Development of a Batch Process for Immobilizing Some CRNL Radioactive Wastes in Glass

Abstract

Bench scale and pilot plant experiments have been carried out over the past two years to re-acquire experience in immobilizing radioactive wastes in glass. A particular objective is to develop a process for a plant at Chalk River Nuclear Laboratories (CRNL) to immobilize radionuclides in the 19 m³ of aged acidic waste solution presently in storage and in fresh waste coming from Mo-99 production.

Sodium borosilicate glasses have been made in crucibles, and wastes such as incinerator ash, ion-exchange regeneration solutions (Na SO), and the CRNL acidic wastes have been put into the glasses successfully. Phosphate glasses have also been explored as possible matrices for such wastes. A pilot plant, based on 5 and 15 cm diameter x 80 cm long 304 L stainless steel canisters, has been operated to define the steps necessary to produce waste glasses batchwise on a larger scale. Results from the pilot plant have led to a flowsheet proposed for a CRNL waste glass plant.