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Monte Carlo testing of new cross-section data sets for thermal and intermediate HEU critical assemblies

Journal Article · · Transactions of the American Nuclear Society
OSTI ID:644276
 [1]
  1. Knolls Atomic Power Lab., Schenectady, NY (United States)
The purpose of this study is to investigate the eigenvalue sensitivity to new {sup 235}U, hydrogen, and oxygen cross-section data sets by comparing RACER Monte Carlo calculations for several thermal and intermediate spectrum critical experiments. Recommendations for future adoption of the new cross-section data sets for the ENDF/B national cross-section database are based on this study and other similar studies. The new {sup 235}U library (version 107) was derived by Leal and Derrien by fitting differential experimental data for {sup 235}U while constraining the fit to match experimental capture and fission resonance integrals and Maxwellian averaged thermal K1 ({nu} fission minus absorption). The new hydrogen library (version 45) consists of the ENDF/B-VI release 3 data with a 332.0-mb 2,200 m/s cross section, which replaces the value of 332.5 mb in the current library. The new {sup 235}U and hydrogen libraries have been adapted by the Cross Section Evaluation Working Group (CSEWG) for inclusion as ENDF/B-VI release 5. The new oxygen library (version 39) is based on a recent evaluation of {sup 16}O by Caro. The new oxygen library is being considered for inclusion in a future release by CSEWG. Nineteen Oak Ridge and Rocky Flats thermal solution benchmark critical assemblies that span a range of hydrogen-to-{sup 235}U (H/U) concentrations (2,052 to 27.1) and above-thermal neutron leakage (ATL) fractions (0.555 to 0.011) were analyzed. In addition, three intermediate spectrum critical assemblies (UH3-UR, UH3-NI, and HISS-HUG) were studied.
OSTI ID:
644276
Report Number(s):
CONF-980606--
Journal Information:
Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 78; ISSN TANSAO; ISSN 0003-018X
Country of Publication:
United States
Language:
English