Accelerator transmutation of waste using thermal neutrons: high-burn-up and weapons-material elimination without recycling

Accelerator-driven thermal-spectrum molten-salt nuclear technology can greatly simplify transmutation of LWR waste by eliminating recycling and greatly enhancing once-through burn-up. In effect the accelerator may be employed as a substitute for frequent recycle and reprocessing. The accelerator makes possible reduction in plutonium and minor actinides (PMA) from current LWRs by a factor of more than ten without reprocessing while converting the plutonium remnant to a non-weapons-useful isotopic composition. More than 90% of the energy in the plutonium and minor actinide can be recovered in a single pass. There are two key innovations in addition to enhancement of the neutron economy by the accelerator. One is the use of liquid fuel flowing continually once through a pool where the PMA is burned and fission product removed without back-end separations. The second is the unanticipated low effective capture cross section of fission product nuclides for such a system which substantially enhances the neutron economy. Recovery of the fission energy in the PMA and destroying the weapons usefulness of the PMA remnant eliminates the primary drivers for disturbing the repository and compromising the repository confinement effectiveness. As a bonus the long term radiotoxicity of the PMA is reduced by a factor of 20 with reductions of Np by the same factor. The elimination of recycle in achieving high burn-up results in no need for fuel storage for cooling, no back-end separations chemistry, and the elimination of a complex transportation infrastructure. The resulting cost savings from these simplifications are expected to more than compensate for the cost of the accelerator