Research and verification on CFD natural convection model of QM400

Abstract

The spent fuel dry storage facility, QM-400, for the Third Qinshan Nuclear Power Co. Ltd. (TQNPC) is the first commercial dry storage facility in operation in China. The heat transfer in QM-400 consists mainly of natural convection, conduction, conjugate heat transfer, and radiation. In our research, we calculated the decay heat of each fuel basket at a typical surrounding temperature. Mesh sensitivity analysis was done, and a set of commercial computational fluid dynamics (CFD) models were established for QM-400 using ANSYS Fluent software. Several thermocouples were set up at typical locations in the QM-400 module in the nuclear power plant to validate the proposed CFD model. Good agreement was achieved between the simulated temperatures and the measured values. The trends varying with the surrounding temperature agreed well too, which showed that the CFD model is suitable for simulating the complex heat transfer phenomena in QM-400. Using the proposed model, we also simulated the temperature field after eliminating insulation panels. The calculation results show that the local concrete temperature was greater than 66 °C and less than 93 °C. The thermal stress and cross-sectional internal force introduced by the high local temperature met the requirements, indicating that it would be feasible to eliminate the insulation panels. The program of eliminating dry cask insulation panels has been approved by China’s National Nuclear Safety Administration.