Finnish nuclear waste plan spans 100,000 years

Finland has decided to permanently bury 6,500 tons of used nuclear fuel 430 meters underground in copper, cast iron, and clay capsules, expecting the material to remain hazardous for 100,000 years. The project, named Onkalo, was officially signed in 2026 and aims to safely store the waste until its radioactivity decreases.

Radioactive waste has varying lifespans

Nuclear waste is categorized based on its radioactivity level, with "very high activity waste" including spent fuel that emits deadly radiation and heat. Different elements in the waste have different decay times, such as cesium 137 and strontium 90, which lose half their radioactivity in about 30 years, and plutonium 239, which takes about 24,100 years.

Nuclear waste management has evolved over time

For decades, decisions on managing nuclear waste were based on intuition, with past practices including dumping waste into the ocean. A 2025 CNRS study found that the Atlantic Ocean still holds traces of such waste. While sending waste into space is being considered, the risk of launching nuclear material makes it impractical, leading Finland to choose underground burial.

France faces challenges with nuclear waste storage

France has 1.89 million cubic meters of radioactive waste, much of it stored in pools at La Hague, where capacity is reached annually. The waste is then densified, and temporary storage has become an official protocol. Open-air waste pools in Narbonne have also raised concerns, especially after recent floods led to unprocessed runoff being discharged.

Germany struggles with leaking nuclear waste

Germany's former Asse II salt mine, which has stored radioactive waste since 1967, is facing increasing groundwater infiltration. In 2024, 12 cubic meters of water flowed daily near radioactive chambers, complicating efforts to safely remove the waste in an emergency.

Greenland's melting ice threatens nuclear waste

In Greenland, melting ice could release nuclear waste into the Atlantic Ocean by 2090, according to the American Court of Audits. A military base established in 1959 left behind 200,000 liters of fuel, 240,000 liters of wastewater, and a 36-meter-long reactor casing buried under ice.

Pacific nuclear waste site is deteriorating

In the Marshall Islands, the Runit dome, built to contain radioactive debris from nuclear tests, is now cracking and at risk of being submerged by rising sea levels. American nuclear engineer Arjun Makhijani noted that no concrete structure can withstand the long-term danger posed by plutonium 239 in the area.

Nuclear waste management remains a global challenge

The long-term storage of nuclear waste has proven difficult, with past assumptions about the safety of concrete domes and other methods failing to account for the extreme longevity of some radioactive materials. Despite uncertainties, projects like Finland's Onkalo continue to support the expansion of nuclear energy.