The NODSSUM interdisciplinary mission, led by CNRS and in collaboration with a team from Ifremer, ASNR and several national and international partners 1 , will set sail for a month on June 15. Scientists are planning two campaigns to use modern tools to map the main dumping zone for the many drums of radioactive waste that have been deliberately dumped for 40 years in the abyssal plains of the North-East Atlantic. This first survey mission is being carried out by the UlyX2 autonomous robot of the French Oceanographic Fleet, operated by IFREMER .
1 This two-phase campaign is led by two CNRS researchers from the Clermont Auvergne Physics Laboratory (CNRS/University of Clermont Auvergne) and the ENS Geology Laboratory (ENS-PSL/CNRS). It also involves scientists from the Clermont Auvergne Physics Laboratory (CNRS/University of Clermont Auvergne) / 2 Infinities Physics Laboratory (CNRS/University of Bordeaux) / Institut pluridisciplinaire Hubert Curien (CNRS/University of Strasbourg) / Subatomic Physics and Associated Technologies Laboratory (CNRS/IMT Atlantique/Nantes University) / Geology Laboratory of the ENS (ENS-PSL/CNRS).ENS (ENS-PSL/CNRS) / Laboratoire d’études en géophysique et océanographie spatiales (CNRS/CNES/IRD/Université de Toulouse) & IRD / Laboratoire microorganismes : génome et environnement (CNRS/Université Clermont Auvergne) / Unité de systèmes sous-marins (Flotte océanographique Française-IFREMER) as well as the Laboratoire de recherche sur les transferts des radionucléides dans les écosystèmes aquatiques (ASNR). This interdisciplinary mission also includes foreign organizations: the University of Bergen (Norway), Memorial University (Canada) and the Johann Heinrich von Thünen Institute (Germany). On land, several laboratories will be involved in the analysis and interpretation of samples and data, including the Lyon Geology Laboratory (CNRS/Université Lyon 1/ENS Lyon) and the University of Girona (Spain). Technical resources (ship, robots, onboard personnel, etc.) are provided and financed by the French Oceanographic Fleet.
2 depending on the clues it detects, it modifies its trajectory. UlyX is battery-powered and capable of descending to depths of over 6,000 meters. Find out more here.
Between 1946 and 1990, more than 200,000 drums filled with radioactive waste were dumped by several European states into the abyssal plain of the North-East Atlantic Ocean, in international waters more than 4,000 meters deep. These drums contain waste embedded in bitumen and cement to fill the empty spaces in the drums.
The NODSSUM project, an interdisciplinary campaign combining nuclear power, geology, oceanography, biology and marine chemistry, aims to map the main immersion zone and understand the behavior of radionuclides 3 in deep waters, as well as their interactions with marine ecosystems. Over the course of a month, the scientists will explore the radioactive drums’ immersion zones using very high-resolution sonar, aboard the autonomous submersible UlyX, which is making its first scientific dives. It will fly over the area at an altitude of around 70 meters to map and locate the drums, and will approach to a distance of around ten meters to photograph them. This will make it possible to identify areas for water, sediment and fauna sampling, initially at a distance from the drums.
For this first interdisciplinary mission, the scientists are combining several cutting-edge technologies and plan to take sediment samples from the ship using corers, as well as water samples using rosettes. Current meters anchored to the seabed will measure currents in the abyssal zone. Scientists will also install fish and shellfish traps to assess the effect of radioactive waste on marine organisms and ecosystem dynamics. On board, the teams will be equipped with instruments for measuring radioactivity. These measurements will then be refined by further analysis in the laboratory.
In order to avoid any possible radiological risk, the project includes an extensive radiation protection system on board. As soon as they arrive, samples and instruments will be checked and inspected to ensure that the appropriate radiation protection measures are in place for their processing and storage. These precautions and controls will continue throughout the scientific work, including in the onshore laboratories.
These measurements and samples will be used to select sites for more detailed study during the second campaign. The second campaign will target the immediate vicinity of the drums. It will use manned robotic or submersible underwater vehicles equipped with mechanical arms to handle and observe the drums directly.
The NODSSUM interdisciplinary mission is an integral part of the PRIME RADIOCEAN project, led by CNRS and linked to the NODSSUM project submitted to the French Oceanographic Fleet.
Full details are available on the mission’s dedicated web page.
3 A radionuclide is an atom whose nucleus is unstable and capable of transforming into another atom by emitting radiation. Waste contains a range of radionuclides, each with its own chemical properties. In addition to their quantity, they may be present in various forms, more or less mobile, and distributed between water and sediments. Some radionuclides are produced by humans, such as cesium 137, while others are naturally present, such as potassium 40 and lead 210. Radionuclides are everywhere. Generally speaking, most exposure to ionizing radiation comes from natural sources (radionuclides in the earth’s crust, cosmic rays).
