Advanced Plutonium Fuel Assembly: An Advanced Concept for Using Plutonium in Pressurized Water Reactors

An objective is to enhance the use of plutonium in conventional or slightly modified pressurized water reactors, while minimizing minor actinide production. Having entirely mixed-oxide-fueled reactors reduces the number of reactors that are affected on plutonium recycling and avoids the need for fuel zoning. However, the overall consumption is <30%, and the mass of minor actinides produced is considerable, representing up to 25 % of the plutonium used. The Advanced Plutonium Fuel Assembly concept, based on a uranium-free plutonium fuel, which achieves high burnups and an increased moderation ratio, enables 60% of the second-generation plutonium to be consumed, while the minor actinides produced only represent 8% of this figure. The heterogeneous design of the fuel assembly, which includes natural uranium or low-enriched uranium fuel rods, guarantees values that suit the physical parameters of the core. The concept was analyzed from a thermo-hydraulic aspect in both rated and accident situations. Technological feasibility is yet to be demonstrated. This study is part of a medium-term strategy for the back end of the fuel cycle.