Numerical Computation of Sodium-Potassium Alloy Heat Pipe in Passive Residual Heat Removal System of Molten Salt Reactor

In the present paper, the transient performance of NaK heat pipe is numerical simulated in the case of MSR accident. The transient, two-dimensional conduction model is established in the region of heat pipe wall and wick by using Finite Element Method（FEM） and the quasi-steady, one-dimensional vapor model is employed in heat pipe vapor space. Finally, the distributions of temperature, velocity and pressure of entire NaK heat pipe are obtained. Numerical results show that NaK heat pipes have a rapid startup and remove the afterheat of fuel salt efficiently.