SAG Modelling of Embalse NPP Fuel Channels

Abstract

An essential aspect in managing the operational lifespan of fuel channels in CANDU reactors is the prevention of contact between the Pressure Tube (PT) and the Calandria Tube (CT). Under normal operation conditions, such contact can occur as a result of irradiation-induced creep. Therefore, the development of computational models that can predict the response of the PT-CT assembly is of great interest in the industry. In this context, an implementation of a beam model based on finite elements is presented, which incorporates a simple irradiation creep constitutive model. This model is used to analyze the behavior of the PT-CT assembly throughout the reactor's operational life. The results are calibrated against values obtained from in-service inspections, enabling estimations of the remaining reactor lifespan.