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 use in its nuclear weapons program, either with or without the acquiescence of […]
· archived 5/21/2026, 6:21:15 PMscreenshotcached html
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 Environment Blog Disaster Policy Nerds Explain the Good, Bad, and Ugly in FEMA Review Council Report After months of delay, the council tasked by President Trump to review the FEMA released its final report. Our disaster policy nerds have thoughts. 05.21.26 | 8 min read read more Global Risk Press release Federation of American Scientists, Future of Life Institute Present Converging Risks Report, AI Impact Awards at Gala FAS and FLI partnered to build a series of convenings and reports across the intersections of artificial intelligence (AI) with biosecurity, cybersecurity, nuclear command and control, military integration, and frontier AI governance. This project brought together leaders across these areas and created a space that was rigorous, transpartisan, and solutions-oriented to approach how we should think about how AI is rapidly changing global risks. 05.20.26 | 9 min read read more Emerging Technology Blog Closing the Strategic Capital Gap: The Case for Modernizing the Export-Import Bank Investment should instead be directed at sectors where American technology and innovation exist but the infrastructure to commercialize them domestically does not—and where the national security case is clear. 05.20.26 | 3 min read read more Clean Energy Blog States Are Plugging into Experimental Electricity Policy to Find Cost-Saving Success To tune into the action on the ground, we convened practitioners, state and local officials, advocates, and policy experts to discuss what it will actually take to deploy clean energy faster, modernize electricity systems, and lower costs for households. 05.13.26 | 5 min read read more