Fertile-free annular fuel for plutonium recycling

摘要: Up to 50% increase in the power density of existing pressurized water reactor (PWR)-type reactors can be achieved by use internally and externally cooled annular fuel geometry. As a result, accumulated stock-piles Pu, especially if incorporated infertile-free inert matrix, burnt at substantially higher rate as compared with conventional mixed oxide-fueled operating standard density. In this work, we explore basic feasibility PWR core fully loaded Pu geometry 150% nominal We evaluate burnable poison designs, management strategies, reactivity feedback coefficients. The three-dimensional full neutronic analysis performed Studsvik Core Management System showed that design such Pu-loaded is feasible but significantly more challenging than fertile-free solid pins main difficulty arises from fact requires least initial loading order maintain cycle length 18 months. Such high results hardening neutron spectrum consequent reduction worth all control mechanisms and, some cases, positive moderator temperature coefficient (MTC). isotopically enriched Gd Er poisons was found beneficial respect maximizing burnup reducing peaking factors. Overall, high-power-density appears feasible, although it still has relatively potential for slightly MTC beginning cycle. However, estimate limiting 140% case would assure acceptable negative times during