INVESTIGATION OF DE-HOMOGENIZATION FOR PWR LATTICE CELLS IN DRAGON5

Abstract

The objective of this study is to inspect the accuracy of the dehomogenization in the 3 x 3 PWR assembly PWR for homogeneous homogenization and heterogeneous homogenization. Based on the Method of Characteristics, the 2-level computational scheme and subgroup projection method is used with SHEM 361 group energy mesh. In this case, homogeneous geometry and heterogeneous geometry are used. Using the NAP: module, a two-level computational scheme including the core with heterogeneous assemblies are generated. Enrich multi-parameter data structure was obtained to keep the pin wise flux for diffusion calculations with different homogenization options. Using Pin Power Reconstruction, the results for both geometries are compared and discrepancies are calculated. It is showed that heterogeneous geometry gives more accurate and promising results. With the generation of multi-parameter reactor database, it is observed that the computational time is also reduced with Method of Characteristics and the two-level scheme approach.