Development of a Thermal Hydraulic Analysis Code and Transient Analysis for a Fluoride Salt Cooled High Temperature Test Reactor

Abstract

The fluoridesaltcooled hightemperature reactor (FHR) is an advanced reactor concept that uses hightemperature tristructural isotropic (TRISO) fuel with a lowpressure liquid salt coolant. Design of the fluoridesaltcooled hightemperature test reactor (FHTR) is a key step in the development of the FHR technology and is currently in progress both in China and the United States. An FHTR based on pebblebed core design with a coolant temperature of 600–700آ°C is being planned for construction by the Chinese Academy of Sciences’ (CAS) Thorium Molten Salt Reactor (TMSR) Research Center, Shanghai Institute of Applied Physics (SINAP). This paper provides preliminary thermalhydraulic transient analyses of an FHTR using SINAP’s pebblebed core design as a reference case. A point kinetic model is implemented using computer code by coupling with a simplified porous medium heat transfer model in the core. The founded models and developed code are applied to analyze the safety characteristics of the FHTR by simulating several transient conditions including the unprotected loss of flow, unprotected overcooling, and unprotected transient overpower accidents. The results show that SINAP’s pebblebed core is a very safe reactor design.