Journal of Nuclear Fuel Cycle and Waste Technology Vol.6 No.2 pp.119-128 DOI :
회수가능 CANDU 사용후핵연료 처분터널에 대한 열 해석
Thermal Analysis of a Retrievable CANDU Spent Fuel Disposal Tunnel
Jeong-Hun Cha, Jong-Youl Lee, Heui-Joo Choi, Dong-Keun Cho, Sang-Nyung Kim, Bum-Soo Youn, Joon-Suk Ji
Thermal assessment of a new CANDU spent fuel disposal system, which improves the retrievability of the spent fuel and enhances the densification factor compared with the Korean Reference disposal System, is carried out in this study. The canisters for CANDU spent fuels are stored for long term and cooled by natural convection in the proposed disposal system for the retrievability. The steady state thermal analyses for proposed CANDU disposal system are carried out with the ANSYS 10.0 CFX code. The thermal analyses are performed through two steps. At the first step, the sensitivity of the disposal tunnel spacing is analysed. The differences of maximum temperatures by several tunnel spacings are calculated at three points in the disposal tunnel. The result shows that the differences of the temperature at the three points are almost negligible because 99% of the decay heat is removed by natural convection. At the second procedure, 60m tunnel spacing with a ventilation system instead of natural convection is considered. The result is applied to the calculation of the canister surface temperature in disposal tunnel as boundary conditions. Consequently, the average and the maximum surface temperature of disposal canisters are and , respectively. The inner maximum temperature of a basket in the disposal canister is calculated as . The maximum temperature of the basket meets the thermal requirement for the CANDU spent fuel cladding.