Dynamic Behavior Analysis of a Supercritical Water Cooled System Using Modified ATHLET

This paper presents the application of the modified ATHLET code to the dynamic behavior analysis of a supercritical water cooled system. A small scale fuel assembly under the “evaporator” condition of the HPLWR core design concept, with a supercritical water cooled experiment loop, is about to be tested in the LVR-15 research reactor of the Nuclear Research Institute in Rez in Czech Republic. With the purpose to analyze the safety characteristic and prepare for the licensing of the test loop, some design based accidents like loss of coolant due to break of coolant supply lines and trip of the primary pump are simulated in this paper. All the results achieved indicate that the modified ATHLET code has good feasibility in simulation of supercritical water cooled systems.