Underestimating the potential impacts of attacks on Iran’s nuclear facilities

Tilman Ruff, Jun 24, 2026

I worked with Kristina Kukolja, a journalist who obtained (heavily redacted) FOI files about the Australian government’s assessment and responses to Israel/US attacks on Iran’s nuclear facilities in 2025 and 2026. Its clear the Australian Radiation Protection and Nuclear Safety Agency underestimated the possible resultant radiological releases. Australia was one of the first countries to support those attacks both in 2025 and 2026 on the basis that any measures to avoid Iran acquiring nuclear weapons were a good thing, despite criticising Russia’s attacks on nuclear facilities in Ukraine.

Close monitoring of developments and modelling of possible scenarios including worst-case scenarios from attacks on nuclear facilities is something one would expect any responsible government to undertake and to use as the basis for informing and protecting their staff and the public, particularly the substantial number of Australian citizens in the Middle East (at least 115,000). 

An additional reason for Australia to thoroughly assess attacks by allies on nuclear power plants is that during 2025-6 Australia chairs the IAEA board of governors. In relation to both Ukraine and the Middle East, the IAEA Director General has been consistently calling out the severe radiological risks of military attacks on nuclear facilities and calling for such attacks, in violation of international law, to end. Australia’s position here was clearly divergent from the IAEA’s.

One wonders whether underestimating the potential risks and keeping the assessments secret might be connected with an incentive to downplay the risks for political reasons. See article in the last Saturday Paper (below)_ o you don’t get stuck behind a paywall.

A year ago the government began receiving modelling on radiation risks from the war in the
Middle East, which experts say understated the danger and should be made public.

Exclusive: DFAT’s secret nuclear briefings

By Kristina Kukolja, Jun 24, 2026

Documents obtained under freedom of information show that a year ago the
Australian government began secretly receiving detailed modelling of radiation risks
from the war in the Middle East and the protective action Australian citizens may
need to take, but did not share this with Australians in the region.

American and Israeli strikes on sites in Iran and Iran’s retaliation against US targets
prompted the Australian government agency responsible for nuclear safety to
produce numerous reports to the Department of Foreign Affairs and Trade (DFAT) –
at times, on a daily basis – detailing “credible worst-case scenarios” for possible
nuclear incidents in Iran, Israel and the United Arab Emirates.

The reports outline protective measures such as evacuation, sheltering and
restrictions of food and drinking water. Australian Radiation Protection and Nuclear
Safety Agency (ARPANSA) experts also briefed the Inter-Departmental Emergency
Task Force (IDETF), convened to manage Australia’s response to the war, chaired by DFAT and attended by top government agencies including the Australian Defence
Force.

The Saturday Paper asked DFAT whether it had informed citizens about the
government’s monitoring and modelling for nuclear worst-case scenarios; whether
diplomatic staff were told to prepare food and water supplies; whether other
Australians, including military personnel, received the same advice; and whether
Australian embassies had secured supplies of potassium iodide tablets for
distribution.

DFAT declined to respond to these questions. A spokesperson said the department
“maintains internal contingency action plans at all Australian embassies and
consulates, intended to respond to crises and support Australians overseas.
Requests for technical advice, such as modelling, are part of prudent, scenario-
based planning and help inform our understanding of how an incident could affect
Australians in different locations.”

As the strikes escalated around nuclear facilities this year, an email to ARPANSA
staff from the emergency management project leader on March 9 said: “DFAT is
facing a major consular crisis, with many Australians unable to return home.

“It’s important to be supportive and respectful of their situation … We should also not
overwhelm DFAT or crowd their decision space unnecessarily.”

At the time of that update, there were about 115,000 Australians in the Middle East,
says DFAT – 24,000 in the UAE.

The results of ARPANSA’s modelling should be made “widely and promptly publicly
available … to inform Australians in making travel or evacuation decisions and be
better equipped to take timely protective measures”, says Dr Tilman Ruff, co-founder
of the Nobel Prize-winning International Campaign to Abolish Nuclear Weapons
(ICAN), based in Australia.

The radiation assessment reports and electronic correspondence released under
freedom of information are heavily redacted, including on the grounds that disclosing
certain information could damage the Commonwealth’s defence or international
relations.

In a statement, ARPANSA says the reports were prepared “for a specific operational
purpose but shared more broadly across government, including through the IDETF”
and “informed public-facing messaging, including through Smartraveller”.

The Smartraveller website provides general advice on nuclear incidents. Despite the
Middle East war, Ukraine is still the only country where Australians have been
specifically warned about a nuclear risk, stating that Russian actions “pose a threat
to Ukraine’s nuclear power plants”.

ARPANSA’s reports to DFAT began in June 2025 after Israel attacked Iranian
nuclear sites and scientists, followed by US strikes the Trump administration
declared had obliterated Iran’s nuclear facilities. Prime Minister Anthony Albanese
said Australia, which had just taken over chairing the International Atomic Energy Agency board of governors, supported the attacks, on the grounds they were
designed to prevent Iran acquiring a nuclear weapon.

The assessments contain plume modelling – how far radiation could spread – and
exposure estimates for 48 hours after a possible incident at facilities such as the
targeted Natanz and Fordow fuel enrichment plants and Isfahan nuclear technology
centre. Projected plumes from Israel’s Dimona nuclear research facility and Iran’s
Bushehr nuclear power station – potentially causing the “greatest radiological
hazard” – reached neighbouring countries, including Iraq, Kuwait, Saudi Arabia,
Qatar and the UAE.

“A military attack, even unintentional, could cause a catastrophic
nuclear accident such as Chernobyl or Fukushima.”

One simulation on June 20 last year showed radiation from a potential Bushehr
incident extending hundreds of kilometres into the Persian Gulf to Abu Dhabi and
Dubai, where Australian civilians and diplomatic staff are based, and the Al Minhad
Air Base, where Australian troops are stationed. While the report noted low
radiological risks for Australian “embassy locations in Kuwait City, Doha, Riyadh and
Bahrain”, the unredacted section did not address cities that would be affected by the
plume.

At the same time, IAEA director-general Rafael Grossi told the United Nations
Security Council an operating nuclear power plant hosts thousands of kilograms of
nuclear material, and a direct hit, or hits to electricity supply, could cause its reactor
core to melt, potentially causing “a very high release of radioactivity to the
environment”.

In the worst case, Grossi said, protective actions would be required: “evacuations and sheltering of the population or the need to take stable iodine, with the reach
extending to distances from a few to several hundred kilometres. Radiation
monitoring would need to cover distances of several hundred kilometres and food
restrictions may need to be implemented.”

“Are we getting this wrong?” asked ARPANSA’s emergency project leader in an
email to a redacted recipient on June 21 referencing DFAT concerns that Grossi’s
comments differed from earlier assessments.

ARPANSA’s subsequent report assured there was no conflict, citing findings of
“similar distances for urgent protective action”. Declassified text messages between
agency staff acknowledge that environmental damage “would be a big issue
following the event”.

The agency’s worst-case scenario for Bushehr involved a “station blackout due to
loss of power after damage to plant infrastructure and backup power supply”.

“Although it is not an ideal state for a nuclear reactor, the backup systems mean that
a core meltdown would not be an immediate concern,” the report stated.

Tilman Ruff says this assessment “unduly downplays the real risks, particularly when
the cause of loss of external power is a major aerial bombardment, which risks
widespread and uncontrolled damage to plant systems.”

Ruff says the reports show the “greatest radiological risks in Iran and Israel arise
from damage to the Bushehr power plant, with 3000 megawatts of thermal capacity,
much larger than the next largest facility between the two countries, the Dimona
nuclear site, with a reactor estimated at 150MWt. Yet in none of the scenarios is the
possibility of damage to reactor containment included for Bushehr, as it is for smaller
reactors at Soreq, Tehran and Dimona.”

He says the reports also fail to specify scenarios involving a core meltdown, reactor
explosion or fire, “or consideration of spent fuel pools, which often contain larger and
longer-lived amounts of radioactive materials than are present in reactor cores”.

Professor Tatsujiro Suzuki, former vice-chairman of Japan’s Atomic Energy
Commission, agrees spent fuel pools are “the most vulnerable part of the nuclear
power project”.

“A military attack, even unintentional, could cause a catastrophic nuclear accident
such as Chernobyl or Fukushima.”

Over time “the radiation consequences could reach India or Pakistan, potentially the
Mediterranean area or even northern Europe”.

When the US and Israel launched new attacks on Iran in February, ARPANSA’s
Radiation Emergency Coordination Centre (RECC) in Melbourne was placed “on
heightened readiness”.

New reports from the RECC warned a large release of radioactive material from
Bushehr or the UAE’s Barakah nuclear power plant could see “radioactive
contamination deposited on land used for food production and in water bodies” in the
region. In worst-case events, they say, embassy staff may need to take protective
actions including sheltering in place with doors and windows sealed and awaiting
further advice.

“Use of potassium iodide tablets may be directed. As a precautionary measure, and
if feasible, having a short-term stockpile of food and water (seven days) at the
Kuwait and Doha embassies may be prudent to avoid ingesting potentially
contaminated food and water … And to provide additional reassurance to embassy
staff as they are within several hundred kilometres of the reactor site.” 

Throughout March and into April, the period covered by the 2026 documents, Iran
reported strikes on multiple nuclear sites to the IAEA, including the Bushehr power
plant. Missiles were also reported near Israel’s Dimona facility. No off-site radiation
was recorded, but Rafael Grossi repeatedly warned attacks on Bushehr threaten a
“major radiological accident affecting a large area in Iran and beyond”.

In late March, DFAT requested radiation projections for possible nuclear incidents in
Pakistan, Türkiye, Syria, Armenia and Iraq. The 2026 modelling generally indicated more severe off-site releases than the 2025 assessments, says Tilman Ruff.

“The maps also depict higher levels of radioactive fallout, with potential exposure
near multiple facilities, including the relatively small research reactors at Soreq and
Tehran reaching over 50 mSv [millisieverts]. The estimated exposures are
significantly greater for Isfahan, Natanz and Fordow enrichment sites.”

Kristina Kukolja is a Walkley Award-winning journalist and broadcaster.

June 26, 2026 - Posted by Christina Macpherson | AUSTRALIA, secrets,lies and civil liberties