568 



As the table indicates, the inlets along the coast of Novaya Zemlya hold one NS with two re- 

 actors containing fuel in place, a reactor compartment with two reactors containing SNF, a reac- 

 tor compartment with one reactor containing SNF in place and one reactor with SNF removed, 

 and an NS reactor with SNF in place. Removing the SNF from all six sunken NS reactors was 

 impossible due to the damaged condition of their cores For the same reason, 1 25 irradiated fuel 

 assemblies (FA's) could not be removed from the core plate of the OK- 150 reactor unit on the 

 nuclear icebreaker Lenin. Thus, according to available official data, six reactors with SNF in place 

 and one shielding assembly from the Lenin with partially removed SNF were dumped in the inlets 

 of Novaya Zemlya and the Novaya Zemlya Depression of the Kara Sea. 



An exact estimate of the radionuclide content of these cores (without knowledge of which the 

 environmental consequences of each dumping cannot be assessed) and determination of their total 

 activity requires laborious scientific research. Such estimates can be made only after analysis of 

 data on the operating conditions of each nuclear reactor throughout its life. Such an analysis has 

 been performed only for the Lenin. This permitted the activity of the SNF at the time the reactor 

 was dumped in 1967 to be estimated at 100 kCi. This work has not been done for NS reactors 

 sunk off Novaya Zemlya, and the minimum estimate of their total activity fijmished by the Navy, 

 120 kCi, is not well enough grounded and requires fijrther calculations that account for the reac- 

 tors' operating conditions. The maximum estimate of the overall total activity at the time of 

 dumping, in the opinion of one Commission expert, could be at least 2.3 MCi (see Table 3 and 

 Fig. 6). 



We should note the activity of the reactor sunk as a result of the accident aboard the NS 

 Komsomolets, which is lying at the boundary between the Norwegian and Barents Seas at a depth 

 of 1,700 meters 300 km from shore. According to expert estimates, the total activity of this NS's 

 reactor core is at least 150 kCi. 



Before sinking, reactor compartments with SNF in place were filled with a hardening flirfu- 

 rol-based mixture (except one NS reactor). According to estimates by the power plant's designer, 

 this filling will prevent the SNF from contacting seawater for a period of several hundred (up to 

 500) years. As noted in Table 3, the shield assembly with SNF from the Lenin was additionally 

 placed in a reinforced concrete container and a metal shell. Table 4 presents available data on the 

 disposal of reactor compartments and reactors with SNF in place in northern seas. These data 

 show that a grand total of 10 reactors with SNF in place have been dumped in the inlets of Nova- 

 ya Zemlya and the Kara Sea. 



It is difficult to determine their total radioactivity accurately enough. In these reactors, most 

 of the radionuclides were produced through the action of neutron fluxes in the working reactor, 

 so their activity is also crucially determined by the reactor's operating history. Moreover, the ac- 

 tivity of these objects depends on their elemental makeup. Thus, in the structural members of the 

 Lenin, cobalt was used, which resulted in a very high level of induced ^''Co activity (about 50 

 kCi). An expert estimate of the total induced activity is at least 1000 kCi at the time of sinking. 



Thus, available data show that RW was discharged and dumped in the Barents and Kara Seas 

 beginning in 1960. This was were mainly liquid and solid RW (the latter low-, intermediate-, and 

 high-level, including reactor compartments from NS's with fuel in place) produced during opera- 

 tion of nuclear icebreakers and Naval vessels. 



Analysis of the situation with radioactive contamination of the northern seas will not be suf- 

 ficiently complete without an account of the possible entry into the marine environment of man- 

 made radioactive substances from the atmosphere, from river runoff, possible drifl from the Gulf 



26 



