Multi-physics development for the hot-channel calculation of fast reactivity transients

In this study, transient and stationary fuel behaviour codes were coupled to reactor-physics and thermal-hydraulic programmes for the hot-channel analysis of fast reactivity-initiated accidents. This study surveys the general arguments for the usefulness and even necessity of the multi-physics treatment for this type of the analysis. The primary features of the codes to be coupled are presented. Specifically, the necessity of parallel thermal-mechanical and thermal-hydraulic calculations is emphasised, and the method by which these calculations are coupled online is discussed. As a demonstration, the results of the hot-channel analysis of a control rod ejection event are presented and compared to those obtained by using the traditional method.