Nuclear Data and Measurement Series: A method to construct covariance files in ENDF/B format for criticality safety applications

Technical Report · Tue Jun 01 04:00:00 EDT 1999

DOI:https://doi.org/10.2172/12069· OSTI ID:12069

Naberejnev, Dimitri G. ^[1]; Smith, Donald L. ^[1]

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1. Argonne National Lab. (ANL), Argonne, IL (United States)

Argonne National Laboratory is providing support for a criticality safety analysis project that is being performed at Oak Ridge National Laboratory. The ANL role is to provide the covariance information needed by ORNL for this project. The ENDF/B-V evaluation is being used for this particular criticality analysis. In this evaluation, covariance information for several isotopes or elements of interest to this analysis is either not given or needs to be reconsidered. For some required materials, covariance information does not exist in ENDF/B-V: ²³³U, ²³⁶U, Zr, Mg, Gd, and Hf. For others, existing covariance information may need to be re-examined in light of the newer ENDF/B-V evaluation and recent experimental data. In this category are the following materials: ²³⁵U, ²³⁸U, ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Pu, Fe, H, C, N, O, Al, Si, and B. A reasonable estimation of the fractional errors for various evaluated neutron cross sections from ENDF/B-V can be based on the comparisons between the major more recent evaluations including ENDF/B-VI, JENDL3.2, BROND2.2, and JEF2.2, as well as a careful examination of experimental data. A reasonable method to construct correlation matrices is proposed here. Coupling both of these considerations suggests a method to construct covariances files in ENDF/B format that can be used to express uncertainties for specific ENDF/B-V cross sections.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 12069
• Report Number(s): ANL/NDM-148
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALUMINIUM
BORON
CARBON
CRITICALITY
CROSS SECTIONS
Correlation Matrix
Covariance Matrix
DATA COVARIANCES
Data Uncertainty
GADOLINIUM
HAFNIUM
HYDROGEN
IRON
MAGNESIUM
NITROGEN
Nuclear Criticality Safety Program (NCSP)
Nuclear Data Evaluation
OXYGEN
PLUTONIUM 239
PLUTONIUM 240
PLUTONIUM 241
SAFETY ANALYSIS
SILICON
URANIUM 233
URANIUM 235
URANIUM 236
URANIUM 238
ZIRCONIUM