International Concerns Mount Over Iran's Nuclear Stockpile, Including 2,100 kg of Bushehr Plutonium

Apr 23, 2026

International concerns are mounting over Iran's nuclear capabilities as the Bulletin of the Atomic Scientists reveals that approximately 2,100 kilograms of weapons-usable plutonium—enough for over 200 nuclear weapons—sits in spent fuel storage at the Russian-built Bushehr nuclear power plant, yet remains absent from current US-Iran negotiations. While Vice President JD Vance recently attempted to secure a 20-year uranium enrichment suspension and President Trump demands a permanent ban, the plutonium stockpile represents a potentially greater threat that Iran mastered separating 30 years ago. Russia's Rosatom built and has operated Bushehr for 15 years, producing 210 tons of spent fuel, but never fulfilled its 2005 promise to remove the material. International Atomic Energy Agency inspectors last visited Bushehr eight months ago and face 90-day delays in accessing surveillance footage, while Iran rejected requests for near real-time monitoring of the accessible above-ground storage pool.

Iran's Plutonium Stockpile at Bushehr Nuclear Plant

▪The Bushehr nuclear power plant has produced a total of 7,851,750 megawatt-days of thermal power according to the International Atomic Energy Agency's Power Reactor Information System.
▪Russian state-owned nuclear conglomerate Rosatom built the Bushehr nuclear power plant and has helped operate it for 15 years.
▪Rosatom's Director General Alexey Likhachev says that 210 tons of spent nuclear fuel are now stored at Bushehr.
▪The very first batch of uranium fuel loaded into Bushehr produced 0.4 grams of plutonium per megawatt-day of thermal power.
▪The 210 tons of spent fuel in the storage pool at Bushehr contain more than 2,000 kilograms of plutonium, enough to make more than 200 nuclear weapons.
▪The first fuel was loaded into the reactor building at the Russian-built Bushehr nuclear power plant in Iran in 2010.
▪The Bushehr nuclear power plant has produced approximately 2,100 kilograms of weapons-usable plutonium.

Technical Feasibility of Plutonium Weapons Production

▪A 1977 US General Accounting Office study examined a plutonium separation facility design that could be built within a warehouse of 130 feet long by 60 feet wide by 30 feet high.
▪A plutonium separation facility could separate a bomb's worth of plutonium after only 10 days of operation, then separate a bomb's worth of plutonium every day thereafter.
▪Assuming 10 kilograms of plutonium per bomb, Iran's plutonium stockpile is enough to make more than 200 bombs.
▪The 1977 US General Accounting Office plutonium separation facility design would take no more than six months to build and would require technology no more advanced than that needed to produce dairy or pour concrete.
▪Iran mastered the chemistry needed to chemically strip plutonium from spent fuel rods 30 years ago with gloveboxes at their Tehran Nuclear Research Center.
▪The Energy Department concluded in the 1990s that all reactor-grade plutonium is usable for weapons.

Proposed US Demands for Enhanced Monitoring and Fuel Removal

▪The International Atomic Energy Agency sought near real-time surveillance of Bushehr after the Joint Comprehensive Plan of Action was negotiated, but Iran said no.
▪In 2005, Russia agreed to fuel Bushehr and promised to take back the spent fuel, but Russia never did.
▪International Atomic Energy Agency cameras at Bushehr currently run for 90 days before inspectors can access the footage.
▪Vice President JD Vance demanded Iran suspend uranium enrichment for 20 years, but the Iranians said no.
▪The United States failed to demand near real-time surveillance of Bushehr when it negotiated the Joint Comprehensive Plan of Action with Iran in 2015.