Transmutation Study of Minor Actinides in Mixed Oxide Fueled Typical Pressurized Water Reactor Assembly

The management of long-lived radionuclides in spent fuel is a key issue to achieve the closed nuclear fuel cycle and the sustainable development of nuclear energy. The partitioning-transmutation method is supposed to efficiently treat the long-lived radionuclides. Accordingly, the transmutation of long-lived minor actinides (MAs) is significant for the postprocessing of spent fuel. In the present work, the transmutations in pressurized water reactor (PWR) mixed oxide (MOX) fuel are investigated through the Monte Carlo neutron transport method. Two types of MAs are homogeneously incorporated into MOX fuel assembly with different mixing ratios. In addition, two types of design of semihomogeneous loading of ²³⁷Np in MOX fuels are studied. The results indicate an overall nice efficiency of transmutation in PWR with MOX fuel, especially for ²³⁷Np and ²⁴¹Am, which are primarily generated in the current uranium oxide fuel. In addition, the transmutation efficiency of ²³⁷Np is excellent, while its inclusion has no much influence on other MAs. The flattening of power and burnup are achieved by semihomogeneous loading of MAs. The uncertainties of Monte Carlo method are negligible, while those due to nuclear data change little the conclusions of the transmutation of MAs. The transmutation of MAs in MOX fuel is expected to be an efficient method for spent fuel management.