The destruction of uranium enrichment sites that support Iran’s nuclear program would not likely have severe environmental consequences, several nuclear experts told ABC News.

Israel has stated that its attack on Iran is aimed at destroying its capabilities of producing nuclear weapons, alleging that the uranium enrichment sites within Iran are producing materials to make a nuclear weapon.

Facilities across Iran range from those extracting uranium to processing facilities where the uranium is transformed into the right chemical form before it goes through the process of enrichment — or increasing the quantity or concentration, Kathryn Ann Higley, distinguished professor of nuclear science and engineering at Oregon State University and president of the National Council on Radiation Protection and Measurements, told ABC News.

“Iran would deny that those are nuclear weapon facilities,” Matthew Bunn, who leads nuclear policy research at Harvard University, told ABC News. “They’re nuclear facilities for sure. Iran claims they’re for producing civilian fuel.”

The enrichment sites are located in Fordo, deep inside a mountain in northwestern Iran, and in Natanz — which was targeted by military strikes last week.

Other facilities targeted include the Isfahan Nuclear Technology Center, used for metallic uranium production, and the Bushehr Nuclear Power Plant, according to the International Atomic Energy Agency.

Israel confirmed that they struck Isfahan again Friday night, targeting centrifuge production areas.

While the conflict is concerning, radioactivity as a result of the military strikes is not a top concern, nuclear experts say.

“There’s plenty to worry about in the Iran-Israel war, but the release of radioactivity is not one of them,” Lee Berstein, a professor in the nuclear engineering department at the University of California, Berkeley, told ABC News.

Uranium isn’t radioactive enough to present a widespread threat

The sites targeted so far in Iran contain centrifuges that spin really fast and separate and enrich uranium into a higher grade, Emily A. Caffrey, director for the Health Physics Program at the University of Alabama at Birmingham, told ABC News.

However, the rule of thumb with radioactive materials is, the longer the half life, the less dangerous it tends to be in the short-term, Berstein said. But even materials with long half-lives can be hazardous over longer periods of time.

The half life of Uranium-235 is more than 700 million years, according to the U.S. Centers for Disease Control and Prevention.

There is radiological and chemical contamination at the Natanz facility, where an above-ground portion of the fuel enrichment plant was damaged after a military strike on June 13, International Atomic Energy Agency Director-General Rafael Grossi told the United Nations Security Council on Friday.

The facility likely contained canisters of uranium hexafluoride gas that was released into the environment as a large gas cloud once it was hit, Caffrey said.

Uranium hexafluoride is the main risk stemming from the uranium enrichment sites, Di Fulvio said. The gas results from the separating of uranium that is essentially a “precursor” of nuclear fuel.

But those gas clouds do not have the ability to cause long-term contamination or radioactive issues, Caffrey said.

“It’s just a big, heavy gas molecule, so it’s not going to go very far,” Caffrey said.

Enrichment operates at very low pressure, almost near-vacuum pressure, Bunn said, adding that the centrifuges themselves have very little uranium hexafluoride. The canisters would contain the majority of the gas.

While there is destruction at multiple sites — including Natanz, Isfahan and Arak as well as sites in Tehran — there are no sites where radiological activity has been identified outside facilities, Grossi said.

No radiation leaks were reported at Natanz during previous incidents in which the facility sustained damage in 2020 and 2021 — the latter being a cyber attack, said Angela Di Fulvio, an associate professor at the University of Illinois Urbana-Champaign and director of the Arms Control Domestic and International Security Program.

How far radiation spreads from any particular release depends on the weather — wind in particular, but also rain, Bunn said.

If hexafluoride interacts with water, it can create hydrofluoric acid, causing some chemical issues but not radioactive ones, Caffrey said.

“There are a lot of countries that have borders on the Persian Gulf that would not want to see the water in the Gulf contaminated by clouds of radioactive particles blowing in the wind passing over the coasts,” said John Erath, senior policy director of the Center for Arms Control and Non-Proliferation.

However, uranium hexafluoride appears to be confined within the facilities that were targeted and is manageable with appropriate procedures and safety precautions, Di Fulvio said.

Over time, the leaked uranium hexafluoride would get diluted and diffuse out of the environment, Higley said.

How does exposure to uranium affect the human body

If ingested or inhaled, uranium hexafluoride gas — in which each of the molecules has six fluorine atoms — can cause kidney damage, Caffrey said. Atoms combined with a heavy metal can be a “really toxic substance,” but usually in large quantities, Bunn said.

“You would need to inhale or imbibe a humongous amount of it into your body in order for there to be any effect,” Berstein said.

The danger isn’t radioactivity but rather the heavy metals, Bernstein said.

Another ‘Chernobyl’ situation is unlikely, experts say

The 1986 nuclear disaster at Chernobyl likely wouldn’t be replicated, even if one of the nuclear reactors in Iran were targeted by military strikes, the experts said.

“The Chernobyl disaster was a very special event that was a result of a really badly designed power plant,” Bernstein said.

Israel and the U.S. are likely being very cognizant of avoiding the nuclear reactors due to the potential disaster that could result if they are hit, Erath said.

Nuclear reactors are also now solidly built and would require a large amount of fire power — such as the U.S. military’s massive bunker-buster bombs — to cause an explosion, the experts said. One of the factors that exacerbated the Chernobyl disaster was a design flaw within the nuclear reactor that exploded, Bernstein said, adding that the design is no longer used.

Striking Iran’s nuclear reactors — used to generate nuclear power — wouldn’t release nearly as much radioactive material as Chernobyl, the experts said.

The Khondab reactor was under construction and did not contain fuel or other nuclear materials when it was hit on Thursday, according to the IAEA.

The Bushehr Nuclear Power Plant, a 1,000-megawatt facility built by Russia, has also been a focus of recent concern, Di Fulvio said.

Expulsion of radioactive materials from Bushehr could result from one of three ways: a direct hit by a rocket or missile; damage to the pool of water where spent fuel, the radioactive nuclear fuel that has been removed after it has generated electricity, is stored for cooling; and if the electricity supplied to the plant is interrupted and the plant loses all backup means to generate electricity, M.V. Ramana, a physicist and professor at the University of British Columbia’s school of public policy and global affairs, told ABC News.

“Although the Israeli military might not be deliberately targeting Bushehr, it is a possibility given the extensive bombing that Iran has been subject to,” Ramana said.

Grossi warned that the Bushehr nuclear facility might be hit, saying that this would be, “the nuclear site in Iran where the consequences of an attack could be most serious.”

“It is an operating nuclear power plant and as such it hosts thousands of kilograms of nuclear material, Grossi said.

This plant is used for energy production and not for uranium enrichment, Di Fulvio said. Iran is required to return spent fuel rods from Bushehr back to Russia when they are safe for transport.

The consequences of attacking the Tehran Nuclear Research Reactor would be amplified by the high-density population of Tehran, Di Fulvio said.