200,000 Barrels Of Radioactive Waste Dumped In The Atlantic: NODSSUM Project Patrick Chardon Javier Escartín CNRS French National Center Scientific Research L’Atalante June 2025 UlyX AUV Maps 3355 Barrels Pourquoi Pas May 2026 Nautile Three-Person Submersible 19 Dives 4700m 100+ Barrels Imaged Heavily Corroded Material Visibly Oozing Surrounding Sand Cobalt-60 Niobium-94 Cesium-137 Americium-241 Above Background
Between 1949 and 1982, European nations dumped more than 200,000 barrels of low-level radioactive waste; totalling over 150,000 tons into the Atlantic Ocean, mostly at depths between 3,000 and 5,000 metres. The reasoning was not entirely irrational: guidelines at the time suggested containers needed only to reach the seafloor intact and remain sealed long enough for short-lived radionuclides to decay. The remaining material would then slowly disperse into the surrounding ocean. Not everyone in the barrels would conveniently decay away, however they contained cesium-137, plutonium isotopes, and tritium that can persist for thousands of years. Science Alert
Decades later, scientists have finally gone to look. The NODSSUM project; Nuclear Ocean Dump Site Survey Monitoring, led by nuclear engineer Patrick Chardon and marine geologist Javier Escartín of CNRS, first mapped 3,355 barrels using an autonomous underwater vehicle in June 2025. In May 2026, they returned aboard the Pourquoi Pas? with the Nautile submersible, descending to 4,700 metres over 19 dives to inspect the barrels directly.
What they found was striking. Many barrels were heavily corroded, with material visibly oozing onto the surrounding sand. Instruments detected cobalt-60, niobium-94, cesium-137, and americium-241 at levels above background. Yet the barrels had also become unlikely oases; anemones, sponges, sea cucumbers, fish and crabs had colonised the waste containers. Whether radioactivity is accumulating in those animals remains under analysis.
The precedent from the sunken Soviet submarine Komsomolets offers cautious reassurance: radionuclide levels dropped sharply within metres of the leaking reactor. The question for NODSSUM is whether the same applies here and whether the ecosystem around the barrels changes that picture.
The barrels were supposed to be forgotten. The ocean remembers everything. Check out our previous coverage of science and environment on The Trusted Times.
