Sensitivity Analysis of Actinide Decay Heat Focused on Mixed Oxide Fuel

摘要

It is important to evaluate the characteristics of spent MOX fuel, especially decay heat, appropriately. In this study, sensitivity analyses of prediction accuracy of isotopic generation and uncertainty of one-group cross section were performed. Between 100 and 1,000 years after discharge of the spent MOX fuel, the total decay heat is dominated by Am-241. We should pay attention to the generation of Pu-241 which decays into Am-241. The amount of Pu-241 has a close relation to the capture cross section of Pu-239 and -240. The uncertainty of the burnup calculation is discussed. At 100 year after discharge, for example, 7% error of the decay heat will be introduced by 10% uncertainty of Pu-241 generation calculation through Am-241 production.