A Sunken Nuclear Submarine Is Leaking Radiation Into the Ocean. How Worried Should We Be?

Repairs or just outright cleanup would be expensive, extremely difficult, slow, and, of course, quite dangerous.

By Luis Prada, March 25, 2026, https://www.vice.com/en/article/a-sunken-nuclear-submarine-is-leaking-radiation-into-the-ocean-how-worried-should-we-be/

According to new research published in PNAS, a Cold War-era nuclear submarine sitting at the bottom of the Norwegian Sea is still leaking radioactive material. It’s happening slowly, if unevenly, and it’s contained just enough to avoid becoming a full-scale environmental disaster… for now.

The K-278 Komsomolets sank in 1989 after an onboard fire, taking with it a nuclear reactor and two nuclear torpedoes. It now sits more than 1,600 meters below the surface, in a part of the ocean that is freezing and almost entirely out of reach.

A research team led by Justin Gwynn at Norway’s radiation safety authority analyzed years of data, including a 2019 survey using a remotely operated vehicle. The team found that the wreck is leaking radioactive isotopes, including cesium and strontium, through cracks in its deteriorating hull.

The leaks aren’t constant. They come in waves, with visible plumes drifting out from various spots, like the reactor compartment or a ventilation pipe. Radiation levels take a big jump closer to the submarine, with levels reaching hundreds of thousands of times above normal background radiation levels.

At Least the Nuclear Submarine’s Nuclear Torpedoes Are Still Intact

Terrifying, and here’s where it gets strange: measurements taken from just a few feet away dramatically drop off. Researchers believe this is caused by the ocean diluting the problem. That may be why the surrounding ecosystem isn’t showing any obvious signs of collapse, given all of the toxic radiation. There’s still plenty of marine life clinging to the wreck, including sponges, corals, and anemones. They have slightly elevated radiation levels but no visible signs of deformation or damage, though genetic damage wouldn’t be surprising.

Sediment samples collected nearby show minimal contamination. Things wouldn’t be looking so rosy if the nuclear torpedoes inside it weren’t intact, which they very much are and have been since the 1990s.

So far, there are no signs of imminent disaster. Everything is stable and holding steady… for now.

This won’t always be the case, and it is really more a matter not of if but of when. The reactor is still corroding, and the structure is still weakening. Repairs or just outright cleanup will be expensive, extremely difficult, slow, and, of course, quite dangerous. The risk is contained, but that doesn’t mean it’s going away anytime soon.