SEPARATION OF AMERICIUM FROM AGED PLUTONIUM DIOXIDE

Abstract

The Recycle Fuel Fabrication Laboratory (RFFL) is a licensed nuclear facility designed to produce experimental quantities of mixed oxide fuel for reactor physics tests and demonstration irradiations. Since its refurbishment in 1996, several fuel fabrication campaigns and research projects have been completed. The RFFL is the only facility in Canada capable of handling significant quantities of plutonium and other actinides. In this context, effort has been put forth in recent years to demonstrate capabilities in new fields, such as actinide chemistry. One of the first experiments in actinide chemistry conducted in the Facility was devoted to the separation and purification of 241Am from aged PuO2. The experimental work presented here, was conducted to establish actinide separation capability at the RFFL and demonstrate the staff expertise to perform these types of separations. The separation experiments were carried out using ion exchange columns packed with basic anion exchange AG1-X4 resin. More than 92% of the 241Am contained in the starting PuO2 solution was recovered in the experiments; however, some plutonium was also found in the washing effluent fraction. The final americium concentration of the washing effluent fraction was estimated to be about 50% of the total heavy elements present. More than 93% of the purified plutonium retained in the column was eluted. The experimental results are discussed in terms of the speciation behaviour of the Am–Pu–N–H2O systems using E-pH thermodynamic equilibrium diagrams and the maximum ionic exchange capacity of the resin.