Modelling of as-fabricated porosity in UO2 fuel by MFPR code

Abstract

For consistent modelling of behaviour of as-fabricated porosity in UO2 fuel irradiated under various conditions of in-pile and out-of-pile tests as well as under normal and abnormal conditions of nuclear reactor operation, the additional analysis of experimental observations and critical assessment of available models are presented. On this base, the mechanistic MFPR code, including physically-grounded models for the fuel porosity evolution in UO2 fuel under various irradiation and thermal regimes, is refined. These modifications complete the consistent description of the fuel porosity evolution in the MFPR code and result in a notable improvement of the code predictions.