GAO Report on the 1965 NUMEC Affair Declassified - Federation of American Scientists Updated below In 1965, over 200 pounds of weapons-grade highly enriched uranium went missing from the Nuclear Materials and Equipment Corporation (NUMEC) plant in Apollo, Pennsylvania. Circumstantial evidence and popular lore suggested that the material had been clandestinely diverted to Israel for…
· archived 5/18/2026, 12:42:34 AM screenshot cached html click to expand GAO Report on the 1965 NUMEC Affair Declassified - Federation of American Scientists Issues Ecosystems & Entrepreneurship Nuclear Weapons Science Policy Social Innovation Technology & Innovation Publications Get involved Day One Project Talent Hub Fiscal Sponsorship Ways to engage About About us DEIB Staff Careers Contact Donate Search Issues Ecosystems & Entrepreneurship Nuclear Weapons Science Policy Social Innovation Technology & Innovation Publications Get involved Day One Project Talent Hub Fiscal Sponsorship Ways to engage About About us DEIB Staff Careers Contact Donate Search see all publications Share Share publications close Share FAS GAO Report on the 1965 NUMEC Affair Declassified 05.13.10 | 2 min read | Text by Steven Aftergood Updated below In 1965, over 200 pounds of weapons-grade highly enriched uranium went missing from the Nuclear Materials and Equipment Corporation (NUMEC) plant in Apollo, Pennsylvania. Circumstantial evidence and popular lore suggested that the material had been clandestinely diverted to Israel for use in its nuclear weapons program, either with or without the acquiescence of the U.S. Government. A secret 1978 review of the episode (pdf) that was performed for Congress by the General Accounting Office (as it was then known) has recently been declassified and released. But instead of resolving the mystery of the missing uranium, it only highlights it. The Department of Energy and the Nuclear Regulatory Commission cooperated fully with the GAO, but the CIA and the FBI did not. “GAO was continually denied necessary reports and documentation on the alleged incident by the Central Intelligence Agency and the Federal Bureau of Investigation…. The lack of access to CIA and FBI documents made it impossible for GAO to corroborate or check all information it obtained,” the GAO report said. “Based on its review of available documents held by DOE and discussions with those involved in and knowledgeable about the NUMEC incident, GAO cannot say whether or not there was a diversion of material from the NUMEC facility…. Agents from the FBI involved in the current investigation told GAO that while there exists circumstantial information which could lead an individual to conclude that a diversion occurred, there is no substantive proof of a diversion.” “All investigations of the alleged incident ended with no definitive answer and GAO found no evidence that the 200 pounds of nuclear material has been located,” the GAO said. The GAO report was obtained by the Institute for Research: Middle East Policy, a group critical of pro-Israel advocacy in the U.S. See “Nuclear Diversion in the U.S.? 13 Years of Contradiction and Confusion,” U.S. General Accounting Office report EMD-79-8, December 18, 1978. Update: The most recent account of the case is “Revisiting the NUMEC Affair” (sub. req’d) by former NRC officials Victor Gilinsky and Roger J. Mattson, Bulletin of the Atomic Scientists, March/April 2010. “The circumstantial evidence supports the conclusion that the HEU ended up in Israel,” said former NRC Commissioner Gilinsky. “Our conclusion, which was based on a lot more information and analysis than was available to the GAO in 1978, thus goes well beyond that of the just released report. Moreover when we talk about the HEU we include not only the unexplained losses found in the famous 1965 inventory, but also unexplained losses for the subsequent few years, which are even larger.” “The bottom line of the article,” said Dr. Mattson, “is that it is time to end FBI and CIA secrecy on the now 40+ year old Apollo/NUMEC affair.” publications See all publications Nuclear Weapons Blog New Voices on Nuclear Weapons Fellowship: Creative Perspectives on Rethinking Nuclear Deterrence To empower new voices to start their career in nuclear weapons studies, the Federation of American Scientists launched the New Voices on Nuclear Weapons Fellowship. 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