Scientists probe deteriorating Cold-War nuclear waste barrels on Atlantic seabed

From 1946 to 1993, several Western nations dumped around 200,000 radioactive waste barrels into the northeast Atlantic, and a 2026 scientific cruise has now revisited one of those sites. Over a period of roughly one month, a crew of thirty scientists on the French research ship Pourquoi Pas? conducted deep-sea dives with the Nautile submersible, retrieving sediment cores and documenting barrels that had become heavily corroded and were leaking their contents.

Radiation measurements around the dump showed levels higher than normally expected, although some of the signal may stem from other sources. The researchers also recorded a community of sea life—anemones, sponges, crabs—colonising the metal structures, and they collected specimens for comparative study. Led by the NODSSUM (Nuclear Ocean Dump Site Survey Monitoring) initiative launched in 2025, the multinational team from France, Norway, Germany and Spain will analyse the samples to determine which radionuclides are present, how far they have spread, and whether they are entering the food chain. So far, no evidence suggests that commercial seafood is contaminated, but the work aims to clarify long-term environmental risks of past ocean dumping practices.