An assessment of the use of recycled uranium to fuel LEU reactor

Considerable stocks of uranium at enrichments between 50% and 80% U235 exist in the United Kingdom as a result of reprocessing Research and Test Reactor fuel. With the advent of the Reduced Enrichment for Research and Test Reactor (RERTR) programme an opportunity exists to provide a cost effective method of securing fuel supplies by blending existing medium enriched uranium (MEU) to low enriched uranium (LEU). The principal characteristics which differentiate recycled uranium from fresh uranium are the isotopic composition and the presence of trace fission products and transuranic elements. Each unit operation in the Research and Test Reactor fuel cycle is considered and the impact of the above named characteristics is examined. It is concluded that the adoption of a fuel cycle utilising recycled uranium will have no significant impact on fuel fabrication, reactor operation, transportation, reprocessing or waste disposal. This conclusion is in accordance with United Kingdom Atomic Energy Authority (UKAEA) experience, as the reactors Dido and Pluto have utilised recycled uranium for 30 years with no deleterious effects. (author)