An Advanced Computational Scheme for the Optimization of 2D Radial Reflectors in Pressurized Water Reactors

TL;DR

This paper introduces a new computational method to optimize 2D heterogeneous reflectors in PWRs, improving core power distribution accuracy by integrating advanced data assimilation and coupling with core and lattice codes.

Contribution

The paper develops a novel computational scheme combining data assimilation, full-core, and lattice codes to optimize 2D reflector models in PWRs, validated against established models.

Findings

Significant reduction in power discrepancy distributions.

Enhanced accuracy using both diffusion and SP_N operators.

Validated approach with the OPTEX reflector model.

Abstract

This paper presents a computational scheme for the determination of equivalent 2D multi-group heterogeneous reflectors in a Pressurized Water Reactor (PWR). The proposed strategy is to define a full-core calculation consistent with a reference lattice code calculation such as the Method Of Characteristics (MOC) as implemented in APOLLO2 lattice code. The computational scheme presented here relies on the data assimilation module known as "Assimilation de donn\'{e}es et Aide \`{a} l'Optimisation (ADAO)" of the SALOME platform developed at \'{E}lectricit\'{e} De France (EDF), coupled with the full-core code COCAGNE and with the lattice code APOLLO2. A first validation of the computational scheme is made using the OPTEX reflector model developed at \'{E}cole Polytechnique de Montr\'{e}al (EPM). As a result, we obtain 2D multi-group, spatially heterogeneous 2D reflectors, using both diffusion or $\text{SP}_{\text{N}}$ operators. We observe important improvements of the power discrepancies distribution over the core when using reflectors computed with the proposed computational scheme, and the $\text{SP}_{\text{N}}$ operator enables additional improvements.