The NUMEC / Apollo Affair

Summary

Hundreds of pounds of highly enriched, weapons-grade uranium went unaccounted for between the late 1950s and 1968 at the Nuclear Materials and Equipment Corporation (NUMEC), a nuclear-fuel plant in Apollo, Pennsylvania, run by chemist Zalman Shapiro — estimates of the loss ranged from roughly 200 to 600 pounds, with the FBI investigation focused on about 206. The U.S. government investigated for fifteen years whether the missing material had been diverted to Israel’s nuclear weapons program. The CIA, after covertly collecting environmental samples near Israel’s Dimona reactor that revealed uranium enriched to a signature consistent with U.S. naval-fuel material, came to believe a diversion was likely. No criminal charges were ever filed against anyone. The case was never definitively proven, and key CIA and FBI files remain classified or heavily redacted to this day. This article documents the affair from the declassified record while keeping its unproven status front and center.

Background

NUMEC was founded in 1957 by Zalman Shapiro, a respected chemist who had contributed to early U.S. nuclear work. The company processed government-owned enriched uranium into fuel for naval reactors and commercial use — meaning it handled large quantities of weapons-usable highly enriched uranium (HEU) under contract, with strict accounting requirements.

Shapiro was, by the documented record, a committed Zionist with extensive business and personal contacts in Israel, including at the highest levels of its defense and nuclear establishment. This is not an inference about his ethnicity but a matter of documented association: he had contacts with Israel’s head of military intelligence and the head of its nuclear weapons program, and he later acknowledged knowing Binyamin Blumberg, head of Israel’s “bureau of scientific liaison” (LAKAM) — the same economic-espionage unit central to the Pollard and Milchan cases documented elsewhere in this archive.

What Happened

The core anomaly was an accounting one: NUMEC could not account for large quantities of HEU. Later U.S. Department of Energy records showed NUMEC had the largest highly-enriched-uranium inventory loss of any U.S. commercial site — 269 kilograms before 1968 and another 76 kilograms thereafter. Some of this could be attributable to ordinary processing losses (material lost in pipes, filters, and waste), which is the innocent explanation. But the scale drew sustained federal scrutiny.

The investigation’s trajectory is documented in declassified records. When the Atomic Energy Commission (AEC) investigated in 1966, the effort was, by the later assessment of former NRC commissioner Victor Gilinsky analyzing the declassified files, “anemic at best” — officials visited NUMEC but took no formal statements and did not pursue leads. Senior AEC officials, notably chairman Glenn Seaborg, pressed to keep the matter an in-house affair and to keep FBI investigators at arm’s length, with Seaborg writing that while diversion was possible, it was “unlikely.”

The decisive shift came from the CIA. In the months before April 1968, CIA operatives in Israel covertly collected environmental samples around the Dimona reactor. The results were, in the word of one account, disturbing: they showed the presence of a rare type of uranium used in naval fuels, enriched to 97.7 percent — a signature pointing toward U.S.-origin material of exactly the kind NUMEC processed. Having discounted the possibility that Israel had domestically enriched such material at the time, attention turned back to NUMEC.

In April 1968, CIA Director Richard Helms wrote to Attorney General Ramsey Clark stating that HEU processed at Apollo might have ended up at Dimona, and requested the FBI resume its investigation (the CIA being legally barred from domestic investigation). Helms also personally informed President Lyndon Johnson of the CIA’s suspicions. According to the declassified record, Johnson told Helms: “Don’t tell anyone else, even [Secretary of State] Dean Rusk and [Defense Secretary] Robert McNamara.” Attorney General Clark then ordered Shapiro placed under electronic and physical surveillance, which revealed meetings between Shapiro and known Israeli intelligence figures.

The Rafi Eitan Connection

One declassified detail provides the affair’s most striking corroborating thread. FBI and AEC documents describe a September 1968 visit to the NUMEC plant at Apollo by four Israeli citizens known to be affiliated with Israeli intelligence. These documents took on far greater significance years later: one of those visitors was Rafi Eitan — who was subsequently exposed in 1987 as the head of LAKAM, the Israeli unit that ran the Jonathan Pollard espionage operation. The presence of the future LAKAM chief at the very plant under investigation for uranium diversion, during the period of heightened suspicion, is among the more pointed facts in the declassified file — though it remains, like the rest of the case, circumstantial.

The Expert Assessments

The strongest articulations of the diversion conclusion come from credentialed nuclear officials analyzing the declassified record, not from partisan sources. In 2010, Victor Gilinsky (former NRC commissioner) and Roger Mattson (former NRC physicist who had investigated NUMEC) published a reassessment in the Bulletin of the Atomic Scientists titled “Revisiting the NUMEC Affair,” concluding plainly: “When the known facts are put together, it is difficult to escape the conclusion that Israel probably did steal highly enriched uranium from the United States.” Mattson later published a full-length study, Stealing the Atom Bomb, through the National Security Archive.

These assessments are weighty because of who made them — nuclear regulators with direct knowledge of the files — but they are careful in their wording: “probably,” not “certainly.” That qualification is essential and is retained here.

The Unresolved Status

The affair has never been resolved, and the documented reason for that is itself part of the story. No criminal charges were ever filed against Shapiro or anyone else across the fifteen-year investigation. Shapiro consistently denied diverting any material and died in 2016 at age 96 without any charge against him.

The official position remains studiedly inconclusive. In 2009, at the prompting of Shapiro’s lawyer, Senator Arlen Specter asked the Nuclear Regulatory Commission to clear Shapiro of suspicion. The NRC refused to do so, stating that it “found no documents that provided specific evidence that the diversion of nuclear materials occurred” — but also that it did “not have information that would allow it to unequivocally conclude that nuclear material was not diverted from the site.” In other words, the government would neither confirm the diversion nor exonerate the man at the center of it. A declassified Government Accountability Office study of the investigations concluded that “a timely, concerted effort on the part of these three agencies would have greatly aided and possibly solved the NUMEC diversion questions, if they desired” — pointedly suggesting the agencies may not have desired to solve it.

Key Figures

• Zalman Shapiro — Chemist; founder and president of NUMEC; subject of a 15-year FBI investigation; documented contacts with Israeli intelligence and nuclear leadership; never charged; died 2016.
• Richard Helms — CIA Director; concluded HEU may have gone to Dimona; informed President Johnson.
• Rafi Eitan — Israeli intelligence figure who visited NUMEC in 1968; later exposed as head of LAKAM in the Pollard affair.
• Victor Gilinsky and Roger Mattson — Former NRC officials; authors of the 2010 Bulletin of the Atomic Scientists reassessment concluding diversion was probable.
• Glenn Seaborg — AEC chairman; pressed to keep the matter in-house and characterized diversion as “unlikely.”
• National Security Archive (GWU) — Published the declassified documentation (Mattson, Cohen, and Burr, eds.).

Official Position

The U.S. government has never officially concluded that a diversion occurred, and no charges were filed. The AEC’s contemporaneous position was that there was no evidence of diversion; the NRC’s modern position is that it can neither confirm nor rule out diversion. The innocent explanation — that the missing material represented ordinary, if unusually large, processing losses — has never been disproven and remains the official non-conclusion.

The contrary assessment — that Israel probably did obtain U.S. weapons-grade uranium through NUMEC — is held by the CIA’s contemporaneous suspicion (backed by the Dimona environmental samples), by the former NRC officials who analyzed the files, and by the leading scholarship on the subject. As with the Vela Incident, the gap between the strength of the circumstantial evidence and the government’s refusal to reach a conclusion is the documented heart of the matter.

Consequences

If the diversion occurred, it would mean that the initial fissile material for Israel’s nuclear arsenal — or a significant portion of it — was stolen from the United States, under contract, by a U.S. company, and that the U.S. government, having developed strong evidence of it, declined to prosecute or even to conclude. President Johnson’s instruction to Helms to keep the matter from his own Secretaries of State and Defense, and the AEC’s documented preference to keep the FBI at bay, fit the pattern visible throughout the nuclear cases in this archive: when evidence of Israeli nuclear activity became too strong to dismiss, the U.S. government’s institutional response was containment and non-conclusion rather than confrontation.

The affair also left a physical legacy: the Apollo and Parks Township sites remained contaminated and required extensive, costly federal cleanup by the Army Corps of Engineers decades later — a tangible consequence of the plant’s poorly accounted-for operations.

Significance

The NUMEC affair is the nuclear counterpart to the Vela incident: a case where the United States developed serious evidence of Israeli nuclear activity, where credentialed officials concluded the troubling explanation was the probable one, and where the government nonetheless declined to reach a conclusion or impose a consequence. Its particular significance is that NUMEC concerns not testing but the fissile material itself — the possibility that the weapons-grade uranium at the core of Israel’s first bombs was diverted from a U.S. plant, under U.S. contract, and that Washington, after the CIA detected the telltale signature near Dimona, chose containment over confrontation, with a President instructing his spy chief to conceal the matter from the rest of his own cabinet. The case must be stated with care, because it was never proven and the innocent explanation of processing losses was never disproven — the honest verdict is the NRC’s own refusal either to confirm or to exonerate. But the documented record, analyzed by the nuclear regulators who knew it best, points toward a probable theft of American bomb material by a U.S. ally, met by an American non-investigation. That a matter of this gravity could remain officially unresolved for sixty years, with key files still classified, is itself the clearest possible illustration of the strategic silence this category documents.

Sources

• National Security Archive (GWU), “The NUMEC Affair: Did Highly Enriched Uranium from the U.S. Aid Israel’s Nuclear Weapons Program?” (Roger Mattson, Avner Cohen, William Burr, eds.), 2010/2016 — declassified documents including the Helms-Clark correspondence and the Rafi Eitan visit
• Victor Gilinsky and Roger Mattson, “Revisiting the NUMEC Affair,” Bulletin of the Atomic Scientists, 2010, and “Did Israel Steal Bomb-Grade Uranium from the United States?” 2014
• Roger Mattson, Stealing the Atom Bomb: How Denial and Deception Armed Israel (2016)
• Foreign Policy, “What Lies Beneath,” March 23, 2015 — documents the CIA Dimona environmental sampling and the Johnson instruction
• Nuclear Regulatory Commission statement declining to clear Zalman Shapiro, 2009 (prompted by Sen. Arlen Specter)
• U.S. Government Accountability Office study of the NUMEC investigations (declassified May 2010)
• U.S. Department of Energy inventory-loss records for NUMEC