Thermalhydraulics Response of a Conceptual CANDU Reactor with a highly Advanced Core subject to various Loss-of-Coolant Accidents

Abstract

Thermalhydraulic simulations of a conceptual CANDU plant with a highly advanced core WAC) have been conducted for various loss-of-coolant accident (LOCA) scenarios. A distinctive feature of the HAC core is the lack of a power pulse due to zero void-reactivity. In the present study, the following LOCA cases were investigated: a 100% reactor outlet header break and reactor inlet header breaks ranging in size from 5% to 25%. A SOPHT circuit model was employed to predict the system response during the initial high-pressure stage of emergency core coolant (ECC) injection. Only one ECC train was assumed to be operable. The investigation focused on core flow characteristics, in particular, stagnation conditions in the critical pass. Other aspects of interest include void distributions and depressurization rates of the heat transport system. Detailed fuel-element analyses were also performed to estimate maximum sheath temperatures, based on header boundary conditions from the SOPHT simulations.