REDUCTION OF PLUTONIUM(VI) TO PLUTONIUM(III) AND (IV) BY SODIUM NITRITE

The use of anion exchange for final Pu purification in the Redox facility requires the adjustment of Pa(VI) to Pu(IV). Two methods of reduction were investigated: ferrous sulfamate and nitrite. The ferrous sulfamate method was adopted. Data on reduction of Pu(VI) to Pu(IV) and Pu(III) by nitrite are presented. The reduction by nitrite was found to be dependent on nitrite concentration, temperature, acidity, ferric ion concentration, and time, and it is possible to obtain >90% reduction to Pu(HI) by controlling the above conditions. (D.L.C.