Nuclear Fuel Cycle

Oak Ridge, USA (1943—44): The first reprocessing of irradiated fuel was performed on a laboratory scale at Oak Ridge National Laboratory. The purpose was to recover plutonium for the Manhattan Project (nuclear weapons programme).

Hanford, USA (1944—45): The first industrial-scale reprocessing was carried out at Hanford using the bismuth phosphate carrier-precipitation process. Centrifuges were used to separate plutonium precipitates from large volumes of active solution. The process had to be repeated several times to achieve acceptable purity. Scaling up was limited by criticality safety considerations. The recovery yield was approximately 98%.

Hanford REDOX (1951): The first solvent extraction process for reprocessing was brought online at Hanford. It used the organic solvent methyl isobutyl ketone (Hexone) and was known as the REDOX process. Recovery of plutonium increased to 99.5%, but chemical salts (aluminium nitrate) were needed as salting agents, adding to waste volumes.

Savannah River, USA (1954): The crucial development of tri-n-butyl phosphate (TBP) as a solvent. TBP provided better separation per stage, was chemically more stable, more resistant to radiation, and cheaper than Hexone. This became the basis of the PUREX process (Plutonium Uranium Refining by EXtraction).

Pulsed Column Technology (1956): Development of pulsed columns enabled a move from batch to continuous processing, increasing throughput and reducing criticality risk.