Effect of acetohydroxamic acid on the extraction of plutonium by dilute tri-n-butyl phosphate/n-dodecane in the presence of a high concentration of Al(NO3)3

Acetohydroxamic acid (AHA) is a hydrophilic organic complexing agent with excellent masking or stripping effects on the tetravalent actinides in the extraction operations. Therefore, AHA is a promising reagent for the spent nuclear fuel reprocessing. In the reprosessing of spent uranium-aluminum fuel with a high U-235 enrichment which is used in research reactor, the dissolver solution contains a high concentration of Al(NO3)3, several orders of magnitude higher than that of minor actinides such as plutonium, and dilute tri-n-butyl phosphate(TBP)/n-dodecane is adopted as the extractant. In this research, complexation of Pu(IV) with AHA under the condition of U-Al fuel reprocessing is investigated. Results show that Al(NO3)3 insignificantly affects the mentioned complexation reaction. Further, the possibility of uranium purification against Pu(VI) is also investigated by using AHA in the presence of a high concentration of Al(NO3)3 by simulating some experiments on the separation process.