Enormous quantities of decommissioned Soviet and Russian nuclear reactors and radioactive waste were dumped into the Arctic Ocean north of Siberia over a course of decades. According to reports given to the Norwegian Radiation Protection Authority by Russian officials in August of last year, the quantity of such waste is far more staggering that initially believed, even by Russian officials themselves.
Boris Stepennov, a representative of the Kurchatov Institute, which has been examining the problem of sunken nuclear installations for the last 20 years, Friday told a Moscow conference entitled “Projects to Eliminate Nuclear and Radiologically Hazardous Facilities in the Northern Regions of of Russia – Status, Problems and Prospects,” that getting a bead on where dumped radiological hazards from reactors, fuel assembllies to entire submarines lie is of the essence.
The conference was co-hosted by Bellona and Russian state nuclear corporation Rosatom.
Stepennov stressed that the the nuclear and radiological junk heaps must be inventoried, further researched, and a master plan for dealing with it be developed.
For many years, this problem has simply been hushed up or forgotten. But over the last two to three years, discussions of making an inventory of the nuclear trash and determining its geographical location have ramped up. The last three years have seen the first expeditions to this end. The sunken submarines pose the greatest radiological threats. According to officials, some three Russian nuclear submarines lie at the bottom of Arctic seas.
The most dangerous of these is the K-27 submarine, which was scuttled in 50 meters of water in Stepovogo Bay of the Novaya Zemlya Archipelago in the Kara Sea in 1981 after a serious reactor accident that killed nine. Its reactors contain 90 kilograms of uranium 235.
“This is highly enriched uranium. A seepage of only 5 liters of water into the reactors could cause criticality and lead to an uncontrolled nuclear chain reaction” or explosion, said the Kurchatov Institute’s Stepennov.
“Something must be done with this vessel,” he said. “The optimal decision would be to raise it.”
The condition of the underwater region and condition of the K-27 were inspected three times last year – including a joint Russian-Norwegian expedition in September. It was found that the vessel is standing evenly on its keel and was embedded at an insignificant depth. There was no damaging corrosion discovered on the hull, nor were radionuclides found to be escaping the vessel.
The level of gamma radiation in the immediate vicinity of the ship remained unchanged in comparison with similar measurements taken in 2006.
The radiation situation in the area of the K-27 is determined by radionuclides of natural origin – and the absence of added man-made radionuclides. The inspections indicate it is for divers to aid in studies of the sub.
“Scuba diving work in the area of the vessels is safe,” said Stepennov. “This was planned for this year, but has not taken place because of a lack of financing.”
The most important item right now is to prepare to raise the vessel and evaluate various options for raising it. To do this the condition of the hull and other hurdles will have to be determined.
No less dangerous is the K-159, which sank in 238 meters of water while under tow from the former naval base of Gremika on its way to Polyarny for decommissioning in 2003, killing nine crew members. The vessel is twice as radioactive as other nuclear debris in the Kara Sea.
The vessel lacks additional defense barriers between its spent nuclear fuel and the marine grave in which it sits, which escalates the risk of possible radioactive contamination.
The sub also sank while exiting the Kola Bay, near shipping routes and fishing grounds.
“Thank God the [first reactor] circuit has not lost its hermetic seal,” said Stepennov.
The K-159 belongs to the Russian Ministry of Defense, but still no one in the ministry is dealing with the question of the sunken vessel, or even seems to remember it is there. Since 2007, the submarine has undergone no research and its condition is unknown.
The infamous Komsomolets is the third submarine lying under arctic waters. The sub sank after a fire in 1989, killing 42 under conditions that remain closely guarded secrets within the Russian Naval establishment, despite Bellona efforts to declassify the information.
What is known of the sub is that it has two nuclear warheads on board with a radioactivity content of 564 Curie. It is the one submarine that has registered radioactive releases – up to 10 Curie a year. This is not considered a dangerous level.
The shielding assembly (neutron reflector) from the retired nuclear icebreaker Lenin contains the highest amount of radioactivity among all the old irradiated nuclear fleet components, containers with spent nuclear fuel, and other radioactive scrap dumped in the Kara Sea.
Despite damage to the outer Lenin’s shielding assembly of the caisson containing the spent fuel, the hermetic seals of the remaining barriers of the dumped foundling have remained intact, and no escape of technogenic radionuclides have yet escaped into the marine environment.
Nevertheless, corrosion of the defensive barriers as well as loss of container integrity would make the radiological situation in the Kara Sea notably worse.
Unidentified dumps containing spent nuclear fuel
“The place where the reactor from [Russian] nuclear submarine [K-140, order No. 421] was sunk in the Novaya Zemlya Trough has not been found,” said Stepennov in reference the K-140 sub. The sub was scuttled in the late 1960s after a serious reactor accident that contaminated the vessel. “They try to find it periodically, but haven’t found it.”
There are several categories of sunken radioactive scrap sunk in the Ambrosimova Bay on the southwest end of the Novaya Zemlya archipelago: reactor chambers with spent nuclear fuel (including that of the first Russian first generation nuclear sub, the K-19); barges loaded with solid radioactive waste, both in and out of containers. The trash has been found but not identified: It remains unknown where debris with spent nuclear fuel is located, and where dumps without it are located. The condition of the defensive barriers of the containers also remains unknown. It is also unknown if they are leaking, though elevated local levels at Ambrosimova Bay would suggest that possibility.
This points to another prescient difficulty: No one can say how quickly the degradation of the defensive barriers of the sunken nuclear refuse is progressing. The behavior of spent nuclear fuel rods in the seawater remains unknown. Only one experiment on spent fuel rods’ behavior in sea water has been conducted, which has been ongoing for a year at Atomflot, the Murmansk based home port of Russia’s nuclear icebreaker fleet.
“The reason the situation is developing like this is a lack of financing for the work, but the chief difficulty is that these items have no owner and no one is responsible for them,” said Stepennov. “It is even complicated to find someone in the Defense Ministry who understands anything about this.”
Charles Digges contributed to this report.