Study on heat scaling experiment and simulation correction of a scaled-down model of spent fuel dry storage vaults

The complex internal structure of spent fuel dry storage vaults causes deviations between theoretically derived heat scaling experiments and actual conditions, and the results of model experiments are somewhat different from those of full-scale storage vaults. The main purpose of this study is to correct the heat scaling errors of spent fuel dry storage vaults and to improve the rationality and accuracy of storage vault model experiments. Firstly, a 1∶4 scale model of the storage vaults is built, and the experiments on storage vault power variation and outdoor temperature variation are conducted to determine the basic characteristics of the storage vault under normal operation. Secondly, a numerical simulation is conducted on the full-scale storage vault, and by comparing the simulation result with experimental result, the optimal heat scaling range is determined. Finally, the theoretical heat scaling formula for the experimental model of the spent fuel dry storage vault is revised. The results indicate that the optimal scaling power range, where the key parameters (inner cylinder temperature and annular gap air temperature) of the spent fuel dry storage vault before and after scaling are highly consistent, is 360 W to 390 W. The optimal heat scaling range for the storage vault is 1∶16.41 to 1∶17.78, and the correction factor range for the revised theoretical heat scaling formula is 0.64 to 0.69.