Radiolysis modeling in PWR core. A parametric analysis based on radiation field contributors along fuel assemblies and simulation of the inhibition of water α-radiolysis via H2 addition

Abstract

The present paper is dedicated to the modeling of radiolysis products’ profiles developed along a fuel assembly in pressurized water reactor (PWR) conditions. For this purpose, different representative dose rate profiles have been considered with either peaking at the bottom or the top of the fuel assembly, corresponding to classical trends observed at beginning, middle and end of a PWR fuel cycle. At the same time, boron concentration and consequently alpha contribution varies with the dose rate. To assess the influence of alpha particles on the creation of oxidizing species (H₂O₂ , O₂ ) and to test the hypothesis that the critical hydrogen concentration (CHC) may be increased because no radicals are produced in α radiation, a parametric approach has been conducted.