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Inlet, and the eastern part of Ussuri Inlet is caused by concentration of radionuclides, mainly ^Co, 

 by bottom sediments. The activity of radionuclides in the seawater in these areas is at the level of 

 background values typical of other parts of the Pacific coast. All activity is concentrated in the 

 bottom sludge and can be removed only along with it or from the surface mud layer. 



The observed tendency for radioactive contamination in the bottom layer to move and dis- 

 perse along the bottom of Chazhma Bay will entail no serious ecological consequences, since the 

 total radionuclide activity in the bottom sediments is relatively low (about 5 Ci), and the leading 

 radionuclide is *'^Co, with a half-life of 5.26 years. 



During the accident and cleanup, 290 persons were exposed to elevated radiation. At the time 

 of the accident, 10 persons died of their injuries (eight officers and two enlisted men). Ten per- 

 sons developed acute radiation sickness, and 39 displayed radiation reactions. 



Continuous monitoring of radiation conditions in the accident area and in the radioactive 

 plume has been performed by the yard's radiation safety service. Periodic monitoring of radioac- 

 tive contamination of natural environmental systems is being performed by units of the Pacific 

 Fleet's Chemical and Medical Services, the Maritime Flotilla, the Maritime Territory Sanitary and 

 Epidemiological Service, and the Maritime Hydrometeorological Administration. 



In the future, radioecological studies of the consequences of the NS accident in Chazhma Bay 

 (including to refine the boundaries of the radioactive plume in the marine environment and its rate 

 of dispersion along the bottom of the bay and inlet) must be continued. 



3.5. Accident on the Nuclear Submarine Komsomolets in the North Atlantic, 1989 



On April 7, 1 989, a fire broke out in the stem section of the Komsomolets, a nuclear subma- 

 rine. The vessel surfaced, but af^er several hours' struggle for survival, it sank, killing 42 crew 

 members. The NS reached bottom at a depth of 1680 m at a point with coordinates 73 "43' 16" N 

 by 13''15'52" E, near the island of Medvezhiy. The site is about 300 nautical miles from the Nor- 

 wegian coast. 



One difference between this accident and others, including those involving American NS's, is 

 the threat of accelerated release of radionuclides into the marine environment. The reason is that 

 the Komsomolets has a titanium pressure hull. The rate of corrosion is increased manyfold when a 

 titanium hull reacts in seawater with the steel reactor parts and other ship components made of 

 various metallic materials. 



The reactor was switched to stable cooldown mode, ensuring nuclear safety, both at the time 

 of sinking and when the vessel remained sunken. 



From the time of sinking, engineering design features of its NWH's made a nuclear explosion 

 absolutely impossible, so the problem of nuclear safety for the ship in its sunken position can be 

 regarded as solved. However, the problem of ensuring radioecological safety remains. 



From information on the power generated by the power plant of the Komsomolets, experts 

 estimate that the reactor core contains approximately 42 kCi of '^Sr and 55 kCi of ■'"'Cs. The ra- 

 dioactivity of its NWH's, resulting from their ^^'Pu content, is about 430 Ci. 



The area where the accident took place is among the most biologically productive in the 

 world's oceans, and is of special economic importance. It falls within the spheres of interest of 

 Russia, Norway, Sweden, Great Britain, and Iceland. Even minimal transport of radionuclides 

 (fission products and transuranian elements) up the food chain from seawater to plankton to fish 

 could have grave political and economic consequences. 



The first expedition in the area of the NS's sinking was undertaken in May 1989 by the RA' 

 Akademik Mstislav Keldysh. The results of the study were of a reconnaissance nature. 



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