Design of Passive Heat-Switch between Pressure Tube and Calandria Tube Based on the Principle of Metal Expand on Heating and Contract on Cooling of TACR

The paper presents a design of passive heat-switch between pressure tube and calandria tube of Thorium-based Advanced CANDU Reactor（TACR）.The heat switch is designed on the principle of heated metal expanding and contract on cooling.The valve driven by a metal stick controls the type of heat conductor between pressure tube and calandria tube.The design meets the requirement of high heat transfer resistance in normal operation and low heat transfer resistance to remove the residual heat in accident.The design is reliable and effective.