Advanced Homogenization Methods for Pressurized Water Reactors

Abstract

Macroscopic cross section generation is key part of core calculation. Commonly, the data are prepared independently without a knowledge of fuel loading pattern. The fuel assemblies are simulated in infinite lattice (with mirror boundary conditions). Rehomogenization method is based on combination of actual neutron flux in fuel assembly with macroscopic data from infinite lattice. Rehomogenization method was implemented into the macrocode Andrea and tested on a reference cases. Cases consist of fuel cases, cases with strong absorber, cases with absorption rods, or cases with reflector assemblies. Testing method is based on a comparisons of homogenized and rehomogenized macroscopic cross sections and later on a comparisons of relative power of each fuel assembly. Above that there is comparison of eigenvalue.

Methods of Xs Data Preparation for Geometry With Fuel Dummy

“…The reactor core does not consist of the same fuel assemblies, some flux tilt inside the fuel assemblies can be presented. Some advantages of this approach can be found in the rehomogenization process, which is described in papers [2] or [3]. The research reactors and NPPs are almost always operated in the critical state, but during the data preparation process, the infinite medium of the the fuel assemblies can be sub-critical or super-critical in case of their enrichment and geometry.…”