Could US strikes on Iran’s nuclear sites cause radiation leak?

The US has inserted itself into the Israel-Iran conflict. On Sunday (June 22), US President Donald Trump said Iran’s main nuclear sites – Fordow, Natanz and Isfahan – had been “obliterated” in military strikes overnight.

Fordow is “gone” , Trump wrote in a post on Truth Social, after the deeply buried facility was bombed. However, Iran has downplayed the attack, with one lawmaker saying that there was no serious damage and the strikes were superficial.

There is, of course, fear that the destruction of the nuclear sites could pose dangers – possible radiation leaks. While the International Atomic Energy Agency (IAEA) , the United Nations nuclear watchdog, has said that no increased off-site radiation levels had been reported following the US attacks, it has called for an emergency meeting on Monday (June 22).

Which nuclear sites in Iran have been targeted by the US and Israel?

The US military on Sunday struck sites at Fordow, Natanz and Isfahan. Donald Trump said Iran’s key nuclear enrichment facilities had been “completely and totally obliterated”.

Calling the US attack on Iran “historic” and “brave”, Israeli President Isaac Herzog told the BBC “… It’s quite clear to me that the Iranian nuclear programme has been hit substantially.”

However, Iran’s nuclear regulatory authority has said that there is no danger to residents living near these facilities. The nuclear sites struck by the US did not contain materials that cause radiation, an official at the Iranian Broadcasting Corporation said.

“No signs of contamination have been recorded,” Iranian state media quoted the country’s National Nuclear Safety System Centre as saying. “There is no danger to the residents living around the aforementioned sites.”

Sunday’s strikes come after previously announced Israeli attacks on nuclear sites in Natanz , Isfahan, Arak and Tehran. Israel says it aims to stop Iran from building a nuclear bomb, and the US maintains that Tehran would not be allowed to get such weapons. Iran denies ever seeking nuclear arms.

The international nuclear watchdog IAEA has previously reported damage to the uranium enrichment plant at Natanz, the nuclear complex at Isfahan that includes the Uranium Conversion Facility, and to centrifuge production facilities in Karaj and Tehran.

Israel has also attacked Arak, also known as Khondab . The IAEA said Israeli military strikes hit the Khondab Heavy Water Research Reactor, which was under construction and had not begun operating and damaged the nearby plant that makes heavy water, reports Reuters.

The IAEA said it was not operational and contained no nuclear material, so there were no radiological effects. Heavy-water reactors can be used to produce plutonium, which, like enriched uranium , could be utilised to produce an atom bomb.

Speaking to Reuters before the US attack, experts said Israel’s strikes had posed limited contamination risks so far. Darya Dolzikova, a senior research fellow at London think-tank RUSI, said attacks on facilities at the front end of the nuclear fuel cycle – the stages where uranium is prepared for use in a reactor – pose primarily chemical, not radiological risks.

At enrichment facilities, UF6, or uranium hexafluoride, is the concern. “When UF6 interacts with water vapour in the air, it produces harmful chemicals,” she told the news agency. “In low winds, much of the material can be expected to settle in the vicinity of the facility; in high winds, the material will travel farther, but is also likely to disperse more widely. The risk of harmful chemicals being dispersed is lower for underground facilities.”

Simon Bennett, who leads the civil safety and security unit at the University of Leicester in Britain, said risks to the environment were minimal when subterranean facilities are hit because you are “burying nuclear material in possibly thousands of tonnes of concrete, earth and rock”.

James Acton, co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace, said that before uranium goes into a nuclear reactor it is barely radioactive. “The chemical form uranium hexafluoride is toxic … but it actually doesn’t tend to travel large distances and it’s barely radioactive.”

Attacks on enrichment facilities were “unlikely to cause significant off-site consequences”, he said, while stating his opposition to Israel’s campaign.

What if nuclear reactors are hit?

The big concern would be a strike on Iran’s nuclear reactor at Bushehr on the Gulf coast. Fears of catastrophe rippled through the Gulf on June 19 when the Israeli military said it had struck a site in Bushehr, only to say later that the announcement was a mistake.

Israel says it wants to avoid any nuclear disaster.

Richard Wakeford, honorary professor of epidemiology at the University of Manchester, told Reuters that while contamination from attacks on enrichment facilities would be “mainly a chemical problem” for the surrounding areas, extensive damage to large power reactors “is a different story”.

Radioactive elements would be released either through a plume of volatile materials or into the sea, he added.

Acton of the Carnegie Endowment for International Peace said an attack on Bushehr “could cause an absolute radiological catastrophe”.

Who would be worst affected if Bushehr is hit?

For Gulf states, the impact of any strike on Bushehr would be worsened by the potential contamination of Gulf waters, jeopardising a critical source of desalinated potable water.

The Gulf Cooperation Council (GCC) is on high alert to monitor for any possible environmental contamination after the attacks, said a source with knowledge of the matter. There have been no signs of radiological contamination so far, the source said, adding that the GCC had emergency plans in place in case of a threat to water and food security in the Gulf, reports Reuters.

In the United Arab Emirates, desalinated water accounts for more than 80 per cent of drinking water, while Bahrain became fully reliant on desalinated water in 2016, with 100 per cent of groundwater reserved for contingency plans, authorities say.

Qatar is also 100 per cent dependent on desalinated water.

In Saudi Arabia, a much larger nation with a greater reserve of natural groundwater, about 50 per cent of the water supply came from desalinated water as of 2023, according to the General Authority for Statistics.

While some Gulf states, such as Saudi Arabia, Oman and the UAE, have access to more than one sea to draw water from, Qatar, Bahrain and Kuwait are crowded along the shoreline of the Gulf with no other coastline. “If a natural disaster, oil spill, or even a targeted attack were to disrupt a desalination plant, hundreds of thousands could lose access to freshwater almost instantly,” said Nidal Hilal, professor of engineering and director of New York University Abu Dhabi’s Water Research Center.

“Coastal desalination plants are especially vulnerable to regional hazards like oil spills and potential nuclear contamination,” he said.

With inputs from Reuters