A Criticality Safety Analysis of PWR Spent Fuel Storage Pool with Burnup Credit and Axial Burnup Profile

The purpose of this work is to give the detailed criticality analysis of a PWR spent fuel storage pool with consideration of burnup credit and realistic axial burnup profiles and to evaluate the loading curves for various cooling times. In this work, the extensive study of the criticality analysis was performed with STARBUCS sequence of SCALE 6.1 for evaluating the end effects and the loading curves of the PWR spent fuel storage pool. From the results of the analysis, it was shown that the end effects with the burnup credit with only actinides are all negative while the ones with the actinides and fission products are all positive with the axial burnup profiles obtained with the reload core follow calculations. For the spent fuels discharged from the 6th cycle of Hanbit Unit 3, all of them can be loaded with the burnup credit in actinides and fission products, and even without consideration of the cooling time. As expected, the consideration of actinides and fission products in burnup credit significantly extends the acceptable region in comparison with the cases with only actinides in burnup credit. Also, we estimated the acceptable spent fuel assemblies through the projection of all the discharged fuel assemblies from Hanbit Unit 3 on the loading curves.