Norwegian researchers have discovered that a Soviet nuclear submarine that sank in the Barents Sea 30 years ago, killing 41 sailors, is leaking radiation at nearly 1 million times normal levels.

The submarine, called the Komsomolets, was at the time the most advanced in the Soviet Navy. When it went down on April 7,1989, it was carrying two plutonium warheads, which now lie at a depth of 1,680 meters with the rest of the sub’s wreckage, including its reactor. The wreck has caused concern about possible radioactive leakage ever since.

Now those worries have been confirmed. Using a remote-controlled vehicle to probe the wreck, researchers from the Norwegian Radiation and Nuclear Safety Authority found extensive damage to the sub’s hull. Of particular disquiet, they say, are exceptionally high radiation levels in the area around one of the sub’s ventilation pipes.

The highest measurement researchers recorded stood at 800 becquerel per liter. Radiation levels in that body of water typically remain around 0.001 Bq per liter, the authority said.

“We found levels of radioactive cesium…that were close to 1 million times higher than the levels we find in [uncontaminated] seawater,” Hilde Elise Heldal, a researcher from Norway’s Institute of Marine Research who participated in the July 7 mission, told RFE/RL. In remarks to Reuters, she added that: “This is, of course, a higher level than we would usually measure out at sea, but the levels we have found now are not alarming.”

Heldal said team members “weren’t surprised” to discover elevated radiation levels, the BBC reported. Radioactive cesium is easily diluted in the depths of the Barents Sea, and few fish live in the area surrounding the wreck.

The Komsomolets at sea. Credit: Courtesy of the Barents Observer

“What we have found … has very little impact on Norwegian fish and seafood,” Heldal said, according to the Associated Press. “In general, cesium levels in the Norwegian Sea are very low, and as the wreck is so deep, the pollution from Komsomolets is quickly diluted.”

Still, the confirmation that the submarine is actively leaking radiation comes weeks after a fire aboard a top-secret Russian nuclear submarine in the Barents Sea killed 14 sailors, making it the deadliest submarine incident to hit the Russian Navy since 2008.

Norwegian scientists have been monitoring the wreck of the Komsomolets – which lies 180 kilometers southwest of Norway’s Bear Island and 350 kilometers northwest of the country’s mainland coast – since the 1990s.

The Norwegian monitoring expeditions, which occur on an annual basis, entail taking core samples from the sea floor. Russian investigators had previously found small radiation leaks near the wreck in the 1990s and in 2007

This year, Norway deployed an undersea drone called the Aegir 600 to investigate the sub’s remains, allowing researchers to take film. On July 8, the researchers released eerie footage of the wreckage, showing intact torpedoes lying amid the destruction that fire and time have wrought on the titanium-hulled sub.

A map of the wreckage of the Komsomolets, Credit: Map courtesy of the Barents Observer,

The drone, Heldal told RFE/RL, also enabled researchers to take a sample of the ventilation pipe that is leaking radiation.

One sample was not found to be above normal. One was 30,000 times higher than that found in uncontaminated seawater. Two samples showed levels 100,000 times more than normal ­– in keeping with previous recorded samples. And one, she said, was close to 1 million times higher. Norway’s Institute of Marine Research later specified that the highest sample was more than 800,000 times higher than normal.

Heldal described the findings as “comparable” to the results of the previous Russian surveys, and said they showed that the Komsomolets had been leaking radiation “the whole time.”

While Russia has made numerous promises over the years to raise the Komsomolets and other radioactive debris abandoned in the Arctic by the Soviet Navy, Heldal suggested that attempting to lift the sub from the depths would be a dangerous scenario, risking leakage at the surface.

Yet even in its watery grave, the Komosomolets is the stuff of Cold War legend. Launched in May of 1983 from Severodvinsk on the Barents Sea, the sub could dive to deeper depths than any other vessel at the time. It was manned by a crew of 69 and could launch both nuclear and conventional weapons.

The Komsomolets had been patrolling the waters for 39 days when a fire broke out in one compartment and quickly spread through the submarine on April 7, 1989, according to the CIA report. Forty-two crew died either in the fire or while awaiting rescue, and the sub sank to the bottom of the sea.

The matter of the Komsomolets shook faith in an already ailing navy. Within two years of the accident, the Soviet Union would cease to be – leaving in its wake hundreds of derelict decommissioned nuclear submarines, and a host of other radioactive hazards dumped by the military.

By 1994, the government in Moscow would reveal the scale of its irradiated legacy in the Arctic. The Soviet navy had scuttled hundreds of barrels of nuclear waste in the Kara Sea, along with old nuclear reactors, and, in one case, an entire nuclear submarine.