Radionuclide characterization and handling strategy of irradiated Fission Product Material (FPM) capsule waste from molybdenum-99 production

Abstract Irradiated FPM Capsule waste is one of the types of radioactive waste generated from Molybdenum-99 (99Mo) production. This 99Mo is a 99mTc parent radionuclide that is used for the diagnosis of human organ disorders. In its production, the capsule is used for the emplacement of uranium target for irradiation in the GA Siwabessy Reactor. Since the beginning of production until now, the irradiated FPM capsules waste are still being stored in the hot cells because no data on their characteristics and handling systems that are necessary for their treatment. However, long-term storage of the FPM capsules waste in the hot cells shall be avoided because it can disrupt the production process of 99Mo and pose radiation risk to workers. The objectives of this research are to characterize radionuclides composition in the FPM capsule waste and identify its appropriate handling system. The radionuclides characterization was carried out using ORIGEN 2.1 software whereas the selection of the handling system was based on the suitability or modification of the available facilities at Radioactive Waste Management Installation (RWMI)-BRIN. The characterization results show that up to a decay time of 50 years, an FPM capsule waste contains activation product radionuclides such as 55Fe, 59Ni, and 63Ni with a total specific activity of 7.11x106 Bq/g. Three FPM capsule waste handling systems were identified that can be implemented at the RWMI facility, namely by using a 350 -liter concrete shell and then storing in an interim storage for low and intermediate-level waste, using a 60-liter stainless-steel canister which is then stored in the interim storage pit for high-level waste, or by modifying the interim storage pit for high-level waste. Radionuclide characterization and appropriate handling systems are required for the safe management of irradiated FPM capsule waste. This FPM capsule waste management is important for human and environmental protection.