Technology for Reprocessing Mother–Wash Solution after Crystallization Purification of Spent Nuclear Fuel from High Temperature Gas-Cooled Reactor.

The extractants diphenyl-N,N-dioctylcarbamoylmethylphosphine oxide and diphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide for the SNF reprocessing were tested. The conditions for extraction and separation of uranium and TPE–REE were determined. A flowsheet was proposed for reprocessing SNF from high-temperature gas-cooled reactors. Upon dynamic testing, at least 99.9% of uranium and plutonium and at least 99.5% of americium and rare earth elements were separated. The TPE + REE and U + Pu fractions were recovered. The U + Pu fraction contained approximately 5% Am, while the TPE + REE fraction had less than 0.1% U and Pu. [ABSTRACT FROM AUTHOR]