(September 12, 2003) A Russian "November" class attack submarine, the K-159, sank in bad weather on 30 August in the Barents Sea five kilometers northwest of the Arctic Island of Kildin. The nuclear powered submarine was being towed on pontoons from the Gremikha naval base to the Polyarny shipyard, where it was headed for dismantling. Nine crew members were killed, only one survived the accident.
(592.5542) WISE Amsterdam - The K-159 was towed by a tugboat, floating on four air-filled pontoons for a 350-kilometer journey. The pontoons however, came loose from the sub as the tugboat-submarine convoy was hit by stormy weather. This weather was forecasted, but despite this the convoy left for the trip. The K-159 is now at 240 meters below sea level.
Searching for a cause of the accident, on 3 September a source at the naval general staff stated that the captain of the K-159 called the towing vessel by radio, saying a leak had been found a the propeller joints at the rear of the sub, in compartment nine. That may have caused the accident.
The Norwegian based NGO Bellona commissioned its own independent investigation which has, so far, shown no abnormal extra radiation in the surroundings of the sunken sub. But it will take much more time to see whether there is a leak as a possible result of the accident. Bellona can only measure quite far away downstream as they cannot trespass into Russian waters.
On the long term the depth poses great dangers to the vessel's two reactor compartments as they will be under even more strain from the additional water pressure, said Alexander Nikitin, chairman of Bellona's St. Petersburg office. The about 25 atmospheres bearing down on the already rusting and hulking vessel makes the situation even more dangerous, for the hazard that some reactor leak could occur, contaminating the fish-rich area of the Barents Sea, said Nikitin.
There is a further possibility that Gulf Stream currents, which run east through the Barents Sea, will carry that radioactivity further afield. But there is also a possibility that, given the Barents' complicated stream patterns, the radioactive materials will travel west.
Further dangers to the reactor compartments are posed by the submarine's age. The K-159 was decommissioned in 1989, but it had been last refuelled in 1972, making the spent uranium fuel that is still in its reactors far more radioactive than if the vessel had gone down with a fresher fuel load. After decommissioning, the control rods (which control the chain reaction in the reactor core) were welded in a lower position to prevent the reactor from restarting. But how solid these rods were set in place and what the possible consequences have been of the impact of the sub with the seafloor is yet unknown. Added to this all is the corrosion of the boat's hull as it has been awaiting decommissioning for more than a decade.
The K-159 has two VMA-type reactors, each with a thermal capacity of 70 MW. The reactor cores of these reactors contain approximately 800 kilograms of spent nuclear fuel with the radioactivity of 750 curies per kilogram.
The Norwegian radiation protection Authority (NRPA) has started taking samples for their own research and judgement as soon as they were notified that the K-159 sank. Norwegian fishing vessels in the area were immediately ordered to get as close as possible to the spot and start taking measurements which have, as the Nuclear Monitor goes to press, not been officially published.
The Russian Navy has announced it will salvage the K-159 but the spokesperson said this is unlikely to happen before May next year. Given the depth at which the vessel is and the usually stormy conditions in the Barents Sea this will be complex and expensive operation.
Bellona says that the Russian Navy should investigate all possibilities of lifting the vessel without causing further damage to both reactor cores. According to environmental organizations towing is far too dangerous. A saver method is sending a ship, specially designed to unload fuel from subs. In Northwest Russia, there is such a ship called the Imandra, which is operated by the Murmansk Shipping Company. This method is more expensive.
Another option, suggested by Bellona, is shipping submarines with the help of a floating dry dock, which is also saver but more expensive. Bellona warned the Russian Navy already in 2001 that towing submarines from Gremikha carried with it precisely the sort of risks that caused the 30 August catastrophe, and recommended to the Russian government that the submarines at this base be dismantled onsite.
One of the many burning questions about the sinking that still remain unanswered is why a crew was aboard the K-159 at all. The fact that this crew would remain on board while the vessel was being towed for dismantling far away is a striking anomaly, according to former naval officers and submariners. Every safety rule was violated, said retired Admiral Eduard Baltin, who once commanded the K-159.
Russia's Minister of Defense has also ordered a temporary halt to the towing of decommissioned nuclear submarines.
Earlier Russian nuke sub accidents
Besides the K-159-accident much more serious accidents and disasters have been hitting the Russian nuclear fleet, especially the submarines. Bellona has published a report on these accidents in July 1996 (*). Following are some of the incidents documented in the 1996 report.
K-8 - During exercise 'Okean', early 1970, the K-8 submarine was operating in the Atlantic southwest of the UK. On 8 April 1970 fire broke out in two separate compartments of the sub. The vessel surfaced as the crew attempted to extinguish the fires. For two days the crew struggled to keep the vessel afloat. On 11 April the K-8 sank and went to the bottom in 4,680 meters of water. The Commanding Officer and 51 of his crew died in this accident.
K-219 - In October 1986, in the western Atlantic east of Bermuda, the K-219 got into trouble. Smoke and steam were seen issuing from one of the 16 missile tubes on the vessel. The sub was on a regular patrol off the North American coast when an explosion happened in one of the loaded missile tubes. The subsequent damage caused the missile compartment to leak and the submarine was forced to surface. Then fire broke out in the damaged missile tube. While the crew was trying to deal with that problem, an electrical short tripped off the emergency systems and one of the reactors shut down. The second reactor had also to be shut down and the vessel was left without power. On 6 October the K-219 sank, four crewmembers died. The cause of the explosion remains unknown.
K-278 - On 7 April 1989 the K-278 Komsomolets sub, one of the few named submarines in the Soviet Navy, was submerged at a depth of 160 meters in the Norwegian Sea some 180 kilometers south of Bear Island on passage back to her Northern Fleet base. In the morning fire broke out in one of the compartments. The vessel went to surface with the crew fully engaged in fighting the fire. The fire however spread. The power failures triggered the emergency systems which automatically shut down the reactor. Around five o'clock in the afternoon the K-278 sank at a depth of 1,685 meters, taking the 42 of the crew members with her to the bottom.
Three years ago, on 12 August 2000, the Kursk (K-141), an Oscar-II class submarine sank in the Barents Sea, killing all 118 crew aboard. Eventually the vessel (at 108 meters depth) was raised in autumn 2001 by a Dutch consortium after a year of complex preparations and at a cost of US$65 million.
The K-27 submarine did not sink after an accident but was scuttled in the Kara Sea in 1981 when necessary repairs were deemed impossible and decommissioning considered to be too expensive.
K-8 - The earliest documented nuclear incident involved the November Class K-8 on exercise in the Barents Sea on 13 October 1960. A leak in the steam generator occurred which led to a subsequent damage in pipes of the reactor coolant circuit. Large amounts of radioactive gas leaked from the reactor. A reactor meltdown was prevented by the crew. The reactor compartment apparently was not sealed off and the entire submarine was contaminated by the radioactive gas. Some crewmembers suffered potentially fatal doses of radiation.
K- 19 - The Hotel-class missile submarine K-19, Russia's first nuclear power powered submarine, had a leaking pipe in the pressure regulating circuit of the primary cooling system of the reactor on 4 July 1961 in the North Atlantic. The coolant supply diminished and excess heat began to build up within the reactor core. The crew was exposed to substantial doses of radiation and eight of them died of acute radiation sickness.
K-11 - On 6 February 1965 the November Class submarine K-11 lay in dock at the naval yard Severodvinsk for refueling. Because of control rods in the wrong position radioactive steam escaped when the reactor lid had been opened. Six days later fire broke out. There are no data on radiation exposure to the personnel.
K-27 - On 24 May 1968, a sudden and unexplained loss of reactor power occurred in the November Class submarine. The crew was unable to restore power levels and radioactive gases began to leak into the reactor compartment. The level of radiation in the rest of the sub increased. The crew managed to shut down the reactor but there was major damage to the fuel rod assemblies. Nine members of the crew died from radiation sickness. The K-27 never returned to service. In February 2003 a scientific expedition discovered 237 containers holding solid radioactive waste and the burial site of the K-27 in the Kara Sea in northern Russia (see above at sunken submarines).
K-140 - On 27 August 1968 the Yankee Class submarine K-140 was at Severodvinsk for repairs. An uncontrolled increase in reactor power occurred (18 times normal levels) when control rods were raised automatically because of incorrect installation of electrical cables. Radiation levels aboard the vessel deteriorated.
K-329 - In 1970, while the Charlie Class K-329 lay in harbor at the shipbuilding yard Krasnoe Sormovo, there was an uncontrolled start up of the ship's reactor. This led to a fire and the release of radioactivity.
K-222 - On 30 September 1980, the K-222 was at Severodvinsk for a reactor check. Following a failure in automatic equipment, the control rods were raised and the reactor started up. As a result, the reactor core was damaged.
K-123 - On 8 August 1982, the Alfa Class K-123 suffered a loss of coolant accident because of a leak in a steam generator. Two tons of liquid cooling metal damaged the reactor. It took nine years to repair the submarine.
K-314 - On 10 August 1985, the Victor-I Class K-314 was at Chazhma Bay yard near Vladivostok. Due to mispositioned control rods the reactor became critical during refueling. The subsequent explosion spread a plume of radioactivity up to 6 kilometers. Ten people died in the accident.
K-431 - In December 1985, the Echo-II Class K-431 reactor overheated outside Vladivostok.
K-192 (formerly K-131) - On 25 June 1989, the Echo-II class submarine K-192 suffered an accident involving one of the two reactors on board. The vessel was in the Norwegian Sea when a leak was discovered in the primary coolant circuit. The contaminated water from the leak was pumped out into the sea. The Soviet Northern Fleet service ship Amur came to assist the K-192. Amur took over the task of supplying coolant to the reactor and the reactor core temperature started to come down. The supply of coolant was shut off for repairs but afterwards not reconnected. The cold coolant caused the overheated fuel assemblies to crack, and water came into contact with the uranium fuel. The crew who worked on the repair received doses of radiation which could cause premature death.
Other accidents involving radiation
Northern Fleet submarines also experienced other accidents in which radioactivity was released. In most cases the releases were caused by leaks in the primary circuit or steam generators. In these cases however, there was no damage to the reactor core (as above).
*The report The Russian Northern Fleet (Report 2:1996) can be found at http://www.bellona.org/en/international/russia/navy/northern_fleet/report_2-1996/index.html" target="_blank">www.bellona.org/en/international/russia/navy/northern_fleet/report_2-199...
Sources: Bellona website (www.bellona.org), "Hazardous Duty - Nuclear Submarine Accidents" by Micheal Young, The Naval Officers Association of Canada (www.naval.ca/article/young/nuclearsubmarineaccidents_bymichaelyoung.html), World Environment News, 19 November 2002