High-Level Waste Glass

Abstract

Glass is a good material in which to incorporate high-level radioactive waste (HLW) for permanent storage. HLW, a complex mixture of fission products and actinides, results from the reprocessing of spent power reactor fuel elements to reclaim uranium and plutonium. Processes for making low-temperature waste glasses (1050°C processing temperature) have been developed to the stage that they can be utilized in commercial reprocessing plants in the early 1980’s. A representative low-melting waste glass formulation has been shown, in accelerated tests, to possess satisfactory thermal and radiation stability for many centuries of storage, and indications are that this stability will be maintained for longer times. The waste glass can be melted and stored in Type 304L stainless-steel canisters, although investigations of metals that may have increased high-temperature strength is continuing. A ceramic melting process that will permit manufacture of higher melting HLW glass, if this proves desirable, is also being developed.