The presence of nuclear weapons does not mean a nuclear explosion occurred. The precise circumstances surrounding the submarine’s loss remain disputed.
Environmental investigations conducted by American authorities in 1979, 1986, and 1998 included samples of seawater, sediment, and marine organisms collected near the wreckage.
According to the Navy’s findings, researchers identified no evidence of radioactive fuel escaping from the submarine’s reactor and no evidence of plutonium leakage from its nuclear weapons.
Small quantities of cobalt-60 were detected in nearby sediments. The Navy attributed this material to reactor cooling systems and reported no discernible radiological effects under the conditions studied.
An important distinction remains: the report was published in 2025, but the latest sampling campaign it identifies at the Scorpion wreck occurred in 1998.
Consequently, its findings document conditions during the periods investigated. They do not constitute a contemporary assessment of the wreckage.
The MSC Carla: Radioactive Cargo Lost in a Storm
Nearly three decades later, another maritime disaster brought radioactive material to the Atlantic seabed.
On November 24, 1997, the Panamanian-flagged container ship MSC Carla, traveling from Le Havre, France, to Boston, Massachusetts, broke apart during a violent storm.
All 34 crew members were rescued by helicopter.
The disaster resulted in the loss of 74 containers carrying various materials, including hazardous chemicals.
One container held three biological irradiators containing sealed sources of cesium-137, a radioactive isotope.
According to a 2001 report by the International Atomic Energy Agency, the lost cargo contained radioactive sources with a combined activity of 326 terabecquerels.
That figure describes the radioactivity contained in the missing cargo, not the amount released into the ocean.
France’s maritime pollution research center, Cedre, reported that the equipment had been designed to withstand pressure equivalent to approximately 200 meters of water but was lost at an estimated depth of 3,000 meters.
The equipment reportedly imploded under the immense pressure.
However, the implosion of the surrounding equipment does not, by itself, establish that the sealed radioactive sources ruptured.
The International Atomic Energy Agency recorded no reported release of radioactive activity from the cargo.
French safety assessments at the time considered the potential risks to marine organisms and seafood consumers to be limited under the conditions examined.
Nevertheless, the fate of the radioactive material remains part of the documented history of the accident.
When the Atlantic Became a Nuclear Waste Repository
Beyond these individual disasters lies a much larger and more troubling historical reality.
Between 1949 and 1982, several European countries deliberately deposited radioactive waste in the Northeast Atlantic.
According to the OSPAR Commission, which oversees the protection of the Northeast Atlantic marine environment, more than 150,000 metric tons of radioactive waste were deposited during this period, representing approximately 42.4 petabecquerels of recorded activity.
These figures refer to the wider Northeast Atlantic, not specifically to waters surrounding the Azores.
Participating countries included the United Kingdom, Belgium, France, the Netherlands, Switzerland, Sweden, Germany, and Italy.
The United Kingdom accounted for the largest share of recorded radioactive activity.
Much of the waste consisted of low-level radioactive material originating from nuclear facilities, scientific research, hospitals, and related activities. Deposits were frequently made at depths ranging from 3,000 to 5,000 meters.
For decades, the ocean was treated as a place where unwanted materials could be removed from immediate human contact.
The assumption was that enormous depths, geographic isolation, and the ocean’s capacity for dilution would limit potential harm.
Scientific understanding and environmental policy have evolved considerably since those operations ended.
International monitoring programs conducted through the 1990s did not establish significant harmful environmental effects at the sites examined. Some studies nevertheless identified evidence of radioactive material escaping from containers, generally at levels considered to present limited radiological risk.
A German federal radiation protection study published in 2019 identified indications that radionuclides had moved from waste containers into deep-sea organisms at low levels.
The study also emphasized the limitations created by irregular monitoring after the 1990s and the importance of renewed scientific observation.
New Scientific Expeditions Return to the Deep
Recent research has brought renewed attention to these historical disposal sites.
During 2025 and 2026, the NODSSUM project, coordinated by France’s National Center for Scientific Research, returned to former radioactive waste dumping areas in the Northeast Atlantic.
During its first expedition, researchers mapped 3,355 waste containers, collected approximately 5,000 liters of seawater, obtained 345 sediment samples, and gathered 34 marine organisms for analysis.
A second expedition, completed on June 28, 2026, included 20 dives by the scientific submersible Nautile to depths exceeding 4,700 meters.
The underwater images revealed containers in varying states of deterioration. Some were heavily corroded, with portions of their contents scattered across the seabed.
In a July 2, 2026, communication, French researchers reported detecting radionuclides characteristic of radioactive waste at levels higher than expected in the surveyed area.
The measured levels were nevertheless described as low, and the comprehensive environmental assessment remained dependent on laboratory analysis of collected water, sediments, and marine organisms.
These observations demonstrate that deterioration and localized radiological signals are not merely theoretical possibilities.
They do not, however, establish widespread significant environmental damage or justify assuming similar conditions throughout the waters surrounding the Azores and Madeira.
Portugal has also remained involved in discussions concerning historical radioactive waste disposal.
According to OSPAR, Portugal presented an update in February 2026 concerning monitoring of a former disposal site in Macaronesia.
The publicly described information did not establish a connection between that monitoring activity and the alleged discoveries near Santa Maria or Madeira reported in 2003.
What the Evidence Establishes—and What Remains Unknown
The historical documentation supports several conclusions.
Radioactive waste was deliberately deposited in the Northeast Atlantic by European countries. The USS Scorpion sank southwest of the Azores carrying two nuclear-armed torpedoes. The MSC Carla lost radioactive cargo during a 1997 maritime disaster. And concerns about alleged radioactive deposits near the Portuguese Atlantic islands reached the European Parliament in 2004.
But the evidence also requires important qualifications.
The reported 2003 discovery by the French survey vessel has not been independently confirmed in the documentation examined.
American investigations did not identify plutonium leakage from the Scorpion‘s nuclear weapons during the sampling periods studied.
The International Atomic Energy Agency did not record a reported radioactive release from the MSC Carla‘s lost cargo.
And the scientific findings available do not demonstrate that these incidents caused significant widespread environmental damage in Atlantic waters.
The newer research into historical dumping sites, however, provides evidence of container deterioration and localized radioactive signals, reinforcing the importance of continued monitoring.
For the Azores, this history raises questions extending beyond nuclear science.
The archipelago occupies an immense maritime space whose environmental protection is inseparable from its economic future, scientific responsibilities, and relationship with the Atlantic.
The ocean sustains fisheries, biodiversity, international communications, scientific research, and the cultural identity of island communities. Its depths cannot be regarded simply as remote spaces where the consequences of past decisions cease to matter.
The absence of demonstrated widespread environmental harm is reassuring, but it should not be confused with proof that every risk has disappeared.
Nearly six decades after the loss of the USS Scorpion, almost thirty years after the sinking of the MSC Carla, and more than four decades after deliberate radioactive waste dumping ceased in the Northeast Atlantic, the scientific obligation to understand these submerged legacies remains.
The Atlantic is vast, but its immensity is not a guarantee of immunity. Its depths may conceal the evidence of human decisions for generations, yet concealment is not the same as disappearance.
And perhaps the most enduring lesson of these three histories is that what humanity consigns to the darkness does not necessarily cease to exist.
The ocean’s silence is not proof of safety. Beneath the Atlantic, where sunlight cannot reach and memory seems suspended in the water, scientific vigilance must continue long after the world has stopped looking.
Based on the investigation “Resíduos denunciados, um submarino com armas atómicas e uma carga radioactiva perdida — O Atlântico guarda três histórias nucleares junto aos Açores,” by Paulo Hugo Viveiros, published in Diário dos Açores. The original reporting draws on European parliamentary records, United States Navy reports, International Atomic Energy Agency documentation, OSPAR records, and French scientific research. This English adaptation preserves the distinction between documented historical events, reported allegations, and scientifically established environmental effects.