Middle-term thorium strategy for PWR fleets

Guillaume Martin (1) , R. Girieud (1)

1 SPRC - Service de Physique des Réacteurs et du Cycle

Thorium constitutes a natural resource alternative to uranium to fuel nuclear fission power plants. This study explores an original way to benefit from thorium with pressurized water reactors (PWR). It relies on a versatile reactor EPR™ core concept which well circumscribes thorium fuel reprocessing and re-fabrication Fleets representative of what can be deployed at the scale of a small country were simulated using the scenario software COSI6. The cornerstone of this study is here the possibility to multi-recycle plutonium into Pu/Th fuel as plutonium degradation is softened by mixing it with high-grade fissile matters. Plutonium content inside Pu/Th fuel remains then far below the limit existing in PWR for safety reasons. This synergistic effect between U/Pu and U/Th cycles enables a better valorization of fissile elements present in spent fuels. Improved plutonium management makes possible to stabilize spent fuel stocks and the plutonium inventory at the cycle back-end. Thanks to multi-recycling allowed by the U/Pu/Th studied scheme, uranium resource savings exceed 25%. Minor actinides production is also reduced even though production of curium alone increases. These results reveal that thorium introduction in standard PWR may be a sustainable middle-term option, assuming that U/Pu/Th fuel reprocessing and re-fabrication would become available.

Domaines: Sciences de l'ingénieur [physics]

Guillaume Martin, R. Girieud. Middle-term thorium strategy for PWR fleets. Energy Policy, 2016, 99, pp.147 - 153. ⟨10.1016/j.enpol.2016.09.062⟩. ⟨cea-01908264⟩