Studies on Novel Matrices for High Level Waste from Fast Reactor Fuel Reprocessing

High level waste (HLW) originating from aqueous reprocessing of fast reactor fuels consists mainly of fission products, minor actinides and noble metals which are higher in concentration compared to that from thermal reactors. Borosilicate glass may not be an efficient matrix to fix this waste. Similarly, chloride HLW arising from the pyro-metallurgical reprocessing has poor solubility in borosilicate glass. The present study explores various alternate systems consisting of a glass (iron phosphate glass, IPG), ceramic (monazite) and glass -ceramic (apatite) for the immobilization of such HLW. Studies related to synthesis, thermal stability and waste loading, point to the potential of the three matrices to emerge as viable waste forms for different types of HLW