TY - GEN
T1 - Extensive set of low-fidelity cross sections covariances in fast neutron region
AU - Pigni, M. T.
AU - Herman, M.
AU - Obložinský, P.
PY - 2008
Y1 - 2008
N2 - We produced a large set of neutron cross section covariances in the energy range of 5 keV - 20 MeV. The covariance matrices were calculated for 307 isotopes divided into three major regions: structural materials, fission products, and heavy nuclei. These results have been developed to provide initial, but consistent estimates of covariance data for nuclear criticality safety applications. The methodology for the determination of such covariance matrices is presented. It combines the nuclear reaction model code EMPIRE which calculates sensitivity of cross sections to nuclear reaction model parameters, and the Bayesian code KALMAN that propagates uncertainties of the model parameters to cross sections. Taking into account large number of materials, only marginal reference to experimental data was made. The covariances were derived from the perturbation of several key model parameters selected by the sensitivity analysis. These parameters refer to the optical model potential, the level densities and the strength of the pre-equilibrium emission. This work represents the first try ever to generate nuclear data covariances on such a large scale.
AB - We produced a large set of neutron cross section covariances in the energy range of 5 keV - 20 MeV. The covariance matrices were calculated for 307 isotopes divided into three major regions: structural materials, fission products, and heavy nuclei. These results have been developed to provide initial, but consistent estimates of covariance data for nuclear criticality safety applications. The methodology for the determination of such covariance matrices is presented. It combines the nuclear reaction model code EMPIRE which calculates sensitivity of cross sections to nuclear reaction model parameters, and the Bayesian code KALMAN that propagates uncertainties of the model parameters to cross sections. Taking into account large number of materials, only marginal reference to experimental data was made. The covariances were derived from the perturbation of several key model parameters selected by the sensitivity analysis. These parameters refer to the optical model potential, the level densities and the strength of the pre-equilibrium emission. This work represents the first try ever to generate nuclear data covariances on such a large scale.
UR - http://www.scopus.com/inward/record.url?scp=79953878401&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:79953878401
SN - 9781617821219
T3 - International Conference on the Physics of Reactors 2008, PHYSOR 08
SP - 154
EP - 161
BT - International Conference on the Physics of Reactors 2008, PHYSOR 08
PB - Paul Scherrer Institut
T2 - International Conference on the Physics of Reactors 2008, PHYSOR 08
Y2 - 14 September 2008 through 19 September 2008
ER -