REDOX SPECIATION OF PLUTONIUM

Knowledge of the oxidation state distribution of plutonium in natural waters is necessary in modeling its behavior in environmental systems. The redox speciation of plutonium is complicated by such effects as h ydrolysis, complexation, disproportionation, solubility, and redox int erchange reactions. The insolubility of Pu(OH)(4) is often the limitin g factor of the net solubility of plutonium in oxic natural waters whe re Pu(V)O-2(+) is the most stable oxidation state. perturbations to th e oxidation state speciation due to the complexation chemistry of the different oxidation states of plutonium and to the insolubility of plu tonium(IV) in neutral aquatic systems are discussed. The merits and li mitations of sane chemical separation techniques used to study redox s peciation of plutonium are presented, and recommendations made for obt aining reliable oxidation state distribution data.