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Leakages from sunken nuclear sub not dangerous for Barents Sea cod

Hilde Elise Heldal (left) is researcher with the Norwegian Institute of Marine Research. Here onboard the expedition vessel "Ivan Petrov" that was used for the joint Norwegian-Russian expedition to K-159.

Even if all radioactive Cesium-137 in the reactors leak out, levels will still be under the 600 Becquerel limit set by food authorities, according to researchers with the Norwegian Institute of Marine Research.

Russian and Norwegian scientists disagree on the danger posed by an old Soviet-built nuclear powered submarine that sank during tow in the Barents Sea in August 2003.

“In a study calculating the effects from various contamination scenarios, we have shown that even with the most dramatic pollution, the levels of Cesium-137 in fish will be under the limits set by Norwegian Food Safety Authority,” says scientist Hilde Elise Heldal in an article posted on the institute’s portal.

Norway follows the same recommended maximum levels as the EU, 600 Bq/kg of fish. 

Hilde Elise Heldal is Norwegian partner is a joint expert group with Russian scientists that last year participated in a research expedition to the site of K-159. 

It was last week BarentsObserver reported that other Russian scientists are deeply worried about the shape of the sunken submarine. Mikhail Kobrinsky with the Nuclear Safety Institute of the Russian Academy of Science told the audience at a seminar in Murmansk that some areas in the Barents Sea could be sealed off for commercial fisheries for up to two years, if the radioactivity in the two reactors of the sunken sub leaks out to the marine environment.

Hilde Elise Heldal admits there will be negative effects of such a worst-case release of radioactivity. She points to a 2013-study showing the concentrations of Cesium-137 in cod could increase by 100 times today’s levels, in approximately two years after the release. Today’s level of Cesium-137 is generally under 0,2 Bq/kg in fish in the Barents Sea.

“Even if the levels will increase by 100 times it will still be under the limits of 600 Bq/kg. The limit was set by the Food Safety Authorities after the 1986 Chernobyl accident.

There are some 800 kilograms of irradiated uranium fuel in the two reactors onbord the K-159 submarine. The sub lays on the seafloor at a depth of 238 metres.