Overview

• The Nodssum mission deployed the autonomous Ulyx submersible for 17 dives and mapped 3,350 barrels across a 163 km² zone at depths over 4,000 meters.
• Radioprotection sensors recorded radiation levels consistent with natural background even near barrels showing significant corrosion.
• Researchers retrieved more than 300 sediment cores, 5,000 liters of seawater and 17 grenadier fish for detailed laboratory assessments of radioactivity.
• This marks the first systematic evaluation of the mid-20th-century dump site since 1980s CEA and Ifremer surveys and follows the 1993 London Convention ban on sea dumping of radioactive waste.
• A second expedition is planned within two years to sample organisms inhabiting the barrels and refine long-term ecological impact assessments without pursuing costly recovery efforts.