They Dumped 200,000 Radioactive Barrels Into the Atlantic: 35 Years Later, French Scientists Are Going After Them
For decades, they lay untouched and largely forgotten—hundreds of thousands of barrels filled with radioactive waste, scattered across the abyssal plains of the Atlantic Ocean. Now, more than 30 years after the last were submerged, a French scientific mission is preparing to search for them, raising fresh questions about the long-term impact of nuclear dumping at sea.
Decades-Old Barrels, Deep-Sea Mysteries
Between 1946 and 1990, over 200,000 barrels of radioactive waste were deliberately sunk into the Atlantic by various nations, including France. Packed in bitumen or cement, the containers were lowered into what scientists at the time considered to be lifeless zones, thousands of meters below the ocean surface and far from any coastline.
The practice was permitted until 1990, when it was banned under the London Convention following growing awareness of deep-sea ecosystems and the potential environmental risks of radioactive leakage. The barrels were never retrieved, and no comprehensive effort has since been made to assess their state—or their potential impact on marine life.
An Ambitious Mission Beneath 4,000 Meters
This summer, a group of French researchers will head into the Atlantic to do just that. The mission, called Nodssum, is a collaboration involving CNRS, Ifremer, and the French Oceanographic Fleet. Their immediate goal is to map a 6,000-square-kilometer section of the seafloor where a significant number of barrels are believed to be resting.
To locate them, the team will deploy a high-resolution sonar system and the autonomous submersible UlyX, one of the few underwater vehicles capable of operating at depths greater than 4,000 meters. UlyX will scan the ocean bottom, helping to establish the precise location of the containers and assess their current condition.
Questions of Leakage and Contamination
So far, the environmental effects of the submerged barrels remain unknown. As the article notes, “no one knows what impact the dumping of these barrels may have had on deep-sea ecosystems, or whether they still represent a radiological risk.” Part of the challenge lies in the vastness and inaccessibility of the ocean floor where the barrels were dropped.
Once the mapping phase is complete, a second campaign will be launched to collect samples of sediments, seawater, and marine organisms near the barrels. These samples will help determine whether radioactive materials have begun to escape their containers and what effect, if any, that may be having on surrounding ecosystems.
Unknowns Beneath the Surface
The mission represents one of the first large-scale scientific efforts to investigate this Cold War-era dumping ground. While scientists long assumed that the deep sea was barren and isolated, more recent research has shown that it is home to complex ecosystems, many of which remain poorly understood.
The researchers hope that the project will provide new insights into the long-term stability of radioactive waste in deep-sea environments and offer a clearer understanding of how past nuclear policies continue to shape today’s oceans.