Radioactive waste discovered in deep ocean

More than 200,000 barrels of radioactive waste have been found resting at depths of 4,700 meters in the North-East Atlantic. The CNRS NODSSUM mission used the submersible Nautile to inspect the site in May 2026 and discovered ruptured containers.

Waste has been in the ocean for decades

The waste has been at the bottom of the ocean since the 1950s, with some barrels having released their contents onto the seabed sediments. Measured radioactivity levels remain low but exceed expected levels, prompting researchers to investigate whether the abyssal fauna is affected.

Historical disposal by multiple countries

Between 1949 and 1990, several European countries, including the United Kingdom, Belgium, and France, disposed of containers filled with radioactive materials in the abyssal plains. A total of fourteen countries participated in these disposals across different oceans.

Disposal site spans large area

The main area covers approximately 14,500 square kilometers in international waters, between 3,000 and 5,000 meters depth. The materials were encased in concrete or bitumen before being immersed.

Original plan for temporary containment

The metal cylinders were intended to contain the waste for about twenty years, with the natural decay of isotopes expected to neutralize the radioactivity. No one anticipated retrieving the barrels once they were placed on the seabed, and the strategy relied on the ocean to dilute the residues after degradation.

Ocean disposal practice phased out

The practice of ocean disposal was gradually restricted by the London Convention, adopted in 1972, and ceased entirely in 1993. The barrels have remained on the seabed without monitoring for decades, with no follow-up program accompanying the deep-water disposal operations.