Decades After Dumping 200,000 Radioactive Barrels Into the Ocean, Researchers Study the Consequences

Since the Industrial Revolution, humanity has produced a dizzying amount of waste, and getting rid of it has not always been easy. Among the most worrying are the hundreds of thousands of radioactive barrels dumped into the Atlantic Ocean between 1950 and 1990.

Large-Scale Dumping at Sea

During the early decades of civilian nuclear energy, it was assumed that disposing of low-activity radioactive waste sealed in metal drums by throwing them into the ocean was a fairly safe strategy. In 1975, the London Convention put a serious brake on this practice, which did not completely stop until the early 1990s.

In the span of four decades, some 200,000 barrels were left to drift in the Atlantic Ocean alone, and it is only recently that scientists have begun to seriously examine the environmental consequences of these dumpings.

In May, members of the Nodssum project, led by the National Centre for Scientific Research (CNRS), boarded the vessel “Pourquoi Pas ?”. In total, around twenty dives, aboard the crewed submersible Nautile, were conducted in the northeast Atlantic, at depths exceeding 4,700 meters.

A first campaign conducted in 2025 had allowed the precise mapping of 3,355 barrels over an area of roughly 160 square kilometers. The most recent expedition focused on the most interesting containers.

Scientists descend 15,400 feet into Atlantic and find leaking radioactive waste barrels
The expedition documented severely corroded barrels and spilled material on the seafloor at a site where more than 200,000 barrels of radioactive waste were dumped decades ago pic.twitter.com/vAq43R5ltZ

— Nature is Amazing ☘️ (@AMAZlNGNATURE) August 10, 2026

Radioactivity Levels Lower Than Expected

Overall, the barrels observed were in an advanced state of deterioration, with in many cases the contents leaking into the surrounding waters. Good news, however: in-situ measurements revealed overall radioactivity levels lower than anticipated.

Although waste-associated radionuclides, such as cobalt-60 and niobium-94, were detectable, the team explained that they were able to handle the samples (water, sediments, and marine organisms) without using substantial radiological protection equipment. The next step will be to study these samples in more detail to determine precisely the impact of this type of radiation on deep-sea life.

Researchers also observed marine animals directly colonizing the barrels, including anemones, sponges, and crabs. A situation reminiscent of the Chernobyl Exclusion Zone, which was quickly repopulated by wildlife after the disaster.

Of course, this is not the only source of marine pollution. It is estimated that some 11 million tonnes of additional waste enter the oceans and seas each year.