Missing from US-Iran talks: plutonium for more than 200 nuclear bombs

Two days after Vice President JD Vance tried to get Tehran to give up its nuclear program in Pakistan earlier this month, Iran offered to suspend its uranium enrichment activities for five years. Vance demanded 20. The Iranians said no. Vance left.

Now, President Donald Trump says nothing less than a permanent ban will do. That certainly would be desirable for the United States. But even if the President got this injunction, it would leave a major nuclear weapons loophole: Iran still could make a significant number of bombs from the plutonium that sits at the Bushehr nuclear power plant.

Whatever final agreement the Trump administration reaches with Iran, it should eliminate this option. The United States should demand increased inspections and the routine removal of spent fuel from Bushehr.

More than 200 plutonium bombs. Russian state-owned nuclear conglomerate Rosatom built Bushehr 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 International Atomic Energy Agency’s (IAEA) Power Reactor Information System indicates Bushehr has produced a total of 7,851,750 megawatt-days of thermal power (MWd-thermal). Using an average plutonium production rate of 0.25 grams of plutonium produced per MWd-thermal, the plant has produced 2,000 kilograms of plutonium.

The very first batch of uranium fuel loaded into Bushehr, however, was not as enriched as subsequent batches and was unloaded much sooner. As a result, it produced more plutonium—0.4 grams of plutonium per MWd-thermal. Also, it produced plutonium containing a higher percentage of plutonium 239, which is optimal for building the most efficient plutonium bombs. (The Energy Department concluded in the 1990s that all reactor-grade plutonium is usable for weapons.)

Adjusting for the plutonium from this initial fuel loading, Iran probably has roughly 2,100 kilograms of weapons-usable plutonium. Assuming Tehran needs 10 kilograms of this plutonium per bomb (although an advanced weapon design would require much less), that’s enough to make more than 200 bombs—more than twice as many nuclear weapons as experts believe Israel possesses.

Iran has the chemistry. Why is nobody talking about Iran’s plutonium at Bushehr? The technical difficulty and time required to convert uranium hexafluoride into an insertable bomb core isn’t all that different from what’s required to make bomb cores out of plutonium.

To make a uranium bomb core, one needs to turn the hexafluoride into an oxide, then into a metal, cast it, and machine it. The same is true to make a plutonium bomb core. The key difference is that plutonium initially is contained in spent fuel rods with other radioactive materials. To get at the plutonium, one needs to cut open the zirconium-clad fuel rods and chemically strip out the plutonium. Iran mastered this chemistry 30 years ago with gloveboxes at their Tehran Nuclear Research Center. Iran could cheaply and quickly scale up this process again.

In 1977, the US General Accounting Office (renamed since then as the US Government Accountability Office) examined how such a facility could be built within a relatively small warehouse of 130 feet long (39.6 meters) by 60 feet wide (18.3 meters) by 30 feet high (9.1 meters). The design examined 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. Once built, it could separate a bomb’s worth of plutonium after only 10 days of operation. After that, the plant could separate a bomb’s worth of plutonium every day.

After all of the facilities noted are in place, the timelines for making a uranium or plutonium bomb core are essentially the same—two to three weeks. We don’t know if Iran has all of these facilities, but these uncertainties are the same for making uranium or plutonium bombs.

Addressing Iran’s plutonium problem. Whereas the IAEA believes a significant amount of Iran’s most-enriched uranium is stuck under the rubble at facilities damaged by US and Israeli strikes, almost all of Iran’s plutonium is above ground in an accessible spent fuel storage pool at Bushehr. This plutonium can make at least an order of magnitude more bombs than the uranium Iran has on hand.

As President Trump is pushing to reopen talks with Iran, the US negotiators should make four minimal demands to reduce the proliferation risks of military diversions of this plutonium:

First, require the IAEA to impose near real-time surveillance at Bushehr. Currently, IAEA cameras run for 90 days before inspectors can access the footage. Three months is enough time to divert the spent fuel and make it into a plutonium bomb. The last time the IAEA inspectors were at Bushehr was eight months ago. To eliminate such inspection gaps, near real-time surveillance cameras should be installed to send images securely back to Vienna or some other safe location every 5 or 10 minutes. If there’s a blackout at the plant or if the camera’s view is otherwise obscured, the IAEA will know immediately and be able to send inspectors to the site.

The United States failed to demand near real-time surveillance of Bushehr when it negotiated the Joint Comprehensive Plan of Action (JCPOA) with Iran in 2015. The IAEA sought such surveillance after the fact. Iran said no. This time around, the United States should insist on such scrutiny. This would not only keep Iran from misbehaving and the United States and the rest of the world from worrying, but would set an example for the region and beyond. Near real-time surveillance should be a requirement for all large reactors under IAEA safeguards.

Second, the United States should insist on the routine removal of the spent fuel from Bushehr. In 2005, Russia agreed to fuel Bushehr and promised to take back the spent fuel. But it never did. Now, the spent fuel has piled up. The fix is to get Saudi Arabia or another Gulf Cooperation Council member to assume responsibility, including the cost of routinely shipping this material back to Russia. After the spent fuel has cooled for 36 months, it should be shipped out. Likewise, removing spent fuel at Bushehr would set a useful precedent for reactors outside of Iran. When the IAEA was first created, the United States proposed that the agency take back spent fuel. That idea is worth revisiting.

Third, Iran must halt construction of its second reactor at Bushehr. This construction suspension should last until the negotiated enrichment moratorium period is over, in 5, 10, 20, or more years. After the first Bushehr reactor was nearly complete, analysts discovered that Iran had used this peaceful, “safeguarded” nuclear project as a procurement front to secretly acquire much of the technology needed to make nuclear weapons. The United States should not allow this to happen again.

Finally, to seal the deal, Iran must forswear producing oxides or metallic forms of plutonium and uranium or reprocessing of any spent fuel. The United States also should demand no-notice inspections to verify compliance. Verification would be difficult, but without this prohibition in place, it would be virtually impossible. At the very least, this requirement would help deter Iran from further weaponization.

In Washington, it’s said that every crisis presents an opportunity to make sounder policy. The Trump administration is now in the midst of such a crisis. Taking these minimal actions is what is now required.