(663a) Technetium Management in Deployed Reprocessing Flowsheets

Reprocessing plants of the late 20th century in the United Kingdom, France and Japan were focused on recovery of uranium and plutonium from Used Nuclear Fuel (UNF) based on an evolution of the PUREX solvent extraction technology. The recovered fissile material could then be recycled as Mixed Oxide (MOX) fuel for recycle into light water reactors. The PUREX technology uses an organic extractant, tri-butyl phosphate (TBP), dissolved in an organic diluent such as odorless kerosene (OK) to make an immiscible organic solution. The technology is employed by first dissolving the UNF in nitric acid and then contacting the aqueous solution with and organic solution of TBP/OK in pulsed columns. The TBP/OK extracts the uranium and plutonium and leaves most of the fission products and actinides in the aqueous raffinate. Arguably the most important fission products co-extracted are technetium and zirconium. Both fission products play an important and deleterious role in the subsequent separation of uranium from plutonium and must be actively managed in the flowsheet and in the design of the process equipment. This presentation compares the two different approaches implemented for the British and French reprocessing plants.