CODE | NUCLIDE | ORIGINAL DATA TAKEN FROM | MODIFICATION | ADDITIONAL FILE MODIFICATIONS | ORIGINAL DATA TAKEN FROM | MODIFICATION | ADDITIONAL FILE MODIFICATIONS | COMMENTS |
1092234 | 092_U_234 | ENDF/B-VI.8 | Covariances - BNL, Oct, 2011: Covariances were adopted from COMMARA-2.0, which were supplied by BNL. Covariances are a combination of the uncertainties recommended in the assessment of Ref. [1] and correlation matrices produced by the WPEC Subgroup 26 [2] which were converted to the AFCI 33-energy group structure. The initial estimates were obtained using EMPIRE/KALMAN system with default parameterization roughly adjusted to reproduce trends in the experimental data. The KALMAN code was run with default uncertainties assigned to the key model parameters to produce covariances. Following the low-fidelity approach, the uncertainties in the low energy region are based on experimental uncertainties of thermal cross sections, uncertainties of the resonance integrals and uncertainty of the scattering radius. The assessment of Ref. [1] set elastic uncertainty at 4%, confirmed Subgroup 26 fission and (n,2n) uncertainties, modified inelastic, an slightly increased capture uncertainty. 12/09/2010 S.T. Holloway on behalf of LANL [1] V.M. Maslov, P. Oblozinsky, M. Herman [2] D. Rochman, M. Herman, P. Oblozinsky, and S. F. Mughabghab |