Technical report. From Abstract : "The separation of neptunium and plutonium by anion exchange in nitrate solutions was studied under a wide variety of experimental conditions. A method of separation was developed that is adaptable to remote operation in the plant. In the method, Np(IV) and Pu(IV) are absorbed on an anion exchange resin from 8M nitrate solution. The column is washed with 8M HNO3 to remove contaminants; then the Pu is removed as Pu(III) by washing the column with HNO3 containing ferrous sulfamate and hydrazine. Finally, the Np is eluted with dilute HNO3."