Overview

• The CNRS-led NODSSUM team used the research vessel L’Atalante and the UlyX ROV to chart some 163 km² of seabed and locate roughly 3,350 waste barrels at a depth of 4,700 m.
• Preliminary inspections reveal a spectrum of barrel conditions, from intact and deformed to corroded containers with visible leaks of tar-like material.
• Onboard radioprotection instruments measured radiation in sediments, water and marine life at levels matching natural background readings.
• Expedition scientists collected 345 sediment cores, 5,000 L of water and various deep-sea organisms now bound for laboratory analysis to refine radiological assessments.
• A second campaign deploying teleoperated vehicles such as Victor or Nautile is planned for 2026–2027 to sample barrel exteriors and nearby substrates and track potential environmental impacts.