Multirecycling of Pu, Am and Cm in BWR

We have investigated neutronics aspects of multirecycling of Pu, Am and Cm in BWRs, employing three uranium and three thorium-supported transmutation fuels. Our results show, that thorium-based cores allow for higher shares of MA in the fuel and thereby higher MA incineration without encountering a positive total void worth at any point of the multirecycling. In the uranium-based configuration the total void worth sets the limit on the MA share around 2.45%. The thorium-based fuels also exhibit a stronger Doppler feedback and somewhat degraded reactivity as compared to uranium-fuels. The alpha-heating in the fuel reaches equilibrium after six cycles, maintaining values of 24-31 W/kgFUEL in the uranium-based configurations and 32-37 W/kgFUEL in the thorium-based configurations. The neutron emission keeps rising through the multirecycling, the maximum value reached in the XV cycle ranges from 1.4 × 106 to 1.7 × 106 n/s/g for uranium fuels and 2 × 106 n/s/g for the thorium-based fuels.