used for analysis of ATWS events leading to instability (ATWS-I);the other [5] for ATWS events leading to emergency depressurization (ATWS-ED). Both models included a large portion of the nuclear steam supply system and controls, and a detailed core model, presented henceforth.

  17. Cladding metallurgy and fracture behavior during reactivity-initiated accidents at high burnup

    SciTech Connect (OSTI)

    Chung, H.M.; Kassner, T.F.

    1996-12-01

    High-burnup fuel failure during a reactivity-initiated accident has been the subject of safety-related concern. Because of wide variations in metallurgical and simulation test conditions, it has been difficult to understand the complex failure behavior from major tests in NSRR and CABRI reactors. In this paper, a failure model based on fracture toughness and microstructural characteristics is proposed in which fracture toughness of high-burnup cladding is assumed to be sensitive to temperature and exhibit ductile-brittle transition phenomena similar to those of irradiated bcc alloys. Significant effects of temperature and shape of the pulse are predicted when a simulated test is conducted near the material`s transition temperature. Temperature dependence of fracture toughness is, in turn, sensitive to cladding microstructure such as density, distribution, and orientation of hydrides, oxygen distribution in the metallic phase, and irradiation-induced damage. Because all these factors are strongly influenced by corrosion, the key parameters that influence susceptibility to failure are oxide layer thickness and hydriding behavior. Therefore, fuel failure is predicted to be strongly dependent on cladding axial location as well as on burnup. 10 figs, 21 refs.

  18. Analysis of molten fuel-coolant interaction during a reactivity-initiated accident experiment. [BWR; PWR

    SciTech Connect (OSTI)

    El-Genk, M.S.; Hobbins, R.R.

    1981-01-01

    The results of a reactivity-initiated accident experiment, designated RIA-ST-4, are discussed and analyzed with regard to molten fuel-coolant interaction (MFCI). In this experiment, extensive amounts of molten UO/sub 2/ fuel and zircaloy cladding were produced and fragmented upon mixing with the coolant. Coolant pressurization up to 35 MPa and coolant overheating in excess of 940 K occurred after fuel rod failure. The initial coolant conditions were similar to those in boiling water reactors during a hot startup (that is, coolant pressure of 6.45 MPa, coolant temperature of 538 K, and coolant flow rate of 85 cm/sup 3//s). It is concluded that the high coolant pressure recorded in the RIA-ST-4 experiment was caused by an energetic MFCI and was not due to gas release from the test rod at failure, Zr/water reaction, or to UO/sub 2/ fuel vapor pressure. The high coolant temperature indicated the presence of superheated steam, which may have formed during the expansion of the working fluid back to the initial coolant pressure; yet, the thermal-to-mechanical energy conversion ratio is estimated to be only 0.3%.

  19. Natural Circulation Patterns in the VHTR Air-Ingress Accident and Related Issues

    SciTech Connect (OSTI)

    Chang H. Oh; Eung S. Kim

    2012-08-01

    Natural circulation patterns in the VHTR during a hypothetical air-ingress accident have been investigated using computational fluid dynamic (CFD) methods in order to compare results from the previous 1-D model which was developed using GAMMA code for the air-ingress analyses. The GT-MHR 600 MWt reactor was selected to be the reference design and modeled by a half symmetric 3-D geometry using FLUENT 6.3, a commercial CFD code. CFD simulations were carried out as the steady-state calculation, and the boundary conditions were either assumed or provided from the 1-D GAMMA code results. Totally, 12 different cases have been reviewed, and many notable results have been obtained through in this work. According to the simulations, natural circulation patterns in the reactor were quite different from the previous 1-D assumptions. A large re-circulation flow with thermal stratification phenomena was clearly observed in the hot-leg and the lower plenum in the 3-D model. This re-circulation flow provided about an order faster air-ingress speed (0.46 m/s in superficial velocity) than previously predicted by 1-D modeling (0.02~0.03 m/s). It indicates that the 1-D air-ingress modeling may significantly distort the air-ingress scenario and consequences. In addition, complicated natural circulation patterns are eventually expected to result in very complex graphite oxidations and corrosion behaviors.

  20. THERMAL ANALYSIS OF A 9975 PACKAGE IN A FACILITY FIRE ACCIDENT

    SciTech Connect (OSTI)

    Gupta, N.

    2011-02-14

    Surplus plutonium bearing materials in the U.S. Department of Energy (DOE) complex are stored in the 3013 containers that are designed to meet the requirements of the DOE standard DOE-STD-3013. The 3013 containers are in turn packaged inside 9975 packages that are designed to meet the NRC 10 CFR Part 71 regulatory requirements for transporting the Type B fissile materials across the DOE complex. The design requirements for the hypothetical accident conditions (HAC) involving a fire are given in 10 CFR 71.73. The 9975 packages are stored at the DOE Savannah River Site in the K-Area Material Storage (KAMS) facility for long term of up to 50 years. The design requirements for safe storage in KAMS facility containing multiple sources of combustible materials are far more challenging than the HAC requirements in 10 CFR 71.73. While the 10 CFR 71.73 postulates an HAC fire of 1475 F and 30 minutes duration, the facility fire calls for a fire of 1500 F and 86 duration. This paper describes a methodology and the analysis results that meet the design limits of the 9975 component and demonstrate the robustness of the 9975 package.

  1. Views of the solar system

    SciTech Connect (OSTI)

    Hamilton, C.

    1995-02-01

    Views of the Solar System has been created as an educational tour of the solar system. It contains images and information about the Sun, planets, moons, asteroids and comets found within the solar system. The image processing for many of the images was done by the author. This tour uses hypertext to allow space travel by simply clicking on a desired planet. This causes information and images about the planet to appear on screen. While on a planet page, hyperlinks travel to pages about the moons and other relevant available resources. Unusual terms are linked to and defined in the Glossary page. Statistical information of the planets and satellites can be browsed through lists sorted by name, radius and distance. History of Space Exploration contains information about rocket history, early astronauts, space missions, spacecraft and detailed chronology tables of space exploration. The Table of Contents page has links to all of the various pages within Views Of the Solar System.

  2. For current viewing resistor loads

    DOE Patents [OSTI]

    Lyons, Gregory R.; Hass, Jay B.

    2011-04-19

    The invention comprises a terminal unit for a flat cable comprising a BNC-PCB connector having a pin for electrically contacting one or more conducting elements of a flat cable, and a current viewing resistor having an opening through which the pin extends and having a resistor face that abuts a connector face of the BNC-PCB connector, wherein the device is a terminal unit for the flat cable.

  3. Natural Convection and Boiling for Cooling SRP Reactors During Loss of Circulation Conditions

    SciTech Connect (OSTI)

    Buckner, M.R.

    2001-06-26

    This study investigated natural convection and boiling as a means of cooling SRP reactors in the event of a loss of circulation accident. These studies show that single phase natural convection cooling of SRP reactors in shutdown conditions with the present piping geometry is probably not feasible.

  4. Accident assessment: role of the containment radiation monitor

    SciTech Connect (OSTI)

    Desrosiers, A.E.; Scherpelz, R.I.; Smith, M.S.; Grimes, B.K.

    1980-01-01

    The containment radiation monitor may provide information to a power reactor operator that can aid assessment of the degree of core damage following a loss-of-coolant accident (LOCA). This paper reports calculations of the exposure rates that would exist in the containment of a commercial pressurized water reactor (PWR) following severe reactor transients. The results indicate exposure rates of 1 to 2 R . h/sup -1/ 30 minutes after a large LOCA, 4 to 5 x 10 R . h/sup -1/ one hour following a release of the gap activity, and 4 . 10/sup 6/ R . h/sup -1/ two hours after a transient that resulted in a fuel melt. Furthermore, differences between the energy spectra of photons released by noble gases and halogens suggest that containment radiation monitors may be designed to differentiate between these radioelements. The calculated exposure rates are not in agreement with the response of containment radiation monitors during the incident at the Crystal River Reactor. Inhomogeneous source terms, the operation of containment building systems, and inaccuracies in release estimates, measurements and calculations may have contributed to this discrepancy in one degree or another.

  5. LIGHT WATER REACTOR ACCIDENT TOLERANT FUELS IRRADIATION TESTING

    SciTech Connect (OSTI)

    Carmack, William Jonathan; Barrett, Kristine Eloise; Chichester, Heather Jean MacLean

    2015-09-01

    The purpose of Accident Tolerant Fuels (ATF) experiments is to test novel fuel and cladding concepts designed to replace the current zirconium alloy uranium dioxide (UO2) fuel system. The objective of this Research and Development (R&D) is to develop novel ATF concepts that will be able to withstand loss of active cooling in the reactor core for a considerably longer time period than the current fuel system while maintaining or improving the fuel performance during normal operations, operational transients, design basis, and beyond design basis events. It was necessary to design, analyze, and fabricate drop-in capsules to meet the requirements for testing under prototypic LWR temperatures in Idaho National Laboratory's Advanced Test Reactor (ATR). Three industry led teams and one DOE team from Oak Ridge National Laboratory provided fuel rodlet samples for their new concepts for ATR insertion in 2015. As-built projected temperature calculations were performed on the ATF capsules using the BISON fuel performance code. BISON is an application of INL’s Multi-physics Object Oriented Simulation Environment (MOOSE), which is a massively parallel finite element based framework used to solve systems of fully coupled nonlinear partial differential equations. Both 2D and 3D models were set up to examine cladding and fuel performance.

  6. CASE STUDY FOR ENHANCED ACCIDENT TOLERANCE DESIGN CHANGES

    SciTech Connect (OSTI)

    Prescott, Steven; Smith, Curtis; Koonce, Tony

    2014-09-01

    The ability to better characterize and quantify safety margin is important to improved decision making about Light Water Reactor (LWR) design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margin management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. In addition, as research and development in the LWR Sustainability (LWRS) Program and other collaborative efforts yield new data, sensors, and improved scientific understanding of physical processes that govern the aging and degradation of plant SSCs needs and opportunities to better optimize plant safety and performance will become known. To support decision making related to economics, readability, and safety, the Risk Informed Safety Margin Characterization (RISMC) Pathway provides methods and tools that enable mitigation options known as risk informed margins management (RIMM) strategies. The methods and tools provided by RISMC are essential to a comprehensive and integrated RIMM approach that supports effective preservation of margin for both active and passive SSCs. In this report, we discuss the methods and technologies behind RIMM for an application focused on enhanced accident tolerance design changes for a representative nuclear power plant. We look at a variety of potential plant modifications and evaluate, using the RISMC approach, the implications to safety margin for the various strategies.

  7. INTERCOMPARISON OF RESULTS FOR A PWR ROD EJECTION ACCIDENT

    SciTech Connect (OSTI)

    DIAMOND,D.J.; ARONSON,A.; JO,J.; AVVAKUMOV,A.; MALOFEEV,V.; SIDOROV,V.; FERRARESI,P.; GOUIN,C.; ANIEL,S.; ROYER,M.E.

    1999-10-01

    This study is part of an overall program to understand the uncertainty in best-estimate calculations of the local fuel enthalpy during the rod ejection accident. Local fuel enthalpy is used as the acceptance criterion for this design-basis event and can also be used to estimate fuel damage for the purpose of determining radiological consequences. The study used results from neutron kinetics models in PARCS, BARS, and CRONOS2, codes developed in the US, the Russian Federation, and France, respectively. Since BARS uses a heterogeneous representation of the fuel assembly as opposed to the homogeneous representations in PARCS and CRONOS, the effect of the intercomparison was primarily to compare different intra-assembly models. Quantitative comparisons for core power, reactivity, assembly fuel enthalpy and pin power were carried out. In general the agreement between methods was very good providing additional confidence in the codes and providing a starting point for a quantitative assessment of the uncertainty in calculated fuel enthalpy using best-estimate methods.

  8. K Basins floor sludge retrieval system knockout pot basket fuel burn accident

    SciTech Connect (OSTI)

    HUNT, J.W.

    1998-11-11

    The K Basins Sludge Retrieval System Preliminary Hazard Analysis Report (HNF-2676) identified and categorized a series of potential accidents associated with K Basins Sludge Retrieval System design and operation. The fuel burn accident was of concern with respect to the potential release of contamination resulting from a runaway chemical reaction of the uranium fuel in a knockout pot basket suspended in the air. The unmitigated radiological dose to an offsite receptor from this fuel burn accident is calculated to be much less than the offsite risk evaluation guidelines for anticipated events. However, because of potential radiation exposure to the facility worker, this accident is precluded with a safety significant lifting device that will prevent the monorail hoist from lifting the knockout pot basket out of the K Basin water pool.

  9. Development of Light Water Reactor Fuels with Enhanced Accident Tolerance – Report to Congress

    Energy.gov [DOE]

    This report provides DOE’s plan to develop light water reactor (LWR) fuels with enhanced accident tolerance in response to 2012 Congressional direction and funding authorization. The result of the...

  10. ACCIDENT ANALYSES & CONTROL OPTIONS IN SUPPORT OF THE SLUDGE WATER SYSTEM SAFETY ANALYSIS

    SciTech Connect (OSTI)

    WILLIAMS, J.C.

    2003-11-15

    This report documents the accident analyses and nuclear safety control options for use in Revision 7 of HNF-SD-WM-SAR-062, ''K Basins Safety Analysis Report'' and Revision 4 of HNF-SD-SNF-TSR-001, ''Technical Safety Requirements - 100 KE and 100 KW Fuel Storage Basins''. These documents will define the authorization basis for Sludge Water System (SWS) operations. This report follows the guidance of DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports'', for calculating onsite and offsite consequences. The accident analysis summary is shown in Table ES-1 below. While this document describes and discusses potential control options to either mitigate or prevent the accidents discussed herein, it should be made clear that the final control selection for any accident is determined and presented in HNF-SD-WM-SAR-062.

  11. OVERVIEW OF MODULAR HTGR SAFETY CHARACTERIZATION AND POSTULATED ACCIDENT BEHAVIOR LICENSING STRATEGY

    SciTech Connect (OSTI)

    Ball, Sydney J

    2014-06-01

    This report provides an update on modular high-temperature gas-cooled reactor (HTGR) accident analyses and risk assessments. One objective of this report is to improve the characterization of the safety case to better meet current regulatory practice, which is commonly geared to address features of today s light water reactors (LWRs). The approach makes use of surrogates for accident prevention and mitigation to make comparisons with LWRs. The safety related design features of modular HTGRs are described, along with the means for rigorously characterizing accident selection and progression methodologies. Approaches commonly used in the United States and elsewhere are described, along with detailed descriptions and comments on design basis (and beyond) postulated accident sequences.

  12. The Adequacy of DOE Natural Phenomena Hazards Performance Goals from an Accident Analysis Perspective

    Energy.gov [DOE]

    The Adequacy of DOE Natural Phenomena Hazards Performance Goals from an Accident Analysis Perspective Jeff Kimball Defense Nuclear Facilities Safety Board Staff Department of Energy NPH Conference October 26, 2011

  13. Code System for Calculating Early Offsite Consequences from Nuclear Reactor Accidents.

    Energy Science and Technology Software Center (OSTI)

    1992-06-10

    SMART calculates early offsite consequences from nuclear reactor accidents. Once the air and ground concentrations of the radionuclide are estimated, the early dose to an individual is calculated via three pathways: cloudshine, short-term groundshine, and inhalation.

  14. MLAM assessment of air concentration, deposition, and dose for Chernobyl reactor accident

    SciTech Connect (OSTI)

    Olsen, A.R.; Davis, W.E.; Didier, B.T.; Soldat, J.K.; Napier, B.A.; Peloquin, R.A.

    1989-12-01

    The purpose of this report is to provide estimates for the areas in Europe affected by the accident involving Unit 4 of the Chernobylskaya Atomic Energy Station which resulted in the release of radioactive material to the atmosphere.

  15. Level 1 Accident Report of the March 1, 2010 Bobcat Fatality...

    Energy.gov (indexed) [DOE]

    White Bluffs Substation near Richland, Washington on March 1, 2010. Level 1 Accident Report of the March 1, 2010 Bobcat Fatality at BPA's White Bluffs Substation (679.74 KB) ...

  16. A methodology for analyzing precursors to earthquake-initiated and fire-initiated accident sequences

    SciTech Connect (OSTI)

    Budnitz, R.J.; Lambert, H.E.; Apostolakis, G. and others

    1998-04-01

    This report covers work to develop a methodology for analyzing precursors to both earthquake-initiated and fire-initiated accidents at commercial nuclear power plants. Currently, the U.S. Nuclear Regulatory Commission sponsors a large ongoing project, the Accident Sequence Precursor project, to analyze the safety significance of other types of accident precursors, such as those arising from internally-initiated transients and pipe breaks, but earthquakes and fires are not within the current scope. The results of this project are that: (1) an overall step-by-step methodology has been developed for precursors to both fire-initiated and seismic-initiated potential accidents; (2) some stylized case-study examples are provided to demonstrate how the fully-developed methodology works in practice, and (3) a generic seismic-fragility date base for equipment is provided for use in seismic-precursors analyses. 44 refs., 23 figs., 16 tabs.

  17. Feasibility of on-line fuel-condition monitoring. [PWR; BWR

    SciTech Connect (OSTI)

    Petti, D.A.; Osetek, D.J.; Croucher, D.W.; Hartwell, J.K.

    1982-01-01

    The relationship between fuel rod damage and fission product release is investigated to assess the feasibility of using on-line gamma spectroscopy of reactor coolant to estimate not only numbers of detected fuel rods, but also the type of core damage which may occur during an accident or off-normal transient. Fission product release signatures for various fuel conditions and accident scenarios are compared, and unique indicators of fuel damage, ranging from cladding pinholes to severely damaged fuel rods, are suggested, The configuration of monitoring hardware and data analysis soft ware are described, and the benefits, development needs, and usefulness of the envisaged power plant system are discussed.

  18. Accident Analysis for the NIST Research Reactor Before and After Fuel Conversion

    SciTech Connect (OSTI)

    Baek J.; Diamond D.; Cuadra, A.; Hanson, A.L.; Cheng, L-Y.; Brown, N.R.

    2012-09-30

    Postulated accidents have been analyzed for the 20 MW D2O-moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analysis has been carried out for the present core, which contains high enriched uranium (HEU) fuel and for a proposed equilibrium core with low enriched uranium (LEU) fuel. The analyses employ state-of-the-art calculational methods. Three-dimensional Monte Carlo neutron transport calculations were performed with the MCNPX code to determine homogenized fuel compositions in the lower and upper halves of each fuel element and to determine the resulting neutronic properties of the core. The accident analysis employed a model of the primary loop with the RELAP5 code. The model includes the primary pumps, shutdown pumps outlet valves, heat exchanger, fuel elements, and flow channels for both the six inner and twenty-four outer fuel elements. Evaluations were performed for the following accidents: (1) control rod withdrawal startup accident, (2) maximum reactivity insertion accident, (3) loss-of-flow accident resulting from loss of electrical power with an assumption of failure of shutdown cooling pumps, (4) loss-of-flow accident resulting from a primary pump seizure, and (5) loss-of-flow accident resulting from inadvertent throttling of a flow control valve. In addition, natural circulation cooling at low power operation was analyzed. The analysis shows that the conversion will not lead to significant changes in the safety analysis and the calculated minimum critical heat flux ratio and maximum clad temperature assure that there is adequate margin to fuel failure.

  19. Conceptual design station blackout and loss-of-flow accident analyses for the Advanced Neutron Source Reactor

    SciTech Connect (OSTI)

    Fletcher, C.D.; Ghan, L.S.; Determan, J.C.; Nielsen, H.H. )

    1994-04-01

    A system model of the Advanced Neutron Source Reactor (ANSR) has been developed and used to perform conceptual safety analyses. To better represent thermal-hydraulic behavior in the unique geometry and conditions of the ANSR core, three specific changes in the RELAP5/MOD3 computer code were implemented: a turbulent forced-convection heat transfer correlation, a critical heat flux correlation, and an interfacial drag correlation. The system model includes representations of the ANSR core, heat exchanger coolant loops, and the pressurizing and letdown systems. Analyses of ANSR station blackout and loss-of-flow accident scenarios are described. The results show that the core can survive without exceeding the flow excursion or critical heat flux thermal limits defined for the conceptual safety analysis, if the proper mitigation options are provided.

  20. Bibliography for nuclear criticality accident experience, alarm systems, and emergency management

    SciTech Connect (OSTI)

    Putman, V.L.

    1995-09-01

    The characteristics, detection, and emergency management of nuclear criticality accidents outside reactors has been an important component of criticality safety for as long as the need for this specialized safety discipline has been recognized. The general interest and importance of such topics receives special emphasis because of the potentially lethal, albeit highly localized, effects of criticality accidents and because of heightened public and regulatory concerns for any undesirable event in nuclear and radiological fields. This bibliography lists references which are potentially applicable to or interesting for criticality alarm, detection, and warning systems; criticality accident emergency management; and their associated programs. The lists are annotated to assist bibliography users in identifying applicable: industry and regulatory guidance and requirements, with historical development information and comments; criticality accident characteristics, consequences, experiences, and responses; hazard-, risk-, or safety-analysis criteria; CAS design and qualification criteria; CAS calibration, maintenance, repair, and testing criteria; experiences of CAS designers and maintainers; criticality accident emergency management (planning, preparedness, response, and recovery) requirements and guidance; criticality accident emergency management experience, plans, and techniques; methods and tools for analysis; and additional bibliographies.

  1. Thermal conditions and functional requirements for molten fuel containment

    SciTech Connect (OSTI)

    Kang, C.S.; Torri, A.

    1980-05-01

    This paper discusses the configuration and functional requirements for the molten fuel containment system (MFCS) in the GCFR demonstration plant design. Meltdown conditions following a loss of shutdown cooling (LOSC) accident were studied to define the core debris volume for a realistic meltdown case. Materials and thicknesses of the molten fuel container were defined. Stainless steel was chosen as the sacrificial material and magnesium oxide was chosen as the crucible material. Thermal conditions for an expected quasi-steady state were analyzed. Highlights of the functional requirements which directly affect the MFCS design are discussed.

  2. Critical processes and parameters in the development of accident tolerant fuels drop-in capsule irradiation tests

    DOE PAGES-Beta [OSTI]

    Barrett, K. E.; Ellis, K. D.; Glass, C. R.; Roth, G. A.; Teague, M. P.; Johns, J.

    2015-12-01

    The goal of the Accident Tolerant Fuel (ATF) program is to develop the next generation of Light Water Reactor (LWR) fuels with improved performance, reliability, and safety characteristics during normal operations and accident conditions and with reduced waste generation. An irradiation test series has been defined to assess the performance of proposed ATF concepts under normal LWR operating conditions. The Phase I ATF irradiation test series is planned to be performed as a series of drop-in capsule tests to be irradiated in the Advanced Test Reactor (ATR) operated by the Idaho National Laboratory (INL). Design, analysis, and fabrication processes formore » ATR drop-in capsule experiment preparation are presented in this paper to demonstrate the importance of special design considerations, parameter sensitivity analysis, and precise fabrication and inspection techniques for figure innovative materials used in ATF experiment assemblies. A Taylor Series Method sensitivity analysis approach was used to identify the most critical variables in cladding and rodlet stress, temperature, and pressure calculations for design analyses. The results showed that internal rodlet pressure calculations are most sensitive to the fission gas release rate uncertainty while temperature calculations are most sensitive to cladding I.D. and O.D. dimensional uncertainty. The analysis showed that stress calculations are most sensitive to rodlet internal pressure uncertainties, however the results also indicated that the inside radius, outside radius, and internal pressure were all magnified as they propagate through the stress equation. This study demonstrates the importance for ATF concept development teams to provide the fabricators as much information as possible about the material properties and behavior observed in prototype testing, mock-up fabrication and assembly, and chemical and mechanical testing of the materials that may have been performed in the concept development phase

  3. Analysis of Loss-of-Coolant Accidents in the NBSR

    SciTech Connect (OSTI)

    Baek J. S.; Cheng L.; Diamond, D.

    2014-05-23

    This report documents calculations of the fuel cladding temperature during loss-of-coolant accidents in the NBSR. The probability of a pipe failure is small and procedures exist to minimize the loss of water and assure emergency cooling water flows into the reactor core during such an event. Analysis in the past has shown that the emergency cooling water would provide adequate cooling if the water filled the flow channels within the fuel elements. The present analysis is to determine if there is adequate cooling if the water drains from the flow channels. Based on photographs of how the emergency water flows into the fuel elements from the distribution pan, it can be assumed that this water does not distribute uniformly across the flow channels but rather results in a liquid film flowing downward on the inside of one of the side plates in each fuel element and only wets the edges of the fuel plates. An analysis of guillotine breaks shows the cladding temperature remains below the blister temperature in fuel plates in the upper section of the fuel element. In the lower section, the fuel plates are also cooled by water outside the element that is present due to the hold-up pan and temperatures are lower than in the upper section. For small breaks, the simulation results show that the fuel elements are always cooled on the outside even in the upper section and the cladding temperature cannot be higher than the blister temperature. The above results are predicated on assumptions that are examined in the study to see their influence on fuel temperature.

  4. Environmental remediation following the Fukushima-Daiichi accident

    SciTech Connect (OSTI)

    Tagawa, A.; Miyahara, K.; Nakayama, S.

    2013-07-01

    A wide area of Fukushima Prefecture was contaminated with radioactivity released by the Fukushima Daiichi nuclear accident. The decontamination pilot projects conducted by JAEA aimed at demonstrating the applicability of different techniques to rehabilitate affected areas. As most radioactive cesium is concentrated at the top of the soil column and strongly bound to mineral surfaces, there are 3 options left to decrease the gamma dose rate (usually measured 1 m above the ground surface): the stripping of the contaminated topsoil (i.e. direct removal of cesium), the dilution by mixing and the soil profile inversion. The last two options do not generate waste. As the half-distance of {sup 137}Cs gammas in soil is in the order of 5-6 cm (depending on density and water content), the shielding by 50 cm of uncontaminated deep soil would theoretically reduce gamma doses by about 3 orders of magnitude. Which option is employed depends basically on the Cesium concentration in the topsoil, averaged over a 15-cm thickness. The JAEA's decontamination pilot projects focus on soil profile inversion and topsoil stripping. Two different techniques have been tested for the soil profile inversion: one is the reversal tillage by which surface soil of thickness of several tens of cm is reversed by using a tractor plough and the other is the complete interchanging of contaminated topsoil with uncontaminated subsoil by using a back-hoe. Reversal tillage with a tractor plough cost about 30 yen/m{sup 2}, which is an order of magnitude lower than that of topsoil-subsoil interchange (about 300 yen/m{sup 2}). Topsoil stripping is significantly more costly (between 550 yen/m{sup 2} and 690 yen/m{sup 2} according to the equipment used)

  5. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    SciTech Connect (OSTI)

    Bergman, W.; First, M.W.; Anderson, W.L.; Gilbert, H.; Jacox, J.W.

    1995-02-01

    The authors have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data.

  6. Better Buildings Network View | January 2015

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  7. Better Buildings Network View | November 2015

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  8. Better Buildings Network View | October 2014

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  9. Better Buildings Network View | April 2015

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  10. Better Buildings Network View | March 2015

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  11. Better Buildings Network View | February 2015

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  12. Better Buildings Network View | December 2014

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  13. The Better Buildings Neighborhood View-- July 2012

    Energy.gov [DOE]

    The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program.

  14. Better Buildings Network View | June 2014

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  15. Better Buildings Network View | May 2015

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  16. Better Buildings Network View | June 2015

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  17. Better Buildings Network View | October 2015

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  18. Better Buildings Network View | January 2016

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  19. Better Buildings Network View | February 2016

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  20. Better Buildings Network View | January 2014

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  1. Better Buildings Network View | May 2014

    Energy.gov [DOE]

    The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network.

  2. The Better Buildings Neighborhood View-- May 2012

    Energy.gov [DOE]

    The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program

  3. Type B Accident Investigation of the Subcontractor Employee Injuries from a November 15, 2000, Fall Accident at the Oak Ridge National Laboratory

    Energy.gov [DOE]

    On November 15, 2000, an accident occurred at the U. S. Department of Energy (DOE) Oak Ridge National Laboratory located in Oak Ridge, Tennessee. An employee of Decon and Recovery Services of Oak Ridge, LLC (DRS), working on an Oak Ridge Operations Office (ORO) Environmental Management decommissioning and demolition project received serious injuries from a fall (approximately 13 feet) from a fixed ladder.

  4. Type A Accident Investigation Board Report on the July 1, 2008, of the Vehicle Fatality Accident-Western Area Power Marketing Administration

    Office of Energy Efficiency and Renewable Energy (EERE)

    This report is an independent product of the Type A Accident Investigation Board (Board) appointed by Anthony H. Montoya, Chief Operating Officer, Office of the Chief Operating Officer, Western Area Power Administration.

  5. View Shed - Version 1.0

    Energy Science and Technology Software Center (OSTI)

    2014-09-18

    The View Shed library is a collection of Umbra modules that are used to calculate areas of visual coverage (view sheds). It maps high and low visibility areas and calculates sensor (camera placement for maximum coverage and performance. This assertion includes a managed C++ wrapper code (ViewShedWrapper) to enable C# applications, such as OpShed, to incorporate this library.

  6. December 2015 Most Viewed Documents for Environmental Sciences | OSTI, US

    Office of Scientific and Technical Information (OSTI)

    Dept of Energy Office of Scientific and Technical Information December 2015 Most Viewed Documents for Environmental Sciences Separation of heavy metals: Removal from industrial wastewaters and contaminated soil Peters, R.W.; Shem, L. (1993) 452 Building a secondary containment system Broder, M.F. (1994) 171 Statistical methods for environmental pollution monitoring Gilbert, R.O. (1987) 116 Ammonia usage in vapor compression for refrigeration and air-conditioning in the United States

  7. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Supporting MELCOR calculations, Volume 6, Part 2

    SciTech Connect (OSTI)

    Kmetyk, L.N.; Brown, T.D.

    1995-03-01

    To gain a better understanding of the risk significance of low power and shutdown modes of operation, the Office of Nuclear Regulatory Research at the NRC established programs to investigate the likelihood and severity of postulated accidents that could occur during low power and shutdown (LP&S) modes of operation at commercial nuclear power plants. To investigate the likelihood of severe core damage accidents during off power conditions, probabilistic risk assessments (PRAs) were performed for two nuclear plants: Unit 1 of the Grand Gulf Nuclear Station, which is a BWR-6 Mark III boiling water reactor (BWR), and Unit 1 of the Surry Power Station, which is a three-loop, subatmospheric, pressurized water reactor (PWR). The analysis of the BWR was conducted at Sandia National Laboratories while the analysis of the PWR was performed at Brookhaven National Laboratory. This multi-volume report presents and discusses the results of the BWR analysis. The subject of this part presents the deterministic code calculations, performed with the MELCOR code, that were used to support the development and quantification of the PRA models. The background for the work documented in this report is summarized, including how deterministic codes are used in PRAS, why the MELCOR code is used, what the capabilities and features of MELCOR are, and how the code has been used by others in the past. Brief descriptions of the Grand Gulf plant and its configuration during LP&S operation and of the MELCOR input model developed for the Grand Gulf plant in its LP&S configuration are given.

  8. SILENE Benchmark Critical Experiments for Criticality Accident Alarm Systems

    SciTech Connect (OSTI)

    Miller, Thomas Martin; Reynolds, Kevin H.

    2011-01-01

    In October 2010 a series of benchmark experiments was conducted at the Commissariat a Energie Atomique et aux Energies Alternatives (CEA) Valduc SILENE [1] facility. These experiments were a joint effort between the US Department of Energy (DOE) and the French CEA. The purpose of these experiments was to create three benchmarks for the verification and validation of radiation transport codes and evaluated nuclear data used in the analysis of criticality accident alarm systems (CAASs). This presentation will discuss the geometric configuration of these experiments and the quantities that were measured and will present some preliminary comparisons between the measured data and calculations. This series consisted of three single-pulsed experiments with the SILENE reactor. During the first experiment the reactor was bare (unshielded), but during the second and third experiments it was shielded by lead and polyethylene, respectively. During each experiment several neutron activation foils and thermoluminescent dosimeters (TLDs) were placed around the reactor, and some of these detectors were themselves shielded from the reactor by high-density magnetite and barite concrete, standard concrete, and/or BoroBond. All the concrete was provided by CEA Saclay, and the BoroBond was provided by Y-12 National Security Complex. Figure 1 is a picture of the SILENE reactor cell configured for pulse 1. Also included in these experiments were measurements of the neutron and photon spectra with two BICRON BC-501A liquid scintillators. These two detectors were provided and operated by CEA Valduc. They were set up just outside the SILENE reactor cell with additional lead shielding to prevent the detectors from being saturated. The final detectors involved in the experiments were two different types of CAAS detectors. The Babcock International Group provided three CIDAS CAAS detectors, which measured photon dose and dose rate with a Geiger-Mueller tube. CIDAS detectors are currently in

  9. Interface requirements to couple thermal-hydraulic codes to severe accident codes: ATHLET-CD

    SciTech Connect (OSTI)

    Trambauer, K.

    1997-07-01

    The system code ATHLET-CD is being developed by GRS in cooperation with IKE and IPSN. Its field of application comprises the whole spectrum of leaks and large breaks, as well as operational and abnormal transients for LWRs and VVERs. At present the analyses cover the in-vessel thermal-hydraulics, the early phases of core degradation, as well as fission products and aerosol release from the core and their transport in the Reactor Coolant System. The aim of the code development is to extend the simulation of core degradation up to failure of the reactor pressure vessel and to cover all physically reasonable accident sequences for western and eastern LWRs including RMBKs. The ATHLET-CD structure is highly modular in order to include a manifold spectrum of models and to offer an optimum basis for further development. The code consists of four general modules to describe the reactor coolant system thermal-hydraulics, the core degradation, the fission product core release, and fission product and aerosol transport. Each general module consists of some basic modules which correspond to the process to be simulated or to its specific purpose. Besides the code structure based on the physical modelling, the code follows four strictly separated steps during the course of a calculation: (1) input of structure, geometrical data, initial and boundary condition, (2) initialization of derived quantities, (3) steady state calculation or input of restart data, and (4) transient calculation. In this paper, the transient solution method is briefly presented and the coupling methods are discussed. Three aspects have to be considered for the coupling of different modules in one code system. First is the conservation of masses and energy in the different subsystems as there are fluid, structures, and fission products and aerosols. Second is the convergence of the numerical solution and stability of the calculation. The third aspect is related to the code performance, and running time.

  10. A Computer Code To Analyze The Gas-Phase Transport of Fission Products In Reactor Cooling System Under Severe Accidents.

    Energy Science and Technology Software Center (OSTI)

    1990-12-06

    Version 00 HORN calculates the transport of volatile fission products in a dry primary cooling circuit under severe accidents of water reactors.

  11. Accident Investigation of the October 1, 2013, Tice Electric Company Employee Fatality near Patrick's Knob Radio Station, Bonneville Power Administration

    Energy.gov [DOE]

    The purpose of the investigation was to determine the cause of the accident and to develop recommendations for corrective actions to prevent recurrence

  12. Type B Accident Investigation Board Report on the May 24, 1998, Electrical Arc Blast at the Kansas City Plant

    Office of Energy Efficiency and Renewable Energy (EERE)

    This report is a product of an accident investigation board appointed by Bruce G. Twining, Manager, Albuquerque Operations Office, Department of Energy.

  13. Heat up and potential failure of BWR upper internals during a severe accident

    SciTech Connect (OSTI)

    Robb, Kevin R

    2015-01-01

    In boiling water reactors, the steam dome, steam separators, and dryers above the core are comprised of approximately 100 tons of stainless steel. During a severe accident in which the coolant boils away and exothermic oxidation of zirconium occurs, gases (steam and hydrogen) are superheated in the core region and pass through the upper internals. Historically, the upper internals have been modeled using severe accident codes with relatively simple approximations. The upper internals are typically modeled in MELCOR as two lumped volumes with simplified heat transfer characteristics, with no structural integrity considerations, and with limited ability to oxidize, melt, and relocate. The potential for and the subsequent impact of the upper internals to heat up, oxidize, fail, and relocate during a severe accident was investigated. A higher fidelity representation of the shroud dome, steam separators, and steam driers was developed in MELCOR v1.8.6 by extending the core region upwards. This modeling effort entailed adding 45 additional core cells and control volumes, 98 flow paths, and numerous control functions. The model accounts for the mechanical loading and structural integrity, oxidation, melting, flow area blockage, and relocation of the various components. The results indicate that the upper internals can reach high temperatures during a severe accident; they are predicted to reach a high enough temperature such that they lose their structural integrity and relocate. The additional 100 tons of stainless steel debris influences the subsequent in-vessel and ex-vessel accident progression.

  14. Final Report - SPRU Type B Accident Investigation Report

    Office of Environmental Management (EM)

    ... Since the results were below the RWP Limiting Condition of 0.3 derived air concentration ... utility isolations in building G2 panel 1-2, in order to achieve a "cold and dark" ...

  15. MODELING OF 2LIBH4 PLUS MGH2 HYDROGEN STORAGE SYSTEM ACCIDENT SCENARIOS USING EMPIRICAL AND THEORETICAL THERMODYNAMICS

    SciTech Connect (OSTI)

    James, C; David Tamburello, D; Joshua Gray, J; Kyle Brinkman, K; Bruce Hardy, B; Donald Anton, D

    2009-04-01

    It is important to understand and quantify the potential risk resulting from accidental environmental exposure of condensed phase hydrogen storage materials under differing environmental exposure scenarios. This paper describes a modeling and experimental study with the aim of predicting consequences of the accidental release of 2LiBH{sub 4}+MgH{sub 2} from hydrogen storage systems. The methodology and results developed in this work are directly applicable to any solid hydride material and/or accident scenario using appropriate boundary conditions and empirical data. The ability to predict hydride behavior for hypothesized accident scenarios facilitates an assessment of the of risk associated with the utilization of a particular hydride. To this end, an idealized finite volume model was developed to represent the behavior of dispersed hydride from a breached system. Semiempirical thermodynamic calculations and substantiating calorimetric experiments were performed in order to quantify the energy released, energy release rates and to quantify the reaction products resulting from water and air exposure of a lithium borohydride and magnesium hydride combination. The hydrides, LiBH{sub 4} and MgH{sub 2}, were studied individually in the as-received form and in the 2:1 'destabilized' mixture. Liquid water hydrolysis reactions were performed in a Calvet calorimeter equipped with a mixing cell using neutral water. Water vapor and oxygen gas phase reactivity measurements were performed at varying relative humidities and temperatures by modifying the calorimeter and utilizing a gas circulating flow cell apparatus. The results of these calorimetric measurements were compared with standardized United Nations (UN) based test results for air and water reactivity and used to develop quantitative kinetic expressions for hydrolysis and air oxidation in these systems. Thermodynamic parameters obtained from these tests were then inputted into a computational fluid dynamics model to

  16. Prairie View Gas Recovery Biomass Facility | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    View Gas Recovery Biomass Facility Jump to: navigation, search Name Prairie View Gas Recovery Biomass Facility Facility Prairie View Gas Recovery Sector Biomass Facility Type...

  17. The Better Buildings Neighborhood View - September 2012 | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    BB Neighborhood View -- September 2012 (140.07 KB) More Documents & Publications The Better Buildings Neighborhood View -- Fall 2011 The Better Buildings Neighborhood View -- July ...

  18. RELAP5 Application to Accident Analysis of the NIST Research Reactor

    SciTech Connect (OSTI)

    Baek, J.; Cuadra Gascon, A.; Cheng, L.Y.; Diamond, D.

    2012-03-18

    Detailed safety analyses have been performed for the 20 MW D{sub 2}O moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The time-dependent analysis of the primary system is determined with a RELAP5 transient analysis model that includes the reactor vessel, the pump, heat exchanger, fuel element geometry, and flow channels for both the six inner and twenty-four outer fuel elements. A post-processing of the simulation results has been conducted to evaluate minimum critical heat flux ratio (CHFR) using the Sudo-Kaminaga correlation. Evaluations are performed for the following accidents: (1) the control rod withdrawal startup accident and (2) the maximum reactivity insertion accident. In both cases the RELAP5 results indicate that there is adequate margin to CHF and no damage to the fuel will occur because of sufficient coolant flow through the fuel channels and the negative scram reactivity insertion.

  19. Accident Generated Particulate Materials and Their Characteristics -- A Review of Background Information

    SciTech Connect (OSTI)

    Sutter, S. L.

    1982-05-01

    Safety assessments and environmental impact statements for nuclear fuel cycle facilities require an estimate of the amount of radioactive particulate material initially airborne (source term) during accidents. Pacific Northwest Laboratory (PNL) has surveyed the literature, gathering information on the amount and size of these particles that has been developed from limited experimental work, measurements made from operational accidents, and known aerosol behavior. Information useful for calculating both liquid and powder source terms is compiled in this report. Potential aerosol generating events discussed are spills, resuspension, aerodynamic entrainment, explosions and pressurized releases, comminution, and airborne chemical reactions. A discussion of liquid behavior in sprays, sparging, evaporation, and condensation as applied to accident situations is also included.

  20. Most Viewed Documents - Fission and Nuclear Technologies | OSTI, US Dept of

    Office of Scientific and Technical Information (OSTI)

    Energy Office of Scientific and Technical Information - Fission and Nuclear Technologies Metals design handbook Betts, W.S. (1988) Estimation of gas leak rates through very small orifices and channels. [From sealed PuO/sub 2/ containers under accident conditions] Bomelburg, H.J. () Graphite design handbook Ho, F.H. (1988) Motor-operated valve (MOV) actuator motor and gearbox testing DeWall, K.; Watkins, J.C.; Bramwell, D. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)]

  1. Severe accident modeling of a PWR core with different cladding materials

    SciTech Connect (OSTI)

    Johnson, S. C.; Henry, R. E.; Paik, C. Y.

    2012-07-01

    The MAAP v.4 software has been used to model two severe accident scenarios in nuclear power reactors with three different materials as fuel cladding. The TMI-2 severe accident was modeled with Zircaloy-2 and SiC as clad material and a SBO accident in a Zion-like, 4-loop, Westinghouse PWR was modeled with Zircaloy-2, SiC, and 304 stainless steel as clad material. TMI-2 modeling results indicate that lower peak core temperatures, less H 2 (g) produced, and a smaller mass of molten material would result if SiC was substituted for Zircaloy-2 as cladding. SBO modeling results indicate that the calculated time to RCS rupture would increase by approximately 20 minutes if SiC was substituted for Zircaloy-2. Additionally, when an extended SBO accident (RCS creep rupture failure disabled) was modeled, significantly lower peak core temperatures, less H 2 (g) produced, and a smaller mass of molten material would be generated by substituting SiC for Zircaloy-2 or stainless steel cladding. Because the rate of SiC oxidation reaction with elevated temperature H{sub 2}O (g) was set to 0 for this work, these results should be considered preliminary. However, the benefits of SiC as a more accident tolerant clad material have been shown and additional investigation of SiC as an LWR core material are warranted, specifically investigations of the oxidation kinetics of SiC in H{sub 2}O (g) over the range of temperatures and pressures relevant to severe accidents in LWR 's. (authors)

  2. Sodium fast reactor gaps analysis of computer codes and models for accident analysis and reactor safety.

    SciTech Connect (OSTI)

    Carbajo, Juan; Jeong, Hae-Yong; Wigeland, Roald; Corradini, Michael; Schmidt, Rodney Cannon; Thomas, Justin; Wei, Tom; Sofu, Tanju; Ludewig, Hans; Tobita, Yoshiharu; Ohshima, Hiroyuki; Serre, Frederic

    2011-06-01

    This report summarizes the results of an expert-opinion elicitation activity designed to qualitatively assess the status and capabilities of currently available computer codes and models for accident analysis and reactor safety calculations of advanced sodium fast reactors, and identify important gaps. The twelve-member panel consisted of representatives from five U.S. National Laboratories (SNL, ANL, INL, ORNL, and BNL), the University of Wisconsin, the KAERI, the JAEA, and the CEA. The major portion of this elicitation activity occurred during a two-day meeting held on Aug. 10-11, 2010 at Argonne National Laboratory. There were two primary objectives of this work: (1) Identify computer codes currently available for SFR accident analysis and reactor safety calculations; and (2) Assess the status and capability of current US computer codes to adequately model the required accident scenarios and associated phenomena, and identify important gaps. During the review, panel members identified over 60 computer codes that are currently available in the international community to perform different aspects of SFR safety analysis for various event scenarios and accident categories. A brief description of each of these codes together with references (when available) is provided. An adaptation of the Predictive Capability Maturity Model (PCMM) for computational modeling and simulation is described for use in this work. The panel's assessment of the available US codes is presented in the form of nine tables, organized into groups of three for each of three risk categories considered: anticipated operational occurrences (AOOs), design basis accidents (DBA), and beyond design basis accidents (BDBA). A set of summary conclusions are drawn from the results obtained. At the highest level, the panel judged that current US code capabilities are adequate for licensing given reasonable margins, but expressed concern that US code development activities had stagnated and that the

  3. Development of LWR Fuels with Enhanced Accident Tolerance

    SciTech Connect (OSTI)

    Lahoda, Edward J.; Boylan, Frank A.

    2015-10-30

    Significant progress was made on the technical, licensing, and business aspects of the Westinghouse Electric Company’s Enhanced Accident Tolerant Fuel (ATF) by the Westinghouse ATF team. The fuel pellet options included waterproofed U15N and U3Si2 and the cladding options SiC composites and zirconium alloys with surface treatments. Technology was developed that resulted in U3Si2 pellets with densities of >94% being achieved at the Idaho National Laboratory (INL). The use of U3Si2 will represent a 15% increase in U235 loadings over those in UO₂ fuel pellets. This technology was then applied to manufacture pellets for 6 test rodlets which were inserted in the Advanced Test Reactor (ATR) in early 2015 in zirconium alloy cladding. The first of these rodlets are expected to be removed in about 2017. Key characteristics to be determined include verification of the centerline temperature calculations, thermal conductivity, fission gas release, swelling and degree of amorphization. Waterproofed UN pellets have achieved >94% density for a 32% U3Si2/68% UN composite pellet at Texas A&M University. This represents a U235 increase of about 31% over current UO2 pellets. Pellets and powders of UO2, UN, and U3Si2the were tested by Westinghouse and Los Alamos National Laboratory (LANL) using differential scanning calorimetry to determine what their steam and 20% oxygen corrosion temperatures were as compared to UO2. Cold spray application of either the amorphous steel or the Ti2AlC was successful in forming an adherent ~20 micron coating that remained after testing at 420°C in a steam autoclave. Tests at 1200°C in 100% steam on coatings for Zr alloy have not been successful, possibly due to the low density of the coatings which allowed steam transport to the base zirconium metal. Significant modeling and testing

  4. Passive decay heat removal by natural air convection after severe accidents

    SciTech Connect (OSTI)

    Erbacher, F.J.; Neitzel, H.J.; Cheng, X.

    1995-09-01

    The composite containment proposed by the Research Center Karlsruhe and the Technical University Karlsruhe is to cope with severe accidents. It pursues the goal to restrict the consequences of core meltdown accidents to the reactor plant. One essential of this new containment concept is its potential to remove the decay heat by natural air convection and thermal radiation in a passive way. To investigate the coolability of such a passive cooling system and the physical phenomena involved, experimental investigations are carried out at the PASCO test facility. Additionally, numerical calculations are performed by using different codes. A satisfying agreement between experimental data and numerical results is obtained.

  5. No Recordable Accidents in 17,000 Waste Shipments Across 3.4 Million Miles

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    | Department of Energy No Recordable Accidents in 17,000 Waste Shipments Across 3.4 Million Miles No Recordable Accidents in 17,000 Waste Shipments Across 3.4 Million Miles August 15, 2016 - 12:05pm Addthis Uranium mill tailings from EM’s Moab Uranium Mill Tailings Remedial Action Project are transported to an engineered disposal cell near Crescent Junction, Utah. Uranium mill tailings from EM's Moab Uranium Mill Tailings Remedial Action Project are transported to an engineered disposal

  6. Modular high-temperature gas-cooled reactor core heatup accident simulations

    SciTech Connect (OSTI)

    Ball, S.J.; Conklin, J.C.

    1989-01-01

    The design features of the modular high-temperature gas-cooled reactor (HTGR) have the potential to make it essentially invulnerable to damage from postulated core heatup accidents. Simulations of long-term loss-of-forced-convection (LOFC) accidents, both with and without depressurization of the primary coolant and with only passive cooling available to remove afterheat, have shown that maximum core temperatures stay below the point at which fuel failures and fission product releases are expected. Sensitivity studies also have been done to determine the effects of errors in the predictions due both to uncertainties in the modeling and to the assumptions about operational parameters. 4 refs., 5 figs.

  7. Technical Advisory Team (TAT) report on the rocket sled test accident of October 9, 2008.

    SciTech Connect (OSTI)

    Stofleth, Jerome H.; Dinallo, Michael Anthony; Medina, Anthony J.

    2009-01-01

    This report summarizes probable causes and contributing factors that led to a rocket motor initiating prematurely while employees were preparing instrumentation for an AIII rocket sled test at SNL/NM, resulting in a Type-B Accident. Originally prepared by the Technical Advisory Team that provided technical assistance to the NNSA's Accident Investigation Board, the report includes analyses of several proposed causes and concludes that the most probable source of power for premature initiation of the rocket motor was the independent battery contained in the HiCap recorder package. The report includes data, evidence, and proposed scenarios to substantiate the analyses.

  8. Fatal accidents involving roof falls in coal mining, 1996--1998

    SciTech Connect (OSTI)

    Not Available

    1999-01-01

    This publication presents information on fatalities involving roof and rib falls that occurred in coal mining operations from January 1996 through December 1998. It includes statistics for the fatalities, as well as abstracts, best practices and illustrations. Conclusion statements have been substituted for best practices where no Title 30 Code of Regulations violations were cited during the accident investigation. From January 1996 through December 1998, 36 miners died at coal operations from accidents classified as roof falls. The information in the report is based on statistics taken from the 1996 through 1998 MSHA Fatal Illustration Programs: Roof Fall Fatalities by District.

  9. Fatal accidents involving roof falls in coal mining, 1996--1998

    SciTech Connect (OSTI)

    1999-11-01

    This publication presents information on fatalities involving roof and rib falls that occurred in coal mining operations from January 1996 through December 1998. It includes statistics for the fatalities, as well as abstracts, best practices and illustrations. Conclusion statements have been substituted for best practices where no Title 30 Code of Regulations violations were cited during the accident investigation. From January 1996 through December 1998, 36 miners died at coal operations from accidents classified as roof falls. The information in the report is based on statistics taken from the 1996 through 1998 MSHA Fatal Illustration Programs: Roof Fall Fatalities by District.

  10. Y-12 Construction hits one million-hour mark without a lost-time accident |

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Y-12 National Security Complex Construction hits one ... Y-12 Construction hits one million-hour mark without a lost-time accident Posted: August 30, 2012 - 5:30pm The B&W Y-12 Direct-Hire Construction team has worked one million hours, covering a 633-day period, without a lost-time injury. Some 285 people including building trade crafts, non-manual staff and escorts worked without a lost-time accident during this period. The Construction team's last lost workday was in September 2010. A

  11. High Performance Builder Spotlight: Clifton View Homes

    SciTech Connect (OSTI)

    2011-01-01

    Clifton View Homes’s remodel of a 1962 rambler, on Whidbey Island in Washington State, cut energy costs by two-thirds.

  12. Better Buildings Network View | April 2016 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    6 Better Buildings Network View | April 2016 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View April 2016 (154.45 KB) More Documents & Publications Better Buildings Network View | May 2016 Better Buildings Network View | June 2016 Better Buildings Network View | October 2016

  13. Better Buildings Network View | February 2014 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    4 Better Buildings Network View | February 2014 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View February 2014 (173.15 KB) More Documents & Publications Better Buildings Network View | January 2014 Better Buildings Network View | May 2015 Better Buildings Network View | June 2015

  14. Better Buildings Network View | June 2016 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    6 Better Buildings Network View | June 2016 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View June 2016 (235.96 KB) More Documents & Publications Better Buildings Network View | July-August 2016 Better Buildings Network View | September 2016 Better Buildings Network View | November

  15. Better Buildings Network View | March 2014 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    4 Better Buildings Network View | March 2014 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View March 2014 (129.73 KB) More Documents & Publications Better Buildings Network View | May 2015 Better Buildings Network View | June 2015 Better Buildings Network View | April 2014

  16. Better Buildings Network View | March 2016 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    6 Better Buildings Network View | March 2016 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View March 2016 (211.92 KB) More Documents & Publications Better Buildings Network View | April 2016 Better Buildings Network View | May 2016 Better Buildings Network View | January 2016

  17. Better Buildings Network View | May 2016 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    6 Better Buildings Network View | May 2016 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View May 2016 (196.19 KB) More Documents & Publications Better Buildings Network View | April 2016 Better Buildings Network View | June 2016 Better Buildings Network View | September 2016

  18. Better Buildings Network View | October 2016 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    6 Better Buildings Network View | October 2016 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View October 2016 (176.3 KB) More Documents & Publications Better Buildings Network View | April 2016 Better Buildings Network View | June 2016 Better Buildings Network View | September 2016

  19. Better Buildings Network View | September 2016 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    6 Better Buildings Network View | September 2016 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View September 2016 (121.63 KB) More Documents & Publications Better Buildings Network View | June 2016 Better Buildings Network View | July-August 2016 Better Buildings Network View | October 2016

  20. The Better Buildings Neighborhood View -- April 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    2 The Better Buildings Neighborhood View -- April 2012 The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program. BB Neighborhood View -- April 2012 (136.63 KB) More Documents & Publications The Better Buildings Neighborhood View -- March 2012 The Better Buildings Neighborhood View - September 2012 The Better Buildings Neighborhood View -- July 2012

  1. The Better Buildings Neighborhood View -- April 2013 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    3 The Better Buildings Neighborhood View -- April 2013 The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program - April 2013. BB Neighborhood View -- April 2013 (152.71 KB) More Documents & Publications The Better Buildings Neighborhood View -- July 2013 The Better Buildings Neighborhood View -- January 2013 The Better Buildings Neighborhood View -- December 2013

  2. The Better Buildings Neighborhood View -- Fall 2011 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Fall 2011 The Better Buildings Neighborhood View -- Fall 2011 Better Buildings Neighborhood View, from the Better Buildings Neighborhood Program of the U.S. Department of Energy. BB Neighborhood View -- Fall 2011 (204.44 KB) More Documents & Publications The Better Buildings Neighborhood View -- July 2013 The Better Buildings Neighborhood View - October 2012 The Better Buildings Neighborhood View -- December 2013

  3. The Better Buildings Neighborhood View -- January 2012 | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy 2 The Better Buildings Neighborhood View -- January 2012 The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program. BB Neighborhood View -- January 2012 (214.32 KB) More Documents & Publications The Better Buildings Neighborhood View -- March 2012 The Better Buildings Neighborhood View -- February 2012 The BetterBuildings View

  4. The Better Buildings Neighborhood View -- July 2013 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    3 The Better Buildings Neighborhood View -- July 2013 The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program - July 2013. BB Neighborhood View -- July 2013 (187 KB) More Documents & Publications The Better Buildings Neighborhood View -- Fall 2011 The Better Buildings Neighborhood View - October 2012 The Better Buildings Neighborhood View -- December 2013

  5. The Better Buildings Neighborhood View -- June 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    June 2012 The Better Buildings Neighborhood View -- June 2012 The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program. BB Neighborhood View -- June 2012 (150.31 KB) More Documents & Publications The Better Buildings Neighborhood View -- August 2012 The Better Buildings Neighborhood View - October 2012 The Better Buildings Neighborhood View -- April 2012

  6. Potential health risks from postulated accidents involving the Pu-238 RTG (radioisotope thermoelectric generator) on the Ulysses solar exploration mission

    SciTech Connect (OSTI)

    Goldman, M. ); Nelson, R.C. ); Bollinger, L. ); Hoover, M.D. . Inhalation Toxicology Research Inst.); Templeton, W. ); Anspaugh, L. (Lawren

    1990-11-02

    Potential radiation impacts from launch of the Ulysses solar exploration experiment were evaluated using eight postulated accident scenarios. Lifetime individual dose estimates rarely exceeded 1 mrem. Most of the potential health effects would come from inhalation exposures immediately after an accident, rather than from ingestion of contaminated food or water, or from inhalation of resuspended plutonium from contaminated ground. For local Florida accidents (that is, during the first minute after launch), an average source term accident was estimated to cause a total added cancer risk of up to 0.2 deaths. For accidents at later times after launch, a worldwide cancer risk of up to three cases was calculated (with a four in a million probability). Upper bound estimates were calculated to be about 10 times higher. 83 refs.

  7. Potential health risks from postulated accidents involving the Pu-238 RTG on the Ulysses solar exploration mission

    SciTech Connect (OSTI)

    Goldman, M. ); Nelson, R.C. ); Bollinger, L. ); Hoover, M.D. ); Templeton, W. ); Anspaugh, L. )

    1991-01-01

    Potential radiation impacts from launch of the Ulysses solar exploration experiment were evaluated using eight postulated accident scenarios. Lifetime individual dose estimates rarely exceeded 1 mrem. Most of the potential health effects would come from inhalation exposures immediately after an accident, rather than from ingestion of contaminated food or water, or from inhalation of resuspended plutonium from contaminated ground. For local Florida accidents (that is, during the first minute after launch), an average source term accident was estimated to cause a total added cancer risk of up to 0.2 deaths. For accidents at later times after launch, a worldwide cancer risk of up to three cases was calculated (with a four in a million probability). Upper bound estimates were calculated to be about 10 times higher.

  8. Calculation notes that support accident scenario and consequence development for the leak from a railcar/tank trailer at the 204-ar waste unloading facility

    SciTech Connect (OSTI)

    Ryan, G.W., Westinghouse Hanford

    1996-09-19

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Leak from Railcar/Tank Trailer. The calculations needed to quantify the risk associated with this accident scenario are included within.

  9. Portsmouth Site Plant Surpasses Five Years Without Lost-Time Accident

    Energy.gov [DOE]

    PIKETON, Ohio – The depleted uranium hexafluoride (DUF6) conversion plant at EM’s Portsmouth site marked five years without a lost-time accident this month, equating to 1,826 workdays or 1,916,103 work hours.

  10. SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

    SciTech Connect (OSTI)

    2013-09-25

    U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in a remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.

  11. Calculation notes in support of TWRS FSAR spray leak accident analysis

    SciTech Connect (OSTI)

    Hall, B.W., Westinghouse Hanford

    1996-08-05

    This document includes the calculations needed to quantify the risk associated with unmitigated and mitigated pressurized spray releases from tank farm transfer equipment inside transfer enclosures. The calculations within this document support the spray leak accident analysis reported in the TWRS FSAR.

  12. Advanced Fuels Campaign Light Water Reactor Accident Tolerant Fuel Performance Metrics Executive Summary

    SciTech Connect (OSTI)

    Shannon Bragg-Sitton

    2014-02-01

    Research and development (R&D) activities on advanced, higher performance Light Water Reactor (LWR) fuels have been ongoing for the last few years. Following the unfortunate March 2011 events at the Fukushima Nuclear Power Plant in Japan, the R&D shifted toward enhancing the accident tolerance of LWRs. Qualitative attributes for fuels with enhanced accident tolerance, such as improved reaction kinetics with steam resulting in slower hydrogen generation rate, provide guidance for the design and development of fuels and cladding with enhanced accident tolerance. A common set of technical metrics should be established to aid in the optimization and down selection of candidate designs on a more quantitative basis. “Metrics” describe a set of technical bases by which multiple concepts can be fairly evaluated against a common baseline and against one another. This report describes a proposed technical evaluation methodology that can be applied to evaluate the ability of each concept to meet performance and safety goals relative to the current UO2 – zirconium alloy system and relative to one another. The resultant ranked evaluation can then inform concept down-selection, such that the most promising accident tolerant fuel design option(s) can continue to be developed toward qualification.

  13. Type A Accident Report of the June 26, 2009 Vehicle Fatality at Lawrence Livermore National Laboratory

    Energy.gov [DOE]

    This report is an independent product of the Type A Accident Investigation Board appointed by Thomas P. D’Agostino, Administrator, National Nuclear Security Administration, U.S. Department of Energy and Glenn S. Podonsky, Chief Health, Safety and Security Officer, Office of Health, Safety and Security.

  14. SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

    ScienceCinema (OSTI)

    None

    2016-07-12

    U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in a remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.

  15. Radioactive material release from a containment vessel during a fire accident

    SciTech Connect (OSTI)

    Hensel, S.; Norkus, J.

    2015-02-26

    A methodology is presented to determine the source term for leaks and ruptures of pressurized vessels. The generic methodology is applied to a 9975 Primary Containment Vessel (PCV) which losses containment due to a hypothesized fire accident. The release due to a vessel rupture is approximately two orders of magnitude greater than the release due to a leak.

  16. Arrival condition of spent fuel after storage, handling, and transportation

    SciTech Connect (OSTI)

    Bailey, W.J.; Pankaskie, P.J.; Langstaff, D.C.; Gilbert, E.R.; Rising, K.H.; Schreiber, R.E.

    1982-11-01

    This report presents the results of a study conducted to determine the probable arrival condition of spent light-water reactor (LWR) fuel after handling and interim storage in spent fuel storage pools and subsequent handling and accident-free transport operations under normal or slightly abnormal conditions. The objective of this study was to provide information on the expected condition of spent LWR fuel upon arrival at interim storage or fuel reprocessing facilities or at disposal facilities if the fuel is declared a waste. Results of a literature survey and data evaluation effort are discussed. Preliminary threshold limits for storing, handling, and transporting unconsolidated spent LWR fuel are presented. The difficulty in trying to anticipate the amount of corrosion products (crud) that may be on spent fuel in future shipments is also discussed, and potential areas for future work are listed. 95 references, 3 figures, 17 tables.

  17. Uncertainty and sensitivity analysis of food pathway results with the MACCS Reactor Accident Consequence Model

    SciTech Connect (OSTI)

    Helton, J.C.; Johnson, J.D.; Rollstin, J.A.; Shiver, A.W.; Sprung, J.L.

    1995-01-01

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the food pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 87 imprecisely-known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, milk growing season dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, area dependent cost, crop disposal cost, milk disposal cost, condemnation area, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: fraction of cesium deposition on grain fields that is retained on plant surfaces and transferred directly to grain, maximum allowable ground concentrations of Cs-137 and Sr-90 for production of crops, ground concentrations of Cs-134, Cs-137 and I-131 at which the disposal of milk will be initiated due to accidents that occur during the growing season, ground concentrations of Cs-134, I-131 and Sr-90 at which the disposal of crops will be initiated due to accidents that occur during the growing season, rate of depletion of Cs-137 and Sr-90 from the root zone, transfer of Sr-90 from soil to legumes, transfer of Cs-137 from soil to pasture, transfer of cesium from animal feed to meat, and the transfer of cesium, iodine and strontium from animal feed to milk.

  18. Implementation of numerical simulation techniques in analysis of the accidents in complex technological systems

    SciTech Connect (OSTI)

    Klishin, G.S.; Seleznev, V.E.; Aleoshin, V.V.

    1997-12-31

    Gas industry enterprises such as main pipelines, compressor gas transfer stations, gas extracting complexes belong to the energy intensive industry. Accidents there can result into the catastrophes and great social, environmental and economic losses. Annually, according to the official data several dozens of large accidents take place at the pipes in the USA and Russia. That is why prevention of the accidents, analysis of the mechanisms of their development and prediction of their possible consequences are acute and important tasks nowadays. The accidents reasons are usually of a complicated character and can be presented as a complex combination of natural, technical and human factors. Mathematical and computer simulations are safe, rather effective and comparatively inexpensive methods of the accident analysis. It makes it possible to analyze different mechanisms of a failure occurrence and development, to assess its consequences and give recommendations to prevent it. Besides investigation of the failure cases, numerical simulation techniques play an important role in the treatment of the diagnostics results of the objects and in further construction of mathematical prognostic simulations of the object behavior in the period of time between two inspections. While solving diagnostics tasks and in the analysis of the failure cases, the techniques of theoretical mechanics, of qualitative theory of different equations, of mechanics of a continuous medium, of chemical macro-kinetics and optimizing techniques are implemented in the Conversion Design Bureau {number_sign}5 (DB{number_sign}5). Both universal and special numerical techniques and software (SW) are being developed in DB{number_sign}5 for solution of such tasks. Almost all of them are calibrated on the calculations of the simulated and full-scale experiments performed at the VNIIEF and MINATOM testing sites. It is worth noting that in the long years of work there has been established a fruitful and effective

  19. Accident Investigation of the July 30, 2013, Electrical Fatality on the Bandon-Rogue No. 1 115kV Line at the Bonneville Power Administration

    Energy.gov [DOE]

    This report is an independent product of the Level I Accident Investigation Board appointed by Brad Bea, Chief Safety Officer, Bonneville Power Administration. The Board was appointed to perform a Level I Accident Investigation and to prepare an investigation report in accordance with Bonneville Power Administration Manual, Chapter 181, Accident Investigation and Reporting.

  20. Accident Investigation of the September 20, 2012 Fatal Fall from the Dworshak-Taft #1 Transmission Tower, at the Bonneville Power Marketing Administration

    Office of Energy Efficiency and Renewable Energy (EERE)

    This report is an independent product of the Level l Accident Investigation Board appointed by Brad Bea, Chief Safety Officer, Bonneville Power Administration. The Board was appointed to perform a Levell Accident Investigation and to prepare an investigation report in accordance with Bonneville Power Administration Manual, Chapter 181, Accident Investigation and Reporting

  1. Type B Accident Investigation Board Report, May 8, 2004, Exothermic Metal Reactor Event During Sodium Transfer Activities, East Tennessee Technology Park, Oak Ridge, Tennessee

    Office of Energy Efficiency and Renewable Energy (EERE)

    This report is an independent product of the Type B Accident Investigation Board (Board) appointed by Gerald Boyd, Manager, Oak Ridge Operations Office, U.S. Department of Energy. The Board was appointed to perform a Type B investigation of the accident and prepare an investigation report in accordance with DOE O 225.1A, Accident Investigations.

  2. Methods for Detector Placement and Analysis of Criticality Accident Alarm Systems

    SciTech Connect (OSTI)

    Peplow, Douglas E.; Wetzel, Larry

    2012-01-01

    Determining the optimum placement to minimize the number of detectors for a criticality accident alarm system (CAAS) in a large manufacturing facility is a complex problem. There is typically a target for the number of detectors that can be used over a given zone of the facility. A study to optimize detector placement typically begins with some initial guess at the placement of the detectors and is followed by either predictive calculations of accidents at specific locations or adjoint calculations based on preferred detector locations. Within an area of a facility, there may be a large number of potential criticality accident sites. For any given placement of the detectors, the list of accident sites can be reduced to a smaller number of locations at which accidents may be difficult for detectors to detect. Developing the initial detector placement and determining the list of difficult accident locations are both based on the practitioner's experience. Simulations following fission particles released from an accident location are called 'forward calculations.' These calculations can be used to answer the question 'where would an alarm be triggered?' by an accident at a specified location. Conversely, 'adjoint calculations' start at a detector site using the detector response function as a source and essentially run in reverse. These calculations can be used to answer the question 'where would an accident be detected?' by a specified detector location. If the number of accidents, P, is much less than the number of detectors, Q, then forward simulations may be more convenient and less time-consuming. If Q is large or the detectors are not placed yet, then a mesh tally of dose observed by a detector at any location must be computed over the entire zone. If Q is much less than P, then adjoint calculations may be more efficient. Adjoint calculations employing a mesh tally can be even more advantageous because they do not rely on a list of specific difficult

  3. The Better Buildings Neighborhood View - October 2012 | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy The Better Buildings Neighborhood View - October 2012 The Better Buildings Neighborhood View - October 2012 The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program - October 2012 bb_view_october2012.pdf (136.66 KB) More Documents & Publications The Better Buildings Neighborhood View -- July 2013 The Better Buildings Neighborhood View -- Fall 2011 The Better Buildings Neighborhood View -- December 2013

  4. The BetterBuildings View | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    The BetterBuildings View The BetterBuildings View The BetterBuildings View Newsletter, April 2011, from the U.S. Department of Energy's Better Buildings Neighborhood Program. The BetterBuildings View April 2011 (160.55 KB) More Documents & Publications The Better Buildings Neighborhood View - October 2012 The Better Buildings Neighborhood View -- Fall 2011 The Better Buildings Neighborhood View -- April 2013

  5. Accident source terms for light-water nuclear power plants using high-burnup or MOX fuel.

    SciTech Connect (OSTI)

    Salay, Michael; Gauntt, Randall O.; Lee, Richard Y.; Powers, Dana Auburn; Leonard, Mark Thomas

    2011-01-01

    Representative accident source terms patterned after the NUREG-1465 Source Term have been developed for high burnup fuel in BWRs and PWRs and for MOX fuel in a PWR with an ice-condenser containment. These source terms have been derived using nonparametric order statistics to develop distributions for the timing of radionuclide release during four accident phases and for release fractions of nine chemical classes of radionuclides as calculated with the MELCOR 1.8.5 accident analysis computer code. The accident phases are those defined in the NUREG-1465 Source Term - gap release, in-vessel release, ex-vessel release, and late in-vessel release. Important differences among the accident source terms derived here and the NUREG-1465 Source Term are not attributable to either fuel burnup or use of MOX fuel. Rather, differences among the source terms are due predominantly to improved understanding of the physics of core meltdown accidents. Heat losses from the degrading reactor core prolong the process of in-vessel release of radionuclides. Improved understanding of the chemistries of tellurium and cesium under reactor accidents changes the predicted behavior characteristics of these radioactive elements relative to what was assumed in the derivation of the NUREG-1465 Source Term. An additional radionuclide chemical class has been defined to account for release of cesium as cesium molybdate which enhances molybdenum release relative to other metallic fission products.

  6. Characterization of thermal-hydraulic and ignition phenomena in prototypic, full-length boiling water reactor spent fuel pool assemblies after a complete loss-of-coolant accident.

    SciTech Connect (OSTI)

    Lindgren, Eric Richard; Durbin, Samuel G

    2007-04-01

    The objective of this project was to provide basic thermal-hydraulic data associated with a SFP complete loss-of-coolant accident. The accident conditions of interest for the SFP were simulated in a full-scale prototypic fashion (electrically-heated, prototypic assemblies in a prototypic SFP rack) so that the experimental results closely represent actual fuel assembly responses. A major impetus for this work was to facilitate code validation (primarily MELCOR) and reduce questions associated with interpretation of the experimental results. It was necessary to simulate a cluster of assemblies to represent a higher decay (younger) assembly surrounded by older, lower power assemblies. Specifically, this program provided data and analysis confirming: (1) MELCOR modeling of inter-assembly radiant heat transfer, (2) flow resistance modeling and the natural convective flow induced in a fuel assembly as it heats up in air, (3) the potential for and nature of thermal transient (i.e., Zircaloy fire) propagation, and (4) mitigation strategies concerning fuel assembly management.

  7. Comparative Study of Loss-of-Coolant Accident Using MAAP4.03 and RELAP5/MOD3.2.2

    SciTech Connect (OSTI)

    Chang Hwan Park; Doo Yong Lee; Ik Jeong; Un Chul Lee; Suh, Kune Y.; Goon Cherl Park

    2002-07-01

    Analysis was performed for a large-break loss-of-coolant accident (LOCA) in the APR1400 (Advanced Power Reactor 1400 MWe) with the thermal-hydraulic analysis code RELAP5/ MOD3.2.2 and the severe accident analysis code MAAP4.03. The two codes predicted different sequences for essentially the same initiating condition. As for the break flow and the emergency core cooling (ECC) flow rates, MAAP4.03 predicted considerably higher values in the initial stage than RELAP5/ MOD3.2.2. It was considered that the differing break flow and ECC flow rates would cause the LOCA sequences to deviate from one another between the two codes. Hence, the break flow model in MAAP4.03 was modified with partly implementing the two-phase homogeneous critical flow model and adopting a correction term. The ECC flow model in MAAP4.03 was also varied by changing the hardwired friction factor through the sensitivity study. The modified break flow and ECC flow models yielded more consistent calculational results between RELAP5/MOD3.2.2 and MAAP4.03. It was, however, found that the resultant effect is rather limited unless more mechanistic treatments are done for the primary system in MAAP4.03. (authors)

  8. Ground control failures. A pictorial view of case studies

    SciTech Connect (OSTI)

    Peng, S.S.

    2007-07-01

    The book shows, in pictorial views, many forms and/or stages of types of failures in mines, for instance, cutter, roof falls, and cribs. In each case, the year of occurrence is stated in the beginning so that the environment or technological background under which it occurred are reflected. The narrative than begins with the mining and geological conditions, followed by a description of the ground control problems and recommended solutions and results, if any. The sections cover failure of pillars, roof falls, longwall, roof bolting, multiple-seam mining, floor heave, longwall, flooding and weathering of coal, old workings, and shortwall and thin-seam plow longwall.

  9. Evaluation of selected ex-reactor accidents related to the tritium and medical isotope production mission at the FFTF

    SciTech Connect (OSTI)

    Himes, D.A.

    1997-11-17

    The Fast Flux Test Facility (FFTF) has been proposed as a production facility for tritium and medical isotopes. A range of postulated accidents related to ex-reactor irradiated fuel and target handling were identified and evaluated using new source terms for the higher fuel enrichment and for the tritium and medical isotope targets. In addition, two in-containment sodium spill accidents were re-evaluated to estimate effects of increased fuel enrichment and the presence of the Rapid Retrieval System. Radiological and toxicological consequences of the analyzed accidents were found to be well within applicable risk guidelines.

  10. Source terms released into the environment for a station blackout severe accident at the Peach Bottom Atomic Power Station

    SciTech Connect (OSTI)

    Carbajo, J.J.

    1995-07-01

    This study calculates source terms released into the environment at the Peach Bottom Atomic Power Station after containment failure during a postulated low-pressure, short-term station blackout severe accident. The severe accident analysis code MELCOR, version 1.8.1, was used in these calculations. Source terms were calculated for three different containment failure modes. The largest environmental releases occur for early containment failure at the drywell liner in contact with the cavity by liner melt-through. This containment failure mode is very likely to occur when the cavity is dry during this postulated severe accident sequence.

  11. Psychophysiological and other factors affecting human performance in accident prevention and investigation. [Comparison of aviation with other industries

    SciTech Connect (OSTI)

    Klinestiver, L.R.

    1980-01-01

    Psychophysiological factors are not uncommon terms in the aviation incident/accident investigation sequence where human error is involved. It is highly suspect that the same psychophysiological factors may also exist in the industrial arena where operator personnel function; but, there is little evidence in literature indicating how management and subordinates cope with these factors to prevent or reduce accidents. It is apparent that human factors psychophysological training is quite evident in the aviation industry. However, while the industrial arena appears to analyze psychophysiological factors in accident investigations, there is little evidence that established training programs exist for supervisors and operator personnel.

  12. Light-Weight Radioisotope Heater Unit final safety analysis report (LWRHU-FSAR): Volume 2: Accident Model Document (AMD)

    SciTech Connect (OSTI)

    Johnson, E.W.

    1988-10-01

    The purpose of this volume of the LWRHU SAR, the Accident Model Document (AMD), are to: Identify all malfunctions, both singular and multiple, which can occur during the complete mission profile that could lead to release outside the clad of the radioisotopic material contained therein; Provide estimates of occurrence probabilities associated with these various accidents; Evaluate the response of the LWRHU (or its components) to the resultant accident environments; and Associate the potential event history with test data or analysis to determine the potential interaction of the released radionuclides with the biosphere.

  13. Risk assessment for the Waste Technologies Industries (WTI) hazardous waste incinerator facility (east Liverpool, Ohio). Volume 7. Accident analysis: Selection and assessment of potential release scenarios. Draft report

    SciTech Connect (OSTI)

    1995-11-01

    This report constitutes a comprehensive site-specific risk assessment for the WTI incineration facility located in East Liverpool, OH. The Accident Analysis is an evaluation of the likelihood of occurrence and resulting consequences from several general classes of accidents that could potentially occur during operation of the facility. The Accident Analysis also evaluates the effectiveness of existing mitigation measures in reducing off-site impacts. Volume VII describes in detail the methods used to conduct the Accident Analysis and reports the results of evaluations of likelihood and consequence for the selected accident scenarios.

  14. TotalView Parallel Debugger at NERSC

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    The performance of the GUI can be greatly improved if used in conjunction with free NX software. The TotalView documentation web page is a good resource for learning more...

  15. JOBAID-VIEWING AN EMPLOYEE MATRIX (SUPERVISOR)

    Energy.gov [DOE]

    The purpose of this job aid is to guide supervisor users through the step-by-step process of viewing an employee matrix within SuccessFactors Learning.

  16. A common-view disciplined oscillator

    SciTech Connect (OSTI)

    Lombardi, Michael A.; Dahlen, Aaron P.

    2010-05-15

    This paper describes a common-view disciplined oscillator (CVDO) that locks to a reference time scale through the use of common-view global positioning system (GPS) satellite measurements. The CVDO employs a proportional-integral-derivative controller that obtains near real-time common-view GPS measurements from the internet and provides steering corrections to a local oscillator. A CVDO can be locked to any time scale that makes real-time common-view data available and can serve as a high-accuracy, self-calibrating frequency and time standard. Measurement results are presented where a CVDO is locked to UTC(NIST), the coordinated universal time scale maintained at the National Institute of Standards and Technology in Boulder, Colorado.

  17. Comparison of experimental and analytical temperatures achieved by DT-18 and PC-1 shipping containers during hypothetical thermal accident tests

    SciTech Connect (OSTI)

    Anderson, J.C.

    1992-03-01

    Temperatures were monitored at various locations on DT-18 and PC-1 shipping packages during furnace tests at the Y-12 Plant in Oak Ridge, Tennessee. The furnace tests are intended to simulate hypothetical thermal accident conditions specified in Title 10 CFR, Pt. 71.73 (c)(3). Maximum temperatures of the outer containers ranged from 750 to 965{degrees}C while typical maximum temperatures recorded on the inner containers were 60 to 77{degrees}C. One exceptionally high temperature of 196{degrees}C occurred on the PC-1 inner container. Heating 7.1 models of both the DT-18 and PC-1 packages were developed. Models with and without heat generation in the inner containers were developed for each shipping package. The models with heat generation are intended to simulate condensation and convection of hot vapors generated during the heating of the Celotex{trademark} insulating material used in the packages. In general, the analytical models calculate temperatures for the outer containers which agree well with the test data. The HEATING models with and without heat generation bound the inner container test data. These findings are significant in that they lead to the conclusion that heat is transferred to the inner containers through a mechanism other than conduction alone. The high temperature of 196{degrees}C recorded at the PC-1 inner container is within 4{degrees}C of the maximum temperature calculated by the PC-1 HEATING model with heat generation.

  18. Better Buildings Network View | April 2014 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    4 Better Buildings Network View | April 2014 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View April 2014 (130.28 KB) More Documents & Publications Better Buildings Network View | December 2014 Better Buildings Residential Network Orientation Webinar Better Buildings Network View | May

  19. Better Buildings Network View | November 2014 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    4 Better Buildings Network View | November 2014 The Better Buildings Network View monthly newsletter from the U.S. Department of Energy's Better Buildings Residential Network. Better Buildings Network View November 2014 (162.63 KB) More Documents & Publications Better Buildings Network View | July-August 2014 Better Buildings Residential Network Orientation Webinar Better Buildings Network View | December 2014

  20. The Better Buildings Neighborhood View - September 2012 | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy September 2012 The Better Buildings Neighborhood View - September 2012 Monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program. BB Neighborhood View -- September 2012 (140.07 KB) More Documents & Publications The Better Buildings Neighborhood View -- Fall 2011 The Better Buildings Neighborhood View -- July 2013 The Better Buildings Neighborhood View -- April

  1. The Better Buildings Neighborhood View - Summer 2011 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Summer 2011 The Better Buildings Neighborhood View - Summer 2011 The quarterly update newsletter of the Better Buildings program of the U.S. Department of Energy. BB Neighborhood View -- Summer 2011 (138.07 KB) More Documents & Publications The Better Buildings Neighborhood View -- January 2012 The Better Buildings Neighborhood View -- March 2012 The Better Buildings Neighborhood View -- May

  2. The Better Buildings Neighborhood View -- March 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    March 2012 The Better Buildings Neighborhood View -- March 2012 The Better Buildings Neighborhood View monthly newsletter from the U.S. Department of Energy's Better Buildings Neighborhood Program BB Neighborhood View -- March 2012 (292.36 KB) More Documents & Publications The Better Buildings Neighborhood View -- February 2012 The Better Buildings Neighborhood View -- January 2012 Commercial Buildings Integration Program Overview - 2015 BTO Peer Review

  3. Type A Accident Investigation Board Report on the January 17, 1996, Electrical Accident With Injury in Building 209, Technical Area 21, Tritium Science and Fabrication Facility, Los Alamos National Laboratory

    Office of Energy Efficiency and Renewable Energy (EERE)

    This report is an independent product of the Type A Accident Investigation Board appointed by Tara O’Toole, M.D., M.P.H., Assistant Secretary for Environment, Safety and Health (EH-1).

  4. Preliminary analysis of graphite dust releasing behavior in accident for HTR

    SciTech Connect (OSTI)

    Peng, W.; Yang, X. Y.; Yu, S. Y.; Wang, J.

    2012-07-01

    The behavior of the graphite dust is important to the safety of High Temperature Gas-cooled Reactors. This study investigated the flow of graphite dust in helium mainstream. The analysis of the stresses acting on the graphite dust indicated that gas drag played the absolute leading role. Based on the understanding of the importance of gas drag, an experimental system is set up for the research of dust releasing behavior in accident. Air driven by centrifugal fan is used as the working fluid instead of helium because helium is expensive, easy to leak which make it difficult to seal. The graphite particles, with the size distribution same as in HTR, are added to the experiment loop. The graphite dust releasing behavior at the loss-of-coolant accident will be investigated by a sonic nozzle. (authors)

  5. A preliminary assessment of beryllium dust oxidation during a wet bypass accident in a fusion reactor

    SciTech Connect (OSTI)

    Brad J. Merrill; Richard L. Moore; J. Phillip Sharp

    2008-09-01

    A beryllium dust oxidation model has been developed at the Idaho National Laboratory (INL) by the Fusion Safety Program (FSP) for the MELCOR safety computer code. The purpose of this model is to investigate hydrogen production from beryllium dust layers on hot surfaces inside a fusion reactor vacuum vessel (VV) during in-vessel loss-of-cooling accidents (LOCAs). This beryllium dust oxidation model accounts for the diffusion of steam into a beryllium dust layer, the oxidation of the dust particles inside this layer based on the beryllium-steam oxidation equations developed at the INL, and the effective thermal conductivity of this beryllium dust layer. This paper details this oxidation model and presents the results of the application of this model to a wet bypass accident scenario in the ITER device.

  6. Bounding Radionuclide Inventory and Accident Consequence Calculation for the 1L Target

    SciTech Connect (OSTI)

    Kelsey, Charles T. IV

    2011-01-01

    A bounding radionuclide inventory for the tungsten of the Los Alamos Neutron Science Center (LANSCE) IL Target is calculated. Based on the bounding inventory, the dose resulting from the maximum credible incident (MCI) is calculated for the maximally exposed offsite individual (MEOl). The design basis accident involves tungsten target oxidation following a loss of cooling accident. Also calculated for the bounding radionuclide inventory is the ratio to the LANSCE inventory threshold for purposes of inventory control as described in the target inventory control policy. A bounding radionuclide inventory calculation for the lL Target was completed using the MCNPX and CINDER'90 codes. Continuous beam delivery at 200 {micro}A to 2500 mA{center_dot}h was assumed. The total calculated activity following this irradiation period is 205,000 Ci. The dose to the MEOI from the MCI is 213 mrem for the bounding inventory. The LANSCE inventory control threshold ratio is 132.

  7. Aerosol Sample Inhomogeneity with Debris from the Fukushima Daiichi Nuclear Accident

    SciTech Connect (OSTI)

    Gomez, Reynaido; Biegalski, Steven R.; Woods, Vincent T.

    2014-09-01

    Radionuclide aerosol sampling is a vital component in the detection of nuclear explosions, nuclear accidents, and other radiation releases. This was proven by the detection and tracking of emissions from the Fukushima Daiichi incident across the globe by IMS stations. Two separate aerosol samplers were operated in Richland, WA following the event and debris from the accident were measured at levels well above detection limits. While the atmospheric activity concentration of radionuclides generally compared well between the two stations, they did not agree within uncertainties. This paper includes a detailed study of the aerosol sample homogeneity of 134Cs and 137Cs, then relates it to the overall uncertainty of the original measurement. Our results show that sample inhomogeneity adds an additional 5–10% uncertainty to each aerosol measurement and that this uncertainty is in the same range as the discrepancies between the two aerosol sample measurements from Richland, WA.

  8. Final report of the accident phenomenology and consequence (APAC) methodology evaluation. Spills Working Group

    SciTech Connect (OSTI)

    Brereton, S.; Shinn, J.; Hesse, D; Kaninich, D.; Lazaro, M.; Mubayi, V.

    1997-08-01

    The Spills Working Group was one of six working groups established under the Accident Phenomenology and Consequence (APAC) methodology evaluation program. The objectives of APAC were to assess methodologies available in the accident phenomenology and consequence analysis area and to evaluate their adequacy for use in preparing DOE facility safety basis documentation, such as Basis for Interim Operation (BIO), Justification for Continued Operation (JCO), Hazard Analysis Documents, and Safety Analysis Reports (SARs). Additional objectives of APAC were to identify development needs and to define standard practices to be followed in the analyses supporting facility safety basis documentation. The Spills Working Group focused on methodologies for estimating four types of spill source terms: liquid chemical spills and evaporation, pressurized liquid/gas releases, solid spills and resuspension/sublimation, and resuspension of particulate matter from liquid spills.

  9. Effects of the Chernobyl accident on animal husbandry and production, from a Swedish perspective

    SciTech Connect (OSTI)

    Jones, B.E.

    1989-04-01

    About 20% of the Swedish land area was considerably contaminated by radionuclides released by the nuclear accident at Chernobyl, Ukraine, in April 1986. However, less than 10% of the arable land was contaminated. The heavy contamination was closely correlated with the amount of rain received during the first days of May 1986. Immediate restrictions on grazing limited the early uptake of contaminants in animal products. Changes in management of animals, especially sheep, goats, and reindeer in the contaminated areas have effectively reduced the transfer of radionuclides to human beings. One important factor was the possibility of obtaining uncontaminated feeds from unaffected parts of the country. The direct costs during the first 2 years after the accident were approximately +10 million for analyses and +90 million for compensation to farmers for condemned products (milk, mutton, and reindeer meat) and reimbursement for purchase of uncontaminated feeds from other parts of the country.

  10. Accident Investigation at the Idaho National Laboratory Engineering Demonstration Facility, February 2013

    Energy.gov [DOE]

    On Monday, February 12, 2013, a principal investigator at the Idaho National Laboratory (INL) Engineering Demonstration Facility (IEDF) was testing the system configuration of experimental process involving liquid sodium carbonate. An unanticipated event occurred that resulted in the ejection of the 900° C liquid sodium carbonate from the system. The ejected liquid came into contact with the principal investigator and caused multiple second and third degree burn injuries to approximately 10 percent of his body. The Office of Health, Safety and Security (HSS) Site Lead for the Idaho Site shadowed the accident investigation team assembled by the contractor in an effort to independently verify that a rigorous, thorough, and unbiased investigation was taking place, and to maintain awareness of the events surrounding the accident

  11. Simulation of impact of the Generic Accident-Resistant Packaging (GAP)

    SciTech Connect (OSTI)

    Slavin, A.M.

    1994-10-01

    Finite element simulations modelling impact of the Generic Accident-Resistant Packaging (GAP) have been performed. The GAP is a nuclear weapon shipping container that will be used by accident response groups from both the United States and the United Kingdom. The package is a thin-walled steel structure filled with rigid polyurethane foam and weighs approximately 5100 lbs when loaded. The simulations examined 250 ft/s impacts onto a rigid target at several orientations. The development of the finite element model included studies of modelling assumptions and material parameters. Upon completion of the simulation series, three full-scale impact tests were performed. A comparison of the simulation results to the test data is given. Differences between the results and data are examined, and possible explanations for the differences are discussed.

  12. A methodology for generating dynamic accident progression event trees for level-2 PRA

    SciTech Connect (OSTI)

    Hakobyan, A.; Denning, R.; Aldemir, T. [Ohio State Univ., Nuclear Engineering Program, 650 Ackerman Road, Columbus, OH 43202 (United States); Dunagan, S.; Kunsman, D. [Sandia National Laboratory, Albuquerque, NM 87185 (United States)

    2006-07-01

    Currently, the development and analysis of Accident Progression Event Trees (APETs) are performed in a manner that is computationally time consuming, difficult to reproduce and also can be phenomenologically inconsistent. A software tool (ADAPT) is described for automated APET generation using the concept of dynamic event trees. The tool determines the branching times from a severe accident analysis code based on user specified criteria for branching. It assigns user specified probabilities to every branch, tracks the total branch probability, and truncates branches based on the given pruning/truncation rules to avoid an unmanageable number of scenarios. While the software tool could be applied to any systems analysis code, the MELCOR code is used for this illustration. A case study is presented involving station blackout with the loss of auxiliary feedwater system for a pressurized water reactor. (authors)

  13. Recent SCDAP/RELAP5 improvements for BWR severe accident simulations

    SciTech Connect (OSTI)

    Griffin, F.P.

    1995-12-31

    A new model for the SCDAP/RELAP5 severe accident analysis code that represents the control blade and channel box structures in a boiling water reactor (BWR) has been under development since 1991. This model accounts for oxidation, melting, and relocation of these structures, including the effects of material interactions between B{sub 4}C, stainless steel, and Zircaloy. This paper describes improvements that have been made to the BWR control blade/channel box model during 1994 and 1995. These improvements include new capabilities that represent the relocation of molten material in a more realistic manner and modifications that improve the usability of the code by reducing the frequency of code failures. This paper also describes a SCDAP/RELAP5 assessment calculation for the Browns Ferry Nuclear Plant design based upon a short-term station blackout accident sequence.

  14. Calculation notes in support of TWRS FSAR spray leak accident analysis

    SciTech Connect (OSTI)

    Hall, B.W.

    1996-09-25

    This document contains the detailed calculations that support the spray leak accident analysis in the Tank Waste Remediation System (TWRS) Final Safety Analysis Report (FSAR). The consequence analyses in this document form the basis for the selection of controls to mitigate or prevent spray leaks throughout TWRS. Pressurized spray leaks can occur due to a breach in containment barriers along transfer routes, during waste transfers. Spray leaks are of particular safety concern because, depending on leak dimensions, and waste pressure, they can be relatively efficient generators of dispersible sized aerosols that can transport downwind to onsite and offsite receptors. Waste is transferred between storage tanks and between processing facilities and storage tanks in TWRS through a system of buried transfer lines. Pumps for transferring waste and jumpers and valves for rerouting waste are located inside below grade pits and structures that are normally covered. Pressurized spray leaks can emanate to the atmosphere due to breaches in waste transfer associated equipment inside these structures should the structures be uncovered at the time of the leak. Pressurized spray leaks can develop through holes or cracks in transfer piping, valve bodies or pump casings caused by such mechanisms as corrosion, erosion, thermal stress, or water hammer. Leaks through degraded valve packing, jumper gaskets, or pump seals can also result in pressurized spray releases. Mechanisms that can degrade seals, packing and gaskets include aging, radiation hardening, thermal stress, etc. An1782other common cause for spray leaks inside transfer enclosures are misaligned jumpers caused by human error. A spray leak inside a DST valve pit during a transfer of aging waste was selected as the bounding, representative accident for detailed analysis. Sections 2 through 5 below develop this representative accident using the DOE- STD-3009 format. Sections 2 describes the unmitigated and mitigated accident

  15. Input-output model for MACCS nuclear accident impacts estimation¹

    SciTech Connect (OSTI)

    Outkin, Alexander V.; Bixler, Nathan E.; Vargas, Vanessa N

    2015-01-27

    Since the original economic model for MACCS was developed, better quality economic data (as well as the tools to gather and process it) and better computational capabilities have become available. The update of the economic impacts component of the MACCS legacy model will provide improved estimates of business disruptions through the use of Input-Output based economic impact estimation. This paper presents an updated MACCS model, bases on Input-Output methodology, in which economic impacts are calculated using the Regional Economic Accounting analysis tool (REAcct) created at Sandia National Laboratories. This new GDP-based model allows quick and consistent estimation of gross domestic product (GDP) losses due to nuclear power plant accidents. This paper outlines the steps taken to combine the REAcct Input-Output-based model with the MACCS code, describes the GDP loss calculation, and discusses the parameters and modeling assumptions necessary for the estimation of long-term effects of nuclear power plant accidents.

  16. (Environmental impact of radionuclide release during the Kyshtym, Windscale, and Chernobyl accidents)

    SciTech Connect (OSTI)

    Trabalka, J.R.

    1990-10-22

    The traveler attended the conference, Comparative Assessment of the Environmental Impact of Radionuclides Released During Three Major Nuclear Accidents: Kyshtym, Windscale, and Chernobyl and presented an invited paper giving a western perspective of the Kyshtym (Chelyabinsk-40) high-level waste explosion that took place in 1957. Papers of interest to several ORNL and DOE programs were presented. These covered the topics of accident source terms, atmospheric dispersion, resuspension, chemical and physical forms of contamination (e.g., hot'' particles), environmental contamination and transfer, radiological effects on humans and the environment, and countermeasures. The traveler also made valuable contacts with Soviet and other scientists related to an ongoing assessment sponsored by the International Union of Radioecologists of releases from the Chelyabinsk-40 site. This included an agreement in principle for direct participation by key Soviet scientists.

  17. Licensing topical report: application of probabilistic risk assessment in the selection of design basis accidents. [HTGR

    SciTech Connect (OSTI)

    Houghton, W.J.

    1980-06-01

    A probabilistic risk assessment (PRA) approach is proposed to be used to scrutinize selection of accident sequences. A technique is described in this Licensing Topical Report to identify candidates for Design Basis Accidents (DBAs) utilizing the risk assessment results. As a part of this technique, it is proposed that events with frequencies below a specified limit would not be candidates. The use of the methodology described is supplementary to the traditional, deterministic approach and may result, in some cases, in the selection of multiple failure sequences as DBAs; it may also provide a basis for not considering some traditionally postulated events as being DBAs. A process is then described for selecting a list of DBAs based on the candidates from PRA as supplementary to knowledge and judgments from past licensing practice. These DBAs would be the events considered in Chapter 15 of Safety Analysis Reports of high-temperature gas-cooled reactors (HTGRs).

  18. Introduction to the Special Issue on the U.S. Response to the Fukushima Accident

    SciTech Connect (OSTI)

    Blumenthal, Daniel J.

    2012-05-01

    Provides an introduction to the May 2012 issue of Health Physics, based on a special session at the 2011 Health Physics Society (HPS) annual meeting that focused on the United States' radiological response to the Fukushima Daiichi Nuclear Power Plant accident. This introduction outlines the papers in this important issue and describes the activities of the U.S. response participants, including the U.S. Department of Energy National Nuclear Security Administration (DOE/NNSA), Department of Defense, the U.S. Nuclear Regulatory Commission (NRC) and other organizations. Observations are provided and the stage is set for the articles in this issue which document many of the activities undertaken during the Fukushima accident and which describe challenges faced and valuable lessons learned.

  19. Analysis of potential for jet-impingement erosion from leaking steam generator tubes during severe accidents.

    SciTech Connect (OSTI)

    Majumdar, S.; Diercks, D. R.; Shack, W. J.; Energy Technology

    2002-05-01

    This report summarizes analytical evaluation of crack-opening areas and leak rates of superheated steam through flaws in steam generator tubes and erosion of neighboring tubes due to jet impingement of superheated steam with entrained particles from core debris created during severe accidents. An analytical model for calculating crack-opening area as a function of time and temperature was validated with tests on tubes with machined flaws. A three-dimensional computational fluid dynamics code was used to calculate the jet velocity impinging on neighboring tubes as a function of tube spacing and crack-opening area. Erosion tests were conducted in a high-temperature, high-velocity erosion rig at the University of Cincinnati, using micrometer-sized nickel particles mixed in with high-temperature gas from a burner. The erosion results, together with analytical models, were used to estimate the erosive effects of superheated steam with entrained aerosols from the core during severe accidents.

  20. Uncertainty and sensitivity analysis of chronic exposure results with the MACCS reactor accident consequence model

    SciTech Connect (OSTI)

    Helton, J.C.; Johnson, J.D.; Rollstin, J.A.; Shiver, A.W.; Sprung, J.L.

    1995-01-01

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the chronic exposure pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 75 imprecisely known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, water ingestion dose, milk growing season dose, long-term groundshine dose, long-term inhalation dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, total latent cancer fatalities, area-dependent cost, crop disposal cost, milk disposal cost, population-dependent cost, total economic cost, condemnation area, condemnation population, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: dry deposition velocity, transfer of cesium from animal feed to milk, transfer of cesium from animal feed to meat, ground concentration of Cs-134 at which the disposal of milk products will be initiated, transfer of Sr-90 from soil to legumes, maximum allowable ground concentration of Sr-90 for production of crops, fraction of cesium entering surface water that is consumed in drinking water, groundshine shielding factor, scale factor defining resuspension, dose reduction associated with decontamination, and ground concentration of 1-131 at which disposal of crops will be initiated due to accidents that occur during the growing season.