Deep Burn Transmutation of Nuclear Waste

Abstract

Helium-cooled, graphite-moderated reactors with ceramic-coated fuel particles offer unique advantages for the destruction of transuranic materials discharged in Light Water Reactor spent fuel. This is accomplished by fission, and capture-followed-by-fission processes. Three major features make it practical: (1) ceramic-coated particles accommodate high levels of burnup in one pass, thus reducing the need for repeated reprocessing; (2) graphite moderation produces valuable opportunities for thermal and epithermal neutrons to interact with fissionable and non-fissionable materials respectively; and (3) ceramic-coated particle kernel sizes can be adjusted to control the rate of such interactions. In the transmutation scheme proposed here, virtually complete destruction of weapons-usable materials, and 95% destruction of all transuranic waste is achieved. Higher levels of destruction are possible by repeated reprocessing and recycling, but there is little incentive to do so since each reprocessing step generates new secondary waste. After transmutation, the impervious ceramic-coated fuel particles provide an ideal residual waste form.