1. Validating nuclear data uncertainties obtained from a statistical analysis of experimental data with the 'Physical Uncertainty Bounds' method
- Author
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Gowri Srinivasan, Denise Neudecker, Morgan C. White, and Diane E. Vaughan
- Subjects
Experimental data ,Nuclear data ,02 engineering and technology ,01 natural sciences ,lcsh:TK9001-9401 ,010305 fluids & plasmas ,Cross section (physics) ,020303 mechanical engineering & transports ,0203 mechanical engineering ,0103 physical sciences ,Statistics ,lcsh:Nuclear engineering. Atomic power ,Neutron ,Statistical analysis ,Mathematics - Abstract
Concerns within the nuclear data community led to substantial increases of Neutron Data Standards (NDS) uncertainties from its previous to the current version. For example, those associated with the NDS reference cross section 239Pu(n,f) increased from 0.6–1.6% to 1.3–1.7% from 0.1–20 MeV. These cross sections, among others, were adopted, e.g., by ENDF/B-VII.1 (previous NDS) and ENDF/B-VIII.0 (current NDS). There has been a strong desire to be able to validate these increases based on objective criteria given their impact on our understanding of various application uncertainties. Here, the “Physical Uncertainty Bounds” method (PUBs) by Vaughan et al. is applied to validate evaluated uncertainties obtained by a statistical analysis of experimental data. We investigate with PUBs whether ENDF/B-VII.1 or ENDF/B-VIII.0 239Pu(n,f) cross-section uncertainties are more realistic given the information content used for the actual evaluation. It is shown that the associated conservative (1.5–1.8%) and minimal realistic (1.1–1.3%) uncertainty bounds obtained by PUBs enclose ENDF/B-VIII.0 uncertainties and indicate that ENDF/B-VII.1 uncertainties are underestimated.
- Published
- 2020