plutonium-uranium extraction process

The plutonium-uranium extraction (PUREX) process is a chemical method used in the nuclear fuel cycle to reprocess spent nuclear fuel. This process allows for the recycling of plutonium and residual uranium-235, which can be used as nuclear fuel or in nuclear weapons.1

The PUREX process begins by dissolving spent fuel in nitric acid. This acidic solution is then mixed with tributyl phosphate (TBP) dissolved in oil. TBP acts as a complexing agent, binding with uranium and plutonium and transferring them into the oil solution. The oil and acid layers are separated, isolating the uranium and plutonium from fission products. The uranium and plutonium are then extracted back into a water solution and further separated from each other.1

This reprocessing not only recovers valuable materials but also reduces the volume and radioactivity of waste that requires permanent disposal. The technologies involved in enrichment and reprocessing are significant factors in the global proliferation of nuclear weapons.123