EVALUATION OF FUEL CHANNEL BEHAVIOR (CANDU NPP) FOR THE LONG TIME NORMAL OPERATING CONDITIONS WHEN THE DELAYED HYDRIDE CRACKING OCCURS

摘要

A critical review of the DHC (Delayed Hydride Cracking) phenomenon in the specific case of the pressure tube subcomponent of the fuel channel assembly of the Cernavoda Nuclear Power Plant (NPP) is presented. For the both stages of DHC - initiation and propagation - the models are discussed and an appropriate numerical assessment was implemented into CANTUP computer code. A first task of the present work is to couple the routines for DHC initiation and propagation steps for better modeling of the characteristics of this damaging phenomenon. Finally, the assessment of DHC rates in the case of various locations of the virtual crack on the CANDU pressure tube is performed. The normal operation conditions for ten years period of time are assumed to consider their influence on the material properties.