Actinide coordination sphere in various U, Np and Pu nitrato coordination complexes

Waste management of nuclear fuel represents one of the major environmental concerns of the decade. To recycle fissile valuable materials intimate know ledge of complexation mechanisms involved in the solvent extraction process es is indispensable. Evolution of the actinide coordination sphere of AnO(2 )(NO3)(2)TBP-type complexes (An = U, Np, Pu; TBP = tributylphosphate) with the actinide valence state have been probed by XAS at the metal L-III edge. Dramatic changes in the actinide coordination sphere appeared when the An( VI) metal is reduced to An(IV). However, no significant evolution in the ac tinide environment has been noticed across the series UO22+, NpO22+ and PUO 22+.