Apex Nuclear Fuel Cycle for Production of Light Water Reactor Fuel and Elimination of Radioactive Waste

Received October 9, 1981 Accepted for Publication March 18, 1982 The development of a nuclear fission fuel cycle is proposed that eliminates all the radioactive fission product (FP) waste effluent and the need for geological age high-level waste storage and provides a longterm supply of fissile fuel for a light water reactor (LWR) economy. The fuel cycle consists of reprocessing LWR spent fuel (1 to 2 yr old) to remove the stable nonradioactive FPs (NRFPs) (e.g., lanthanides, etc.) and short-lived FPs (SLFP) (e.g., half-lives of <1 to 2 yr) and returning, in dilute form, the long-lived FPs (LLFPs) (e.g., 30-yr half-life cesium and strontium, 10-yr krypton, and 16 X10⁶-yr iodine) and the transuranics (TUs) (e.g., plutonium, americium, curium, and neptunium) to be refabricated into fresh fuel elements. Makeup fertile and fissile fuel (FF) are to be supplied through the use of the spallator (linear accelerator spallation-target fuel producer). The reprocessing of LWR fuel elements is to be performed by means of the chelox process, which consists of chopping and leaching with an organic chelating reagent (β-diketonate) and distillation of the organo-metallic compounds formed for purposes of separating and partitioning the FPs. The stable NRFPs and SLFPs are allowed to decay to background in 10 to 20 yr for final disposal to the environment. The fertile material (FM) (e.g., ²³⁸U) and TUs are returned to be reincorporated into LWR fuel elements. The even mass-numbered TUs are efficiently converted to odd mass-numbered FF in the reactor, which then fissions to produce thermal energy and FPs in the LWR. The TUs have high thermal neutron cross sections and are therefore efficiently converted in the thermal LWR. The LLFPs (e.g., cesium, strontium, krypton, and iodine) are recycled in the fuel cycle to decay and become transmuted both in the spallator and the LWR to SLFP and stable NRFP products. Decay is the major mode of transmutation of the LLFPs because of their small thermal neutron cross sections. Some neutron transmutation does occur and shortens the storage times for the LLFPs. In this manner, long-term geological age storage of FP waste is avoided and the need for a new fast breeder reactor economy is no longer a necessity by the utility power industry. The APEX fuel cycle can be beneficially applied to the Th/²³³U cycle as well as the described U/²³⁹Pu cycle. A number of development efforts will be required to bring this system into production; however, no new basic scientific or technical proof-of-principle is needed.