If Iran's bunkers are busted, what might escape?

News.com.au

7 hours ago

Remember Chernobyl? Remember Fukushima? So, is bombing Iran's nuclear facilities really such a good idea?
Concern is growing across the Middle East that the fallout of Israel's assault on Iran will not just be political, economic and potentially military. They're anxiously watching for spikes in radiation.
Qatar's energy ministry has announced it has enhanced its monitoring activities and is working with neighbouring states to plan for any necessary response.
'We have to emphasise, when we are talking about the waters of the Gulf, it's the main source of water for all of us here in the region,' foreign ministry spokesman Majed al-Ansari told media this week.
'The international community has to make it very clear that any targeting of nuclear facilities, any targeting of fuel or energy facilities in this region, would have ramifications that are unknown to us in the Gulf.'
Iran has only one functioning nuclear reactor, at Bushehr on the country's southwestern coast. There is also a small research reactor near Tehran.
But it does have several uranium processing plants and nuclear research facilities scattered around the country. Usually deep underground.
Israel has struck several nuclear sites in the past week.
It's hit Iran's largest uranium enrichment plant at Natanz in the central province of Isfahan. The smaller Fordow fuel enrichment plant near the city of Qom has been damaged. As has a heavy water nuclear plant in Arak.
The International Atomic Energy Agency (IAEA) has confirmed that radioactive material has been released at at least one site.
'Within the Natanz facility there is both radiological and chemical contamination,' its director general, Rafael Mariano Grossi, stated earlier this week.
'Considering the type of nuclear material at this facility, it is possible that Uranium isotopes contained in Uranium Hexafluoride, Uranyl Fluoride and Hydrogen Fluoride are dispersed inside the facility.'
But Uranium enrichment and heavy water plants are not nuclear reactors.
And that's a critical factor in assessing the risk of any bombing campaign.
Radiological release
Explosions and drone strikes on and around Ukraine's Zaporizhzhia Nuclear Power Plant have sent shivers through the spines of nuclear analysts around the world since President Vladimir Putin's 2022 invasion. His troops now occupy the site. And while it has been idled to halt the flow of electricity, it still poses a serious environmental risk.
Ukraine knows what that means.
The forest surrounding the wreck of the Soviet-era Chornobyl power plant is expected to remain unsafe for human habitation for at least 22,000 years. And the clean-up of Japan's Fukushima isn't likely to be completed before the mid-2050s.
So what about Iran's bombed nuclear facilities?
Only reactors have the highly radioactive fuel rods needed to turn water into the superheated steam that drives generators to produce electricity.
So far, Iran's reactors at Bushehr and Tehran have been spared from attack.
Its uranium enrichment and heavy water manufacturing plants, however, have not.
Uranium enrichment involves powerful centrifuges. These spin uranium yellowcake, as dug out of the ground, into powders and gas. And the spinning separates these materials into their component isotopes (atomic elements) according to their weight.
Weapons-grade enrichment demands concentrations of the isotope U-235 of more than 90 per cent. Nuclear fuel only needs between 3 and 5 per cent.
Iran is alleged to have amassed 400kg of uranium enriched to 60 per cent U-235. And the effort needed to take that to 90 per cent represents only a fortnight inside the centrifuges.
Even then, the material is not suitable for weapons. The gas and powders must be turned into a metal. Only then can it be machined into devices capable of triggering a nuclear detonation.
So, the most significant risk of bombing processing sites such as Natanz is the release of uranium hexafluoride gas.
'It's a big, heavy gas molecule,' says University of Alabama at Birmingham physicist Emily Caffrey. 'It's likely not going to travel super-far.'
That means any escape from sites such as Fordow will likely only contaminate the immediate area.
But the attack on the Arak reactor, some 250km southwest of Tehran, could potentially have produced more severe contamination.
Heavy water is used for medical processes and nuclear research. And while not radioactive itself, the process of making it can produce deadly plutonium and deuterium. Both can be used in nuclear weapons.
Long term threat
'We have nothing to be concerned about right now, but obviously prolonged escalation will have unpredictable consequences,' warns Qatar's al-Ansari.
Assessment of satellite photos reveals most of the above-ground structures at the Natanz uranium enrichment facility have been destroyed. But the sites associated with the deep underground caverns holding the vital centrifuges appear untouched.
That, according to analysts, does not mean they're undamaged.
Sudden interruption to the power control could send the centrifuges spinning out of control. And shockwaves from nearby blasts could topple them from their mountings.
The similar Fordow bunker facility does not yet appear to have been hit. But it is believed to be where most of the highly enriched, 60 per cent U-235 material is located.
'There's not a significant, dire health threat if those materials got released to the environment,' Union of Concerned Scientists spokesman Edwin Lymann told US public media. The kinds of uranium isotopes found within these facilities 'are at the low end of hazard with regard to radioactive materials,' he added.
The IAEA agrees. To a point.
'The radiation, primarily consisting of alpha particles, poses a significant danger if Uranium is inhaled or ingested,' Director Grossi states.
'However, this risk can be effectively managed with appropriate protective measures, such as using respiratory protection devices while inside the affected facilities. The main concern inside the facility is the chemical toxicity of the Uranium Hexafluoride and the Fluoride compounds generated at the contact with water.'
Uranium hexafloride can combine with moisture in the air to create hydrofluoric acid. This is highly corrosive and is used in glass etching and electronics manufacturing. But it can enter the human body through the skin, eyes or inhalation. 'That is an acutely hazardous material that can harm or kill people,' Lyman explains.
Once in the body, it interferes with the nervous system and burns soft tissues.
But not all of Israel's targets are limited to Uranium Hexafluoride.
Images of the heavy water facility at Arak show its central reactor structure has been hit. And analysts say four other nuclear sites, mostly associated with turning the enriched uranium into a metal, have been targeted. This potentially means long-lived, highly radioactive fragments are scattered among the debris.