A method is developed for depositing highly dispersed metallic Pt on V
P-1Ap, anion exchanger. Filtration of a HNO3 solution of Np and Pu tha
t contains N2H4 through a layer of this sorbent deposits Np(IV) on the
anion exchanger and leaves Pu(III) in solution. The effects of variou
s factors on the Np-Pu separation are examined. Under optimal conditio
ns, <2 . 10(-3)% of the Pu remains in the Np.