Semipalatinsk Test Site
|Semipalatinsk Test Site|
|Area||18,000 km2 (6,950 sq mi)|
|In use||1949 – 1991|
|456 (340 underground and 116 aboveground)|
The Semipalatinsk Test Site (STS or Semipalatinsk-21), also known as "The Polygon", was the primary testing venue for the
The Soviet Union conducted 456 nuclear tests at Semipalatinsk from 1949 until 1989 with little regard for their effect on the local people or environment. The full impact of radiation exposure was hidden for many years by Soviet authorities and has only come to light since the test site closed in 1991.
Since its closure, the STS has become the best-researched atomic testing site in the world, and the only one in the world open to the public.
The site was selected in 1947 by
Later tests were moved to the Chagan River complex and nearby Balapan in the east of the STS (including the site of the
The Semipalatinsk Complex was of acute interest to foreign governments during its operation, particularly during the phase when explosions were carried out above ground at the experimental field. Several
The Soviet Union conducted its last tests in 1989. After the Soviet Union collapsed in 1991, the site was neglected. Fissile material was left behind in mountain tunnels and bore holes, virtually unguarded and vulnerable to scavengers, rogue states, or potential terrorists. The secret cleanup of Semipalatinsk was made public in the 2010s.
After some of the tests, radioactive material remained on the now abandoned area, including significant amounts of plutonium. The risk that material might fall into the hands of scavengers or terrorists was considered one of the largest nuclear security threats since the collapse of the Soviet Union. The operation to address the problem involved, in part, pouring special concrete into test holes, to bind the waste plutonium. In other cases, horizontal mine test holes were sealed and the entrances covered over. Finally in October 2012, Kazakh, Russian, and American nuclear scientists and engineers celebrated the completion of a secret 17-year, $150 million operation to secure the plutonium in the tunnels of the mountains.
Large parts of the STS have opened up since 2014, and economic activity has resumed: mostly mining, but also agriculture and tourism. Like other areas affected by radioactivity, the lack of human interference has made the STS a haven for wildlife.