Finland is set to open the world's first underground spent nuclear fuel storage facility, Onkalo, by early 2026, marking a significant advancement in nuclear waste management. This facility will store highly radioactive spent nuclear fuel in waterproof copper canisters buried over 400 meters deep for approximately 100,000 years. Managed by Posiva, a company established in 1995, the project has been praised as a crucial step towards sustainable nuclear energy and a potential model for global practices. While proponents highlight its role in addressing nuclear waste challenges, critics voice concerns regarding long-term safety and the broader implications of nuclear power in combating climate change. Finnish Climate Minister Kai Mykkänen sees the initiative as a move towards sustainability, replacing more harmful energy sources. Overall, Onkalo represents both a technological milestone and a focal point of ongoing debate about the future of nuclear energy.