August 2013 Plutonium Mountain Inside the 17-year mission to secure a dangerous legacy of Soviet nuclear testing By Eben Harrell & David E. Hoffman Project on Managing the Atom

Belfer Center for Science and International Affairs  |  

Harvard Kennedy School

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collaboration between Kazakh nuclear scientists and their U.S. counterparts. On January 9, 1998, 

a delegation of Kazakh scientists came to Los Alamos. Among those who met with Hecker was 

Kadyrzhanov, the metallurgist and materials scientist, who had grown up near Semipalatinsk as 

a youth, and later studied in Moscow, doing graduate work in nuclear physics at the Kurchatov 

Institute. At that meeting, Hecker asked Kadyrzhanov about Semipalatinsk. “If you have a com-

mon bond, like the scientific bond, you can cut through a lot of the junk and get to the important 

issues very quickly,” Hecker recalled. Kadyrzhanov responded by saying he had deep concerns 

about the test site. He explained that Kazakhstan had recently set up the National Nuclear Center 

to which the Institute of Nuclear Physics in Almaty reported. He told Hecker that NNC scientists 

had carried out an instrument survey of the area and found signatures suggesting the presence of 

plutonium and enriched uranium. 

Kadyrzhanov said the Kazakhs had turned to Russia for help, but received very little. “They’ve 

tried to get this information” about the type and quantity of material left behind,  “from the Rus-

sians but they only get bits and pieces,” Hecker wrote in his notes of the meeting.

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 “The Russian 

specialists often react very surprised by the amount of plutonium” that the Kazakhs report having 

detected at Semipalatinsk. 

Moreover, Kadyrzhanov told Hecker that the area where the plutonium was buried was wide 

open. The surrounding villages are very poor, he added. Kadyrzhanov described how scavengers 

were searching the area looking for copper cable used for various testing events, and which could 

be sold for profit. “They are beginning to penetrate the former test area,” Kadyrzhanov said. He 

also described how oil and gas drilling in western Kazakhstan was being planned in areas where 

the Soviet Union had carried out nuclear explosions for peaceful purposes such as excavating 

large caverns.

Although some of the dangers had been outlined in Stillman’s earlier memo on Project Amber, 

Hecker found the information from Kadyrzhanov disturbing. When the meeting ended, he wrote 

in his notes, “Pity there was so little time.” He decided that he had to get to Semipalatinsk to see 

for himself. After Kadyrzhanov returned to Kazakhstan, he wrote Hecker within days, imploring 

him to visit. He stated, “We are extremely anxious about the large quantity of scattered plutoni-

um on the territory of Kazakhstan.”

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to help ex-Soviet weapons scientists find civilian research work and keep them from proliferating their know-how. 

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   Excerpt from Siegfried Hecker’s notes, provided to the authors.

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   Kairat Kadyrzhanov email to Hecker, February 13, 1998. Unless otherwise indicated, correspondence with Hecker was pro-

vided by him to the authors.

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Plutonium Mountain: Inside the 17-year mission to secure a dangerous legacy of Soviet nuclear testing

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Source: Siegfried Hecker

Siegfried S. Hecker (right) and James W. Toevs (left) from Los Alamos National 

Laboratory on the Kazakh steppe in 1998.

‘Completely Open to Whomever Wants to Come’

Hecker drafted a message to the United States Embassy in Kazakhstan, alerting them to the po-

tential dangers and his desire to investigate. Describing the plutonium, he said, “This material 

would be easily accessible to recover by a group interested in obtaining weapons materials for 

nuclear proliferation.” If recovered, he estimated, there might be enough plutonium to make five 

or 10 nuclear bombs.

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 “The potential amount of material available at this site is approximately 

one third to one half of the amount recovered from Operation Sapphire….Individuals could eas-

ily access the area and ‘mine’ the material without being detected.”

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 Hecker also invited Russian 

officials from the nuclear weapons laboratory at Arzamas-16 to join him in Kazakhstan, but they 

declined, at least initially.

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Hecker and two other Los Alamos specialists went to Kazakhstan for nine days in April, 1998.

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When he arrived at Semipalatinsk, Hecker found a lone, meager guard gate and no guards. He 

had been warned by Kadyrzhanov about the metal scavengers, but nothing prepared him for 

what he witnessed on the scene. “When I went out there, I was expecting to see guys on camels 

pulling on copper cables,” he recalled. Instead, Hecker saw miles of trenches in the brown, dry 

steppe that could only have been dug by powerful excavating machines. 

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   The actual amount of recoverable material underground at Semipalatinsk remains a matter of dispute. The official U.S. Gov-

ernment position is “approximately a dozen bombs worth of material,” but this estimate includes large uncertainty about the state 

of the material, which would determine how much plutonium could actually be recovered and turned into a form suitable for 

weapons. 

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   “Possible Source of High-Grade Uranium and Plutonium Weapons Materials,” draft note to U.S. Embassy, Kazakhstan.

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   Hecker’s letter to Radi Ilkaev, director of VNIIEF, or Arzamas-16, March 27, 1998. Ilkaev responded on April 7, 1998, saying 

he could not come because he could not obtain permission rapidly enough from the ministry in Moscow, where the leadership had 

changed.

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   The other two specialists were John R. Phillips and James W. Toevs. The trip took place April 16-25, 1998. This account is 

based on Hecker’s trip report and handwritten notes during the visit, as well as photographs and his recollections in the interview.

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