National Library of Energy BETA

Sample records for fission track evidence

  1. Recent rapid uplift in the Bolivian Andes: evidence from fission-track dating

    SciTech Connect (OSTI)

    Benjamin, M.T.; Johnson, N.M.; Naeser, C.W.

    1987-07-01

    Apatite and zircon fission-track cooling ages constrain the Tertiary cooling and uplift history of the eastern Cordillera and Altiplano of Bolivia. Fission-track data are from two Triassic plutons and surrounding Paleozoic metasedimentary rocks in the eastern Andes north of La Paz. Zircon cooling ages indicate that the roof of the Huayna Potosi pluton was emplaced in the zircon partial annealing zone and that the Zongo pluton was emplaced entirely in the zircon total annealing zone. Apatite cooling ages for both plutons record uplift in the past 5-15 m.y., and zircon cooling ages from the Zongo pluton reflect uplift in the past 25-45 m.y. Uplift rates calculated by these apatite and zircon cooling ages suggest that uplift rates were 0.1-0.2 mm/yr between 20 and 40 Ma and increased significantly between 10 and 15 Ma. By 3 Ma, uplift rates may have been as high as 0.7 mm/yr.

  2. Zircon and apatite fission-track evidence for an Early Permian thermal peak and relatively rapid Late Permian cooling in the Appalachian Basin

    SciTech Connect (OSTI)

    Roden, M.K. . Dept. of Earth and Environmental Science); Wintsch, R.P. . Dept. of Geological Sciences)

    1992-01-01

    New zircon fission-track ages compliment published apatite fission-track ages in the Appalachian Basin to narrowly constrain its thermal history. Geologic evidence can only constrain timing of the thermal peak to be younger than late Pennsylvanian sediments ([approximately] 300 Ma) and older than Mesozoic sediments in the Newark and Gettysburg Basins ([approximately] 210 Ma). Apatite fission-track ages as old as 246 Ma require the Alleghanian thermal peak to have been pre-Triassic. Preliminary data on reset zircon fission-track ages from middle Paleozoic sediments range from 255 to 290 Ma. Zircon fission-track apparent ages from samples younger and structurally higher than these are not reset. Thus, the oldest reset zircon fission-track age constraints the time of the Alleghanian thermal peak to be earliest Permian. Rates of post-Alleghanian cooling have not been well-constrained by geologic data and could be very slow. The difference between apatite and zircon fission-track ages for most of the samples range from 100--120 m.y. reflecting Permo-Triassic cooling of only 1 C/m.y. However, one sample with one of the oldest apatite ages, 245 Ma, yields one of the younger zircon ages of 255 Ma. This requires cooling rates of 10 C/m.y. and uplift rates of [approximately] 0.5 mm/yr. Collectively, these data support an early Permian thermal peak and a two-stage cooling history, consisting of > 100 C cooling (> 8 km denundation) in the Permian followed by relatively slow cooling and exhumation throughout the Mesozoic.

  3. Apatite fission track evidence for post-Early Cretaceous erosional unroofing of Middle Pennsylvanian sandstones from the southern Appalachian Basin in Kentucky and Virginia

    SciTech Connect (OSTI)

    Boettcher, S.S.; Milliken, K.L. . Dept. of Geological Sciences)

    1992-01-01

    Apatite fission track ages and mean etchable track lengths for 7 samples of Middle Pennsylvanian (Breathitt Formation) depositional age from the southern Appalachian Basin of KY and VA suggest that 3--4 km of erosional unroofing has occurred since the Early Cretaceous. The samples were collected over a 1,600 km[sup 2] area at the northern end of the Pine Mountain Overthrust southeast of Pikeville, KY. This new data set overlaps 8 published apatite fission track ages and 3 mean etchable lengths from the Cumberland Plateau and Valley and Ridge areas of WV. Because all of the apatite fission track ages are significantly younger than the depositional age, maximum burial temperatures in the area exceeded 125 C, such that fission tracks that formed in the detrital apatite prior to deposition have been totally annealed. Furthermore, mean etchable track lengths show considerable length reduction from initial values revealing that the samples resided in the zone of partial annealing on the order of 100 Ma following attainment of maximum temperatures. The burial history for these samples began with deposition and rapid burial of synorogenic sediments in front of the westward advancing Alleghenian deformation front. The fission track data are compatible with the hypothesis that maximum temperatures were attained during the Late Paleozoic as tectonically driven synorogenic fluids penetrated the foreland basin deposits. Slow erosional unroofing (< 15 m/Ma for a thermal gradient of 30 C/km) has occurred since the onset of Triassic-Jurassic rifting along the atlantic continental margin and continued into the Cenozoic.

  4. Fission track analysis, rift shoulder uplift, and tectonic modeling of the Norwegian Continental Margin

    SciTech Connect (OSTI)

    Andriessen, P.; Van Der Beek, P.; Cloetingh, S.; Rohrman, M. )

    1993-09-01

    Apatite fission track analysis from southern Norway and Sweden, across the Permian Carboniferous Oslo rift, are presented and discussed in relation to different rifting scenarios. Vertical and horizontal apatite fission tack profiles in middle and southern Norway unravel the post-Carboniferous history of the Fennoscandian shield. Fission track apatite ages range from 240 Ma in the south to 160 Ma in the north, and according to spontaneous fission track length measurements, they must be interpreted as mixed ages, indicating minor amounts of Paleozoic-Mesozoic sedimentary cover. Apatite fission track length and age modeling suggest rapid cooling and uplift in the Tertiary for the southernmost part of Norway, suggesting a differential uplift of the basement. the obtained data are important for the reconstruction of burial and thermal histories of Cenozoic sedimentary basins of the Norwegian continental margin in the northern North Sea, where diverse rifting events, intraplate stress regimes, and inversion tectonics are involved. Fission track analysis puts constraints on tectonic modeling of uplift of rift flanks and the Norwegian continental margin and yields information for these assessment of hydrocarbon potentials of the sedimentary basins.

  5. Dating thermal events at Cerro Prieto using fission-track annealing

    SciTech Connect (OSTI)

    Sanford, S.J.; Elders, W.A.

    1981-01-01

    The duration of heating in the Cerro Prieto reservoir was estimated by relating the fading of spontaneous fission tracks in detrital apatite to observed temperatures. The rate of fading is a function of both time and temperature. The apparent fission track age of the detrital apatites then, is a function of both their source age and their time-temperature history. Data from laboratory experiments and geologic fading studies were compiled from published sources to produce lines of iso-annealing for apatite in time-temperature space. Fission track ages were calculated for samples from two wells at Cerro Prieto, one with an apparently simple and one with an apparently complex thermal history. Temperatures were estimated by empirical vitrinite reflectance geothermometry, fluid inclusion homogenization and oxygen isotope equilibrium. These estimates were compared with logs of measured borehole temperatures. The temperature in well T-366, where complete annealing first occurs, was estimated to be between 160 and 180{sup 0}C. Complete annealing at these temperatures requires 10{sup 4} and 10{sup 3} years, respectively. Well M-94 has an apparently complex thermal history. Geothermometers in this well indicate temperatures some 50 to 100{sup 0}C higher than those measured directly in the borehole. Fission tracks are partially preserved in M-94 where paleotemperatures were as high as 200{sup 0}C and are erased where geothermometers indicate temperatures of 250{sup 0}C. This implies a thermal event less than 10{sup 1} years and greater than 10{sup 0} years in duration.

  6. Fission track evidence for widespread early to Middle miocene...

    Open Energy Info (EERE)

    major extension over broad areas of the northern Basin and Range. Authors Dumitru, T.; Miller, E.; Savage, C.; Gans, P.; Brown and R. Published Geological Society of America,...

  7. Fission-track tectonic studies of the Transantarctic Mountains, Beardmore Glacier area

    SciTech Connect (OSTI)

    Fitzgerald, P.G.

    1986-01-01

    The Transantarctic Mountains are a major transcontinental range stretching for some 4000 kilometers, varying from 200-400 kilometers in width, and having elevations up to 4500 meters. The uplift and formation of the Transantarctic Mountains have always been something of an enigma, but recent apatite fission-track analysis is providing important new information not only about their uplift history but also about the implications of that uplift history for the glacial history of Antarctica as a whole. The main field objective of this project was to collect samples for fission-track analysis to determine the timing and rate of uplift of the Transantarctic Mountains and measure relative vertical displacements across faults within the range. Results from southern Victoria Land indicate that uplift of the Transantarctic Mountains was initiated at about 50 million years ago and since that time the mountains have undergone some 5 kilometers of uplift at an average rate of 100 meters per million years. It is important to realize, however, that this is an average rate and may well conceal pulses of faster and slower uplift or even periods of subsidence. The amount of uplift across the mountain range is differential; from the axis of maximum uplift about 30 kilometers inland of the Victoria Land coast, the mountains dip gently westward under the polar ice cap. The study was extended to the Beardmore Glacier area to see whether the uplift history and tectonics varies from that observed in southern Victoria Land.

  8. Singlet fission in tetracene and rubrene: evidence for the direct formation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of entangled triplet pairs | MIT-Harvard Center for Excitonics fission in tetracene and rubrene: evidence for the direct formation of entangled triplet pairs March 6, 2012 at 3pm/36-428 Christopher Bardeen Department of Chemistry, University of California, Riverside bardeen001 Abstract: Singlet fission is a process where an initially created singlet exciton spontaneously splits into a pair of triplet excitons. This spin-allowed process can be very rapid and is of interest as a way to make

  9. Fission track thermochronologic constraints on the timing and nature of major Middle Tertiary extension, Ruby Mountains - East Humboldt Range, Nevada

    SciTech Connect (OSTI)

    Dokka, R.K.; Mahaffie, M.J.; Snoke, A.W.

    1985-01-01

    Fission Track (FT) apatite, zircon, and sphene ages were determined from both mylonitic and non-mylonitic rocks of the Ruby Mountains-East Humboldt Range metamorphic core complex. The analyzed sample suite included various mylonitic orthogneisses as well as amphibolitic orthogneisses from the non-mylonitic infrastructural core. Porphyritic biotite granodiorite of the Oligocene Harrison Pass pluton was also dated. FT ages are concordant and range in age from 27 - 24 Ma. These dates reflect rapid cooling of the lower plate from temperatures above 250/sup 0/C to below 100/sup 0/C during the early Miocene. The general concordance of the FT dates with /sup 40/Ar//sup 39/Ar biotite and hornblende plateau ages from the same sample suite suggest an even more pronounced cooling history. This rapid cooling history is considered to reflect large-scale tectonic denudation (intracrustal thinning), a manifestation of intense crustal extension. Mylonitic rocks that originally formed along ductile shear zones in the middle crust (10-15 km) were quickly brought near the surface and juxtaposed against brittly distended rocks deformed under upper crustal conditions. FT data firmly establish the upper age limit on the timing of mylonitization during the shear zone deformation. This rapid cooling interval also coincides with the inferred age of extensive landscape disruption and the development of an alluvial fan-lacustrine system which included the periodic emplacement of landslide deposits (megabreccias).

  10. Spontaneous Fission

    DOE R&D Accomplishments [OSTI]

    Segre, Emilio

    1950-11-22

    The first attempt to discover spontaneous fission in uranium was made by [Willard] Libby, who, however, failed to detect it on account of the smallness of effect. In 1940, [K. A.] Petrzhak and [G. N.] Flerov, using more sensitive methods, discovered spontaneous fission in uranium and gave some rough estimates of the spontaneous fission decay constant of this substance. Subsequently, extensive experimental work on the subject has been performed by several investigators and will be quoted in the various sections. [N.] Bohr and [A.] Wheeler have given a theory of the effect based on the usual ideas of penetration of potential barriers. On this project spontaneous fission has been studied for the past several years in an effort to obtain a complete picture of the phenomenon. For this purpose the spontaneous fission decay constants {lambda} have been measured for separated isotopes of the heavy elements wherever possible. Moreover, the number {nu} of neutrons emitted per fission has been measured wherever feasible, and other characteristics of the spontaneous fission process have been studied. This report summarizes the spontaneous fission work done at Los Alamos up to January 1, 1945. A chronological record of the work is contained in the Los Alamos monthly reports.

  11. Benchmarking nuclear fission theory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bertsch, G. F.; Loveland, W.; Nazarewicz, W.; Talou, P.

    2015-05-14

    We suggest a small set of fission observables to be used as test cases for validation of theoretical calculations. Thus, the purpose is to provide common data to facilitate the comparison of different fission theories and models. The proposed observables are chosen from fission barriers, spontaneous fission lifetimes, fission yield characteristics, and fission isomer excitation energies.

  12. Fission Spectrum

    DOE R&D Accomplishments [OSTI]

    Bloch, F.; Staub, H.

    1943-08-18

    Measurements of the spectrum of the fission neutrons of 25 are described, in which the energy of the neutrons is determined from the ionization produced by individual hydrogen recoils. The slow neutrons producing fission are obtained by slowing down the fast neutrons from the Be-D reaction of the Stanford cyclotron. In order to distinguish between fission neutrons and the remaining fast cyclotron neutrons both the cyclotron current and the pusle amplifier are modulated. A hollow neutron container, in which slow neutrons have a lifetime of about 2 milliseconds, avoids the use of large distances. This method results in much higher intensities than the usual modulation arrangement. The results show a continuous distribution of neutrons with a rather wide maximum at about 0.8 MV falling off to half of its maximum value at 2.0 MV. The total number of netrons is determined by comparison with the number of fission fragments. The result seems to indicate that only about 30% of the neutrons have energies below .8 MV. Various tests are described which were performed in order to rule out modification of the spectrum by inelastic scattering. Decl. May 4, 1951

  13. Fission meter

    DOE Patents [OSTI]

    Rowland, Mark S.; Snyderman, Neal J.

    2012-04-10

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source.

  14. Fission theory: Its relevance to the nuclear cross section data base

    SciTech Connect (OSTI)

    Lynn, J.E.

    1989-01-01

    The development of fission reaction theory in relation to its predictive power in the calculation of neutron cross-sections is reviewed. The topics covered include the transition state spectrum and the channel theory; the discovery of complex topography in the fission barrier and the consequences of intermediate structure in fission cross-sections; the evidence of experimental data in parameterizing the fission barrier; and the role of other aspects of collective nuclear motion in controlling fission reaction rates. 51 refs., 6 figs.

  15. Microscopic Description of Nuclear Fission: Fission Barrier Heights...

    Office of Scientific and Technical Information (OSTI)

    Conference: Microscopic Description of Nuclear Fission: Fission Barrier Heights of Even-Even Actinides Citation Details In-Document Search Title: Microscopic Description of Nuclear ...

  16. Fission gas detection system

    DOE Patents [OSTI]

    Colburn, Richard P. (Pasco, WA)

    1985-01-01

    A device for collecting fission gas released by a failed fuel rod which device uses a filter to pass coolant but which filter blocks fission gas bubbles which cannot pass through the filter due to the surface tension of the bubble.

  17. Biomodal spontaneous fission

    SciTech Connect (OSTI)

    Hulet, E.K. )

    1989-09-26

    Investigations of mass and kinetic-energy distributions from spontaneous fission have been extended in recent years to an isotope of element 104 and, for half-lives, to an isotope of element 108. The results have been surprising in that spontaneous fission half-lives have turned out to be much longer than expected and mass and kinetic- energy distributions were found to abruptly shift away from those of the lighter actinides, showing two modes of fission. These new developments have caused a re-evaluation of our understanding of the fission process, bringing an even deeper appreciation of the role played by nuclear shell effects upon spontaneous fission properties. 16 refs., 10 figs.

  18. Process for treating fission waste

    DOE Patents [OSTI]

    Rohrmann, Charles A.; Wick, Oswald J.

    1983-01-01

    A method is described for the treatment of fission waste. A glass forming agent, a metal oxide, and a reducing agent are mixed with the fission waste and the mixture is heated. After melting, the mixture separates into a glass phase and a metal phase. The glass phase may be used to safely store the fission waste, while the metal phase contains noble metals recovered from the fission waste.

  19. Fire extinguishant for fissionable material

    DOE Patents [OSTI]

    Schmitt, Charles R.

    1976-01-01

    Carbon microspheres impregnated with a neutron poison are used as an extinguishant for radioactive and fissionable metal fires.

  20. SHAPED FISSIONABLE METAL BODIES

    DOE Patents [OSTI]

    Wigner, E.P.; Williamson, R.R.; Young, G.J.

    1958-10-14

    A technique is presented for grooving the surface of fissionable fuel elements so that expansion can take place without damage to the interior structure of the fuel element. The fissionable body tends to develop internal stressing when it is heated internally by the operation of the nuclear reactor and at the same time is subjected to surface cooling by the circulating coolant. By producing a grooved or waffle-like surface texture, the annular lines of tension stress are disrupted at equally spaced intervals by the grooves, thereby relieving the tension stresses in the outer portions of the body while also facilitating the removal of accumulated heat from the interior portion of the fuel element.

  1. Extended optical model for fission

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sin, M.; Capote, R.; Herman, M. W.; Trkov, A.

    2016-03-07

    A comprehensive formalism to calculate fission cross sections based on the extension of the optical model for fission is presented. It can be used for description of nuclear reactions on actinides featuring multi-humped fission barriers with partial absorption in the wells and direct transmission through discrete and continuum fission channels. The formalism describes the gross fluctuations observed in the fission probability due to vibrational resonances, and can be easily implemented in existing statistical reaction model codes. The extended optical model for fission is applied for neutron induced fission cross-section calculations on 234,235,238U and 239Pu targets. A triple-humped fission barrier ismore » used for 234,235U(n,f), while a double-humped fission barrier is used for 238U(n,f) and 239Pu(n,f) reactions as predicted by theoretical barrier calculations. The impact of partial damping of class-II/III states, and of direct transmission through discrete and continuum fission channels, is shown to be critical for a proper description of the measured fission cross sections for 234,235,238U(n,f) reactions. The 239Pu(n,f) reaction can be calculated in the complete damping approximation. Calculated cross sections for 235,238U(n,f) and 239Pu(n,f) reactions agree within 3% with the corresponding cross sections derived within the Neutron Standards least-squares fit of available experimental data. Lastly, the extended optical model for fission can be used for both theoretical fission studies and nuclear data evaluation.« less

  2. Microscopic Description of Nuclear Fission: Fission Barrier Heights...

    Office of Scientific and Technical Information (OSTI)

    Resource Type: Conference Resource Relation: Conference: Presented at: 5th International Conference on Fission and properties of neutron-rich nuclei, Sanibel Island, FL, United ...

  3. TRACKING SITE

    Energy Science and Technology Software Center (OSTI)

    003235MLTPL00 AASG Geothermal Data submissions tracking application and site. https://github.com/usgin/aasgtrack

  4. Benchmarking the LAHET fission models

    SciTech Connect (OSTI)

    Prael, R.E.

    1995-12-31

    There has been considerable interest in improving the fission models in the LAHET Monte Carlo code for the transport and interaction of nucleons, pions, muons, fight ions, and antinucleons. Although subactinide fission contributes little to neutron production in lead or tungsten targets, it can be significant for simulation of target activation and fission product contamination. The availability of new data permits new comparisons to be made between experiment and calculation.

  5. Microscopic modeling of mass and charge distributions in the spontaneous fission of 240Pu

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sandhukhan, Jhilam; Nazarewicz, Witold; Schunck, Nicolas

    2016-01-20

    We propose a methodology to calculate microscopically the mass and charge distributions of spontaneous fission yields. We combine the multidimensional minimization of collective action for fission with stochastic Langevin dynamics to track the relevant fission paths from the ground-state configuration up to scission. The nuclear potential energy and collective inertia governing the tunneling motion are obtained with nuclear density functional theory in the collective space of shape deformations and pairing. As a result, we obtain a quantitative agreement with experimental data and find that both the charge and mass distributions in the spontaneous fission of 240Pu are sensitive both tomore » the dissipation in collective motion and to adiabatic fission characteristics.« less

  6. Fission Fragment Angular Distributions measured with a Time Projection Chamber

    SciTech Connect (OSTI)

    Kleinrath, Verena

    2015-04-28

    The subject is presented in a series of slides with the following organization: Introduction (What is anisotropy? Relevance (Theory and ratio cross section), Previous measurements); Experiment (Particle tracking in the fissionTPC, Neutron time of flight, Data analysis & uncertainty calculation, Preliminary result for 235U); and Future Work (Refine 235U result, Process 239Pu data).

  7. Post-scission fission theory: Neutron emission in fission

    SciTech Connect (OSTI)

    Madland, D.G.

    1997-11-01

    A survey of theoretical representations of two of the observables in neutron emission in fission is given, namely, the prompt fission neutron spectrum N (E) and the average prompt neutron multiplicity {bar {nu}}{sub p}. Early representations of the two observables are presented and their deficiencies are discussed. This is followed by summaries and examples of recent theoretical models for the calculation of these quantities. Emphasis is placed upon the predictability and accuracy of the recent models. In particular, the dependencies of N (E) and {bar {nu}}{sub p} upon the fissioning nucleus and its excitation energy are treated. Recent work in the calculation of the prompt fission neutron spectrum matrix N (E, E{sub n}), where E{sub n} is the energy of the neutron inducing fission, is then discussed. Concluding remarks address the current status of our ability to calculate these observables with confidence, the direction of future theoretical efforts, and limitations to current (and future) approaches.

  8. Method for correcting for isotope burn-in effects in fission neutron dosimeters

    DOE Patents [OSTI]

    Gold, Raymond; McElroy, William N.

    1988-01-01

    A method is described for correcting for effect of isotope burn-in in fission neutron dosimeters. Two quantities are measured in order to quantify the "burn-in" contribution, namely P.sub.Z',A', the amount of (Z', A') isotope that is burned-in, and F.sub.Z', A', the fissions per unit volume produced in the (Z', A') isotope. To measure P.sub.Z', A', two solid state track recorder fission deposits are prepared from the very same material that comprises the fission neutron dosimeter, and the mass and mass density are measured. One of these deposits is exposed along with the fission neutron dosimeter, whereas the second deposit is subsequently used for observation of background. P.sub.Z', A' is then determined by conducting a second irradiation, wherein both the irradiated and unirradiated fission deposits are used in solid state track recorder dosimeters for observation of the absolute number of fissions per unit volume. The difference between the latter determines P.sub.Z', A' since the thermal neutron cross section is known. F.sub.Z', A' is obtained by using a fission neutron dosimeter for this specific isotope, which is exposed along with the original threshold fission neutron dosimeter to experience the same neutron flux-time history at the same location. In order to determine the fissions per unit volume produced in the isotope (Z', A') as it ingrows during the irradiation, B.sub.Z', A', from these observations, the neutron field must generally be either time independent or a separable function of time t and neutron energy E.

  9. TREATMENT OF FISSION PRODUCT WASTE

    DOE Patents [OSTI]

    Huff, J.B.

    1959-07-28

    A pyrogenic method of separating nuclear reactor waste solutions containing aluminum and fission products as buring petroleum coke in an underground retort, collecting the easily volatile gases resulting as the first fraction, he uminum chloride as the second fraction, permitting the coke bed to cool and ll contain all the longest lived radioactive fission products in greatly reduced volume.

  10. Fission fragment driven neutron source

    DOE Patents [OSTI]

    Miller, Lowell G.; Young, Robert C.; Brugger, Robert M.

    1976-01-01

    Fissionable uranium formed into a foil is bombarded with thermal neutrons in the presence of deuterium-tritium gas. The resulting fission fragments impart energy to accelerate deuterium and tritium particles which in turn provide approximately 14 MeV neutrons by the reactions t(d,n).sup.4 He and d(t,n).sup.4 He.

  11. Fission Particle Emission Multiplicity Simulation

    Energy Science and Technology Software Center (OSTI)

    2006-09-27

    Simulates discrete neutron and gamma-ray emission from the fission of heavy nuclei that is either spontaneous or neutron induced. This is a function library that encapsulates the fission physics and is intended to be called Monte Carlo transport code.

  12. Fission throughout the periodic table

    SciTech Connect (OSTI)

    Moretto, L.G.; Wozniak, G.J.

    1989-04-01

    The dualistic view of fission and evaporation as two distinct compound nucleus processes is substituted with a unified view in which fission, complex fragment emission, and light particle evaporation are seen as different aspects of a single process. 47 refs., 22 figs.

  13. Microscopic Description of Induced Nuclear Fission (Conference...

    Office of Scientific and Technical Information (OSTI)

    Microscopic Description of Induced Nuclear Fission Citation Details In-Document Search Title: Microscopic Description of Induced Nuclear Fission You are accessing a document ...

  14. Excitation Energy Sorting Mechanisms in Fission (Conference)...

    Office of Scientific and Technical Information (OSTI)

    Excitation Energy Sorting Mechanisms in Fission Citation Details In-Document Search Title: Excitation Energy Sorting Mechanisms in Fission You are accessing a document from the ...

  15. Microstructural Characterization of Irradiated U-7Mo/Al-5Si Dispersion to High Fission Density

    SciTech Connect (OSTI)

    J. Gan; B. D. Miller; D. D. Keiser, Jr.; A. B. Robinson; J. W. Madden; P. G. Medvedev; D. M. Wachs

    2014-11-01

    The fuel development program for research and test reactors calls for improved knowledge on the effect of microstructure on fuel performance in reactors. This work summarizes the recent TEM microstructural characterization of an irradiated U-7Mo/Al-5Si dispersion fuel plate (R3R050) irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory to 5.21021 fissions/cm3. While a large fraction of the fuel grains is decorated with large bubbles, there is no evidence showing interlinking of these large bubbles at the specified fission density. The attachment of solid fission product precipitates to the bubbles is likely the result of fission product diffusion into these bubbles. The process of fission gas bubble superlattice collapse appears through bubble coalescence. The results are compared with the previous TEM work of the dispersion fuels irradiated to lower fission density from the same fuel plate.

  16. Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons

    SciTech Connect (OSTI)

    Baisden, P; Bauge, E; Ferguson, J; Gilliam, D; Granier, T; Jeanloz, R; McMillan, C; Robertson, D; Thompson, P; Verdon, C; Wilkerson, C; Young, P

    2010-03-16

    This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary evaluation of the ILRR-LANL data, have been documented. (3) LANL has also conducted an evaluation of fission product yields for fission spectrum neutrons on plutonium including a meta-analysis of benchmark data as part of a planned upgrade to the ENDF/B compilation. We found that the approach of using meta-analysis provides valuable additional insight for evaluating the sparse data sets involved in this assessment. (4) Both laboratories have provided convincing evidence for energy dependence in the fission product yield of {sup 147}Nd produced from the bombardment of {sup 239}Pu with fission spectrum neutrons over an incident neutron energy range of 0.2 to 1.9 MeV. (5) Consistent, complete, and explicit treatment of

  17. Infrared Spectroscopy of Wild 2 Particle Hypervelocity Tracks in Stardust Aerogel: Evidence for the presence of Volatile Organics in Comet Dust

    SciTech Connect (OSTI)

    Bajt, S; Sandford, S A; Flynn, G J; Matrajt, G; Snead, C J; Westphal, A J; Bradley, J P

    2007-08-28

    Infrared spectroscopy maps of some tracks, made by cometary dust from 81P/Wild 2 impacting Stardust aerogel, reveal an interesting distribution of volatile organic material. Out of six examined tracks three show presence of volatile organic components possibly injected into the aerogel during particle impacts. When particle tracks contained excess volatile organic material, they were found to be -CH{sub 2}-rich. Off-normal particle tracks could indicate impacts by lower velocity particles that could have bounced off the Whipple shield, therefore carry off some contamination from it. However, this theory is not supported by data that show excess organic-rich material in normal and off-normal particle tracks. It is clear that the population of cometary particles impacting the Stardust aerogel collectors also include grains that contained little or none of this volatile organic component. This observation is consistent with the highly heterogeneous nature of the collected grains, as seen by a multitude of other analytical techniques. We propose that at least some of the volatile organic material might be of cometary origin based on supporting data shown in this paper. However, we also acknowledge the presence of carbon (primarily as -CH{sub 3}) in the original aerogel, which complicates interpretation of these results.

  18. Search for Singlet Fission Chromophores

    SciTech Connect (OSTI)

    Havlas, Z.; Akdag, A.; Smith, M. B.; Dron, P.; Johnson, J. C.; Nozik, A. J.; Michl, J.

    2012-01-01

    Singlet fission, in which a singlet excited chromophore shares its energy with a ground-state neighbor and both end up in their triplet states, is of potential interest for solar cells. Only a handful of compounds, mostly alternant hydrocarbons, are known to perform efficiently. In view of the large number of conditions that a successful candidate for a practical cell has to meet, it appears desirable to extend the present list of high performers to additional classes of compounds. We have (i) identified design rules for new singlet fission chromophores and for their coupling to covalent dimers, (ii) synthesized them, and (iii) evaluated their performance as neat solids or covalent dimers.

  19. Process for treating fission waste. [Patent application

    DOE Patents [OSTI]

    Rohrmann, C.A.; Wick, O.J.

    1981-11-17

    A method is described for the treatment of fission waste. A glass forming agent, a metal oxide, and a reducing agent are mixed with the fission waste and the mixture is heated. After melting, the mixture separates into a glass phase and a metal phase. The glass phase may be used to safely store the fission waste, while the metal phase contains noble metals recovered from the fission waste.

  20. High resolution track etch autoradiography

    DOE Patents [OSTI]

    Solares, G.; Zamenhof, R.G.

    1994-12-27

    A detector assembly is disclosed for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns. 13 figures.

  1. High resolution track etch autoradiography

    DOE Patents [OSTI]

    Solares, Guido (Arlington, MA); Zamenhof, Robert G. (Brookline, MA)

    1994-01-01

    A detector assembly for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns.

  2. Delayed Fission Gamma-ray Characteristics of Th-232 U-233 U-235 U-238 and Pu-239

    SciTech Connect (OSTI)

    Lane, Taylor; Parma, Edward J.

    2015-08-01

    Delayed fission gamma-rays play an important role in determining the time dependent ioniz- ing dose for experiments in the central irradiation cavity of the Annular Core Research Reactor (ACRR). Delayed gamma-rays are produced from both fission product decay and from acti- vation of materials in the core, such as cladding and support structures. Knowing both the delayed gamma-ray emission rate and the time-dependent gamma-ray energy spectrum is nec- essary in order to properly determine the dose contributions from delayed fission gamma-rays. This information is especially important when attempting to deconvolute the time-dependent neutron, prompt gamma-ray, and delayed gamma-ray contribution to the response of a diamond photo-conducting diode (PCD) or fission chamber in time frames of milliseconds to seconds following a reactor pulse. This work focused on investigating delayed gamma-ray character- istics produced from fission products from thermal, fast, and high energy fission of Th-232, U-233, U-235, U-238, and Pu-239. This work uses a modified version of CINDER2008, a transmutation code developed at Los Alamos National Laboratory, to model time and energy dependent photon characteristics due to fission. This modified code adds the capability to track photon-induced transmutations, photo-fission, and the subsequent radiation caused by fission products due to photo-fission. The data is compared against previous work done with SNL- modified CINDER2008 [ 1 ] and experimental data [ 2 , 3 ] and other published literature, includ- ing ENDF/B-VII.1 [ 4 ]. The ability to produce a high-fidelity (7,428 group) energy-dependent photon fluence at various times post-fission can improve the delayed photon characterization for radiation effects tests at research reactors, as well as other applications.

  3. Fission matrix capability for MCNP, Part I - Theory

    SciTech Connect (OSTI)

    Brown, F. B.; Carney, S. E.; Kiedrowski, B. C.; Martin, W. R.

    2013-07-01

    The theory underlying the fission matrix method is derived using a rigorous Green's function approach. The method is then used to investigate fundamental properties of the transport equation for a continuous-energy physics treatment. We provide evidence that an infinite set of discrete, real eigenvalues and eigenfunctions exist for the continuous-energy problem, and that the eigenvalue spectrum converges smoothly as the spatial mesh for the fission matrix is refined. We also derive equations for the adjoint solution. We show that if the mesh is sufficiently refined so that both forward and adjoint solutions are valid, then the adjoint fission matrix is identical to the transpose of the forward matrix. While the energy-dependent transport equation is strictly bi-orthogonal, we provide surprising results that the forward modes are very nearly self-adjoint for a variety of continuous-energy problems. A companion paper (Part II - Applications) describes the initial experience and results from implementing this fission matrix capability into the MCNP Monte Carlo code. (authors)

  4. Fusion-Fission Hybrid for Fissile Fuel Production without Processing

    SciTech Connect (OSTI)

    Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

    2012-01-02

    Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in the critical reactors

  5. MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.

    SciTech Connect (OSTI)

    ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

    2005-05-01

    This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

  6. RECOVERY OF ALUMINUM FROM FISSION PRODUCTS

    DOE Patents [OSTI]

    Blanco, R.E.; Higgins, I.R.

    1962-11-20

    A method is given for recovertng aluminum values from aqueous solutions containing said values together with fission products. A mixture of Fe/sub 2/O/ sub 3/ and MnO/sub 2/ is added to a solution containing aluminum and fission products. The resulting aluminum-containing supernatant is then separated from the fission product-bearing metal oxide precipitate and is contacted with a cation exchange resin. The aluminum sorbed on the resin is then eluted and recovered. (AEC)

  7. Small Self-Regulating Fission Reactor System

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Small Self-Regulating Fission Reactor System ANTICIPATED IMPACT PATH FORWARD DESCRIPTION BACKGROUND & MOTIVATION INNOVATION A power system for special government applications Point of Contact: Patrick McClure, NEN-5, pmcclure@lanl.gov (505)667-9534 Small Self-Regulating Fission Reactor System A small self- regulating fission reactor made with U 235 . LANL and NASA with the support of NSTec performed a proof of concept test at the Nevada Test Site. Test apparatus - Nuclear material on left

  8. Fission barriers and half-lives

    SciTech Connect (OSTI)

    Moeller, P.; Nix, J.R.; Swiatecki, W.J.

    1989-01-01

    We briefly review the development of theoretical models for the calculation of fission barriers and half-lives. We focus on how results of actual calculations in a unified macroscopic-microscopic approach provide an interpretation of the mechanisms behind some of the large number of phenomena observed in fission. As instructive examples we choose studies of the rapidly varying fission properties of elements at the end of the periodic system. 31 refs., 10 figs.

  9. FISSION PRODUCT REMOVAL FROM ORGANIC SOLUTIONS

    DOE Patents [OSTI]

    Moore, R.H.

    1960-05-10

    The decontamination of organic solvents from fission products and in particular the treatment of solvents that were used for the extraction of uranium and/or plutonium from aqueous acid solutions of neutron-irradiated uranium are treated. The process broadly comprises heating manganese carbonate in air to a temperature of between 300 and 500 deg C whereby manganese dioxide is formed; mixing the manganese dioxide with the fission product-containing organic solvent to be treated whereby the fission products are precipitated on the manganese dioxide; and separating the fission product-containing manganese dioxide from the solvent.

  10. Fission fragment excited laser system

    DOE Patents [OSTI]

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  11. SOURCE OF PRODUCTS OF NUCLEAR FISSION

    DOE Patents [OSTI]

    Harteck, P.; Dondes, S.

    1960-03-15

    A source of fission product recoil energy suitable for use in radiation chemistry is reported. The source consists of thermal neutron irradiated glass wool having a diameter of 1 to 5 microns and containing an isotope fissionable by thermal neutrons, such as U/sup 235/.

  12. PROCESS FOR SEPARATING URANIUM FISSION PRODUCTS

    DOE Patents [OSTI]

    Spedding, F.H.; Butler, T.A.; Johns, I.B.

    1959-03-10

    The removal of fission products such as strontium, barium, cesium, rubidium, or iodine from neutronirradiated uranium is described. Uranium halide or elemental halogen is added to melted irradiated uranium to convert the fission products to either more volatile compositions which vaporize from the melt or to higher melting point compositions which separate as solids.

  13. Prompt fission neutron spectra of actinides

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Capote, R.; Chen, Y. -J.; Hambsch, F. -J.; Kornilov, N. V.; Lestone, J. P.; Litaize, O.; Morillon, B.; Neudecker, D.; Oberstedt, S.; Ohsawa, T.; et al

    2016-01-06

    Here, the energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.

  14. DOE Science Showcase - Fission Theory | OSTI, US Dept of Energy...

    Office of Scientific and Technical Information (OSTI)

    Fission Theory A predictive theory of nuclear fission has eluded physicists since 1939. ... Additional Links of Interest Office of Nuclear Energy, DOE Nuclear Physics, DOE Office ...

  15. Fifty years of nuclear fission: Nuclear data and measurements...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Fifty years of nuclear fission: Nuclear data and measurements series Citation Details In-Document Search Title: Fifty years of nuclear fission: Nuclear data and ...

  16. Fifty years of nuclear fission: Nuclear data and measurements...

    Office of Scientific and Technical Information (OSTI)

    Fifty years of nuclear fission: Nuclear data and measurements series Citation Details In-Document Search Title: Fifty years of nuclear fission: Nuclear data and measurements series ...

  17. Error estimates for fission neutron outputs (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Error estimates for fission neutron outputs Citation Details In-Document Search Title: Error estimates for fission neutron outputs You are accessing a document from the...

  18. NUCLEAR ENERGY UNIVERSITY PROGRAMS Improved Fission Neutron Data...

    National Nuclear Security Administration (NNSA)

    NUCLEAR ENERGY UNIVERSITY PROGRAMS Improved Fission Neutron Data Base for Active ... the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. ...

  19. Future challenges for nuclear data research in fission (u) (Journal...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Future challenges for nuclear data research in fission (u) Citation Details In-Document Search Title: Future challenges for nuclear data research in fission (u) I ...

  20. Fission Product Separation/Extraction Techniques (Book) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Book: Fission Product SeparationExtraction Techniques Citation Details In-Document Search Title: Fission Product SeparationExtraction Techniques No abstract prepared. Authors: ...

  1. Density Functional Theory Approach to Nuclear Fission (Conference...

    Office of Scientific and Technical Information (OSTI)

    Density Functional Theory Approach to Nuclear Fission Citation Details In-Document Search Title: Density Functional Theory Approach to Nuclear Fission You are accessing a document ...

  2. Overview of Fusion-Fission Hybrid Blankets for Laser Inertial...

    Office of Scientific and Technical Information (OSTI)

    Conference: Overview of Fusion-Fission Hybrid Blankets for Laser Inertial Fusion Energy (LIFE) Engine Citation Details In-Document Search Title: Overview of Fusion-Fission Hybrid ...

  3. Control of a laser inertial confinement fusion-fission power...

    Office of Scientific and Technical Information (OSTI)

    Control of a laser inertial confinement fusion-fission power plant Title: Control of a laser inertial confinement fusion-fission power plant A laser inertial-confinement ...

  4. Time dependent particle emission from fission products (Conference...

    Office of Scientific and Technical Information (OSTI)

    Time dependent particle emission from fission products Citation Details In-Document Search Title: Time dependent particle emission from fission products Decay heating following ...

  5. Description of induced nuclear fission with Skyrme energy functionals...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Description of induced nuclear fission with Skyrme energy functionals: Static potential energy surfaces and fission fragment properties ...

  6. Interplay between compound and fragments aspects of nuclear fission...

    Office of Scientific and Technical Information (OSTI)

    aspects of nuclear fission and heavy-ion reaction Citation Details In-Document Search Title: Interplay between compound and fragments aspects of nuclear fission and ...

  7. Los Alamos National Laboratory fission basis (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Los Alamos National Laboratory fission basis Citation Details In-Document Search Title: Los Alamos National Laboratory fission basis You are accessing a document from the ...

  8. Fusion-Fission Hybrid for Fissile Fuel Production without Processing...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Fusion-Fission Hybrid for Fissile Fuel Production without Processing Citation Details In-Document Search Title: Fusion-Fission Hybrid for Fissile Fuel Production ...

  9. Future challenges for nuclear data research in fission (u) (Journal...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Future challenges for nuclear data research in fission (u) Citation Details In-Document Search Title: Future challenges for nuclear data research in fission (u) ...

  10. Axisymmetric Magnetic Mirror Fusion-Fission Hybrid (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Axisymmetric Magnetic Mirror Fusion-Fission Hybrid Citation Details In-Document Search Title: Axisymmetric Magnetic Mirror Fusion-Fission Hybrid Authors: Moir, R ...

  11. Nuclear Fission and Fission{minus}Product Spectroscopy: Second International Workshop. Proceedings

    SciTech Connect (OSTI)

    Fioni, G.; Faust, H.; Oberstedt, S.; Hambsch, F.

    1998-10-01

    These proceedings represent papers presented at the Second International Workshop on Nuclear Fission and Fission{minus}Product Spectroscopy held in Seyssins, France in April, 1998. The objective was to bring together the specialists in the field to overview the situation and to assess our present understanding of the fission process. The topics presented at the conference included nuclear waste management, incineration, neutron driven transmutation, leakage etc., radioactive beams, neutron{minus}rich nuclei, neutron{minus}induced and spontaneous fission, ternary fission phenomena, angular momentum, parity and time{minus}reversal phenomena, and nuclear fission at higher excitation energy. Modern spectroscopic tools for gamma spectroscopy as applied to fission were also discussed. There were 53 papers presented at the conference,out of which 3 have been abstracted for the Energy,Science and Technology database.(AIP)

  12. Electromechanical solar tracking apparatus

    DOE Patents [OSTI]

    Stromberg, Robert P.

    1981-01-01

    The invention relates to an electromechanical solar tracking device which tracks the position of the sun using paired, partially-shaded bimetallic elements.

  13. Electromechanical solar tracking apparatus

    DOE Patents [OSTI]

    Stromberg, R.P.

    The invention relates to an electromechanical solar tracking device which tracks the position of the sun using paired, partially-shaded bimetallic elements.

  14. Theoretical Description of the Fission Process

    SciTech Connect (OSTI)

    Witold Nazarewicz

    2009-10-25

    Advanced theoretical methods and high-performance computers may finally unlock the secrets of nuclear fission, a fundamental nuclear decay that is of great relevance to society. In this work, we studied the phenomenon of spontaneous fission using the symmetry-unrestricted nuclear density functional theory (DFT). Our results show that many observed properties of fissioning nuclei can be explained in terms of pathways in multidimensional collective space corresponding to different geometries of fission products. From the calculated collective potential and collective mass, we estimated spontaneous fission half-lives, and good agreement with experimental data was found. We also predicted a new phenomenon of trimodal spontaneous fission for some transfermium isotopes. Our calculations demonstrate that fission barriers of excited superheavy nuclei vary rapidly with particle number, pointing to the importance of shell effects even at large excitation energies. The results are consistent with recent experiments where superheavy elements were created by bombarding an actinide target with 48-calcium; yet even at high excitation energies, sizable fission barriers remained. Not only does this reveal clues about the conditions for creating new elements, it also provides a wider context for understanding other types of fission. Understanding of the fission process is crucial for many areas of science and technology. Fission governs existence of many transuranium elements, including the predicted long-lived superheavy species. In nuclear astrophysics, fission influences the formation of heavy elements on the final stages of the r-process in a very high neutron density environment. Fission applications are numerous. Improved understanding of the fission process will enable scientists to enhance the safety and reliability of the nations nuclear stockpile and nuclear reactors. The deployment of a fleet of safe and efficient advanced reactors, which will also minimize radiotoxic

  15. Solar tracking system

    DOE Patents [OSTI]

    Okandan, Murat; Nielson, Gregory N.

    2016-07-12

    Solar tracking systems, as well as methods of using such solar tracking systems, are disclosed. More particularly, embodiments of the solar tracking systems include lateral supports horizontally positioned between uprights to support photovoltaic modules. The lateral supports may be raised and lowered along the uprights or translated to cause the photovoltaic modules to track the moving sun.

  16. Track 3: Exposure Hazards

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 3: Exposure Hazards

  17. Track 9: Quality Assurance

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 9: Quality Assurance

  18. Track 2: Worker Engagement

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 2: Worker Engagement

  19. Chemical behavior of fission products in the ORNL fission product release program. Supplement. [PWR; BWR

    SciTech Connect (OSTI)

    Collins, J.L.; Osborne, M.F.; Lorenz, R.A.

    1983-01-01

    Tests data are presented for BWR and PWR rods in test HI-4 and test HI-5. Operating conditions fission product release data are included.

  20. On the belated discovery of fission

    SciTech Connect (OSTI)

    Pearson, J. Michael

    2015-06-15

    A remarkable sequence of missteps, misfortune, and oversights delayed the discovery of nuclear fission until the eve of World War II—and likely altered history’s course.

  1. Fission barrier properties, resonance fluctuations and isomer...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: Submitted to: Proceedings of the 3rd International Conference on Fission and Properties of Neutron-Rich Nuclei, Nov. 3-9, 2002, Sanibel Island, FL ...

  2. Aqueous cutting fluid for machining fissionable materials

    DOE Patents [OSTI]

    Duerksen, Walter K.; Googin, John M.; Napier, Jr., Bradley

    1984-01-01

    The present invention is directed to a cutting fluid for machining fissionable material. The cutting fluid is formed of glycol, water and boron compound in an adequate concentration for effective neutron attenuation so as to inhibit criticality incidents during machining.

  3. MCNP6 Fission Multiplicity with FMULT Card

    SciTech Connect (OSTI)

    Wilcox, Trevor; Fensin, Michael Lorne; Hendricks, John S.; James, Michael R.; McKinney, Gregg W.

    2012-06-18

    With the merger of MCNPX and MCNP5 into MCNP6, MCNP6 now provides all the capabilities of both codes allowing the user to access all the fission multiplicity data sets. Detailed in this paper is: (1) the new FMULT card capabilities for accessing these different data sets; (2) benchmark calculations, as compared to experiment, detailing the results of selecting these separate data sets for thermal neutron induced fission on U-235.

  4. Modeling Fission Product Sorption in Graphite Structures

    SciTech Connect (OSTI)

    Szlufarska, Izabela; Morgan, Dane; Allen, Todd

    2013-04-08

    The goal of this project is to determine changes in adsorption and desorption of fission products to/from nuclear-grade graphite in response to a changing chemical environment. First, the project team will employ principle calculations and thermodynamic analysis to predict stability of fission products on graphite in the presence of structural defects commonly observed in very high- temperature reactor (VHTR) graphites. Desorption rates will be determined as a function of partial pressure of oxygen and iodine, relative humidity, and temperature. They will then carry out experimental characterization to determine the statistical distribution of structural features. This structural information will yield distributions of binding sites to be used as an input for a sorption model. Sorption isotherms calculated under this project will contribute to understanding of the physical bases of the source terms that are used in higher-level codes that model fission product transport and retention in graphite. The project will include the following tasks: Perform structural characterization of the VHTR graphite to determine crystallographic phases, defect structures and their distribution, volume fraction of coke, and amount of sp2 versus sp3 bonding. This information will be used as guidance for ab initio modeling and as input for sorptivity models; Perform ab initio calculations of binding energies to determine stability of fission products on the different sorption sites present in nuclear graphite microstructures. The project will use density functional theory (DFT) methods to calculate binding energies in vacuum and in oxidizing environments. The team will also calculate stability of iodine complexes with fission products on graphite sorption sites; Model graphite sorption isotherms to quantify concentration of fission products in graphite. The binding energies will be combined with a Langmuir isotherm statistical model to predict the sorbed concentration of fission

  5. Our 50-year odyssey with fission: Summary

    SciTech Connect (OSTI)

    Nix, J.R.

    1989-01-01

    On the occasion of this International Conference on Fifty Years Research in Nuclear Fission, we summarize our present understanding of the fission process and the challenges that lie ahead. The basic properties of fission arise from a delicate competition between disruptive Coulomb forces, cohesive nuclear forces, and fluctuating shell and pairing forces. These static forces are primarily responsible for such experimental phenomena as deformed ground-state nuclear shapes, fission into fragments of unequal size, sawtooth neutron yields, spontaneously fissioning isomers, broad resonances and narrow intermediate structure in fission cross sections, and cluster radioactivity. However, inertial and dissipative forces also play decisive roles in the dynamical evolution of a fissioning nucleus. The energy dissipated between the saddle and scission points is small for low initial excitation energy at the saddle point and increases with increasing excitation energy. At moderate excitation energies, the dissipation of collective energy into internal single-particle excitation energy proceeds largely through the interaction of nucleons with the mean field and with each other in the vicinity of the nuclear surface, as well as through the transfer of nucleons between the two portions of the evolving dumbell-like system. These unique dissipation mechanisms arise from the Pauli exclusion principle for fermions and the details of the nucleon-nucleon interaction, which make the mean free path of a nucleon near the Fermi surface at low excitation energy longer than the nuclear radius. With its inverse process of heavy-ion fusion reactions, fission continues to yield surprises in the study of large-amplitude collective nuclear motion. 87 refs., 12 figs.

  6. Uncertainty evaluation for the matrix 'solidified state' of fissionable elements

    SciTech Connect (OSTI)

    Iliescu, Elena; Iancso, Georgeta

    2012-09-06

    fissionable elements (Thorium e.g.), of which, heavy charged particles, in this case the alpha radiations naturally emitted, were registered in the CR-39 track detectors. The density of alpha track from the obtained track micromaps was studied through common optic microscopy. Micromaps were studied counting the tracks on equal areas, in different measurement points. For the study of the foils prepared within the paper, the studied area was of 4.9 mm2, formed of 10 fields of 0.49 mm2 area each. The estimation of the uncertainty was carried out for all the sizes that were measured within the paper, no matter if they participate, directly or indirectly, in the estimation of the uncertainty regarding the homogeneity of the Thorium atoms distribution in the 'solidified state' foils of the standard solution calibrated in Thorium, such as: i) the weighted masses, ii) the dropped volumes of solution, iii) the alpha duration of exposure of the detectors, iv) the area studied on the surface of the micromap and v) the densities of alpha tracks. The procedure suggested allowed us to considerate that the homogeneity of alpha tracks distribution, on the surface and in thickness, is within the limits of 3.1%.

  7. Event-by-event fission simulation code, generates complete fission events

    Energy Science and Technology Software Center (OSTI)

    2013-04-01

    FREYA is a computer code that generates complete fission events. The output includes the energy and momentum of these final state particles: fission products, prompt neutrons and prompt photons. The version of FREYA that is to be released is a module for MCNP6.

  8. Solar tracking apparatus

    DOE Patents [OSTI]

    Hammons, Burrell E.

    1980-01-01

    The invention relates to a solar tracking device which tracks the position of the sun using paired, partially-shaded photocells. Auxiliary photocells are used for initial acquisition of the sun and for the suppression of false tracking when the sun is obscured by clouds.

  9. Solar tracking apparatus

    DOE Patents [OSTI]

    Hammons, B.E.

    The invention relates to a solar tracking device which tracks the position of the sun using paired, partially-shaded photocells. Auxilliary photocells are used for initial acquisition of the sun and for the suppression of false tracking when the sun is obscured by clouds.

  10. METHOD OF MAKING JACKETED FISSIONABLE SLUG

    DOE Patents [OSTI]

    Young, G.J.; Ohlinger, L.A.

    1959-02-10

    BS>A method is described for fabricating a jacketed fissionable body or slug to provide an effective leak-proof seal between the jacket and the end closure. A housing for the fissionable slug is first formed and then tinned on the interior. The fissionable slug is coated on its exterior surface with the same material used to tin the interior of the housing. The coated slug is then inserted into the housing. A disc shaped end closure for the housing, coated with the tinning material, is inserted into the open end of the housing while the tinning material is still liquid. The end of the housing is then swaged into good contact with the periphery of the closure.

  11. Microscopic Theory of Fission (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Microscopic Theory of Fission Citation Details In-Document Search Title: Microscopic Theory of Fission You are accessing a document from the Department of Energy's (DOE) SciTech ...

  12. Monte Carlo Hauser-Feshbach Calculations of Prompt Fission Neutrons...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Monte Carlo Hauser-Feshbach Calculations of Prompt Fission Neutrons and Gamma Rays: Application to Thermal Neutron-Induced Fission Reactions on U-235 and Pu-239 ...

  13. Room-return scattering in fission neutron outputs (Conference...

    Office of Scientific and Technical Information (OSTI)

    Room-return scattering in fission neutron outputs Citation Details In-Document Search Title: Room-return scattering in fission neutron outputs You are accessing a document from...

  14. Impact of Fission Products Impurity on the Plutonium Content...

    Office of Scientific and Technical Information (OSTI)

    Impact of Fission Products Impurity on the Plutonium Content of Metal- and Oxide- Fuels in Sodium Cooled Fast Reactors Citation Details In-Document Search Title: Impact of Fission ...

  15. Reexamination of fission fragment angular distributions and the fission process: Formalism

    SciTech Connect (OSTI)

    Bond, P.D.

    1985-08-01

    The theory of fission fragment angular distributions is examined and the universally used expression is found to be valid only under restrictive assumptions. A more general angular distribution formula is derived and applied to recent data of high spin systems. At the same time it is shown that the strong anisotropies observed from such systems can be understood without changing the essential basis of standard fission theory. The effects of reaction mechanisms other than complete fusion on fission fragment angular distributions are discussed and possible angular distribution signatures of noncompound nucleus formation are mentioned.

  16. Optimally moderated nuclear fission reactor and fuel source therefor

    DOE Patents [OSTI]

    Ougouag, Abderrafi M.; Terry, William K.; Gougar, Hans D.

    2008-07-22

    An improved nuclear fission reactor of the continuous fueling type involves determining an asymptotic equilibrium state for the nuclear fission reactor and providing the reactor with a moderator-to-fuel ratio that is optimally moderated for the asymptotic equilibrium state of the nuclear fission reactor; the fuel-to-moderator ratio allowing the nuclear fission reactor to be substantially continuously operated in an optimally moderated state.

  17. The Microscopic Theory of Fission (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: The Microscopic Theory of Fission Citation Details In-Document Search Title: The Microscopic Theory of Fission Fission-fragment properties have been calculated for thermal neutron-induced fission on a {sup 239}Pu target, using constrained Hartree-Fock-Bogoliubov calculations with a finite-range effective interaction. A quantitative criterion based on the interaction energy between the nascent fragments is introduced to define the scission configurations. The validity of this

  18. Recent advances in modeling fission cross sections over intermediate...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 73; APPROXIMATIONS; CROSS SECTIONS; DECAY AMPLITUDES; DEFORMATION; FISSION; FLUCTUATIONS; INTERMEDIATE STRUCTURE; ...

  19. Fission Product Sorptivity in Graphite

    SciTech Connect (OSTI)

    Tompson, Jr., Robert V.; Loyalka, Sudarshan; Ghosh, Tushar; Viswanath, Dabir; Walton, Kyle; Haffner, Robert

    2015-04-01

    Both adsorption and absorption (sorption) of fission product (FP) gases on/into graphite are issues of interest in very high temperature reactors (VHTRs). In the original proposal, we proposed to use packed beds of graphite particles to measure sorption at a variety of temperatures and to use an electrodynamic balance (EDB) to measure sorption onto single graphite particles (a few ?m in diameter) at room temperature. The use of packed beds at elevated temperature is not an issue. However, the TPOC requested revision of this initial proposal to included single particle measurements at elevated temperatures up to 1100 C. To accommodate the desire of NEUP to extend the single particle EDB measurements to elevated temperatures it was necessary to significantly revise the plan and the budget. These revisions were approved. In the EDB method, we levitate a single graphite particle (the size, surface characteristics, morphology, purity, and composition of the particle can be varied) or agglomerate in the balance and measure the sorption of species by observing the changes in mass. This process involves the use of an electron stepping technique to measure the total charge on a particle which, in conjunction with the measured suspension voltages for the particle, allows for determinations of mass and, hence, of mass changes which then correspond to measurements of sorption. Accommodating elevated temperatures with this type of system required a significant system redesign and required additional time that ultimately was not available. These constraints also meant that the grant had to focus on fewer species as a result. Overall, the extension of the original proposed single particle work to elevated temperatures added greatly to the complexity of the proposed project and added greatly to the time that would eventually be required as well. This means that the bulk of the experimental progress was made using the packed bed sorption systems. Only being able to recruit one

  20. Muon Tracking to Detect Special Nuclear Materials

    SciTech Connect (OSTI)

    Schwellenbach, D.; Dreesen, W.; Green, J. A.; Tibbitts, A.; Schotik, G.; Borozdin, K.; Bacon, J.; Midera, H.; Milner, C.; Morris, C.; Perry, J.; Barrett, S.; Perry, K.; Scott, A.; Wright, C.; Aberle, D.

    2013-03-18

    Previous experiments have proven that nuclear assemblies can be imaged and identified inside of shipping containers using vertical trajectory cosmic-ray muons with two-sided imaging. These experiments have further demonstrated that nuclear assemblies can be identified by detecting fission products in coincidence with tracked muons. By developing these technologies, advanced sensors can be designed for a variety of warhead monitoring and detection applications. The focus of this project is to develop tomographic-mode imaging using near-horizontal trajectory muons in conjunction with secondary particle detectors. This will allow imaging in-situ without the need to relocate the objects and will enable differentiation of special nuclear material (SNM) from other high-Z materials.

  1. Sun tracking controller

    SciTech Connect (OSTI)

    Menser, H.K.; Newcomb, R.D.

    1981-11-24

    An apparatus is described which controls the electric tracking motors of solar energy collectors and other solar devices which are adapted to be aimed at the sun.

  2. Liquid uranium alloy-helium fission reactor

    DOE Patents [OSTI]

    Minkov, Vladimir (Skokie, IL)

    1986-01-01

    This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

  3. Fission Barriers of Compound Superheavy Nuclei

    SciTech Connect (OSTI)

    Pei, Junchen; Nazarewicz, Witold; Sheikh, J. A.; Kerman, A. K.

    2009-01-01

    The dependence of fission barriers on the excitation energy of the compound nucleus impacts the survival probability of superheavy nuclei synthesized in heavy-ion fusion reactions. We study the temperature-dependent fission barriers by means of the self-consistent nuclear density functional theory. The equivalence of isothermal and isentropic descriptions is demonstrated. The effect of the particle gas is found to be negligible in the range of temperatures studied. Calculations have been carried out for ^{264}Fm, ^{272}Ds, ^{278}112, ^{292}114, and ^{312}124. For nuclei around ^{278}112 produced in "cold fusion" reactions, we predict a more rapid decrease of fission barriers with temperature as compared to the nuclei around ^{292}114 synthesized in "hot fusion" experiments. This is explained in terms of the difference between the ground-state and fission-barrier temperatures. Our calculations are consistent with the long survival probabilities of the superheavy elements produced in Dubna with the ^{48}Ca beam.

  4. Liquid uranium alloy-helium fission reactor

    DOE Patents [OSTI]

    Minkov, V.

    1984-06-13

    This invention describes a nuclear fission reactor which has a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200 to 1800/sup 0/C range, and even higher to 2500/sup 0/C.

  5. Large scale tracking algorithms.

    SciTech Connect (OSTI)

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  6. Fission rate measurements in fuel plate type assembly reactor cores

    SciTech Connect (OSTI)

    Rogers, J.W.

    1988-01-01

    The methods, materials and equipment have been developed to allow extensive and precise measurement of fission rate distributions in water moderated, U-Al fuel plate assembly type reactor cores. Fission rate monitors are accurately positioned in the reactor core, the reactor is operated at a low power for a short time, the fission rate monitors are counted with detectors incorporating automated sample changers and the measurements are converted to fission rate distributions. These measured fission rate distributions have been successfully used as baseline information related to the operation of test and experimental reactors with respect to fission power and distribution, fuel loading and fission experiments for approximately twenty years at the Idaho National Engineering Laboratory (INEL). 7 refs., 8 figs.

  7. TRACKED VEHICLE Rev 75

    SciTech Connect (OSTI)

    Raby, Eric Y.

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parameters of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.

  8. TRACKED VEHICLE Rev 75

    Energy Science and Technology Software Center (OSTI)

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parametersmore » of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.« less

  9. Fusion-fission energy systems evaluation

    SciTech Connect (OSTI)

    Teofilo, V.L.; Aase, D.T.; Bickford, W.E.

    1980-01-01

    This report serves as the basis for comparing the fusion-fission (hybrid) energy system concept with other advanced technology fissile fuel breeding concepts evaluated in the Nonproliferation Alternative Systems Assessment Program (NASAP). As such, much of the information and data provided herein is in a form that meets the NASAP data requirements. Since the hybrid concept has not been studied as extensively as many of the other fission concepts being examined in NASAP, the provided data and information are sparse relative to these more developed concepts. Nevertheless, this report is intended to provide a perspective on hybrids and to summarize the findings of the rather limited analyses made to date on this concept.

  10. Emilio Segrè and Spontaneous Fission

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Emilio Segrè and Spontaneous Fission As the staff at Los Alamos began research in the spring of 1943, the most formidable problems it confronted were related to the new materials that would be used in atomic bombs. These materials, uranium-235 and plutonium, were largely unknown. Uranium-235 formed only a tiny fraction of natural uranium (less than 1 percent) and plutonium had been discovered only two years earlier at the University of California, Berkeley, Radiation Laboratory by chemistry

  11. Capture and fission with DANCE and NEUANCE

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jandel, M.; Baramsai, B.; Bond, E.; Rusev, G.; Walker, C.; Bredeweg, T. A.; Chadwick, M. B.; Couture, A.; Fowler, M. M.; Hayes, A.; et al

    2015-12-23

    A summary of the current and future experimental program at DANCE is presented. Measurements of neutron capture cross sections are planned for many actinide isotopes with the goal to reduce the present uncertainties in nuclear data libraries. Detailed studies of capture gamma rays in the neutron resonance region will be performed in order to derive correlated data on the de-excitation of the compound nucleus. New approaches on how to remove the DANCE detector response from experimental data and retain the correlations between the cascade gamma rays are presented. Studies on 235U are focused on quantifying the population of short-lived isomericmore » states in 236U after neutron capture. For this purpose, a new neutron detector array NEUANCE is under construction. It will be installed in the central cavity of the DANCE array and enable the highly efficient tagging of fission and capture events. In addition, developments of fission fragment detectors are also underway to expand DANCE capabilities to measurements of fully correlated data on fission observables.« less

  12. Undergraduate Measurements For Fission Reactor Applications

    SciTech Connect (OSTI)

    Hicks, S. F.; Kersting, L. J.; Lueck, C. J.; McDonough, P.; Crider, B. P.; McEllistrem, M. T.; Peters, E. E.; Vanhoy, J. R.

    2011-06-01

    Undergraduate students at the University of Dallas (UD) have investigated elastic and inelastic neutron scattering cross sections on structural materials important for criticality considerations in nuclear fission processes. Neutrons scattered off of {sup 23}Na and {sup Nat}Fe were detected using neutron time-of-flight techniques at the University of Kentucky Low-Energy Nuclear Accelerator Facility. These measurements are part of an effort to increase the efficiency of power generation from existing fission reactors in the US and in the design of new fission systems. Students have learned the basics of how to operate the Model CN Van de Graaff generator at the laboratory, setup detectors and electronics, use data acquisition systems, and they are currently analyzing the angular dependence of the scattered neutrons for incident neutron energies of 3.57 and 3.80 MeV. Most students participating in the project will use the research experience as the material for their undergraduate research thesis required for all Bachelor of Science students at the University of Dallas. The first student projects on this topic were completed during the summer of 2010; an overview of student participation in this investigation and their preliminary results will be presented.

  13. Capture and fission with DANCE and NEUANCE

    SciTech Connect (OSTI)

    Jandel, M.; Baramsai, B.; Bond, E.; Rusev, G.; Walker, C.; Bredeweg, T. A.; Chadwick, M. B.; Couture, A.; Fowler, M. M.; Hayes, A.; Kawano, T.; Mosby, S.; Stetcu, I.; Taddeucci, T. N.; Talou, P.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.

    2015-12-23

    A summary of the current and future experimental program at DANCE is presented. Measurements of neutron capture cross sections are planned for many actinide isotopes with the goal to reduce the present uncertainties in nuclear data libraries. Detailed studies of capture gamma rays in the neutron resonance region will be performed in order to derive correlated data on the de-excitation of the compound nucleus. New approaches on how to remove the DANCE detector response from experimental data and retain the correlations between the cascade gamma rays are presented. Studies on 235U are focused on quantifying the population of short-lived isomeric states in 236U after neutron capture. For this purpose, a new neutron detector array NEUANCE is under construction. It will be installed in the central cavity of the DANCE array and enable the highly efficient tagging of fission and capture events. In addition, developments of fission fragment detectors are also underway to expand DANCE capabilities to measurements of fully correlated data on fission observables.

  14. Calculated fission properties of the heaviest elements

    SciTech Connect (OSTI)

    Moeller, P.; Nix, J.R.; Swiatecki, W.J.

    1986-09-01

    A quantitative calculation is presented that shows where high-kinetic-energy symmetric fission occurs and why it is associated with a sudden and large decrease in fission half-lives. The study is based on calculations of potential-energy surfaces in the macroscopic-microscopic model and a semi-empirical model for the nuclear inertia. For the macroscopic part a Yukawa-plus-exponential model is used and for the microscopic part a folded-Yukawa single-particle potential is used. The three-quadratic-surface parameterization generates shapes for which the potential-energy surfaces are calculated. The use of this parameterization and the use of the finite-range macroscopic model allows for the study of two touching spheres and similar shapes. The results of the calculations in terms of potential-energy surfaces and fission half-lives are presented for heavy even nuclei. The surfaces are displayed in the form of contour diagrams as functions of two moments of the shape. 53 refs., 15 figs., 1 tab.

  15. Energy Tracking Software Platform

    SciTech Connect (OSTI)

    Ryan Davis; Nathan Bird; Rebecca Birx; Hal Knowles

    2011-04-04

    Acceleration has created an interactive energy tracking and visualization platform that supports decreasing electric, water, and gas usage. Homeowners have access to tools that allow them to gauge their use and track progress toward a smaller energy footprint. Real estate agents have access to consumption data, allowing for sharing a comparison with potential home buyers. Home builders have the opportunity to compare their neighborhood's energy efficiency with competitors. Home energy raters have a tool for gauging the progress of their clients after efficiency changes. And, social groups are able to help encourage members to reduce their energy bills and help their environment. EnergyIT.com is the business umbrella for all energy tracking solutions and is designed to provide information about our energy tracking software and promote sales. CompareAndConserve.com (Gainesville-Green.com) helps homeowners conserve energy through education and competition. ToolsForTenants.com helps renters factor energy usage into their housing decisions.

  16. MATERIAL TRACKING USING LANMAS

    SciTech Connect (OSTI)

    Armstrong, F.

    2010-06-07

    LANMAS is a transaction-based nuclear material accountability software product developed to replace outdated and legacy accountability systems throughout the DOE. The core underlying purpose of LANMAS is to track nuclear materials inventory and report transactions (movement, mixing, splitting, decay, etc.) to the Nuclear Materials Management and Safeguards System (NMMSS). While LANMAS performs those functions well, there are many additional functions provided by the software product. As a material is received onto a site or created at a site, its entire lifecycle can be tracked in LANMAS complete to its termination of safeguards. There are separate functions to track material movements between and within material balance areas (MBAs). The level of detail for movements within a MBA is configurable by each site and can be as high as a site designation or as detailed as building/room/rack/row/position. Functionality exists to track the processing of materials, either as individual items or by modeling a bulk process as an individual item to track inputs and outputs from the process. In cases where sites have specialized needs, the system is designed to be flexible so that site specific functionality can be integrated into the product. This paper will demonstrate how the software can be used to input material into an account and track it to its termination of safeguards.

  17. Time dependent particle emission from fission products (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Time dependent particle emission from fission products Citation Details In-Document Search Title: Time dependent particle emission from fission products Decay heating following nuclear fission is an important factor in the design of nuclear facilities; impacting a variety of aspects ranging from cooling requirements to shielding design. Calculations of decay heat, often assumed to be a simple product of activity and average decay product energy, are complicated by the so

  18. A microscopic theory of low energy fission: fragment properties

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: A microscopic theory of low energy fission: fragment properties Citation Details In-Document Search Title: A microscopic theory of low energy fission: fragment properties Authors: Younes, W ; Gogny, D ; Schunck, N Publication Date: 2013-01-11 OSTI Identifier: 1062214 Report Number(s): LLNL-PROC-609985 DOE Contract Number: W-7405-ENG-48 Resource Type: Conference Resource Relation: Conference: Presented at: Fifth International Conference on Fission

  19. Fifty years of nuclear fission: Nuclear data and measurements series

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Fifty years of nuclear fission: Nuclear data and measurements series Citation Details In-Document Search Title: Fifty years of nuclear fission: Nuclear data and measurements series This report is the written version of a colloquium first presented at Argonne National Laboratory in January 1989. The paper begins with an historical preamble about the events leading to the discovery of nuclear fission. This leads naturally to an account of early results and

  20. Neutron flux profile monitor for use in a fission reactor

    DOE Patents [OSTI]

    Kopp, Manfred K.; Valentine, Kenneth H.

    1983-01-01

    A neutron flux monitor is provided which consists of a plurality of fission counters arranged as spaced-apart point detectors along a delay line. As a fission event occurs in any one of the counters, two delayed current pulses are generated at the output of the delay line. The time separation of the pulses identifies the counter in which the particular fission event occured. Neutron flux profiles of reactor cores can be more accurately measured as a result.

  1. September 2013 Most Viewed Documents for Fission And Nuclear...

    Office of Scientific and Technical Information (OSTI)

    September 2013 Most Viewed Documents for Fission And Nuclear Technologies Estimation of ... Tianfu; Pruess, Karsten (2001) 45 LWR nuclear fuel bundle data for use in fuel bundle ...

  2. June 2015 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    June 2015 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas ... MIGRATION IN SOILS OF THE CHERNOBYL NUCLEAR POWER PLANT EXCLUSION ZONE Farfan, E ...

  3. Most Viewed Documents for Fission and Nuclear Technologies: December...

    Office of Scientific and Technical Information (OSTI)

    Most Viewed Documents for Fission and Nuclear Technologies: December 2014 Stress analysis ... States)) (1992) 67 Behavior of spent nuclear fuel in water pool storage Johnson, A.B. ...

  4. March 2016 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    March 2016 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas ... methods and test results utilized for nuclear core applications (LWBR Development ...

  5. December 2015 Most Viewed Documents for Fission And Nuclear Technologi...

    Office of Scientific and Technical Information (OSTI)

    December 2015 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas ... methods and test results utilized for nuclear core applications (LWBR Development ...

  6. Singlet Exciton Fission in Polyacenes: Photophysics and Photovoltaic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Exciton Fission in Polyacenes: Photophysics and Photovoltaic Applications December 13, ... However, the efficiency of any single-bandgap photovoltaic device under solar irradiation ...

  7. Description of Induced Nuclear Fission with Skyrme Energy Functionals...

    Office of Scientific and Technical Information (OSTI)

    Fragment Properties Citation Details In-Document Search Title: Description of Induced Nuclear Fission with Skyrme Energy Functionals: I. Static Potential Energy Surfaces and...

  8. Microscopic description of fission dynamics: finite element method...

    Office of Scientific and Technical Information (OSTI)

    Title: Microscopic description of fission dynamics: finite element method resolution of ... This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and ...

  9. Multiple scattering effects in fission neutron outputs (Conference...

    Office of Scientific and Technical Information (OSTI)

    Los Alamos National Laboratory Publication Date: 2011-02-24 OSTI Identifier: 1053153 ... Resource Relation: Conference: Fission fprogram Review, ; February 28, 2011 ; Livermore, ...

  10. Sequential Detection of Fission Processes for Harbor Defense...

    Office of Scientific and Technical Information (OSTI)

    with some interesting and feasible results; however, the fission process of SNM has not received as much attention due to its inherent complexity and required predictive nature. ...

  11. SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

    DOE Patents [OSTI]

    Boyd, G.E.; Adamson, A.W.; Schubert, J.; Russell, E.R.

    1958-10-01

    A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This process provides a convenient and efficient means for isolating plutonium.

  12. IMPACT OF FISSION PRODUCTS IMPURITY ON THE PLUTONIUM CONTENT...

    Office of Scientific and Technical Information (OSTI)

    This charter specifies that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies (UOX SNF) is not perfect and that, ...

  13. Flowsheet Testing of the Fission Product Extraction Process as...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Flowsheet Testing of the Fission Product ... generation of spent nuclear fuel requiring geologic disposal is currently being addressed. ...

  14. Fission Younes, W; Gogny, D 73 NUCLEAR PHYSICS AND RADIATION...

    Office of Scientific and Technical Information (OSTI)

    in a Time-Dependent Microscopic Theory of Fission Younes, W; Gogny, D 73 NUCLEAR PHYSICS AND RADIATION PHYSICS Abstract not provided Lawrence Livermore National Laboratory...

  15. Logging Calibration Models for Fission Neutron Sondes (September...

    Energy Savers [EERE]

    A Model for Water Factor Measurements With Fission-Neutron Logging Tools (May 1983) Field Calibration Facilities for Environmental Measurement of Radium, Thorium, and Potassium ...

  16. Yields of fission products from various actinide targets (Conference...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: Fourth International Conference on Fission and Properties of Neutron-Rich Nuclei, Sanibel Island, FL, USA, 20071111, 20071117 Research Org: Oak Ridge ...

  17. A microscopic theory of low energy fission: fragment properties...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: Presented at: Fifth International Conference on Fission and Properties of Neutron Rich Nuclei, Sanibel Island, FL, United States, Nov 04 - Nov 10, ...

  18. Axisymmetric Magnetic Mirror Fusion-Fission Hybrid (Conference...

    Office of Scientific and Technical Information (OSTI)

    Conference: Axisymmetric Magnetic Mirror Fusion-Fission Hybrid Citation Details ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  19. Axisymmetric Magnetic Mirror Fusion-Fission Hybrid (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Axisymmetric Magnetic Mirror Fusion-Fission Hybrid Citation Details ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  20. Accelerator-driven subcritical fission in molten salt core: Closing...

    Office of Scientific and Technical Information (OSTI)

    Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy Citation Details In-Document Search Title: Accelerator-driven ...

  1. Fission fragment charge and mass distributions in Pu 239 ( n...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Fission fragment charge and mass distributions in Pu 239 ( n , f ) in the adiabatic nuclear energy density functional theory Citation Details In-Document Search ...

  2. Spontaneous fission half-lives for ground state nuclides

    SciTech Connect (OSTI)

    Holden, N.E. [Brookhaven National Lab., Upton, NY (United States); Hoffman, D.C. [Lawrence Berkeley Lab., CA (United States)

    1993-08-01

    Measurements of the spontaneous fission half-lives of nuclides of elements Z = 90 to 108 have been compiled and evaluated. Recommended values are presented.

  3. January 2013 Most Viewed Documents for Fission And Nuclear Technologie...

    Office of Scientific and Technical Information (OSTI)

    January 2013 Most Viewed Documents for Fission And Nuclear Technologies Laboratory studies of shearleach processing of zircaloy clad metallic uranium reactor fuel Swanson, J.L.; ...

  4. Overview of Fusion-Fission Hybrid Blankets for Laser Inertial...

    Office of Scientific and Technical Information (OSTI)

    Hybrid Blankets for Laser Inertial Fusion Energy (LIFE) Engine Citation Details In-Document Search Title: Overview of Fusion-Fission Hybrid Blankets for Laser Inertial Fusion ...

  5. Description of Induced Nuclear Fission with Skyrme Energy Functionals...

    Office of Scientific and Technical Information (OSTI)

    Description of Induced Nuclear Fission with Skyrme Energy Functionals: II. Finite Temperature Effects Citation Details In-Document Search Title: Description of Induced Nuclear ...

  6. Nuclear fission and transuranium elements: Fifty years ago

    SciTech Connect (OSTI)

    Seaborg, G.T.

    1988-09-01

    This paper reviews some historical aspects of the knowledge and discovery of transuranium elements. This fission of plutonium is discussed also. 12 refs., 6 figs.

  7. Track 10: Feedback and Improvement

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 10: Feedback and Improvement

  8. Finite Element Solver for Fission Dynamics

    Energy Science and Technology Software Center (OSTI)

    2015-01-30

    FELIX is a physics computer code used to model fission fragment mass distributions in a fully quantum-mechanical, misroscopic framework that only relies on our current knowledge of nuclear forces. It is an implementation of the time-dependent generator coordinate method (TDGCM), which simulates the dynamics of a collective quantum wave-packet assuming the motion is adiabatic. In typical applications of the TDGCM, the nuclear collective wavepacket is obtained as a superposition of wavefunctions obtained by solving themore » Hartree-Fock-Bogoliubov equations of nuclear density functional theory (DFT). The program calculates at each time step the coefficients of that superposition.« less

  9. Fission gas retention in irradiated metallic fuel

    SciTech Connect (OSTI)

    Fenske, G.R.; Gruber, E.E.; Kramer, J.M.

    1987-01-01

    Theoretical calculations and experimental measurements of the quantity of retained fission gas in irradiated metallic fuel (U-5Fs) are presented. The calculations utilize the Booth method to model the steady-state release of gases from fuel grains and a simplified grain-boundary gas model to predict the gas release from intergranular regions. The quantity of gas retained in as-irradiated fuel was determined by collecting the gases released from short segments of EBR-II driver fuel that were melted in a gas-tight furnace. Comparison of the calculations to the measurements shows quantitative agreement with both the magnitude and the axial variation of the retained gas content.

  10. SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS

    DOE Patents [OSTI]

    Nicholls, C.M.; Wells, I.; Spence, R.

    1959-10-13

    The separation of uranium and plutonium from neutronirradiated uranium is described. The neutron-irradiated uranium is dissolved in nitric acid to provide an aqueous solution 3N in nitric acid. The fission products of the solution are extruded by treating the solution with dibutyl carbitol substantially 1.8N in nitric acid. The organic solvent phase is separated and neutralized with ammonium hydroxide and the plutonium reduced with hydroxylamine base to the trivalent state. Treatment of the mixture with saturated ammonium nitrate extracts the reduced plutonium and leaves the uranium in the organic solvent.

  11. Controlled Document Tracking Software

    Energy Science and Technology Software Center (OSTI)

    1992-08-24

    MANTRACK is an automated, controlled document tracking system which does the following and reduces staff time required to perform these tasks: generates transmittal letters/receipts for every controlled copy issued (merged from a current distribution list), tracks the return of transmittal receipts, facilitates the check-in of the large number of transmittal receipts returned (using a barcode reader), generates a reminder list which prompts the cyclic review and evaluation of existing documents, generates overdue reminders for themore » return of past-due transmittal receipts, tracks the number of Procedure Change Directives (PCD) currently in effect for each procedure, generates and maintains current distribution lists for each document, generates a current table of contents when updates to the document (usually a procedure manual) are made.« less

  12. Pairing-induced speedup of nuclear spontaneous fission

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sadhukhan, Jhilam; Dobaczewski, J.; Nazarewicz, W.; Sheikh, J. A.; Baran, A.

    2014-12-22

    Collective inertia is strongly influenced at the level crossing at which the quantum system changes its microscopic configuration diabatically. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of these configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of 264Fm and 240Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM* and a density-dependentmore » pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of 264Fm, where the effect of triaxiality on the fission barrier is large, the geometry of the fission pathway in the space of the shape degrees of freedom is weakly impacted by pairing. This is not the case for 240Pu, where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. As a result, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.« less

  13. Pairing-induced speedup of nuclear spontaneous fission

    SciTech Connect (OSTI)

    Sadhukhan, Jhilam; Dobaczewski, J.; Nazarewicz, W.; Sheikh, J. A.; Baran, A.

    2014-12-22

    Collective inertia is strongly influenced at the level crossing at which the quantum system changes its microscopic configuration diabatically. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of these configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of 264Fm and 240Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM* and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of 264Fm, where the effect of triaxiality on the fission barrier is large, the geometry of the fission pathway in the space of the shape degrees of freedom is weakly impacted by pairing. This is not the case for 240Pu, where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. As a result, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.

  14. Electroplating method for producing ultralow-mass fissionable deposits

    DOE Patents [OSTI]

    Ruddy, Francis H.

    1989-01-01

    A method for producing ultralow-mass fissionable deposits for nuclear reactor dosimetry is described, including the steps of holding a radioactive parent until the radioactive parent reaches secular equilibrium with a daughter isotope, chemically separating the daughter from the parent, electroplating the daughter on a suitable substrate, and holding the electroplated daughter until the daughter decays to the fissionable deposit.

  15. SEPARATION OF FISSION PRODUCTS FROM PLUTONIUM BY PRECIPITATION

    DOE Patents [OSTI]

    Seaborg, G.T.; Thompson, S.G.; Davidson, N.R.

    1959-09-01

    Fission product separation from hexavalent plutonium by bismuth phosphate precipitation of the fission products is described. The precipitation, according to this invention, is improved by coprecipitating ceric and zirconium phosphates (0.05 to 2.5 grams/liter) with the bismuth phosphate.

  16. REGENERATION OF FISSION-PRODUCT-CONTAINING MAGNESIUM-THORIUM ALLOYS

    DOE Patents [OSTI]

    Chiotti, P.

    1964-02-01

    A process of regenerating a magnesium-thorium alloy contaminated with fission products, protactinium, and uranium is presented. A molten mixture of KCl--LiCl-MgCl/sub 2/ is added to the molten alloy whereby the alkali, alkaline parth, and rare earth fission products (including yttrium) and some of the thorium and uranium are chlorinated and

  17. Recent advances in nuclear fission theory: pre- and post-scission...

    Office of Scientific and Technical Information (OSTI)

    Recent advances in nuclear fission theory: pre- and post-scission physics Citation Details In-Document Search Title: Recent advances in nuclear fission theory: pre- and ...

  18. Fission energy program of the US Department of Energy, FY 1981

    SciTech Connect (OSTI)

    Ferguson, Robert L.

    1980-03-01

    Information is presented concerning the National Energy Plan and fission energy policy; fission energy program management; converter reactor systems; breeder reactor systems; and special nuclear evaluations and systems.

  19. RES Energy Track

    Broader source: Energy.gov [DOE]

    ​The Office of Indian Energy is hosting an Energy Track featuring breakout sessions on a variety of topics, including workforce development, energy technology, and capacity building, to help tribal energy leaders and professionals make informed decisions about energy projects.

  20. Solar tracking device

    SciTech Connect (OSTI)

    Wyland, R.R.

    1981-01-20

    A solar tracking device having a plurality of reflector banks for reflecting the sun rays onto collector tubes and heating a fluid circulated therethrough. The reflector banks synchronized to follow the sun during the daily and yearly cycle of the earth as the earth orbits around the sun. The device by accurately following the sun provides a more efficient means of collecting solar energy.

  1. Fission matrix capability for MCNP, Part II - Applications

    SciTech Connect (OSTI)

    Carney, S. E.; Brown, F. B.; Kiedrowski, B. C.; Martin, W. R.

    2013-07-01

    This paper describes the initial experience and results from implementing a fission matrix capability into the MCNP Monte Carlo code. The fission matrix is obtained at essentially no cost during the normal simulation for criticality calculations. It can be used to provide estimates of the fundamental mode power distribution, the reactor dominance ratio, the eigenvalue spectrum, and higher mode spatial eigenfunctions. It can also be used to accelerate the convergence of the power method iterations. Past difficulties and limitations of the fission matrix approach are overcome with a new sparse representation of the matrix, permitting much larger and more accurate fission matrix representations. Numerous examples are presented. A companion paper (Part I - Theory) describes the theoretical basis for the fission matrix method. (authors)

  2. Improved Fission Neutron Data Base for Active Interrogation of Actinides

    SciTech Connect (OSTI)

    Pozzi, Sara; Czirr, J. Bart; Haight, Robert; Kovash, Michael; Tsvetkov, Pavel

    2013-11-06

    This project will develop an innovative neutron detection system for active interrogation measurements. Many active interrogation methods to detect fissionable material are based on the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. The energy spectrum of the fission neutrons provides data to identify the fissionable isotopes and materials such as shielding between the fissionable material and the detector. The proposed path for the project is as follows. First, the team will develop new neutron detection systems and algorithms by Monte Carlo simulations and bench-top experiments. Next, They will characterize and calibrate detection systems both with monoenergetic and white neutron sources. Finally, high-fidelity measurements of neutron emission from fissions induced by fast neutrons will be performed. Several existing fission chambers containing U-235, Pu-239, U-238, or Th-232 will be used to measure the neutron-induced fission neutron emission spectra. The challenge for making confident measurements is the detection of neutrons in the energy ranges of 0.01 1 MeV and above 8 MeV, regions where the basic data on the neutron energy spectrum emitted from fission is least well known. In addition, improvements in the specificity of neutron detectors are required throughout the complete energy range: they must be able to clearly distinguish neutrons from other radiations, in particular gamma rays and cosmic rays. The team believes that all of these challenges can be addressed successfully with emerging technologies under development by this collaboration. In particular, the collaboration will address the area of fission neutron emission spectra for isotopes of interest in the advanced fuel cycle initiative (AFCI).

  3. Turkey Track Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    Track Wind Farm Jump to: navigation, search Name Turkey Track Wind Farm Facility Turkey Track Wind Farm Sector Wind energy Facility Type Commercial Scale Wind Facility Status In...

  4. Tracking the Elusive QOOH Radical

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Tracking Santa With Our Eyes in the Sky Tracking Santa With Our Eyes in the Sky December 24, 2013 - 10:00am Addthis The Energy Department's Los Alamos National Lab is tracking Santa Claus as he circles the globe the night before Christmas. The Energy Department's Los Alamos National Lab is tracking Santa Claus as he circles the globe the night before Christmas. Michael Hess Michael Hess Former Digital Communications Specialist, Office of Public Affairs Every year since 1998, the Energy

  5. Control system for a small fission reactor

    DOE Patents [OSTI]

    Burelbach, J.P.; Kann, W.J.; Saiveau, J.G.

    1985-02-08

    A system for controlling the reactivity of a small fission reactor includes an elongated, flexible hollow tube in the general form of a helical coiled spring axially positioned around and outside of the reactor vessel in an annular space between the reactor vessel and a surrounding cylindrical-shaped neutron reflector. A neutron absorbing material is provided within the hollow tube with the rate of the reaction controlled by the extension and compression of the hollow tube, e.g., extension of the tube increases reactivity while its compression reduces reactivity, in varying the amount of neutron absorbing material disposed between the reactor vessel and the neutron reflector. Conventional mechanical displacement means may be employed to control the coil density of the hollow tube as desired.

  6. Detecting fission from special nuclear material sources

    DOE Patents [OSTI]

    Rowland, Mark S.; Snyderman, Neal J.

    2012-06-05

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. The system includes a graphing component that displays the plot of the neutron distribution from the unknown source over a Poisson distribution and a plot of neutrons due to background or environmental sources. The system further includes a known neutron source placed in proximity to the unknown source to actively interrogate the unknown source in order to accentuate differences in neutron emission from the unknown source from Poisson distributions and/or environmental sources.

  7. Suppressed-fission ICF hybrid reactor

    SciTech Connect (OSTI)

    Hogan, W.J.; Meier, W.R.

    1986-05-20

    A suppressed-fission ICF hybrid reactor has been designed to maximize the production of /sup 233/U. In this design, Be is used as a neutron multiplier. An annular array of Be columns surrounds the fusion pulse inside the reaction chember. The Be columns consist of short cylinders of Be joined together with steel snap rings. Vertical holes in the Be carry liquid lithium coolant and steel-clad thorium fuel pins. The lithium coolant is supplied at the top of the chamber, traverses through the Be columns and exits at the bottom. The columns are attached to top and bottom plates in such a way as to tolerate radiation-induced swelling and the vibrations resulting from each fusion pulse. A thin (10 cm) liquid Li fall region protects the Be columns from direct exposure to the X-rays and debris emitted by the fuel capsule. A neutronics study of this design indicates that the specific production of /sup 233/U fuel is increased by operating at relatively large thorium volume fractions. A design at a fertile fuel fraction of 30 vol % produces a total breeding ratio of over 2.1. The /sup 6/Li to /sup 7/Li ratio is adjusted to keep the tritium breeding ratio at about 1.0. In such a reactor, about 3400 kg of /sup 233/U can be produced per full power year at a fusion power level of 800 MW. Reactor support ratios greater than 13 can be achieved, leading to beneficial results even if the fusion reactor cost is significantly greater than that of a fission reactor.

  8. Feasibility of an antiproton catalyzed fission fragment rocket

    SciTech Connect (OSTI)

    Hdinger, D.S.

    1992-03-01

    The purpose of this project was to investigate the feasibility of an antiproton catalyzed fission fragment rocket (FFR). The FFR is characterized by the extraction of fission fragments from the fissile fuel, and the utilization of their kinetic energy for thrust generation. A significant drawback to previous FFR designs was the requirement to maintain a critical nuclear pile as the fission fragment source. The author examined the possibility of replacing the critical pile with a sub-critical pile driven by antiprotons. Recent experiments have revealed that antiprotons stimulate highly energetic fissions in {sup 238}U, with a neutron multiplicity of 13.7 neutrons per fission. This interaction was used as a throttled neutron source. The pile consisted of layers of fissile coated fibers which are designed to allow fission fragments to escape them, where the fragments collide with a fluid. The heated fluid is then ejected from the rocket to provide thrust. The calculations performed indicate that each antiproton injected into the pile can stimulate 8 or more fissions while maintaining a neutron multiplication of less than 0.4. Based on the results seen, the engine design presented is inadequate. Limitations introduced by the reaction fluid far outweigh the simplicity-of-design gained. Despite this, the basic idea of using the antiproton-U interaction as a source of spacecraft propulsion warrants further study.

  9. A New Method of Prompt Fission Neutron Energy Spectrum Unfolding

    SciTech Connect (OSTI)

    Zeynalova, O. V. [Moscow State Institute of Radioengineering, Electronics and Automation, Moscow (Russian Federation); Joint Institute for Nuclear Research, Dubna (Russian Federation); Zeynalov, Sh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Hambsch, F.-J.; Oberstedt, S. [EC-JRC-Institute for Reference Materials and Measurements, Geel (Belgium)

    2010-11-25

    The prompt neutron emission in spontaneous fission of {sup 252}Cf has been investigated applying digital signal electronics along with associated digital signal processing algorithms. The goal was to find out the reasons of a long time existing discrepancy between theoretical calculations and the measurements of prompt fission neutron (PFN) emission dependence on the total kinetic energy (TKE) of fission fragments (FF). On the one hand the {sup 252}Cf(sf) reaction is one of the main references for nuclear data, on the other hand the understanding of PFN emission mechanism is very important for nuclear fission theory. Using a twin Frisch-grid ionization chamber for fission fragment (FF) detection and a NE213-equivalent neutron detector in total about 10{sup 7} fission fragment-neutron coincidences have been registered. Fission fragment kinetic energy, mass and angular distribution, neutron time-of-flight and pulse shape have been investigated using a 12 bit waveform digitizer. The signal waveforms have been analyzed using digital signal processing algorithms. For the first time the dependence of the number of emitted neutrons as a function of total kinetic energy (TKE) of the fragments is in very good agreement with theoretical calculations in the range of TKE from 140-220 MeV.

  10. PARTICLE BEAM TRACKING CIRCUIT

    DOE Patents [OSTI]

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  11. The fusion-fission process in the reaction {sup 34}S+{sup 186}W near the interaction barrier

    SciTech Connect (OSTI)

    Harca, I. M.; Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K.; Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D.; Hanappe, F.; Piot, J.; Schmitt, C.; Vardaci, E.

    2015-02-24

    The reaction {sup 34}S+{sup 186}W at E{sub lab}=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF–γ coincidence method is of better use then the γ – γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

  12. Lesson 5 - Fission and Chain Reactions | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    5 - Fission and Chain Reactions Lesson 5 - Fission and Chain Reactions Lesson Four showed how the nuclei of atoms store energy and how unstable atoms decay and release energy. How do nuclear engineers use this knowledge to help them harness energy to make electricity? The answer lies in being able to start a nuclear chain reaction in fuel inside a nuclear power plant and keep it going. This lesson examines nuclear reactions called fission as well as how uranium is processed from ore to fuel.

  13. Sensitivity analysis of the fission gas behavior model in BISON.

    SciTech Connect (OSTI)

    Swiler, Laura Painton; Pastore, Giovanni; Perez, Danielle; Williamson, Richard

    2013-05-01

    This report summarizes the result of a NEAMS project focused on sensitivity analysis of a new model for the fission gas behavior (release and swelling) in the BISON fuel performance code of Idaho National Laboratory. Using the new model in BISON, the sensitivity of the calculated fission gas release and swelling to the involved parameters and the associated uncertainties is investigated. The study results in a quantitative assessment of the role of intrinsic uncertainties in the analysis of fission gas behavior in nuclear fuel.

  14. Interplay between compound and fragments aspects of nuclear fission and

    Office of Scientific and Technical Information (OSTI)

    heavy-ion reaction (Conference) | SciTech Connect Conference: Interplay between compound and fragments aspects of nuclear fission and heavy-ion reaction Citation Details In-Document Search Title: Interplay between compound and fragments aspects of nuclear fission and heavy-ion reaction The scission point in nuclear fission plays a special role where one-body system changes to two-body system. Inverse of this situation is realized in heavy-ion fusion reaction where two-body system changes to

  15. Measurements of actinide-fission product yields in Caliban and Prospero metallic core reactor fission neutron fields

    SciTech Connect (OSTI)

    Casoli, P.; Authier, N. [CEA, Centre de Valduc, 21120 Is-sur-Tille (France); Laurec, J.; Bauge, E.; Granier, T. [CEA, Centre DIF, 91297 Arpajon (France)

    2011-07-01

    In the 1970's and early 1980's, an experimental program was performed on the facilities of the CEA Valduc Research Center to measure several actinide-fission product yields. Experiments were, in particular, completed on the Caliban and Prospero metallic core reactors to study fission-neutron-induced reactions on {sup 233}U, {sup 235}U, and {sup 239}Pu. Thick actinide samples were irradiated and the number of nuclei of each fission product was determined by gamma spectrometry. Fission chambers were irradiated simultaneously to measure the numbers of fissions in thin deposits of the same actinides. The masses of the thick samples and the thin deposits were determined by mass spectrometry and alpha spectrometry. The results of these experiments will be fully presented in this paper for the first time. A description of the Caliban and Prospero reactors, their characteristics and performances, and explanations about the experimental approach will also be given in the article. A recent work has been completed to analyze and reinterpret these measurements and particularly to evaluate the associated uncertainties. In this context, calculations have also been carried out with the Monte Carlo transport code Tripoli-4, using the published benchmarked Caliban description and a three-dimensional model of Prospero, to determine the average neutron energy causing fission. Simulation results will be discussed in this paper. Finally, new fission yield measurements will be proposed on Caliban and Prospero reactors to strengthen the results of the first experiments. (authors)

  16. September 2015 Most Viewed Documents for Fission And Nuclear...

    Office of Scientific and Technical Information (OSTI)

    September 2015 Most Viewed Documents for Fission And Nuclear Technologies Estimation of ... structures Chen, S.S. (1985) 167 LWR nuclear fuel bundle data for use in fuel bundle ...

  17. March 2015 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    5 Most Viewed Documents for Fission And Nuclear Technologies Stress analysis and ... Maimoni, A. (1980) 101 Behavior of spent nuclear fuel in water pool storage Johnson, A.B. ...

  18. Most Viewed Documents for Fission And Nuclear Technologies: September...

    Office of Scientific and Technical Information (OSTI)

    Most Viewed Documents for Fission And Nuclear Technologies: September 2014 Estimation of ... H.J. (1977) 71 Behavior of spent nuclear fuel in water pool storage Johnson, A.B. ...

  19. March 2014 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    4 Most Viewed Documents for Fission And Nuclear Technologies Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (1977) 72 Peer-review study of the draft ...

  20. July 2013 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    July 2013 Most Viewed Documents for Fission And Nuclear Technologies Estimation of gas ... Ho, F.H. (1988) 136 Behavior of spent nuclear fuel in water pool storage Johnson, A.B. ...

  1. June 2014 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    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 ...

  2. Most Viewed Documents - Fission and Nuclear Technologies | OSTI...

    Office of Scientific and Technical Information (OSTI)

    Fission and Nuclear Technologies Metals design handbook Betts, W.S. (1988) Estimation of gas leak rates through very small orifices and channels. From sealed PuOsub 2 containers ...

  3. April 2013 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    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 ...

  4. Microscopic Theory of Nuclear Fission: Recent Highlights | Argonne...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    world, a predictive theory of fission should instead be based solely on quantum many-body methods and our best knowledge of nuclear forces. Today, there is a consensus that...

  5. Fusion-fission hybrid studies in the United States

    SciTech Connect (OSTI)

    Moir, R.W.; Lee, J.D.; Berwald, D.H.; Cheng, E.T.; Delene, J.G.; Jassby, D.L.

    1986-05-20

    Systems and conceptual design studies have been carried out on the following three hybrid types: (1) The fission-suppressed hybrid, which maximizes fissile material produced (Pu or /sup 233/U) per unit of total nuclear power by suppressing the fission process and multiplying neutrons by (n,2n) reactions in materials like beryllium. (2) The fast-fission hybrid, which maximizes fissile material produced per unit of fusion power by maximizing fission of /sup 238/U (Pu is produced) in which twice the fissile atoms per unit of fusion power (but only a third per unit of nuclear power) are made. (3) The power hybrid, which amplifies power in the blanket for power production but does not produce fuel to sell. All three types must sell electrical power to be economical.

  6. Reference reactor module for NASA's lunar surface fission power...

    Office of Scientific and Technical Information (OSTI)

    The reactor concept uses stainless-steel based. UOsub 2-fueled, pumped-NaK fission reactor coupled to free-piston Stirling converters. The reactor shielding approach utilizes ...

  7. Harvesting Solar Energy from Singlet Fission Materials | MIT...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Harvesting Solar Energy from Singlet Fission Materials April 19, 2016 at 4:30pm 36-428 Sean Roberts Department of Chemistry, The University of Texas at Austin s.roberts.001 A loss ...

  8. New Type of Asymmetric Fission in Proton-Rich Nuclei

    SciTech Connect (OSTI)

    Andreyev, A. N.; Elseviers, J.; Huyse, M.; Van Duppen, P.; Bree, N.; Cocolios, T. E.; Diriken, J.; Ivanov, O.; Van den Bergh, P.; Antalic, S.; Barzakh, A.; Fedorov, D.; Comas, V. F.; Heredia, J. A.; Fedosseev, V.; Marsh, B. A.; Van De Walle, J.; Franchoo, S.; Nishio, K.

    2010-12-17

    A very exotic process of {beta}-delayed fission of {sup 180}Tl is studied in detail by using resonant laser ionization with subsequent mass separation at ISOLDE (CERN). In contrast to common expectations, the fission-fragment mass distribution of the post-{beta}-decay daughter nucleus {sup 180}Hg (N/Z=1.25) is asymmetric. This asymmetry is more surprising since a mass-symmetric split of this extremely neutron-deficient nucleus would lead to two {sup 90}Zr fragments, with magic N=50 and semimagic Z=40. This is a new type of asymmetric fission, not caused by large shell effects related to fragment magic proton and neutron numbers, as observed in the actinide region. The newly measured branching ratio for {beta}-delayed fission of {sup 180}Tl is 3.6(7)x10{sup -3}%, approximately 2 orders of magnitude larger than in an earlier study.

  9. Interplay between compound and fragments aspects of nuclear fission...

    Office of Scientific and Technical Information (OSTI)

    The scission point in nuclear fission plays a special role where one-body system changes to two-body system. Inverse of this situation is realized in heavy-ion fusion reaction ...

  10. Spontaneous fission half-lives for ground state nuclides

    SciTech Connect (OSTI)

    Holden, N.E. (Brookhaven National Lab., Upton, NY (United States)); Hoffman, D.C. (Lawrence Berkeley Lab., CA (United States))

    1991-01-01

    Measurements of the spontaneous fission half-lives of nuclides of elements Z = 90 to 107 have been compiled and evaluated. Recommended values are presented. 126 refs., 96 tabs.

  11. Advanced modeling of prompt fission neutrons (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    work are reviewed briefly, and a preliminary assessment of uncertainties associated with the evaluated prompt fission neutron spectrum for n (0.5 MeV)+sup 239Pu is discussed. ...

  12. Microscopic Calculation of Fission Fragment Energies for the...

    Office of Scientific and Technical Information (OSTI)

    for the 239Pu(nth,f) Reaction Citation Details In-Document Search Title: Microscopic Calculation of Fission Fragment Energies for the 239Pu(nth,f) Reaction We calculate the ...

  13. Evaluation and compilation of fission product yields 1993

    SciTech Connect (OSTI)

    England, T.R.; Rider, B.F.

    1995-12-31

    This document is the latest in a series of compilations of fission yield data. Fission yield measurements reported in the open literature and calculated charge distributions have been used to produce a recommended set of yields for the fission products. The original data with reference sources, and the recommended yields axe presented in tabular form. These include many nuclides which fission by neutrons at several energies. These energies include thermal energies (T), fission spectrum energies (F), 14 meV High Energy (H or HE), and spontaneous fission (S), in six sets of ten each. Set A includes U235T, U235F, U235HE, U238F, U238HE, Pu239T, Pu239F, Pu241T, U233T, Th232F. Set B includes U233F, U233HE, U236F, Pu239H, Pu240F, Pu241F, Pu242F, Th232H, Np237F, Cf252S. Set C includes U234F, U237F, Pu240H, U234HE, U236HE, Pu238F, Am241F, Am243F, Np238F, Cm242F. Set D includes Th227T, Th229T, Pa231F, Am241T, Am241H, Am242MT, Cm245T, Cf249T, Cf251T, Es254T. Set E includes Cf250S, Cm244S, Cm248S, Es253S, Fm254S, Fm255T, Fm256S, Np237H, U232T, U238S. Set F includes Cm243T, Cm246S, Cm243F, Cm244F, Cm246F, Cm248F, Pu242H, Np237T, Pu240T, and Pu242T to complete fission product yield evaluations for 60 fissioning systems in all. This report also serves as the primary documentation for the second evaluation of yields in ENDF/B-VI released in 1993.

  14. Exciton Dynamics and Structural Investigations of Singlet Fission in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Molecular Solids | MIT-Harvard Center for Excitonics Exciton Dynamics and Structural Investigations of Singlet Fission in Molecular Solids October 11, 2012 at 3pm/36-428 Michael R. Wasielewski Director, Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University Wasielewski-002 Abstract: We are examining new dye molecules, which undergo singlet fission (SF), using guidance from electronic structure calculations to assure the requisite relationships between molecular

  15. Microscopic Theory of Fission (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Microscopic Theory of Fission Citation Details In-Document Search Title: Microscopic Theory of Fission Authors: Younes, W ; Gogny, D Publication Date: 2008-01-03 OSTI Identifier: 924187 Report Number(s): LLNL-PROC-400347 DOE Contract Number: W-7405-ENG-48 Resource Type: Conference Resource Relation: Conference: Presented at: Compound Nuclear Reactions and Related Topics, Fish Camp, CA, United States, Oct 22 - Oct 26, 2007 Research Org: Lawrence Livermore National Laboratory (LLNL), Livermore, CA

  16. Advancing the Fundamental Understanding of Fission: 2014 LDRD 20120077DR

    Office of Scientific and Technical Information (OSTI)

    Review (Technical Report) | SciTech Connect Advancing the Fundamental Understanding of Fission: 2014 LDRD 20120077DR Review Citation Details In-Document Search Title: Advancing the Fundamental Understanding of Fission: 2014 LDRD 20120077DR Review The following slides were presented as part of the LDRD 20120077DR Progress Appraisal Review held Tuesday, February 4, 2014. This is part of an ongoing project assessment the previous of which was documented in LA-UR-13-21182. This presentation

  17. METHOD OF TESTING THERMAL NEUTRON FISSIONABLE MATERIAL FOR PURITY

    DOE Patents [OSTI]

    Fermi, E.; Anderson, H.L.

    1961-01-24

    A process is given for determining the neutronic purity of fissionable material by the so-called shotgun test. The effect of a standard neutron absorber of known characteristics and amounts on a neutronic field also of known characteristics is measured and compared with the effect which the impurities derived from a known quantity of fissionable material has on the same neutronic field. The two readings are then made the basis of calculation from which the amount of impurities can be computed.

  18. Description of true and delayed ternary nuclear fission accompanied by the emission of various third particles

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@vsu.ru; Kadmensky, S. S.; Lyubashevsky, D. E. [Voronezh State University (Russian Federation)

    2010-08-15

    The mechanisms and the features of the main types of nuclear ternary fission (that is, true ternary fission, in which a third particle is emitted before the rupture of the fissioning nucleus into fragments, and delayed ternary fission, in which a third particle is emitted from fission fragments going apart) are investigated within quantum-mechanical fission theory. The features of T-odd asymmetry in true ternary nuclear fission induced by cold polarized neutrons are investigated for the cases where alpha particles, prescission neutrons, and photons appear as third particles emitted by fissioning nuclei, the Coriolis interaction of the spin of the polarized fissioning nucleus with the spin of the third particle and the interference between the fission amplitudes for neutron resonances excited in the fissioning nucleus in the case of projectile-neutron capture being taken into account. For the cases where third particles emitted by fission fragments are evaporated neutrons or photons, T-odd asymmetries in delayed ternary nuclear fission induced by cold polarized neutrons are analyzed with allowance for the mechanism of pumping of large fission-fragment spins oriented orthogonally to the fragment-emission direction and with allowance for the interference between the fission amplitudes for neutron resonances.

  19. Prompt fission gamma-ray studies at DANCE

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jandel, M.; Rusev, G.; Bond, E. M.; Bredeweg, T. A.; Chadwick, M. B.; Couture, A.; Fowler, M.. M; Haight, R. C.; Kawano, T.; Keksis, A. L.; et al

    2014-11-26

    Measurements of correlated data on prompt-fission γ-rays (PFG) have been carried out for various actinide isotopes in recent years using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL). We have developed a model that conveniently parametrizes the correlated data of γ-ray multiplicity and energy. New results on two- dimensional prompt-fission γ-ray multiplicity versus energy distributions from spontaneous fission on ²⁵²Cf and neutron-induced fission on 242mAm are presented together with previously obtained results on 233,235U and ²³⁹Pu. Correlated PFG data from ²⁵²Cf are also compared to results of the detailed theoretical model developed at LANL,more » for different thresholds of PFG energies. Future plans to measure correlated data on fission fragments, prompt fission neutrons and γ-rays at DANCE are presented.« less

  20. Event-by-Event Simulation of Induced Fission

    SciTech Connect (OSTI)

    Vogt, R; Randrup, J

    2007-12-13

    We are developing a novel code that treats induced fission by statistical (or Monte-Carlo) simulation of individual decay chains. After its initial excitation, the fissionable compound nucleus may either deexcite by evaporation or undergo binary fission into a large number of fission channels each with different energetics involving both energy dissipation and deformed scission prefragments. After separation and Coulomb acceleration, each fission fragment undergoes a succession of individual (neutron) evaporations, leading to two bound but still excited fission products (that may further decay electromagnetically and, ultimately, weakly), as well as typically several neutrons. (The inclusion of other possible ejectiles is planned.) This kind of approach makes it possible to study more detailed observables than could be addressed with previous treatments which have tended to focus on average quantities. In particular, any type of correlation observable can readily be extracted from a generated set of events. With a view towards making the code practically useful in a variety of applications, emphasis is being put on making it numerically efficient so that large event samples can be generated quickly. In its present form, the code can generate one million full events in about 12 seconds on a MacBook laptop computer. The development of this qualitatively new tool is still at an early stage and quantitative reproduction of existing data should not be expected until a number of detailed refinement have been implemented.

  1. The MAP kinase Pmk1 and protein kinase A are required for rotenone resistance in the fission yeast, Schizosaccharomyces pombe

    SciTech Connect (OSTI)

    Wang, Yiwei; Gulis, Galina; Buckner, Scott; Johnson, P. Connor; Sullivan, Daniel; Busenlehner, Laura; Marcus, Stevan

    2010-08-20

    Research highlights: {yields} Rotenone induces generation of ROS and mitochondrial fragmentation in fission yeast. {yields} The MAPK Pmk1 and PKA are required for rotenone resistance in fission yeast. {yields} Pmk1 and PKA are required for ROS clearance in rotenone treated fission yeast cells. {yields} PKA plays a role in ROS clearance under normal growth conditions in fission yeast. -- Abstract: Rotenone is a widely used pesticide that induces Parkinson's disease-like symptoms in rats and death of dopaminergic neurons in culture. Although rotenone is a potent inhibitor of complex I of the mitochondrial electron transport chain, it can induce death of dopaminergic neurons independently of complex I inhibition. Here we describe effects of rotenone in the fission yeast, Schizosaccharomyces pombe, which lacks complex I and carries out rotenone-insensitive cellular respiration. We show that rotenone induces generation of reactive oxygen species (ROS) as well as fragmentation of mitochondrial networks in treated S. pombe cells. While rotenone is only modestly inhibitory to growth of wild type S. pombe cells, it is strongly inhibitory to growth of mutants lacking the ERK-type MAP kinase, Pmk1, or protein kinase A (PKA). In contrast, cells lacking the p38 MAP kinase, Spc1, exhibit modest resistance to rotenone. Consistent with these findings, we provide evidence that Pmk1 and PKA, but not Spc1, are required for clearance of ROS in rotenone treated S. pombe cells. Our results demonstrate the usefulness of S. pombe for elucidating complex I-independent molecular targets of rotenone as well as mechanisms conferring resistance to the toxin.

  2. Integrated Management Tracking System

    Energy Science and Technology Software Center (OSTI)

    2000-03-30

    The Integrated Management Tracking System (IMTS) is a "Web Enabled" Client/Server Business application that provides for the Identification and Resolution of commitments, situations, events and problems. The IMTS engine is written with Microsoft Active Server Pages (ASP) for IIS4. The system provides for reporting, entering, editing, closing and administration over a Intranet, Extranet or Internet. This Application facilitates: Electronic assignment, acceptance and tracking to completion. Email notifications of assigned action. Establishment of Due Dates. Electronicmore » search and retrieval based on keywords in combination with user specified database parameters (Document Type, Date Ranges, etc.). Coded for Trending and Reporting. User selected reports. Various levels of access for reports and administration. The "Server" side of this application consists of a Microsoft Access database running on a NT Server with Internet Information Server (IIS). As the "Client" side of the application runs on any Web browser, this solution is a cost effective, user friendly application that lends itself to organizations not physically colocated in one location providing information immediately available to everyone at once.« less

  3. Control system for a small fission reactor

    DOE Patents [OSTI]

    Burelbach, James P.; Kann, William J.; Saiveau, James G.

    1986-01-01

    A system for controlling the reactivity of a small fission reactor includes an elongated, flexible hollow tube in the general form of a helical coiled spring axially positioned around and outside of the reactor vessel in an annular space between the reactor vessel and a surrounding cylindrical-shaped neutron reflector. A neutron absorbing material is provided within the hollow tube with the rate of the reaction controlled by the extension and compression of the hollow tube, e.g., extension of the tube increases reactivity while its compression reduces reactivity, in varying the amount of neutron absorbing material disposed between the reactor vessel and the neutron reflector. Conventional mechanical displacement means may be employed to control the coil density of the hollow tube as desired. In another embodiment, a plurality of flexible hollow tubes each containing a neutron absorber are positioned adjacent to one another in spaced relation around the periphery of the reactor vessel and inside the outer neutron reflector with reactivity controlled by the extension and compression of all or some of the coiled hollow tubes. Yet another embodiment of the invention envisions the neutron reflector in the form of an expandable coil spring positioned in an annular space between the reactor vessel and an outer neutron absorbing structure for controlling the neutron flux reflected back into the reactor vessel.

  4. Fission Product Transmutation in Mixed Radiation Fields

    SciTech Connect (OSTI)

    Harmon, Frank; Burgett, Erick; Starovoitova, Valeriia; Tsveretkov, Pavel

    2015-01-15

    Work under this grant addressed a part of the challenge facing the closure of the nuclear fuel cycle; reducing the radiotoxicity of lived fission products (LLFP). It was based on the possibility that partitioning of isotopes and accelerator-based transmutation on particular LLFP combined with geological disposal may lead to an acceptable societal solution to the problem of management. The feasibility of using photonuclear processes based on the excitation of the giant dipole resonance (GDR) by bremsstrahlung radiation as a cost effective transmutation method was accessed. The nuclear reactions of interest: (γ,xn), (n,γ), (γ,p) can be induced by bremsstrahlung radiation produced by high power electron accelerators. The driver of these processes would be an accelerator that produces a high energy and high power electron beam of ~ 100 MeV. The major advantages of such accelerators for this purpose are that they are essentially available “off the shelf” and potentially would be of reasonable cost for this application. Methods were examined that used photo produced neutrons or the bremsstrahlung photons only, or use both photons and neutrons in combination for irradiations of selected LLFP. Extrapolating the results to plausible engineering scale transmuters it was found that the energy cost for 129I and 99Tc transmutation by these methods are about 2 and 4%, respectively, of the energy produced from 1000MWe.

  5. REC Tracking Systems Design Guide

    SciTech Connect (OSTI)

    Meredith Wingate

    2004-02-03

    OAK-B135 The Design Guide is presented in three parts. Section II describes the need for REC tracking, the two principal tracking methods available, and, in simple terms, the operation of certificate-based systems. Section III presents the major issues in the design of certificate-based tracking systems and discusses the advantages and disadvantages of alternative solutions. Finally, Section IV offers design principles or recommendations for most of these issues.

  6. A scintillating fission detector for neutron flux measurements

    SciTech Connect (OSTI)

    Stange, Sy; Esch, Ernst I; Burgett, Eric A; May, Iain; Muenchausen, Ross E; Taw, Felicia; Tovesson, Fredrik K

    2010-01-01

    Neutron flux monitors are commonly used for a variety of nuclear physics applications. A scintillating neutron detector, consisting of a liquid scintillator loaded with fissionable material, has been developed, characterized, and tested in the beam line at the Los Alamos Neutron Science Center, and shows a significant improvement in neutron sensitivity compared with a conventional fission chamber. Recent research on nanocomposite-based scintillators for gamma-ray detection indicates that this approach can be extended to load nanoparticles of fissionable material into a scintillating matrix, with up to three orders of magnitude higher loading than typical fission chambers. This will result in a rugged, cost-efficient detector with high efficiency, a short signal rise time, and the ability to be used in low neutron-flux environments. Initial efforts to utilize the luminescence of uranyl oxide to eliminate the need for wavelength-shifting dyes were unsuccessful. Excitation of uranyl compounds has been reported at wavelengths ranging from 266 nm to 532 nm. However, neither the 300 nm emission of toluene, nor the 350 nm emission of PPO, nor the 410 nm emission of POPOP resulted in significant excitation of and emission by uranyl oxide. As indicated by UV/visible spectroscopy, light emitted at these wavelengths was absorbed by the colored solution. {sup 235}U remains the most attractive candidate for a fissionable scintillator, due to its high fission cross-section and lack of a threshold fission energy, but all solutions containing molecular uranium compounds will be colored, most more highly than the U{sup 6+} compounds used here. Research is therefore continuing toward the fabrication of uranium nanoparticles, in which, due to Rayleigh scattering, the coloration should be less pronounced. The characterization of the thorium-loaded liquid scintillator and the fabrication of the 100 mL detectors for use at LANSCE demonstrated the feasibility of loading fissionable

  7. Solar Array Tracking Control

    Energy Science and Technology Software Center (OSTI)

    1995-06-22

    SolarTrak used in conjunction with various versions of 68HC11-based SolarTrack hardware boards provides control system for one or two axis solar tracking arrays. Sun position is computed from stored position data and time from an on-board clock/calendar chip. Position feedback can be by one or two offset motor turn counter square wave signals per axis, or by a position potentiometer. A limit of 256 counts resolution is imposed by the on-board analog to digital (A/D)more » convertor. Control is provided for one or two motors. Numerous options are provided to customize the controller for specific applications. Some options are imposed at compile time, some are setable during operation. Software and hardware board designs are provided for Control Board and separate User Interface Board that accesses and displays variables from Control Board. Controller can be used with range of sensor options ranging from a single turn count sensor per motor to systems using dual turn-count sensors, limit sensors, and a zero reference sensor. Dual axis trackers oriented azimuth elevation, east west, north south, or polar declination can be controlled. Misalignments from these orientations can also be accommodated. The software performs a coordinate transformation using six parameters to compute sun position in misaligned coordinates of the tracker. Parameters account for tilt of tracker in two directions, rotation about each axis, and gear ration errors in each axis. The software can even measure and compute these prameters during an initial setup period if current from a sun position sensor or output from photovoltaic array is available as an anlog voltage to the control board''s A/D port. Wind or emergency stow to aj present position is available triggered by digital or analog signals. Night stow is also available. Tracking dead band is adjustable from narrow to wide. Numerous features of the hardware and software conserve energy for use with battery powered systems.« less

  8. Intrinsic Feature Motion Tracking

    Energy Science and Technology Software Center (OSTI)

    2013-03-19

    Subject motion during 3D medical scanning can cause blurring and artifacts in the 3D images resulting in either rescans or poor diagnosis. Anesthesia or physical restraints may be used to eliminate motion but are undesirable and can affect results. This software measures the six degree of freedom 3D motion of the subject during the scan under a rigidity assumption using only the intrinsic features present on the subject area being monitored. This movement over timemore » can then be used to correct the scan data removing the blur and artifacts. The software acquires images from external cameras or images stored on disk for processing. The images are from two or three calibrated cameras in a stereo arrangement. Algorithms extract and track the features over time and calculate position and orientation changes relative to an initial position. Output is the 3D position and orientation change measured at each image.« less

  9. The Future of Energy from Nuclear Fission

    SciTech Connect (OSTI)

    Kim, Son H.; Taiwo, Temitope

    2013-04-13

    Nuclear energy is an important part of our current global energy system, and contributes to supplying the significant demand for electricity for many nations around the world. There are 433 commercial nuclear power reactors operating in 30 countries with an installed capacity of 367 GWe as of October 2011 (IAEA PRIS, 2011). Nuclear electricity generation totaled 2630 TWh in 2010 representing 14% the worlds electricity generation. The top five countries of total installed nuclear capacity are the US, France, Japan, Russia and South Korea at 102, 63, 45, 24, and 21 GWe, respectively (WNA, 2012a). The nuclear capacity of these five countries represents more than half, 68%, of the total global nuclear capacity. The role of nuclear power in the global energy system today has been motivated by several factors including the growing demand for electric power, the regional availability of fossil resources and energy security concerns, and the relative competitiveness of nuclear power as a source of base-load electricity. There is additional motivation for the use of nuclear power because it does not produce greenhouse gas (GHG) emissions or local air pollutants during its operation and contributes to low levels of emissions throughout the lifecycle of the nuclear energy system (Beerten, J. et. al., 2009). Energy from nuclear fission primarily in the form of electric power and potentially as a source of industrial heat could play a greater role for meeting the long-term growing demand for energy worldwide while addressing the concern for climate change from rising GHG emissions. However, the nature of nuclear fission as a tremendously compact and dense form of energy production with associated high concentrations of radioactive materials has particular and unique challenges as well as benefits. These challenges include not only the safety and cost of nuclear reactors, but proliferation concerns, safeguard and storage of nuclear materials associated with nuclear fuel cycles

  10. SRNL Tagging and Tracking Video

    ScienceCinema (OSTI)

    None

    2016-06-15

    SRNL generates a next generation satellite base tracking system. The tagging and tracking system can work in remote wilderness areas, inside buildings, underground and other areas not well served by traditional GPS. It?s a perfect response to customer needs and market demand.

  11. BIA Providers Conference Energy Track

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy (DOE) Office of Indian Energy is offering an energy track at the 25th Annual BIA Tribal Providers Conference Dec. 2-3, 2015. The track will feature breakout sessions on a variety of topics to help tribal energy leaders and professionals make informed decisions about energy projects.

  12. Kinetic energy deficit in the symmetric fission of /sup 259/Md. [Light particle emission in /sup 256/Fm fission

    SciTech Connect (OSTI)

    Hulet, E.K.; Wild, J.F.; Lougheed, R.W.; Baisden, P.A.; Dougan, R.J.; Mustafa, M.G.

    1980-10-01

    The fragment energies of about 725 coincidence events have now been observed in the spontaneous fission (SF) decay of 105-min /sup 259/Md since its discovery in 1977. The fission of /sup 259/Md is characterized by a symmetric mass distribution, similar to those of /sup 258/Fm and /sup 259/Fm, but with a broad total kinetic energy (anti TKE) distribution which peaks at about 195 MeV, in contrast to those of /sup 258/Fm and /sup 259/Fm, for which the anti TKE is about 240 MeV. This kinetic energy deficit, approx. 40 MeV, has been postulated to be due to the emission of hydrogen-like particles by /sup 259/Md at the scission point in a large fraction of the fissions, leaving the residual fissioning nucleus with 100 protons. The residual nucleus would then be able to divide into two ultrastable tin-like fission fragments, but with less kinetic energy than that observed in the SF of /sup 258/Fm and /sup 259/Fm, because of binding-energy losses and a reduction in the Coulomb repulsion of the major fragments. To test this hypothesis, counter-telescope experiments aimed at detecting and identifying these light particles were performed. In 439 SF events 3 + 3 protons of the appropriate energy were observed, too few to account for the kinetic energy deficit in the fission of /sup 259/Md. There seems to be no explanation for this problem within the framework of current fission theory. These results are discussed along with preliminary measurements of light-particle emission in the SF of /sup 256/Fm. 5 figures.

  13. Initial Back-to-Back Fission Chamber Testing in ATRC

    SciTech Connect (OSTI)

    Benjamin Chase; Troy Unruh; Joy Rempe

    2014-06-01

    Development and testing of in-pile, real-time neutron sensors for use in Materials Test Reactor experiments is an ongoing project at Idaho National Laboratory. The Advanced Test Reactor National Scientific User Facility has sponsored a series of projects to evaluate neutron detector options in the Advanced Test Reactor Critical Facility (ATRC). Special hardware was designed and fabricated to enable testing of the detectors in the ATRC. Initial testing of Self-Powered Neutron Detectors and miniature fission chambers produced promising results. Follow-on testing required more experiment hardware to be developed. The follow-on testing used a Back-to-Back fission chamber with the intent to provide calibration data, and a means of measuring spectral indices. As indicated within this document, this is the first time in decades that BTB fission chambers have been used in INL facilities. Results from these fission chamber measurements provide a baseline reference for future measurements with Back-to-Back fission chambers.

  14. Modeling of Fission Gas Release in UO2

    SciTech Connect (OSTI)

    MH Krohn

    2006-01-23

    A two-stage gas release model was examined to determine if it could provide a physically realistic and accurate model for fission gas release under Prometheus conditions. The single-stage Booth model [1], which is often used to calculate fission gas release, is considered to be oversimplified and not representative of the mechanisms that occur during fission gas release. Two-stage gas release models require saturation at the grain boundaries before gas is release, leading to a time delay in release of gases generated in the fuel. Two versions of a two-stage model developed by Forsberg and Massih [2] were implemented using Mathcad [3]. The original Forsbers and Massih model [2] and a modified version of the Forsberg and Massih model that is used in a commercially available fuel performance code (FRAPCON-3) [4] were examined. After an examination of these models, it is apparent that without further development and validation neither of these models should be used to calculate fission gas release under Prometheus-type conditions. There is too much uncertainty in the input parameters used in the models. In addition. the data used to tune the modified Forsberg and Massih model (FRAPCON-3) was collected under commercial reactor conditions, which will have higher fission rates relative to Prometheus conditions [4].

  15. The behavior of fission products during nuclear rocket reactor tests

    SciTech Connect (OSTI)

    Bokor, P.C.; Kirk, W.L.; Bohl, R.J.

    1991-01-01

    The experience base regarding fission product behavior developed during the Rover program, the nuclear rocket development program of 1955--1972, will be useful in planning a renewed nuclear rocket program. During the Rover program, 20 reactors were tested at the Nuclear Rocket Development Station in Nevada. Nineteen of these discharged effluent directly into the atmosphere; the last reactor tested, a non-flight-prototypic, fuel-element-testing reactor called the Nuclear Furnace (NF-1) was connected to an effluent cleanup system that removed fission products before the hydrogen coolant (propellant) was discharged to the atmosphere. In general, we are able to increase both test duration and fuel temperature during the test series. Therefore fission product data from the later part of the program are more interesting and more applicable to future reactors. We have collected fission product retention (and release) data reported in both formal and informal publications for six of the later reactor tests; five of these were Los Alamos reactors that were firsts of a kind in configuration or operating conditions. We have also, with the cooperation of Westinghouse, included fission product data from the NRX-A6 reactor, the final member of series of developmental reactors with the same basic geometry, but with significant design and fabrication improvements as the series continued. Table 1 lists the six selected reactors and the test parameters for each.

  16. Fission gas release restrictor for breached fuel rod

    DOE Patents [OSTI]

    Kadambi, N. Prasad; Tilbrook, Roger W.; Spencer, Daniel R.; Schwallie, Ambrose L.

    1986-01-01

    In the event of a breach in the cladding of a rod in an operating liquid metal fast breeder reactor, the rapid release of high-pressure gas from the fission gas plenum may result in a gas blanketing of the breached rod and rods adjacent thereto which impairs the heat transfer to the liquid metal coolant. In order to control the release rate of fission gas in the event of a breached rod, the substantial portion of the conventional fission gas plenum is formed as a gas bottle means which includes a gas pervious means in a small portion thereof. During normal reactor operation, as the fission gas pressure gradually increases, the gas pressure interiorly of and exteriorly of the gas bottle means equalizes. In the event of a breach in the cladding, the gas pervious means in the gas bottle means constitutes a sufficient restriction to the rapid flow of gas therethrough that under maximum design pressure differential conditions, the fission gas flow through the breach will not significantly reduce the heat transfer from the affected rod and adjacent rods to the liquid metal heat transfer fluid flowing therebetween.

  17. Calculated fission-fragment yield systematics in the region 74

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Möller, Peter; Randrup, Jørgen

    2015-04-01

    Background: In the seminal experiment by Schmidt et al. [Nucl. Phys. A 665, 221 (2000)] in which fission-fragment charge distributions were obtained for 70 nuclides, asymmetric distributions were seen above nucleon number A ≈ 226 and symmetric ones below. Because asymmetric fission had often loosely been explained as a preference for the nucleus to always exploit the extra binding of fragments near ¹³²Sn it was assumed that all systems below A ≈ 226 would fission symmetrically because available isotopes do not have a proton-to-neutron Z/N ratio that allows division into fragments near ¹³²Sn. But the finding by Andreyev et al.more »[Phys. Rev. Lett. 105, 252502 (2010)] did not conform to this expectation because the compound system ¹⁸⁰Hg was shown to fission asymmetrically. It was suggested that this was a new type of asymmetric fission, because no strong shell effects occur for any possible fragment division. Purpose: We calculate a reference database for fission-fragment mass yields for a large region of the nuclear chart comprising 987 nuclides. A particular aim is to establish whether ¹⁸⁰Hg is part of a contiguous region of asymmetric fission, and if so, its extent, or if not, in contrast to the actinides, there are scattered smaller groups of nuclei that fission asymmetrically in this area of the nuclear chart. Methods: We use the by now well benchmarked Brownian shape-motion method and perform random walks on the previously calculated five-dimensional potential-energy surfaces. The calculated shell corrections are damped out with energy according to a prescription developed earlier. Results: We have obtained a theoretical reference database of fission-fragment mass yields for 987 nuclides. These results show an extended region of asymmetric fission with approximate extension 74 ≤ Z ≤ 85 and 100 ≤ N ≤ 120. The calculated yields are highly variable. We show 20 representative plots of these variable features and summarize the main

  18. Comparison of Fission Product Yields and Their Impact

    SciTech Connect (OSTI)

    S. Harrison

    2006-02-01

    This memorandum describes the Naval Reactors Prime Contractor Team (NRPCT) Space Nuclear Power Program (SNPP) interest in determining the expected fission product yields from a Prometheus-type reactor and assessing the impact of these species on materials found in the fuel element and balance of plant. Theoretical yield calculations using ORIGEN-S and RACER computer models are included in graphical and tabular form in Attachment, with focus on the desired fast neutron spectrum data. The known fission product interaction concerns are the corrosive attack of iron- and nickel-based alloys by volatile fission products, such as cesium, tellurium, and iodine, and the radiological transmutation of krypton-85 in the coolant to rubidium-85, a potentially corrosive agent to the coolant system metal piping.

  19. Fluorescent image tracking velocimeter

    DOE Patents [OSTI]

    Shaffer, Franklin D.

    1994-01-01

    A multiple-exposure fluorescent image tracking velocimeter (FITV) detects and measures the motion (trajectory, direction and velocity) of small particles close to light scattering surfaces. The small particles may follow the motion of a carrier medium such as a liquid, gas or multi-phase mixture, allowing the motion of the carrier medium to be observed, measured and recorded. The main components of the FITV include: (1) fluorescent particles; (2) a pulsed fluorescent excitation laser source; (3) an imaging camera; and (4) an image analyzer. FITV uses fluorescing particles excited by visible laser light to enhance particle image detectability near light scattering surfaces. The excitation laser light is filtered out before reaching the imaging camera allowing the fluoresced wavelengths emitted by the particles to be detected and recorded by the camera. FITV employs multiple exposures of a single camera image by pulsing the excitation laser light for producing a series of images of each particle along its trajectory. The time-lapsed image may be used to determine trajectory and velocity and the exposures may be coded to derive directional information.

  20. PIA - Security Clearance Tracking System | Department of Energy

    Office of Environmental Management (EM)

    Tracking System PIA - Security Clearance Tracking System PIA - Security Clearance Tracking System PIA - Security Clearance Tracking System (209.32 KB) More Documents & Publications ...

  1. 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.

  2. Sequential Detection of Fission Processes for Harbor Defense

    SciTech Connect (OSTI)

    Candy, J V; Walston, S E; Chambers, D H

    2015-02-12

    With the large increase in terrorist activities throughout the world, the timely and accurate detection of special nuclear material (SNM) has become an extremely high priority for many countries concerned with national security. The detection of radionuclide contraband based on their γ-ray emissions has been attacked vigorously with some interesting and feasible results; however, the fission process of SNM has not received as much attention due to its inherent complexity and required predictive nature. In this paper, on-line, sequential Bayesian detection and estimation (parameter) techniques to rapidly and reliably detect unknown fissioning sources with high statistical confidence are developed.

  3. Singlet Fission | MIT-Harvard Center for Excitonics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fission April 3, 2012 at 3:00pm/36-428 Josef Michl Dept. of Chemistry and Biochemistry, University of Colorado, Boulder tramvajenka1_000 Abstract: Singlet fission is a process in which an excited singlet molecule shares some of its energy with a nearby ground state singlet molecule and both end up in their respective triplet excited states. By splitting one excitation into two, it has the potential for producing two electron-hole pairs from a single absorbed photon. A detailed analysis showed

  4. Liquid-Metal Technology Options for A Lunar-Based Fission Surface...

    Office of Scientific and Technical Information (OSTI)

    Liquid-Metal Technology Options for A Lunar-Based Fission Surface Power System Citation Details In-Document Search Title: Liquid-Metal Technology Options for A Lunar-Based Fission...

  5. Energy Dependence of Fission Product Yields for 239Pu, 235U,...

    Office of Scientific and Technical Information (OSTI)

    Energy Dependence of Fission Product Yields for 239Pu, 235U, and 238U Citation Details In-Document Search Title: Energy Dependence of Fission Product Yields for 239Pu, 235U, and ...

  6. Recent advances in nuclear fission theory: pre- and post-scission...

    Office of Scientific and Technical Information (OSTI)

    Recent advances in the modeling of the nuclear fission process for data evaluation ... Two examples are given: (i) the modeling of fission cross-sections in the R-matrix ...

  7. Abrasion resistant track shoe grouser

    DOE Patents [OSTI]

    Fischer, Keith D; Diekevers, Mark S; Afdahl, Curt D; Steiner, Kevin L; Barnes, Christopher A

    2013-04-23

    A track shoe for a track-type vehicle. The track shoe includes a base plate and a grouser projecting away from the base plate. A capping surface structure of substantially horseshoe shaped cross-section is disposed across a distal portion of the grouser. The capping surface structure covers portions of a distal edge surface and adjacent lateral surfaces. The capping surface structure is formed from an material characterized by enhanced wear resistance relative to portions of the grouser underlying the capping surface structure.

  8. DOUBLE TRACKS Test Site interim corrective action plan

    SciTech Connect (OSTI)

    1996-06-01

    The DOUBLE TRACKS site is located on Range 71 north of the Nellis Air Force Range, northwest of the Nevada Test Site (NTS). DOUBLE TRACKS was the first of four experiments that constituted Operation ROLLER COASTER. On May 15, 1963, weapons-grade plutonium and depleted uranium were dispersed using 54 kilograms of trinitrotoluene (TNT) explosive. The explosion occurred in the open, 0.3 m above the steel plate. No fission yield was detected from the test, and the total amount of plutonium deposited on the ground surface was estimated to be between 980 and 1,600 grams. The test device was composed primarily of uranium-238 and plutonium-239. The mass ratio of uranium to plutonium was 4.35. The objective of the corrective action is to reduce the potential risk to human health and the environment and to demonstrate technically viable and cost-effective excavation, transportation, and disposal. To achieve these objectives, Bechtel Nevada (BN) will remove soil with a total transuranic activity greater then 200 pCI/g, containerize the soil in ``supersacks,`` transport the filled ``supersacks`` to the NTS, and dispose of them in the Area 3 Radioactive Waste Management Site. During this interim corrective action, BN will also conduct a limited demonstration of an alternative method for excavation of radioactive near-surface soil contamination.

  9. Methods to Collect, Compile, and Analyze Observed Short-lived Fission Product Gamma Data

    SciTech Connect (OSTI)

    Finn, Erin C.; Metz, Lori A.; Payne, Rosara F.; Friese, Judah I.; Greenwood, Lawrence R.; Kephart, Jeremy D.; Pierson, Bruce D.; Ellis, Tere A.

    2011-09-29

    A unique set of fission product gamma spectra was collected at short times (4 minutes to 1 week) on various fissionable materials. Gamma spectra were collected from the neutron-induced fission of uranium, neptunium, and plutonium isotopes at thermal, epithermal, fission spectrum, and 14-MeV neutron energies. This report describes the experimental methods used to produce and collect the gamma data, defines the experimental parameters for each method, and demonstrates the consistency of the measurements.

  10. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2001-09-30

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001

  11. Recent advances in nuclear fission theory: pre- and post-scission physics

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Recent advances in nuclear fission theory: pre- and post-scission physics Citation Details In-Document Search Title: Recent advances in nuclear fission theory: pre- and post-scission physics Recent advances in the modeling of the nuclear fission process for data evaluation purposes are reviewed. In particular, it is stressed that a more comprehensive approach to fission data is needed if predictive capability is to be achieved. The link between pre- and

  12. DOE Science Showcase - Fission Theory | OSTI, US Dept of Energy Office of

    Office of Scientific and Technical Information (OSTI)

    Scientific and Technical Information Fission Theory A predictive theory of nuclear fission has eluded physicists since 1939. Because understanding the fission process is crucial for many areas of scientific research, including particle systems, the development of carbon-free energy and to national security, much work continues at the Department of Energy (DOE) to understand fission's inherent complexity. Today, scientists are performing new experiments and using both microscopic and

  13. Tracking Individual Gold Nanoparticles | The Ames Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Tracking Individual Gold Nanoparticles Researchers have developed a new way to track gold nanorods as they move around and re-orient themselves on metal surfaces, with ...

  14. Quantum mechanical method of fragment's angular and energy distribution calculation for binary and ternary fission

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V.; Pen'kov, N. V. [Voronezh State University (Russian Federation)

    2006-08-15

    In the framework of quantum-mechanical fission theory, the method of calculation for partial fission width amplitudes and asymptotic behavior of the fissile nucleus wave function with strong channel coupling taken into account has been suggested. The method allows one to solve the calculation problem of angular and energy distribution countation for binary and ternary fission.

  15. FFTF Asbestos Location Tracking Program

    SciTech Connect (OSTI)

    Reynolds, J.A.

    1994-09-15

    An Asbestos Location Tracking Program was prepared to list, locate, and determine Asbestos content and to provide baseline {open_quotes}good faith{close_quotes} for yearly condition inspections for the FFTF Plant and buildings and grounds.

  16. MCNP6. Simulating Correlated Data in Fission Events

    SciTech Connect (OSTI)

    Rising, Michael Evan; Sood, Avneet

    2015-12-03

    This report is a series of slides discussing the MCNP6 code and its status in simulating fission. Applications of interest include global security and nuclear nonproliferation, detection of special nuclear material (SNM), passive and active interrogation techniques, and coincident neutron and photon leakage.

  17. Browse by Discipline -- E-print Network Subject Pathways: Fission...

    Office of Scientific and Technical Information (OSTI)

    Fission and Nuclear Technologies Go to Research Groups Preprints Provided by Individual Scientists: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Go back to Individual ...

  18. SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS BY ADSORPTION

    DOE Patents [OSTI]

    Seaborg, G.T.; Willard, J.E.

    1958-01-01

    A method is presented for the separation of plutonium from solutions containing that element in a valence state not higher than 41 together with uranium ions and fission products. This separation is accomplished by contacting the solutions with diatomaceous earth which preferentially adsorbs the plutonium present. Also mentioned as effective for this adsorbtive separation are silica gel, filler's earth and alumina.

  19. Fission-suppressed hybrid reactor: the fusion breeder

    SciTech Connect (OSTI)

    Moir, R.W.; Lee, J.D.; Coops, M.S.

    1982-12-01

    Results of a conceptual design study of a /sup 233/U-producing fusion breeder are presented. The majority of the study was devoted to conceptual design and evaluation of a fission-suppressed blanket and to fuel cycle issues such as fuel reprocessing, fuel handling, and fuel management. Studies in the areas of fusion engineering, reactor safety, and economics were also performed.

  20. THERMAL FISSION REACTOR COMPOSITIONS AND METHOD OF FABRICATING SAME

    DOE Patents [OSTI]

    Blainey, A.

    1959-10-01

    A body is presented for use in a thermal fission reactor comprising a sintered compressed mass of a substance of the group consisting of uranium, thorium, and oxides and carbides of uranium and thorium, enclosed in an envelope of a sintered, compacted, heat-conductive material of the group consisting of beryllium, zirconium, and oxides and carbides of beryllium and zirconium.

  1. Fission gas retention and axial expansion of irradiated metallic fuel

    SciTech Connect (OSTI)

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.

    1986-05-01

    Out-of-reactor experiments utilizing direct electrical heating and infrared heating techniques were performed on irradiated metallic fuel. The results indicate accelerated expansion can occur during thermal transients and that the accelerated expansion is driven by retained fission gases. The results also demonstrate gas retention and, hence, expansion behavior is a function of axial position within the pin.

  2. Fission properties and production mechanisms for the heaviest known elements

    SciTech Connect (OSTI)

    Hoffman, D.C.

    1981-01-01

    Mass yields of the spontaneous fission of Fm isotopes, Cf isotopes, and /sup 259/Md are discussed. Actinide yields were measured for bombardments of /sup 248/Cm with /sup 16/O, /sup 18/O, /sup 20/Ne, and /sup 22/Ne. A superheavy product might be produced by bombarding /sup 248/Cm with /sup 48/Ca ions. 12 figures. (DLC)

  3. Science based stockpile stewardship, uncertainty quantification, and fission fragment beams

    SciTech Connect (OSTI)

    Stoyer, M A; McNabb, D; Burke, J; Bernstein, L A; Wu, C Y

    2009-09-14

    Stewardship of this nation's nuclear weapons is predicated on developing a fundamental scientific understanding of the physics and chemistry required to describe weapon performance without the need to resort to underground nuclear testing and to predict expected future performance as a result of intended or unintended modifications. In order to construct more reliable models, underground nuclear test data is being reanalyzed in novel ways. The extent to which underground experimental data can be matched with simulations is one measure of the credibility of our capability to predict weapon performance. To improve the interpretation of these experiments with quantified uncertainties, improved nuclear data is required. As an example, the fission yield of a device was often determined by measuring fission products. Conversion of the measured fission products to yield was accomplished through explosion code calculations (models) and a good set of nuclear reaction cross-sections. Because of the unique high-fluence environment of an exploding nuclear weapon, many reactions occurred on radioactive nuclides, for which only theoretically calculated cross-sections are available. Inverse kinematics reactions at CARIBU offer the opportunity to measure cross-sections on unstable neutron-rich fission fragments and thus improve the quality of the nuclear reaction cross-section sets. One of the fission products measured was {sup 95}Zr, the accumulation of all mass 95 fission products of Y, Sr, Rb and Kr (see Fig. 1). Subsequent neutron-induced reactions on these short lived fission products were assumed to cancel out - in other words, the destruction of mass 95 nuclides was more or less equal to the production of mass 95 nuclides. If a {sup 95}Sr was destroyed by an (n,2n) reaction it was also produced by (n,2n) reactions on {sup 96}Sr, for example. However, since these nuclides all have fairly short half-lives (seconds to minutes or even less), no experimental nuclear reaction

  4. Nuclear Design of the HOMER-15 Mars Surface Fission Reactor

    SciTech Connect (OSTI)

    Poston, David I.

    2002-07-01

    The next generation of robotic missions to Mars will most likely require robust power sources in the range of 3 to 20 kWe. Fission systems are well suited to provide safe, reliable, and economic power within this range. The goal of this study is to design a compact, low-mass fission system that meets Mars surface power requirements, while maintaining a high level of safety and reliability at a relatively low cost. The Heat pipe Power System (HPS) is one possible approach for producing near-term, low-cost, space fission power. The goal of the HPS project is to devise an attractive space fission system that can be developed quickly and affordably. The primary ways of doing this are by using existing technology and by designing the system for inexpensive testing. If the system can be designed to allow highly prototypic testing with electrical heating, then an exhaustive test program can be carried out quickly and inexpensively, and thorough testing of the actual flight unit can be performed - which is a major benefit to reliability. Over the past 4 years, three small HPS proof-of-concept technology demonstrations have been conducted, and each has been highly successful. The Heat pipe-Operated Mars Exploration Reactor (HOMER) is a derivative of the HPS designed especially for producing power on the surface of Mars. The HOMER-15 is a 15-kWt reactor that couples with a 3-kWe Stirling engine power system. The reactor contains stainless-steel (SS)-clad uranium nitride (UN) fuel pins that are structurally and thermally bonded to SS/sodium heat pipes. Fission energy is conducted from the fuel pins to the heat pipes, which then carry the heat to the Stirling engine. This paper describes conceptual design and nuclear performance the HOMER-15 reactor. (author)

  5. Field Mapping At Raft River Geothermal Area (1993) | Open Energy...

    Open Energy Info (EERE)

    extension over broad areas of the northern Basin and Range. References Dumitru, T.; Miller, E.; Savage, C.; Gans, P.; Brown, R. (1 April 1993) Fission track evidence for...

  6. Field Mapping At Northern Basin and Range Geothermal Region ...

    Open Energy Info (EERE)

    extension over broad areas of the northern Basin and Range. References Dumitru, T.; Miller, E.; Savage, C.; Gans, P.; Brown, R. (1 April 1993) Fission track evidence for...

  7. Core Analysis At Valles Caldera - Sulphur Springs Geothermal...

    Open Energy Info (EERE)

    into younger strata. References Hisatoshi Ito, Kazuhiro Tanaka (1995) Insights On The Thermal History Of The Valles Caldera, New Mexico- Evidence From Zircon Fission-Track...

  8. Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal...

    Open Energy Info (EERE)

    into younger strata. References Hisatoshi Ito, Kazuhiro Tanaka (1995) Insights On The Thermal History Of The Valles Caldera, New Mexico- Evidence From Zircon Fission-Track...

  9. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U

    SciTech Connect (OSTI)

    Selby, H.D.; Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C.

    2010-12-15

    We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for {sup 99}Mo, {sup 95}Zr, {sup 137}Cs, {sup 140}Ba, {sup 141,143}Ce, and {sup 147}Nd. Modest incident-energy dependence exists for the {sup 147}Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by {approx}5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried

  10. Track 4: Employee Health and Wellness

    Office of Energy Efficiency and Renewable Energy (EERE)

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 4: Employee Health and Wellness