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Russian authorities have disclosed the precise sites where four nuclear submarines laden with missiles and torpedoes have sunk as well as the locations near the Arctic island of Novaya Zemlaya where several Russian reactors and other radioactive waste were dumped over the last 30 years.
The disclosures are part of Russian-American negotiations on how to monitor the dumped radioactive material and do what is possible to prevent its escape.
The negotiators on the Russian side included leading military officials, submarine designers and nuclear engineers. The American delegation was led by Dr. Charles D. Hollister, a senior scientist of the Woods Hole Oceanographic Institution.
Besides four submarines lost at sea, the Russians have said that several decommissioned naval nuclear reactors were dumped in shallow waters in the Eastern Arctic. These include four submarine reactor compartments, dumped in the Abrosimov Gulf in 20 to 40 meters of water in 1965 and 1966.
Three reactors from the nuclear-powered icebreaker Lenin were dropped into the Sivolky Gulf in 1967. A barge with a submarine reactor was sunk in the Kara Sea 1972. The submarine K-27 was jettisoned after an emergency with two fuel-laden reactors in Stepovov Gulf 1982. In 1988, a reactor was dumped with Techeniya Gulf.
The United States Navy has lost two nuclear submarines at sea, the Thresher and the Scorpion, and has dumped one reactor, that of the Seawolf in 1959.
The radioactivity in submarine reactors, at least those of American design, has several layers of containment, including the reactor vessel and the fuel elements themselves. In addition the Thresher is being covered by ocean sediment, which may in time provide a further means of containment.
Of possibly greater concern is the radioactive waste dumped at sea. Russian authorities told Dr. Hollister that 11,000 to 17,000 waste containers, holding 61,407 curies of radioactivity, were dumped off Novaya Zemlya from 1964 to 1990. In addition, 165,000 cubic meters of liquid waste were dumped in the Barents Sea west of Novaya Zemlaya from 1961 to 1990. For comparison, the Chernobyl accident released about 86,000,000 curies of radioactivity.
Dr. Hollister reckons the amount of nuclear material within some of the Soviet sunken submarines at seven times that in the ill-fated Chernobyl reactor.
The Russian Government has made a strong commitment to environmental monitoring and protection, but Dr. Hollister said the problem was formidable. A large amount of nuclear waste is being discharged into the Arctic Ocean from nuclear weapon plants along the Ob River in addition to the many deposits on the sea floor.
Dr. Hollister noted that escaping radioactive materials tend to be absorbed by clay on the bottom but a new concern is the discovery of "storms" on the deep sea floor that could disperse the radioactivity.
In contrast to the earlier view that only gentle currents flow over the ocean floor, Russian measurements with current meters on the bottom in the North Atlantic have revealed "benthic storms" in which water flow reaches three or more knots.
Among the possibilities, Dr. Hollister said, is installation of a circle of devices surrounding a sunken wreck or dump site that detect escape of radioactive material and that perhaps even neutralize it.
He himself made a recent dive to the Thresher wreck and found it a shambles. The pressure hull had not imploded until it neared the bottom at 8,500 feet. This was clear because the debris was not widely dispersed. But the event was so violent that the two sides flew through and past one another as though the submarine was turning inside out. Its reactor and nuclear weapons, if any, will have to be watched closely.
A concern is the imminent decommissioning by Russia of 79 of its older nuclear submarines, since they have reactors as well as nuclear weapons that must be disposed of, Dr. Hollister said. Another 30 are in the pipeline.
In September, a delegation of American specialists led by Dr. Hollister met with an array of Russian specialists from institutes throughout Russia. The main purpose of their meeting was to discuss the dangers presented by the submarine Komsomolets. The Russians reported that the pressure hull had been broken and that radioactivity was leaking from the reactor but not at "radiologically significant" levels.
Damage to the bow, they said, makes recovery of the torpedoes impractical. The nuclear warheads were no longer watertight and they estimated that plutonium released as a result of corrosion might begin in 1995 or 1996. There was, however, no agreement among the Russians on the extent to which this might come from the torpedoes or reactor. The Russians made it clear that they hoped the United States would be similarly forthcoming and cooperate on the monitoring program
The decree by Boris N. Yeltsin establishing the Government Committee of Nuclear Waste Disposal in the Sea with representatives from more than nine ministries and agencies was promulgated on Oct. 24. It said in part, "Ministries and departments should provide the committee with all available documents, materials and information, including materials of secret character which have concern to the scope of the Committee and provide the Committee with necessary support."