Excavational explosions

One of the first directions of the Program for commercial application of underground nuclear explosions with soil outbursts was creation of artificial water reservoirs in arid areas and canals for diversion of water from northern rivers to the southern territories which permanently suffered from water shortage. As a result of emergency situations during tests at the wells No. 101, No. 125 (testing ground Sary-Uzen), No.1204 (Balapan) and targeted tests in the places of detonation of nuclear charges (wells No.1004 (Balapan), No. 1003 (Sary-Uzen), Telkem-1, Telkem-2) the shell-holes of hundreds of meters in diameter and depth of dozens of meters were formed.
On January 15, 1965, in the place of merging of two main waterways in the region, the Shagan and Ashisu rivers, the underground nuclear test with the yield 140 kg, which formed a shell-hole 100m in depth and 400m in diameter, was performed. As a result of shell-hole filling with flood waters a so-called Atomic lake was formed. 

Atomic lake

The majority of radionuclides formed during the explosions precipitated directly in the places of tests. Traces of clouds from the tests in wells No.1004, No.1003 and No.101 moved beyond the Site, but nowadays scientists do not detect any radioactive pollution of the environment beyond the Site caused by those tests. 
At the present time the most contaminated area there is in the vicinity of the wells No.101 and 1004 (MED values go up to 7 μSv/h, specific activity: 137Cs – 9*103 and 3*104 Bq/kg, 90Sr – 1.2*104 and 8.5*103 Bq/kg, respectively). Specific activity of 239+240Pu in soil in some parts of “Atomic” lake is as high as 2*104 Bq/kg.
With the increase of the distance from the epicenters of explosions, the specific activity of radionuclides in all wells significantly decreases. Even 200-500 m away from the shell-hole the values of radiation parameters are the same as background ones. However, radionuclide contamination in the vicinity of “Atomic” lake is observed even at a distance of 3-4 km in northern direction.

 

Crater formed by underground nuclear explosion with soil outburst in the well 1003 at Sary Uzen testing ground

Investigation of the well No.1003 gave maximal MED values of up to 2 μSv/h and density of -particles radiation of 140 part/(min*cm2). Maximal specific activity of radionuclides in soil sampled in the points along the profile passing through the center of the shell-hole was 7*103 for 137Cs - 7*103 and 2.5*103 Bq/kg for 90Sr and 241Am. 
Plum of radionuclide pollution moved in the north-eastern direction, which is well detected on the map. Radionuclide pollution in south-western direction is caused by the test made in the well No.215.
In the south-eastern part of the Semipalatinsk Test Site two underground nuclear tests with soil outburst – a single test “Telkem”-1 (21.10.1968) and a group test “Telkem”-2 (12.11.1968) were performed. Later, water filled the hole formed by the group explosion.  
During the experiments, technologies for construction of canals to be used in re-direction of major waterflows from Arctic regions of the USSR to the Volga river basin and the Caspian sea were tested. The important data needed to plan works on construction of the Pechora-Kama canal were obtained. Radioactive traces of explosions stretched at a distance of tens of kilometers but did not go beyond the Site territory. The results of radio-ecological tests on the Site territory showed considerable decrease in the concentration of radionuclides with the distance from the epicenters of explosions. Even at a distance of 200m from the shell-hole, it is difficult to detect the concentration of radionuclides which considerably exceeds the values of global fall-outs.


Crater formed due to serial nuclear explosion with soil outburst at Telkem-2 testing ground
3-D model of a crater with radioactive contamination (Telkem-2)