582 



western Kara Sea, the concentration of radionuclides C'Cs) rises at depth (Table li 

 Fig. 10). 



Table 11. '"Cs Concentration (Bq/m') at Various Depths 

 in the Southwestern Kara Sea at Five Sampling Points 



see also 



Future analyses must be done with the awareness that in a number of cases, sunken vessels 

 were loaded with highly toxic substances such as heptyi. 



The majority of noncontainerized SRW dumped at sea is equipment manufactured of high 

 alloy steels. Such steel is subject to corrosion at a rate of about 1 mm per 100 years. The thick- 

 ness of the radioactive layer on articles made of this steel removed from a reactor is 0.1-0.5 mm. 

 Consequently, all the activity from noncontainerized SRW of this type must have passed into the 

 marine environment within 10-12 years after disposal. The release (flushing) of radionuclides from 

 other noncontainerized wastes proceeds even more rapidly. Consequently, a large portion of the 

 radionuclides from noncontainerized RW must have entered the environment. However, since the 

 total activity of this RW is low, it must not have had a noticeable effect on shaping overall radio- 

 ecological conditions in the sea. 



However, we should keep in mind that accidental contact with individual radiologically rather 

 hazardous objects is possible, for example due to removal during diving work, or when storms 

 cast them ashore from the shallow bays and inlets of the islands of Novaya Zemlya, where a large 

 portion of RW has been dumped (Fig. 11). 



To prevent people from accidentally contacting radiologically hazardous objects thrown 

 ashore, the Novaya Zemlya Northern Test Site performs an annual visual inspection of the eastern 

 coastline of the archipelago. In Maritime Territory, aerial gamma-ray photography was performed 

 in 1991 in the area of the NS accident at Chazhma and along the coast of the Sea of Japan. No 

 radiologically hazardous objects or articles have been found, with the exception of an unidentified 

 metal object with high levels of radiation (over 100 r/hr: fragments of fuel rods) in 1984 on the 

 coast of Abrosimov Inlet, Novaya Zemlya. 



We must note two other circumstances that increase the potential radioecological hazard of 

 dumped SRW. The first concerns the possibility of a significant acceleration of corrosion process- 

 es affecting RW composed of different metals (for example, steel with copper, zinc, titanium, etc.) 

 in seawater. In such cases, electrolytic reactions can occur, in which the corrosion rate of metals 

 can be increased manyfold. Just such a process characterizes the rapid destruction of elements of 

 the NS Komsomolets (the steel-titanium combination). 



The second circumstance is the possibility of unauthorized disposal of RW at sea, or its dis- 

 posal in violation of approved standards. 



Everything that has been said with respect to SRW forces the Commission to refrain from 

 any final conclusions on the degree of their radioecological hazard until each and every disposal 

 site has been inspected. 



40 



