ADVANCED HOMOGENIZATION METHODS FOR PRESSURIZED WATER REACTORS

Pavel Suk

doi:10.14311/app.2018.19.0014

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.

Highlights

Introduction and main motivationCalculation of main neutronic data for power nuclear reactors is complicated multi-level process
The main goal of study is to analyse the benefits, which the method can bring to the full core calculation
New sets of macroscopic data were calculated via Flux-Weighted Volume method (FWV) with reconstructed neutron flux and macroscopic cross sections for each cell

Summary

Introduction

Introduction and main motivationCalculation of main neutronic data for power nuclear reactors is complicated multi-level process. Despite steadily rising computational power of computers, there is no way to calculate real fuel loading pattern using accurate deterministic or stochastic codes. This problematic is divided in two levels: preparation of macroscopic data and calculation real core with macrocodes with diffusion or simplified transport solution. The data preparation process for fuel assemblies is provided by deterministic or stochastic codes (microcodes). The data for macrocodes are prepared with simulation of identical fuel assemblies in infinite lattice. This approach is called Standard Homogenization Method. The method considered some simplification which are not fulfilled in the real fuel loading pattern.

Methods

Results

Conclusion