Assessing the advantages of using nitride and carbide fuel based on reactor-grade plutonium in a new fuel assembly of APR-1400

The accumulation of plutonium isotopes in spent nuclear fuel from reactors worldwide presents a significant concern. Consequently, international efforts are focused on addressing and reducing existing plutonium stockpiles. In this study, accident-tolerant fuel (ATF) concepts based on reactor-grade plutonium (rgPu)—specifically (Pu, Th)O 2 , (Pu,Th)N and (Pu,Th)C—are investigated within a newly proposed APR-1400 fuel assembly designed to enhance reactor performance. A mathematical calculation model for the suggested APR-1400 fuel assembly was developed to evaluate the performance of the suggested ATFs. Various enrichments have been examined to flatten the infinity multiplication factor and enhance the incineration of the rgPu. The study involved a detailed analysis of the evolution of heavy nuclide concentrations, the production of fissile isotopes, the consumption of plutonium isotopes, and the behavior of key fission products. The radioactivity of both actinides and selected non-actinides was tracked over the reactor operation period to assess the requirements for cooling and reprocessing of the spent fuel. Additionally, the decay of radioactivity was evaluated over a period of 2,440 days to determine the long-term radiological behavior of the proposed fuels. The results demonstrate that the proposed fuels—(Pu,Th)N and (Pu,Th)C—exhibit superior performance in the APR-1400 reactor compared to conventional oxide fuels.