Scientific Mission to Track Radioactive Waste Barrels at the Bottom of the Atlantic Ocean

As part of the project “Monitoring of Nuclear Storage Sites in the Open Sea” (NODSSUM), a scientific mission led by the French National Center for Scientific Research (CNRS) set sail for the northeastern Atlantic Ocean on 14-15 June to investigate the long-term effects of radioactive waste dumping at sea between the 1950s and 1990s.

For four decades, the United Kingdom, Belgium, and France dumped radioactive waste into the Atlantic Ocean until the practice was banned. The barrels are believed to contain low- and intermediate-level radioactive waste, including process sludge, contaminated metal components, ion-exchange resins, laboratory equipment, and other types of waste. This waste was encapsulated in bitumen or cement in order to withstand the pressure of ocean depths.

With support from the French Research Institute for Exploitation of the Sea (Ifremer) and the French Authority for Nuclear Safety and Radiation Protection(ASNR), among other organizations, the NODSSUM Project aims to map and assess the condition of more than 200,000 barrels of radioactive waste submerged at depths of 3,000 to 5,000 meters on the Atlantic deep-sea plains, over 600 kilometers off the French coast.

This is the first of two scientific missions planned by the CNRS to examine the condition of the barrels with a shelf life of 25 years , as well as to understand how radionuclides behave in deep-sea conditions and what potential impact they may have on marine ecosystems.

During the first mission, scientists will survey the waste disposal sites using a high-precision sonar aboard the new UlyX autonomous underwater vehicle, which will undertake its first scientific dives. Initially, UlyX will operate at an altitude of about 90 meters above the seabed to create a map and identify the barrels, then photograph them from a height of nine meters. This will help determining locations for initial sampling of water, sediment, and fauna without disturbing the integrity of the barrels.

The second mission scheduled for next year involves measuring the presence of radionuclides in the water, sediments, and organisms collected nearby. Background radiation levels will also be analyzed to distinguish the effects caused by the sunken barrels from those originating from nuclear accidents, tests, and authorized discharges from nuclear power plants.