Combustion engineering's experience with improved fuel managements and their impact on uranium utilization

This paper is a review of the fuel management changes that have evolved during the last few years at Combustion Engineering operating reactors, and the effect these changes have had on uranium requirements. The most substantive change in the fuel management of C-E fueled reactors has been the steady increase in discharge burnups. In very simple terms, discharge burnup, usually measured as Megawatt-days per metric ton of uranium, refers to the total amount of fission energy as Megawatt-days which has been released from each ton of enriched uranium when the uranium is finally discharged from the reactor. This roughly corresponds to the total number of uranium and plutonium fissions which have occurred in the fuel. With increased discharge burnup more plutonium is formed and thus fissioned. This increased energy production from the plutonium fissions results in improved uranium utilization