355 



Along with the investigation of the explosion sites, radiometric investigations were 

 conducted on food products and drinking water (the total beta activity was measured 

 with RKB4-IeM by V.I. Cherepanov, the senior engineer of the Department of Radiation 

 Hygiene of the Republic [illegible]. During these investigations concern was aroused by 

 ansilyses of drinking water from water intakes in the Taas-Yuryakh and Ulakhan- 

 Botuobuy Rivers, which indicated 2.3 and 3.3 -lO'*" Ci/1 (as a rule, the total beta activity 

 of drinking water in Yakutia is below the sensitivity level of the RKB4-IeM). 



The results of the analyses were repeated again on June 27, 1990 in the town of 

 Mirny, which was the reason why part of the group (A.G. Tsyganov, V.I. Cherepanov, 

 V.A. Danilov) returned after completing the planned operations in the town of Taas- 

 Yuryakh to meticulously test the water in the Taas-Yuryakh and Ulakhan-Botuobuy 

 Rivers. Sampling was conducted on July 7, 1990, i.e. two weeks later. Four samples 

 were taken from the Taas-Yuiyakh River, from the site of explosion to the town at 1.5 

 km intervals, and five samples at the same intervals from the Ulakhan-Botuobuy River. 

 The results of the analysis indicated total beta activity below the sensitivity of the RKB4- 

 leM. As we have mentioned above, some of the operations, i.e. testing, were duplicated 

 by utilizing several methods of testing and analysis. In this case, on July 26, 1990 

 Yakutgidromet representative Zh.L. Dokhturov took a large sample of 20 liters from the 

 Ulakhan-Botuobuy River, and used the method of concentration of radioactive strontium 

 by sorption on ion-exchange resins. The analysis of this sample performed at the 

 PUGMS of the city of Vladivostok showed 13.2 Bq/m^. For comparison, a similar 

 sample from the Markha River 1 km upstream from the site of discharge of a nuclear 

 explosion (Kraton-3), showed 3.2 Bq/m . 



There are six underground nuclear explosion sites in the Ulakhan-Botuobuy River 

 valley, situated above the site of sampling and in close proximity to shaft No. 47. Hence 

 the need for systematic monitoring of the water, a very detailed investigation of all 

 explosion sites and possibly a more in-depth examination of the entire problem than the 

 present concept, including: explosions, tectonics, permafrost, etc. 



# 



The natural gamma background around the site of underground explosions (1976- 

 1987) was investigated during a radiometric survey in 1972-1976 carried out by the 

 Botuobuy expedition (Report on a geological survey on a scale of 1:200,000 in the 

 territory in sheets R-49-XXI, XXII, XXni, XXTV, XXVIII, and XXK, from work 

 performed by the Taas-Yuryakh team, I.N. Antipin et al., Mirny, 1977, YATGF, 

 inventory No. 13134). These operations included a radiometric survey on a scale of ^ 

 1:200,000 over 22,885 km^; additional investigation, 979 km^; gamma profiling of the bore 

 holes, 4,475.6 linear meters; trenches, 636.8 m'; gamma logging, 661.1 linear meters; core 

 listening with UPB-25, 1010.6 linear meters. Rock radioactivity: quaternary deposits 

 (loams, sand, clay, pebbles) - 4-10 /ir/hr, dolerites - 4-6 /xr/hr, marine deposits of the 

 Toar and Pliensbachian stages - 4-8 /ir/hr, tuSs • 8-10 /xr/hr. The series of Ukugut, 

 Irelyakh, Dga and Upper Lena, as well Middle Paleozoic and Ordovician deposits 



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