Plutonium and minor actinides multi-recycling in PWR using hydride fuels

The hydride fuel PuH2-ZrH1.6 (PUZH) allows multi-recycling of Pu in PWR an unlimited number of times when uniformly loaded in all fuel assemblies in the core. This unique feature of hydride fuels is due to the incorporation of a significant fraction of the hydrogen moderator in the fuel thereby reducing the effect of spectrum hardening due to coolant voiding accidents; the large void reactivity coefficient remains negative. Additionally, hydride fuels allow multi-recycling of Pu+Np at least 6 times, before getting a positive void reactivity feedback. This corresponds to approximately 86 years of recycling campaign. The number of recycles of the entire TRU stream is limited to 2 or 3; the limit imposed by positive large void reactivity feedback. For PuH2-ZrH1.6 fuel the fractional transmutation is about 64% at the first recycle and gradually decreases to about 20% towards the equilibrium recycle. Some of the physical characteristics of Pu bearing hydrides are investigated. The use of deuterium instead of hydrogen of PuH2-ZrH1.6 fuel was found an effective approach for making the fuel temperature coefficient of reactivity negative during the first recycle. (authors)