Impact on the amount of high-level waste of minor actinide in combination with americium transmutation and TRU generation reduction UO2 fuel in BWR

Abstract

We performed americium transmutation in uranium fuel with a transuranic generation reduction fuel, which uses BWR fuel and increases the ²³⁵U enrichment within the range of High-Assay Low-Enriched Uranium (HALEU). We evaluated the relationship between the total decay heat of ²⁴¹Am and ²⁴⁴Cm. The increase in decay heat from ²⁴⁴Cm when the ²³⁵U enrichment is 3.8 wt%, which is the example case of LEU application as that of existing fuel. The generation of ²⁴⁴Cm comes from a smaller mass number of TRU nuclides decrease as the neutron flux and neutron capture reactions decrease with increasing enrichment. As a result, in the range where the enrichment exceeds about 7.5 wt%, and the ratio of the decrease in the weight fraction of ²⁴¹Am to the increase in the weight fraction of ²⁴⁴Cm decreases below 4.1 %, and the total decay heat of the two nuclides is lower than it would be in no-transmutation.