Evaluation of efficient cementation of fission 99Mo production process waste and feasibility disposal of cement waste form

Abstract

The Korea Atomic Energy Research Institute (KAERI) is planning the construction of the KIJANG Research Reactor (KJRR), which is currently undergoing licensing procedures. The fission 99Mo production process (FMPP) of the KJRR generates intermediate-level liquid waste (ILLW) and alumina residue (Al2O3 cake), which is a solid waste. In the present study, an efficient method of reducing the amount of generated cement waste form by mixing the ILLW and Al2O3 cake together, into low-level waste, was developed. The purpose of this study was to determine if the cement waste form produced by mixing cement with the waste from the FMPP would satisfy the acceptance criteria of a low- and intermediate-level waste disposal facility in Korea. The process operating range and the optimum operating conditions were found by investigating the mixability of the cement waste form, by considering the presence of free standing water after curing, and by performing a water immersion test depending on the mixing ratios of Portland cement (type I), ILLW, and Al2O3 cake. The feasibility of treating the cement waste form produced under the optimum operating conditions was evaluated in relation to the acceptance criteria of a low- and intermediate-level waste disposal facility in Korea. The results showed that the cement waste form satisfied the acceptance criteria with regard to structural stability (compressive strength test, thermal cycling test, water immersion test, and irradiation test) and leachability (leaching test).