Sensitivity and uncertainty studies of average cross section parameters with Monte-Carlo sampling

Conference · Sat Jul 01 04:00:00 EDT 2006

OSTI ID:22039499

De Saint Jean, C; Noguere, G; Iooss, B ^[1]

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1. CEA, French Atomic Energy Commission, Nuclear Energy Directorate DEN CEA/Cadarache, 13108 Saint-Paul-Lez Durance Cedex (France)

Hauser Feshbach formalism with width fluctuation corrections and some Optical Model recipes are widely used for the calculation of average cross sections. Each model involved in the calculation is parametrized. The parameters can be adjusted to reproduce experimental datasets. As a result, a covariance matrix can be deduced from the fit and used in uncertainty calculation of the group averaged cross sections. Nevertheless, some parameters, such as the mean level spacing, the binding and pairing energy, are not supposed to be adjusted. They have a-priori uncertainties that should be properly taken into account and propagated into the previous adjustment as well as to group averaged cross sections. In this paper, we propose to use a Monte-Carlo propagation method based on an exact mathematical description to treat these non-adjusted parameters and their effects on the adjusted ones. A full covariance matrix for all the parameters will then be evaluated. Two isotopes will be treated {sup 240}Pu and {sup 177}Hf to illustrate the involved methods. (authors)

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22039499
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CORRECTIONS
CROSS SECTIONS
DATASETS
EXPERIMENTAL DATA
HAFNIUM 177
MONTE CARLO METHOD
OPTICAL MODELS
PAIRING ENERGY
PLUTONIUM 240
SENSITIVITY ANALYSIS