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The shaft, where an underground nuclear explosion was conducted in 1978 

 accompanied by an accidental discharge of radioactive substances, is located on the right 

 bank of the Markha River (120 m from the water's edge), 3,250 ra upstream from the 

 mouth of the River Chukuka. 



There are no remnants of machinery and equipment in the drilling area, 

 production facilities and living quarters were demolished, and the soil layer was plowed 

 up by a bulldozer within the radius of the first one hundred meters. A tomb was 

 constructed next to the shaft An earth embankment protects the shaft mouth and the 

 tomb on the side of the slope. 



The shaft mouth is a 3 m high pfle of earth with broken boards, pieces of cables, 

 pipes, and pieces of concrete, topped with a cast iron sign 'T)ANGER ZONE," which 

 forbids earth moving and is securely fastened to a drill pipe. Radioactivity at certain 

 points reaches 740 /if/hr. 



The tomb is a rectangular flat hUl, 2 m high measuring 10 x 30 and located 

 parallel to the river bank 100 m from the water's edge. It is fenced by several rows of 

 barbed wire welded to pipes which are welded into half-barrels filled with cement The 

 fence was destroyed by frost because the wire was too taut Radioactivity on the surface 

 of the tomb is 120-280, and at some points up to 700 /ir/hr. 



The embankment protecting the tomb and the shaft mouth from flood and rain 

 water from the side of the slope is made of earth with broken boards and bushes up to 1 

 m high, and adjoins the edge of the flood plain terrace as a semi-ring 7S m in radius. 



Up the slope from the drilling area, toward the geodetic sign "Mouth of the 

 Qiukuk", there is a strip up to several himdred meters wide and 2J km long of "dead" 

 forest which consists of standing dead trees, bushes, grass, moss, and reindeer moss, all 

 dead The only green plants are single, sparse, young willow sprouts spaced 20 to 30 

 meters apart, 1.0-1.2 m high with 2-3 leaves. Radioactive background in the axial portion 

 of the trace: SO-W tir/br, on the ground surface: 100-120, up to ISO /ir/hr. 



Dosimetric Measurements 



Because of the substantial length of the contamination spot within the sector 

 investigated by airborne gamma-spectrometric survey (S km), the scale of 1:25,000 of 

 surface dosimetric operations was used. Measurements were conducted with a pitch of 

 20 m over profiles every 250 m. The tnmk line was cut along the compass traverse, 

 profiles were passed using inclinatoriums. The minimum limitation was determined by 

 triple repetition of the measured level of 9-10 tir/hr. The natural background of the 

 rock making up the area studied was 8 /xr/hr. 



