Finnish firm produces copper blank for waste nuclear fuel repository

Finnish radioactive waste management company Posiva has produced its first copper casting blank for fabricating a final disposal canister intended for the Onkalo spent nuclear fuel repository, the world’s first deep geological repository for spent nuclear fuel. The casting, completed at Luvata’s plant in Pori, weighed over 17 tons initially and will be machined down to about 12 tons before delivery to the cylinder manufacturer. The casting process was overseen by Finland’s Radiation and Nuclear Safety Authority (STUK) and involved quality improvements such as a larger gravity die to increase casting diameter, ensuring high-quality copper blanks essential for subsequent canister production phases. The copper canister, with five-centimeter-thick walls, acts as a corrosion barrier surrounding a cast iron inner structure that holds 12 spent fuel elements. The inner cast iron component provides structural support and fuel placement, while the copper shell and lid are tightly welded to prevent groundwater intrusion, thereby stopping radionuclides from leaking into the environment. After