Development of CASMO5 for WER-1000/1200 analysis and preliminary validation using critical experiments

摘要

Studsvik has recently extended the CASM05 advanced lattice physics code for the analysis of WER 1000 and 1200 reactors. These extensions form the basis of CASM05-VVER, which is primarily intended to compute homogenized nodal data for SIMULATE5-VVER. CASM05-VVER leverages the latest nuclear data and numerical methods to WER analyses. The current CASM05 data library, based on the ENDF/B-VII.1 nuclear data evaluation, features a 586 energy group structure and nuclear data for hundreds of unique nuclides. Resonance self-shielding, based on the Equivalence Theory and an Optimal Two-Term Rational (OTTR) method, has been extended to support hexagonal geometry. The solution to the two-dimensional transport equation is based on the new Linear Source (LS) approximation for the Method of Characteristics (MOC). The acceleration of the MOC solution is attained through the implementation of a Coarse-Mesh Nonlinear Diffusion (CMND) acceleration. Results from preliminary validation against various critical experiments are presented in this work.