Nuclear Data Uncertainties in Intermediate Neutron Spectrum Problems and the Intermediate Neutron Spectrum Experiment

Conference · Sun Aug 18 00:00:00 EDT 1996

OSTI ID:249212

Jaegers, P. J. ^[1]; Hayes, D. ^[1]; Sanchez, R. G. ^[1]; Kimpland, R. H. ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

During the investigation of various surplus fissile material disposition proposals, uncertainties in the data of SiO₂/Pu mixtures were discovered. These uncertainties were detected for Si/Pu ratios ranging from approximately 20:1 to 200:1. Additionally, it has been reported that metal/U²³⁵ mixtures also have data uncertainties. These problems with large data uncertainties are typically intermediate spectrum problems, i.e., problems which are dominated by scattering and fissions occurring in the energy range of 10 eV to 1 MeV. ANSI/ANS-8.1-1983 states that the "bias shall be established by correlating the results of criticality experiments with the results obtained for these same systems by the method being validated". There is, however, a definite lack of critical experiments with an intermediate neutron spectrum. We have identified two potential areas from which these uncertainties may arise. The first potential source of uncertainty in the nuclear data is due to fact that the cross-sections of the fissile material have not been tested in an intermediate energy spectrum. The second potential source of uncertainty is that the non-fissile material in the mixture may not have been appropriately tested in a critical experiment. To provide this benchmark data a critical experiment is necessary.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 249212
• Report Number(s): LA-UR-95-4060; CONF-960804-3; ON: DE96004783; TRN: 96:015958
• Resource Relation: Conference: SPECTRUM '96: International Conference on Nuclear and Hazardous Waste Management, Seattle, WA (United States), 18-23 Aug 1996; Other Information: PBD: [1996]
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
97 MATHEMATICS AND COMPUTING
SILICON OXIDES
CRITICAL MASS
PLUTONIUM
FISSILE MATERIALS
NUCLEAR MATERIALS MANAGEMENT
MIXTURES
DATA COVARIANCES
URANIUM 235
CRITICALITY
QUALITY ASSURANCE
MONTE CARLO METHOD
NEUTRON SPECTRA
Nuclear Criticality Safety Program (NCSP)
Fissile Material
Monte Carlo N-Particle Transport (MCNP)
Evaluated Nuclear Data File (ENDF)
SCALE
Hansen-Roach