Physicochemical Characterization of Solidification Agents Used and Products Formed with Radioactive Wastes at LWR Nuclear Power Plants

Abstract

The radioactive wastes (radwastes) routinely generated onsite at light-water-cooled nuclear reactor (LWR) power plants comprise the largest volume of radwastes generated annually in the commercial nuclear fuel cycle, mill tailings excepted. In this consideration, spent fuel is not categorized as waste. The principal wastes considered here are the evaporator concentrates, filter sludges, and spent ion exchange resins that are derived from cleanup of the liquid streams recirculating within or being discharged from LWR plants. From 1975 through 1977, the annual thermal power output from LWRs in the United States was close to 6 × 10⁸ MWhr, and the accompanying average annual waste volume shipped to licensed shallow land burial sites was approximately 3 × 10⁴ m³, as shown in Figures 1 and 2 (1). Until now, most filter sludges and spent resins have merely been dewatered but were not incorporated into a solid matrix, as will be required by future regulations. The introduction of solidification agents to immobilize these sludges and resins can increase the volume of these wastes by a factor of slightly over 1 to greater than 2, depending on the binder chosen.