Testing site “Experimental field”

Location of facilities and grounds at “Opytnoye Pole” siteThe Opytnoye Pole site ("Experimental field") was the first testing site of the Semipalatinsk Nuclear Test Site and it was designated for carrying out aboveground (atmospheric and surface) nuclear tests in the period from 1949 to 1962. The site is a plain of about 20 km in diameter from three sides surrounded by low mountains. The "Experimental field" occupies the area of about 300 km2 and is 64 km in perimeter. The site is situated at a distance of more than 50 km from Kurchatov-city.

The site is a large-scale facility designed to conduct tests and record parameters of nuclear explosions in the conditions of a full-scale experiment. Some fragments of devices and fortification structures with the traces of nuclear explosion impacts have remained till nowadays.

Equipment housing “Gus”The first test of a nuclear device on the Experimental field was made on August, 29, 1949 at 7:00 a.m. local time. On August 12, 1953, at the same location the first thermonuclear device was tested and on November 22, 1955, the first explosion of hydrogen bomb was made. On the whole, 116 nuclear tests were made on the Experimental field, 86 of which were atmospheric and 30 – surface tests.

 

The Site territory and adjacent areas many times experienced impact of radioactive contamination which was mainly caused by atmospheric tests. On the territory of the Experimental field there were technical sites (P‑1, P‑3, P‑5) where surface nuclear tests were made.  In 25 of 30 surface nuclear tests nuclear devices detonated, in 5 cases the devices did not explode. On the site P-1 situated in the center of the Experimental field 3 most powerful surface nuclear tests (29.08.49 – 22 kg, 24.09.51 - 38 kg, 12.08.53 - 400 kg) and one test of capacity of 0.4 kilotons, 05.11.62, were made.  4 aboveground tests were made on site P-3 and 3 aboveground tests were made on site P-4. In the places of tests there are shell-holes with soil heaps and fragments of fused soil containing products of nuclear explosions. These shell-holes are seen on space images. Radioactive contamination of the territory spreads over hundreds of meters. The exposure rate on the soil heap around the shell-hole exceeds 10 μSv/h. In soil samples taken near shell-holes artificial radionuclides 137Cs, 241Am, 60Co, 152Eu, 154Eu, 90Sr, 239+240Pu were discovered.

Radioactive contamination of soil is registered not on all territory of the Experimental field, it is recorded directly in the places where surface nuclear tests, which caused maximal contamination of the surface within the site, were made. Some, the most powerful, explosions caused radioactive contamination of all territory of the Site and adjacent areas. Low-yield surface explosions mainly caused radioactive contamination of the area within the Experimental field and the Site territory.

Craters from nuclear explosions and corresponding EDR distribution at the test ground P-5 П-5 Точки обследования, 2005г. Точки обследования, 2006г.
On other technical sites (P-7, P-2G) hydro-nuclear tests were made. Hydro-nuclear tests practically did not release nuclear energy, but they formed a small number of fission fragments, therefore the impact on the environment during such tests was caused by dispersion of explosive nuclear substances (fission materials) used as components of explosive devices. In the other type of experiments a dispersed substance was uranium, in some other experiments plutonium was dispersed. By experts’ estimations approximately 750 Ci of plutonium activity were dispersed (~12 kg). The character of radioactive pollution of the areas within testing sites differs from that on the places of nuclear tests as in this case the main contaminating radionuclides are 239+240Pu and 241Am, but there are practically no fission products of 137Cs, 60Co, 152Eu, 154Eu and 90Sr