Amchitka, United States

Nuclear Weapons Test Site
1971: The nuclear warhead used in the “Cannikin” test on the Aleutian Island of Amchitka is lowered into the shaft. Photo: © Lawrence Livermore National Laboratory

Three underground nuclear tests were carried out on the island of Amchitka in the North Pacific. The most controversial of these, code-named “Cannikin,” raised concerns over the possibility of causing tectonic incidents such as earthquakes or tsunamis. In the wake of protests against testing on Amchitka, the anti-nuclear organization Greenpeace was formed.

Photo: 1971: The nuclear warhead used in the “Cannikin” test on the Aleutian Island of Amchitka is lowered into the shaft.
© Lawrence Livermore National Laboratory

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In need of a place to test nuclear weapons too large to be detonated at the Nevada Test Site, the U.S. Atomic Energy Commission picked Amchitka, a WWII military outpost in the Aleutian island chain, about 140 km from the USSR’s Siberian naval base Petropavlovsk. At the time, Amchitka was uninhabited, but tectonically highly unstable due to its volcanic origin. Nevertheless, the U.S. conducted the “Long Shot” test of a 80 kiloton nuclear bomb in a 700 meter deep hole on October 29, 1965, to gather data that would improve detection of Soviet underground tests.

“Milrow,” a second test explosion with a yield of about one megaton, followed on October 2, 1969. The news of a third test of an even larger bomb on Amchitka quickly sparked international criticism. Many were worried that an underground explosion could cause earthquakes and tsunamis. In Vancouver, a group of anti-nuclear activists established the “Don’t Make A Wave Committee,” which was later to become Greenpeace.

Despite massive protests, the U.S. went ahead with the test, detonating a five megaton bomb called “Cannikin” on November 6, 1971, in a shaft 1.8 km below ground. The blast created a giant subterranean cavern and a crater with a diameter of 1.6 km, lifted up the ground by about six meters, caused rock-slides and shot cracks all throughout the volcanic base of the island. The blast caused a seismic shock that registered 7.0 on the Richter scale.

Health and environmental effects

According to the International Institute of Concern for Public Health (IICPH), about 2,000 workers were involved in the nuclear tests on Amchitka. These workers were exposed to radioactive particles such as tritium or cesium-137 and were not provided with proper protective clothing. Dose monitoring was limited and radiation exposure records were not kept for long, so that today it is impossible to know how much radioactivity the workers were exposed to. Cancer rates among Amchitka workers are reportedly high, especially leukemia and lymphomas, but again, no comprehensive studies or wide-scale medical follow-ups were ever performed.

Radioactive material was dispersed throughout the underground caverns created by the blast and reached groundwater supplies flowing into the surrounding ocean. Field studies illustrated that the planned self-containment of radioactivity in deep layers of rock turned out to be an optimistic illusion. In 1996 and 1997, Greenpeace biologists found plutonium-239/240 and its beta-decay product americium-241 in fresh water plant samples and creeks on the island.

Greenpeace concluded that “leakage from the Cannikin site is probably extensive, involving groundwater pathways through fissures and through the bottom of Cannikin Lake.” The region is seismically unstable and contains active volcanoes, increasing the risk of leakage into the ocean in the long run. Radioactive contamination of the marine environment is of great concern for local indigenous populations like the Aleut, who depend on marine animals for food.


Due to their large exposure risk and owing to faulty or missing dose exposure monitoring, Amchitka workers received the status of ‘‘Special Exposure Cohort (SEC)’’ under the Energy Employees Occupational Illness Compensation Program Act of 2000. Under this act, former Amchitka workers theoretically have the right to compensation if they develop radiation-induced diseases such as cancer. Despite this measure, many are finding it hard to actually get claim for compensation approved. Calls for a adequate scientific investigation into the environmental and health consequences of the nuclear tests on Amchitka, particularly for the indigenous population, have not abated. They are also Hibakusha.


  • “Amchitka Nuclear Test Workers to Gain Compensation for Occupational Illnesses,” International Institute of Concern for Public Health, October 31, 2000.
  • Benning et al. “The effects of scale and spatial heterogeneities on diffusion in volcanic breccias and basalts: Amchitka Island, Alaska.” J Contam Hydrol. 2009 May 12; 106(3-4):150-65.
  • Miller P. “Nuclear Flashback: Report of a Greenpeace Scientific Expedition to Amchitka Island, Alaska – Site of the Largest Underground Nuclear Test in U.S. History.” Greenpeace, October 30, 1996.
  • “Special Exposure Cohort (SEC).” Website of the National Institute for Occupational Safety and     Health (NIOSH).
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