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Title: Reanalysis of the gas-cooled fast reactor experiments at the zero power facility proteus - Spectral indices

Abstract

The gas-cooled fast reactor (GCFR) concept was investigated experimentally in the PROTEUS zero power facility at the Paul Scherrer Inst. during the 1970's. The experimental program was aimed at neutronics studies specific to the GCFR and at the validation of nuclear data in fast spectra. A significant part of the program used thorium oxide and thorium metal fuel either distributed quasi-homogeneously in the reference PuO{sub 2}/UO{sub 2} lattice or introduced in the form of radial and axial blanket zones. Experimental results obtained at the time are still of high relevance in view of the current consideration of the Gas-cooled Fast Reactor (GFR) as a Generation-IV nuclear system, as also of the renewed interest in the thorium cycle. In this context, some of the experiments have been modeled with modern Monte Carlo codes to better account for the complex PROTEUS whole-reactor geometry and to allow validating recent continuous neutron cross-section libraries. As a first step, the MCNPX model was used to test the JEFF-3.1, JEFF-3.1.1, ENDF/B-VII.0 and JENDL-3.3 libraries against spectral indices, notably involving fission and capture of {sup 232}Th and {sup 237}Np, measured in GFR-like lattices. (authors)

Authors:
;  [1];  [2];  [1];  [3]
  1. Paul Scherrer Inst., 5232 Villigen (Switzerland)
  2. Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland)
  3. (Switzerland)
Publication Date:
Research Org.:
American Nuclear Society, Inc., 555 N. Kensington Avenue, La Grange Park, Illinois 60526 (United States)
OSTI Identifier:
22105744
Resource Type:
Conference
Resource Relation:
Conference: PHYSOR 2012: Conference on Advances in Reactor Physics - Linking Research, Industry, and Education, Knoxville, TN (United States), 15-20 Apr 2012; Other Information: Country of input: France; 17 refs.
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; FAST REACTORS; FISSION; GAS COOLED REACTORS; GEOMETRY; MONTE CARLO METHOD; NEPTUNIUM 237; NEUTRONS; NUCLEAR DATA COLLECTIONS; PLUTONIUM OXIDES; RESEARCH REACTORS; THORIUM; THORIUM 232; THORIUM CYCLE; THORIUM OXIDES; URANIUM DIOXIDE; ZERO POWER REACTORS

Citation Formats

Perret, G., Pattupara, R. M., Girardin, G., Chawla, R., and Ecole Polytechnique Federale de Lausanne, 1015 Lausanne. Reanalysis of the gas-cooled fast reactor experiments at the zero power facility proteus - Spectral indices. United States: N. p., 2012. Web.
Perret, G., Pattupara, R. M., Girardin, G., Chawla, R., & Ecole Polytechnique Federale de Lausanne, 1015 Lausanne. Reanalysis of the gas-cooled fast reactor experiments at the zero power facility proteus - Spectral indices. United States.
Perret, G., Pattupara, R. M., Girardin, G., Chawla, R., and Ecole Polytechnique Federale de Lausanne, 1015 Lausanne. Sun . "Reanalysis of the gas-cooled fast reactor experiments at the zero power facility proteus - Spectral indices". United States. doi:.
@article{osti_22105744,
title = {Reanalysis of the gas-cooled fast reactor experiments at the zero power facility proteus - Spectral indices},
author = {Perret, G. and Pattupara, R. M. and Girardin, G. and Chawla, R. and Ecole Polytechnique Federale de Lausanne, 1015 Lausanne},
abstractNote = {The gas-cooled fast reactor (GCFR) concept was investigated experimentally in the PROTEUS zero power facility at the Paul Scherrer Inst. during the 1970's. The experimental program was aimed at neutronics studies specific to the GCFR and at the validation of nuclear data in fast spectra. A significant part of the program used thorium oxide and thorium metal fuel either distributed quasi-homogeneously in the reference PuO{sub 2}/UO{sub 2} lattice or introduced in the form of radial and axial blanket zones. Experimental results obtained at the time are still of high relevance in view of the current consideration of the Gas-cooled Fast Reactor (GFR) as a Generation-IV nuclear system, as also of the renewed interest in the thorium cycle. In this context, some of the experiments have been modeled with modern Monte Carlo codes to better account for the complex PROTEUS whole-reactor geometry and to allow validating recent continuous neutron cross-section libraries. As a first step, the MCNPX model was used to test the JEFF-3.1, JEFF-3.1.1, ENDF/B-VII.0 and JENDL-3.3 libraries against spectral indices, notably involving fission and capture of {sup 232}Th and {sup 237}Np, measured in GFR-like lattices. (authors)},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jul 01 00:00:00 EDT 2012},
month = {Sun Jul 01 00:00:00 EDT 2012}
}

Conference:
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  • Spectral indices are parameters of major importance to characterize a multiplying medium and to evaluate performances of neutronics calculation tools as well as quality of associated nuclear data. Experiments performed in 2004 at the CEA MINERVE facility loaded with the R1-UO{sub 2} lattice [1], using homemade miniature fission chambers and calibration data acquired at the SCK.CEN BR1 facility in 2001 [2], resulted in ambivalent conclusions. On one hand, spectral indices involving only fissile isotopes gave relevant results and consistent discrepancies between calculation and experiment. On the other hand, spectral indices involving both fissile and fertile isotopes showed inconsistent results dependingmore » on the type of calibration data used. In particular, the {sup 238}U(n,f)/{sup 235}U(n,f) spectral indices resulted in values far from the calculations in all cases. In 2004, those differences between measurement and calculation were mainly attributed to an imprecise knowledge of the isotopic composition of the deposits loaded in the {sup 238}U chambers. At that time, priorities in the development of programs in MINERVE and other considerations about the manufacturing and calibration of new fission chambers did not allow to further investigate these discrepancies. In 2009, the preparation of a new program at the EOLE facility [1] and changes in the regulatory framework for management of fission chambers motivated the manufacturing of new detectors. At the same time, the re-installation of the R1-UO{sub 2} lattice in MINERVE gave the opportunity to carry out a new spectral indices measurement campaign. Nevertheless, although the isotopic composition of active deposits was better known than previously, the comparison between experimental results and calculations still resulted in inconsistent discrepancies. A sensitivity study indicated afterwards that, among all parameters to be considered for the analysis and the assessment of final uncertainty, calibration data have the greatest impact. In April 2010, a new calibration campaign conducted again at the BR1 facility allowed the CEA to reanalyze the spectral indices measurements performed in 2009. With this new set of calibration data, the experimental values of spectral indices finally matched the calculation results within the uncertainty margins. In addition, the confrontation of data from 2001 and 2010 calibration campaigns, both performed with the same experimental conditions, allowed to shed on the light dead time correction issues in the monitoring of calibration measurements. At the end, this also explained the inconsistencies observed during the 2004 campaign. This paper first, presents the two different analysis methods for getting the experimental value of a spectral index and, lists main parameters that influence the determination of the experimental value. It then details the calibration processes that are set-up at the MINERVE and BR1 facilities, describes the various experiments carried out and finally comments the results obtained. (authors)« less
  • The paper presents the status in elaboration of a reactor facility with a Gas Cooled Fast Reactor named BGR-1000 on the initial stage of developments. In the present time, general formulation of the concept is given and analysis of possible design decisions for the active core and first circuit equipment is performed. The design of a reactor facility with the fast helium cooled reactor 1000 MWe is based on the active core with fuel assemblies containing the fixed bed of coated fuel microparticles directly cooled by cross flow of helium coolant with moderate (750 deg. C) outlet temperature. The neutron-physicsmore » characteristics of this reactor and their connection with the parameters of the core layout and fuel cycle options are preliminary evaluated. Preliminary assessments are performed for thermal-hydraulic characteristics, fuel behavior analysis, etc. (authors)« less
  • The vented and pressure-equalized design of gas-cooled fast breeder reactor (GCFR) fuel rods and subassemblies has been studied for several years. The vented design imposes on the reactor designer the requirement of being able to predict the behavior and transport of all important gaseous and volatile radionuclides so that their expected distribution in the plant may be used for component design and safety analysis. The irradiation experiment data base is described from which information on the transporting species and the transported fractions of volatile and gaseous species is obtained. The data are analyzed to define the predominant transporting mechanism formore » the nuclides in each mass chain.« less
  • Analyses of experiments in the initial critical assemblies for the gas-cooled fast breeder reactor (GCFR) were conducted using the calculational methods at General Atomic (GA) for GCFR design. The assemblies, constructed on the ZPR-9 facility at Argonne National Laboratory, simulated features of the 300-MW(e) GCFR demonstration reactor. Studies relating to the safety of this reactor design and to the GCFR concept in general were concerned with (1) reactivity coefficients of fuel and poison materials to evaluate loading and control requirements, (2) the worth of helium coolant in a depressurization event, (3) the Doppler effect in uranium to determine power coefficients,more » and (4) the effect of hypothesized steam ingress into coolant channels as a potential for reactivity addition and altering core neutronic and control characteristics. Results are reported for GA analyses of such safety-related physics measurements in two basic assemblies, the 3150-liter phase I core with a coolant void fraction of 55% and the 1300-liter phase II core with a 45% void fraction.« less