CERAD researchers, together with researchers from the Institute of Marine Research (HI), the Norwegian Radiation and Nuclear Safety Authority (DSA) and from Russia, investigated the sunken nuclear submarine "Komsomolets". The wreck has been lying on the bottom of the sea, at a depth of about 1665 meters, for 30 years, and the researchers have expected that radioactive leakage could occur due to corrosion.
Leakage of radioactive caesium
Water and sediment samples that have been collected with a ROV (mini submarine), around the sunken submarine showed no elevated values of radioactivity. Samples taken from a ventilation pipe on the submarine wreck, however, showed clearly elevated levels of radioactive caesium, approximately 100 Bq per liter, compared to what is normally found in the Norwegian Sea. There was also some radioactivity associated with particles that were retained on the water filter. This is an expected result if the leakage is caused by corrosion. The levels in the Norwegian Sea today are around 0.001 Bq per liter.
However, the researchers believe that the levels of caesium that are documented are not posing any danger to humans and the environment. The sea is large and there is little fish at 1665 meters depth.
- These are the preliminary conclusions, emphasizes CERAD researcher Hans-Christian Teien, who has been on the research cruise.
- Now we are going to start extensive analyzes so that more accurate results would be available later.
Little significance for Norwegian seafood
- What we have found on the research cruise has very little significance for Norwegian fish and seafood. The levels in the Norwegian Sea are generally very low, and the pollution from "Komsomolets" is rapidly diluted, as the wreck is at a great depth, says researcher and cruise leader Hilde Elise Heldal from the Institute of Marine Research (HI).
HI has previously modeled what will happen if all the radioactive cesium in the wreck should leak out at once. The conclusion was that there will hardly be any effect on the fish in the Barents Sea. There is little fish in the actual area where "Komsomolets" is located.
Many samples and advanced analyzes
The research vessel G.O. Sars came to the area where the submarine wreck is located on Sunday. Already on the first dive, the ROV "Ægir 6000" managed to locate the wreck on Sunday night, and thus the researchers could see the condition of the wreck with their own eyes in real time. The last few days, the researchers have taken samples of seawater, sediments from the seabed and organisms that have settled on the wreck itself.
The samples are now on the way to land to be analyzed further.
This is what the former Soviet nuclear submarine "Komsomolets" looks like 30 years after it sank in the Norwegian Sea. The submarine is located at a depth of 1700 meters, and on July 7, 2019, it was filmed by the ROV "Ægir 6000":