CNRS expedition investigates deep-sea radioactive waste off Galicia

An oceanographic expedition led by the French National Centre for Scientific Research (CNRS) has completed the collection of samples near a massive site of historical radioactive waste. Located in the Atlantic abyssal zone approximately 650 kilometers off the coast of Galicia, the site contains more than 200,000 barrels of waste dumped between the 1940s and 1980s from civil nuclear activities and research.

Using the oceanographic vessel Pourquoi Pas? and the manned submersible Nautile, researchers conducted dives at depths exceeding 4,700 meters to collect water, sediment, and marine organisms. The mission aims to determine if radioactive substances have dispersed and to evaluate their interaction with deep-sea ecosystems.

The collected samples will be analyzed at the National Accelerator Center in Seville, Spain. This facility utilizes accelerator mass spectrometry, the only operational installation of its kind in Spain, to detect extremely low concentrations of radionuclides such as uranium and plutonium isotopes. This analysis will help scientists reconstruct dispersion processes and understand the evolution of these residues in the deep ocean.