[en] Some seventeen candidate waste forms have been investigated under US Department of Energy programs as potential media for the immobilization and geologic disposal of the high-level radioactive wastes (HLW) resulting from chemical processing of nuclear reactor fuels and targets. Two of these HLW forms were selected at the end of fiscal year (FY) 1981 for intensive development if FY 1982 to 1983. Borosilicate glass was continued as the reference form. A crystalline ceramic waste form, SYNROC, was selected for further product formulation and process development as the alternative to borosilicate glass. This paper describes the bases on which this decision was made

[en] The seven candidate waste forms, evaluated as potential media for the immobilization and gelogic disposal of high-level nuclear wastes were borosilicate glass, SYNROC, tailored ceramic, high-silica glass, FUETAP concrete, coated sol-gel particles, and glass marbles in a lead matrix. The evaluation, completed on August 1, 1981, combined preliminary waste form evaluations conducted at Department of Energy (DOE) defense waste-sites and at independent laboratories, peer review assessments, a product performance evaluation, and a processability analysis. Based on the combined results of these four inputs, two of the seven forms, borosilicate glass and a titanate-based ceramic, SYNROC, were selected as the reference and alternative forms, respectively, for continued development and evaluation in the National HLW Program. The borosilicate glass and ceramic forms were further compared during FY-1982 on the basis of risk assessments, cost comparisons, properties comparisons, and conformance with proposed regulatory and repository criteria. Both the glass and ceramic forms are viable candidates for use at DOE defense HLW sites; they are also candidates for immobilization of commercial reprocessing wastes. This paper describes the waste form screening process, discusses each of the four major inputs considered in the selection of the two forms in 1981, and presents a brief summary of the comparisons of the two forms during 1982 and the selection process to determine the final form for SRP defense HLW

[en] Seven candidate waste forms were evaluated for immobilization and geologic disposal of high-level radioactive wastes. The waste forms were compared on the basis of leach resistance, mechanical stability, and waste loading. All forms performed well at leaching temperatures of 40, 90, and 150⁰C. Ceramic forms ranked highest, followed by glasses, a metal matrix form, and concrete. 11 tables

[en] The Department of Energy (DOE) has developed a national plan for isolating U.S. nuclear wastes from the human environment. As part of this plan, a program to develop the technology for the immobilization of high-level radioactive wastes generated from reprocessing of spent reactor fuels from both defense and commercial sources is being managed by a DOE lead office at Savannah River. Seven candidate waste forms for immobilization and geologic disposal of high-level wastes were compared on the bases of waste-specific evaluations, peer review recommendations, a product performance evaluation, and a processability analysis. Two of the forms, borosilicate glass and a crystalline ceramic, were selected for continued development as the reference and alternative forms, respectively

[en] A quantitative evaluation method was used to rate seven candidate waste forms for the immobilization and geologic disposal of high-level radioactive wastes. Performance data for leach resistance, impact resistance, and waste loading were compared for waste forms containing simulated Savannah River Plant defense high-level wastes, the first high-level wastes that will be immobilized in the United States. The evaluation method and its results, the type and sources of data, and future requirements for waste form evaluation are discussed