In 1957, Washington handed Tehran the beginnings of a nuclear program. President Dwight Eisenhower’s Atoms for Peace scheme brought a cooperation agreement, and the United States then supplied the five-megawatt Tehran Research Reactor. Against this backdrop, the story that followed reads like a long argument over who controls the fuel.
From the shah to the ayatollahs
The shah’s government announced plans for more than 20 nuclear power reactors. American officials were willing to talk about building them, but from the 1970s they pressed for safeguards stricter than the Non-Proliferation Treaty required. The shah wanted the whole fuel cycle at home, above all reprocessing of used fuel. Washington refused, fearing the plutonium it could yield.
The 1979 revolution interrupted the effort only briefly. Ayatollah Ruhollah Khomeini first opposed nuclear development on theological grounds, according to the Arms Control Association, yet the government resumed the old ambitions, slowly. After Khomeini died in 1989, his successor Ayatollah Ali Khamenei widened Iran’s undeclared nuclear activities.
The same analysis notes that the U.S. intelligence community judged Iran to have abandoned a coordinated weapons program in 2003. It also found that Tehran had built up technologies, among them enrichment and warhead mechanics, that would let it start such an effort in a fairly short time if it chose.
The 2015 bargain and its collapse
Diplomacy produced a deal in 2015. Iran accepted a ceiling of 3.67% purity on enrichment, a stockpile cap of 300 kilograms (661 pounds), and a restriction to basic IR-1 centrifuges. Sanctions relief was the payoff, and U.N. inspectors were given the monitoring job.
Donald Trump, then president, took the United States out of the accord by himself in 2018 and promised a tougher replacement. The Associated Press reported that no replacement came. Tehran began to breach the limits a year later. Joe Biden signaled he would rejoin, yet formal talks on reviving the accord broke down in August 2022.
What the watchdog counted in 2024
By February 2024 the numbers had moved a long way from the 2015 limits. A confidential report from the International Atomic Energy Agency, seen by the AP, estimated Iran’s total enriched uranium stockpile as of February 10 at 5,525.5 kilograms (roughly 12,182 pounds). That was 1,038.7 kilograms more than in the previous quarterly report, from November 2023.
Of that, the agency put 121.5 kilograms at up to 60% purity. The figure was actually 6.8 kilograms lower than before, because Iran had diluted some of the material with lower-grade uranium. The IAEA’s definition gives around 42 kilograms of 60% uranium as the amount at which one weapon becomes theoretically possible. Sixty percent is a short technical step from the 90% that counts as weapons grade.
Eric Brewer of the Nuclear Threat Initiative told the AP that the 60 percent material alone would cover about three weapons if enriched to 90 percent. Making the fuel, he said, would take Iran only a couple of weeks. Building a bomb that could actually be delivered would take much longer, perhaps a year or more.
The agency also reported that Iran still barred its most experienced inspectors, and that Tehran had not explained traces of man-made uranium at two locations it had never declared, named Varamin and Turquzabad. Iran denies ever seeking nuclear weapons and says the program serves energy and medicine.
Sources
- Section 1: Background and Status of Iran's Nuclear Program (Arms Control Association)
- Watchdog Report: Iran Has Further Increased Its Total Stockpile of Uranium (Associated Press via VOA)
