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An Iranian nuclear facility is so deep underground that US airstrikes likely couldn’t reach it

An Iranian nuclear facility is so deep underground that US airstrikes likely couldn’t reach it
By JON GAMBRELL May 22, 2023 GMT

DUBAI, United Arab Emirates (AP) — Near a peak of the Zagros Mountains in central Iran, workers are building a nuclear facility so deep in the earth that it is likely beyond the range of a last-ditch U.S. weapon designed to destroy such sites, according to experts and satellite imagery analyzed by The Associated Press.

The photos and videos from Planet Labs PBC show Iran has been digging tunnels in the mountain near the Natanz nuclear site, which has come under repeated sabotage attacks amid Tehran’s standoff with the West over its atomic program.

With Iran now producing uranium close to weapons-grade levels after the collapse of its nuclear deal with world powers, the installation complicates the West’s efforts to halt Tehran from potentially developing an atomic bomb as diplomacy over its nuclear program remains stalled.

Completion of such a facility “would be a nightmare scenario that risks igniting a new escalatory spiral,” warned Kelsey Davenport, the director of nonproliferation policy at the Washington-based Arms Control Association. “Given how close Iran is to a bomb, it has very little room to ratchet up its program without tripping U.S. and Israeli red lines. So at this point, any further escalation increases the risk of conflict.”

The construction at the Natanz site comes five years after then-President Donald Trump unilaterally withdrew America from the nuclear accord. Trump argued the deal did not address Tehran’s ballistic missile program, nor its support of militias across the wider Middle East.

But what it did do was strictly limit Iran’s enrichment of uranium to 3.67% purity, powerful enough only to power civilian power stations, and keep its stockpile to just some 300 kilograms (660 pounds).

Since the demise of the nuclear accord, Iran has said it is enriching uranium up to 60%, though inspectors recently discovered the country had produced uranium particles that were 83.7% pure. That is just a short step from reaching the 90% threshold of weapons-grade uranium.

As of February, international inspectors estimated Iran’s stockpile was over 10 times what it was under the Obama-era deal, with enough enriched uranium to allow Tehran to make “several” nuclear bombs, according to the head of the International Atomic Energy Agency.

President Joe Biden and Israel’s prime minister have said they won’t allow Iran to build a nuclear weapon. “We believe diplomacy is the best way to achieve that goal, but the president has also been clear that we have not removed any option from the table,” the White House said in a statement to the AP.

The Islamic Republic denies it is seeking nuclear weapons, though officials in Tehran now openly discuss their ability to pursue one.

Iran’s mission to the United Nations, in response to questions from the AP regarding the construction, said that “Iran’s peaceful nuclear activities are transparent and under the International Atomic Energy Agency safeguards.” However, Iran has been limiting access for international inspectors for years.

Iran says the new construction will replace an above-ground centrifuge manufacturing center at Natanz struck by an explosion and fire in July 2020. Tehran blamed the incident on Israel, long suspected of running sabotage campaigns against its program.
Tehran has not acknowledged any other plans for the facility, though it would have to declare the site to the IAEA if they planned to introduce uranium into it. The Vienna-based IAEA did not respond to questions about the new underground facility.

The new project is being constructed next to Natanz, about 225 kilometers (140 miles) south of Tehran. Natanz has been a point of international concern since its existence became known two decades ago.

Protected by anti-aircraft batteries, fencing and Iran’s paramilitary Revolutionary Guard, the facility sprawls across 2.7 square kilometers (1 square mile) in the country’s arid Central Plateau.

Satellite photos taken in April by Planet Labs PBC and analyzed by the AP show Iran burrowing into the Kūh-e Kolang Gaz Lā, or “Pickaxe Mountain,” which is just beyond Natanz’s southern fencing.

A different set of images analyzed by the James Martin Center for Nonproliferation Studies reveals that four entrances have been dug into the mountainside, two to the east and another two to the west. Each is 6 meters (20 feet) wide and 8 meters (26 feet) tall.

The scale of the work can be measured in large dirt mounds, two to the west and one to the east. Based on the size of the spoil piles and other satellite data, experts at the center told AP that Iran is likely building a facility at a depth of between 80 meters (260 feet) and 100 meters (328 feet). The center’s analysis, which it provided exclusively to AP, is the first to estimate the tunnel system’s depth based on satellite imagery.

The Institute for Science and International Security, a Washington-based nonprofit long focused on Iran’s nuclear program, suggested last year the tunnels could go even deeper.

Experts say the size of the construction project indicates Iran likely would be able to use the underground facility to enrich uranium as well — not just to build centrifuges. Those tube-shaped centrifuges, arranged in large cascades of dozens of machines, rapidly spin uranium gas to enrich it. Additional cascades spinning would allow Iran to quickly enrich uranium under the mountain’s protection.

“So the depth of the facility is a concern because it would be much harder for us. It would be much harder to destroy using conventional weapons, such as like a typical bunker buster bomb,” said Steven De La Fuente, a research associate at the center who led the analysis of the tunnel work.

The new Natanz facility is likely to be even deeper underground than Iran’s Fordo facility, another enrichment site that was exposed in 2009 by U.S. and other world leaders. That facility sparked fears in the West that Iran was hardening its program from airstrikes.

Such underground facilities led the U.S. to create the GBU-57 bomb, which can plow through at least 60 meters (200 feet) of earth before detonating, according to the American military. U.S. officials reportedly have discussed using two such bombs in succession to ensure a site is destroyed. It is not clear that such a one-two punch would damage a facility as deep as the one at Natanz.

With such bombs potentially off the table, the U.S. and its allies are left with fewer options to target the site. If diplomacy fails, sabotage attacks may resume.

Already, Natanz has been targeted by the Stuxnet virus, believed to be an Israeli and American creation, which destroyed Iranian centrifuges. Israel also is believed to have killed scientists involved in the program, struck facilities with bomb-carrying drones and launched other attacks. Israel’s government declined to comment.

Experts say such disruptive actions may push Tehran even closer to the bomb — and put its program even deeper into the mountain where airstrikes, further sabotage and spies may not be able to reach it.

“Sabotage may roll back Iran’s nuclear program in the short-term, but it is not a viable, long-term strategy for guarding against a nuclear-armed Iran,” said Davenport, the nonproliferation expert. “Driving Iran’s nuclear program further underground increases the proliferation risk.”
Iran needed the old, discarded Pakistani centrifuges in order to reach the next level. They couldn't build their own.

Israel is a colonial outpost. Without the support from Europe/USA Israel cannot last, especially if Egypt gets its house in order.

Algeria has had exposure to nuclear reality since the French days.

KSA isn't stupid. No one in the region trusts Iran.
and from where and how Pakistan get that design?
The British Empire was weak in the 1700s?
The British Empire was weak in the 1800s?
The Mexican Empire was weak in the 1800s?
The Spanish Empire was weak in the 1800s?
Germany was weak in World War 2?
Japan was weak in World War 2?
North Korea was a weak country in 1950?
Iraq was weak in 1991?
Yugoslavia was weak in the 1990s?

It's not like US was a superpower from the get-go. Americans have fought and won numerous battles even in less-than-ideal conditions throughout history. But Americans have also shown much restraint in conflicts after World War 2 in line with Theory of Limited War.

Do tell me what modern Iran has to show in terms of warfare in comparison.

Taliban has hideouts in neighboring countries and can blend with locals. US wasn't interested in chasing Taliban everywhere in the region. US just made sure that Taliban would agree to not allow Al-Qaeda types to misuse Afghan soil like in the past.

Unlike Taliban who reside in a landlocked environment, Iran is a proper country with infrastructure and government and is accessible through Arabian Sea. War with Iran will be of entirely different character than it was with Taliban - hypothetically speaking.
Iran will show them what is a real war.

When we kill thousands of Yankees you will understand it too.

Every American ships, every bases, every soldiers,... Will see thousands of missiles, drones, and soldiers.

Their military leaders know it and they are in fear. No American is safe in middle east.

Also iranian nukes are an option on table.
This facility is impressive and not easy to disable but articles like these are aimed to give false hope to the perceived enemy in typical American fashion.

Nothing false hope about it. It's the reality of whether their MOP can penetrate the depth required to destroy this facility.

For perspective: scuds were unstoppable;

From the past, I don't recall any serious minded military official stating scuds were "unstoppable". Difficult to potentially shoot down? yes. Unstoppable? no. It's physics at the end of the day. The questions are:

1) Can the technology be made i.e is it even scientifically possible?
2) Does the technology exist today to do so?
3) Can it be done so economically.

then ASBM were unstoppable; then Hypersonic missiles were unstoppable;
It depends at which point of time we are talking about. Can any air defence today reliably stop a HGV? No. Does that mean no air defence will ever be able to shoot them down? of course they will at some point. As wih above, there is nothing about these systems to suggest they will eventually not be countered, at least to some degree.

now facilities are too deep to penetrate.

As with above, the point is at this point in time I don't see any proof any American weapons can penetrate to that depth.

American agencies continue to fool people with these claims from time-to-time while homework is done behind-the-scenes.

They may be trying to do their homework, but have they actually succeeded?

US has a well-developed arms industry and it will continue to develop countermeasures for perceived threats around the world.

Sure, but these things take time. Don't assume they're always ahead of their perceived threats in every scenario. Look at UAVs for example. They're still trying to find ways to reliably deal with them.

People tend to forget that the Americans aim for developing countermeasures to Chinese and Russian threats let alone that of regional powers.

This is an incorrect way of thinking. You're assuming the magnitude of a particular threat is fully dependent on the overall power of that nation. Once again, look at UAVs for example. Iranian cheap and expendable UAVs are being imported by these powers like Russia and there is little answer to them. Different nations pose threats in their own way and they require their own unique countermeasures. The Americans are not necessarily up to to the task of dealing with all threats from nations with your notion of "power" below their near peer advertises just because they are focused on countering their near peers.

Both China and Russia have developed deeply buried facilities so US is focused on how to disable these facilities in case of war.



Taken from here.

- is OUTDATED information. This level of capability was advertised back in 2012.

Americans have continued to improve GBU-57 Massive Ordinance Penetrator (MOP) bunker buster and have not disclosed capabilities of improved variants:

Realistically speaking, even if they improved them, to what extend do you think they can increase their penetration? Answer: not much.

This is a simple matter of physics. There is only so much they can improve on the penetration of these systems, short of creating something much larger.

Therefore, nobody in public domain can tell how capable upgraded variants of GBU-57 are in terms of penetrating layers of earth and concrete.

See above.

More importantly, GBU-57 is a precision munition and two or more can be dropped on the same spot in sequential manner to open up the ground until the target is engaged.

We can create "if" scenarios ad infinitum. The question is how likely are these scenarios?

It also depends upon how an underground facility is constructed and how big it is. Compartmentalization can make some chambers survivable but the facility on the whole would have entrances, exits, and ventilation points.

Exactly. A very important factor you need also bare in the mind is the use of these so called super concretes.

Iran makes some of the world’s toughest concrete.​

Lets not forget the fact these facilities are literally under mountains and I am dubious if Iran's enemies even know the exact location of where they are underground.

These can be targeted to entomb the facility.

That will not achieve as much as you think it will.

The most powerful American bunker buster is B61-12 in fact. This bomb can destroy virtually any underground facility in the world.

That is a nuclear weapon, you're suggesting Americans will resort to the use of nuclear weapons giving Iran the open legitimate reason to go nuclear?

Moreover, where is this evidence that it could even destroy these Iranian facilities?

Check this out.

Iranian members seem to grossly underestimate American warfighting options and capacity.

Actually we are not, what I see however is you are overestimating them.

Iraqi also had similar views but look at the country now.

Iran and Saddams Iraq are not similar in terms of their military doctrine. Iran will not be engaging US in a full on conventional conflict, nor will it have to sit back and watch the Americans build up their forces helplessly like Iraq did.

In comparison, Iranian forces could not capture Basra let alone come close to toppling Saddam regime in the 1980s:

No much to be gained by comparing Iran from the 80's, which had to defend itself from an invasion during a turmoil of a revolution to the combined might of NATO and their allies in 2003.

It is true that Iraq was receiving weapons from several countries to fight a war with Iran but this much is expected in a prolonged war.

Not just any weapons, but chemical weapons and also funds.

Americans seem to have learned numerous lessons from these conflicts. Americans have developed new M1A2 Abrams variants that can withstand anti-tank munitions including ATGMs and IEDs, and outgun any tank in Iranian inventory. Americans have also developed a large number of armored vehicles to protect and support troops on the ground.

The prowess of the western tanks is not something I give much attention to in this context. I hope you are not under the impression the Americans would be foolish to try and engage in a land conflict with Iran?

American ground forces have considerable urban warfare experience courtesy of operations in Iraq. Details of the battles that were fought in Iraqi cities in 2003 are in following link:

I don't think the question at hand is whether the American have experience fighting in urban environment. So do many nations, including Iran.

Let's take a look at American Air and Naval power and options now:

I have discussed Iran ability to target the American using its BMs many times. You can visit the Iranian missile threat to focus on that topic in more details. With the recent test of the Khoramashahr-4 missile and its unique warhead, there is a new added view to this.

US has fought in Iraq in line with its Theory of Limited War philosophy and still managed to defeat it and reshape its political landscape.

IF US had fought in Iraq in line with its Total War philosophy like against Japan in World War 2, it would have crushed Iraqi morale and will to fight long ago.

Minus not utilising nuclear weapons, there was nothing "limited" about the NATO's conduct in the Iraqi conflict.

Sorry but Iran is a regional power and it stands NO chance against US in Total War.

The question is not whether Iran can defeat US in a 'total war'. That is not something people here have discussed. The question is, can the Americans hope to achieve their objective vis a vis Iran in a cost effective manner. Short of a full on nuclear assault on Iran, there really is not much more the Americans can do.

Listen to this Israeli here:

Moreover, the key parameter for us to consider here is: deterrence.
To deter a nation, you need to show their loss > their gain in a potential conflict. Has Iran managed to achieve deterrence against its enemies (which include the USA). Answer: yes.

This is not a discussion about who will win a full on war. It's about whether Iran can inflict enough damage to them.

Iran can throw ballistic missiles at American bases in the Middle East but this will not help win the war.

What does "win the war" mean here exactly? You need to clarify what parameters need to be met in order for us to consider the war as being won.

I can see that Iranians are nationalistic, brave, and motivated fighters but these qualities are not sufficient on their own.

Iranians are actually more than aware of the strengths and weaknesses of our enemies.

I hope that Iran does not experience American fury in any way, shape, or form.

American fury is something which in your mind you have greatly overestimated. Are they a capable conventional power? of course. Are they as powerful as what you're perceiving them to be? Not at all.

I don't think that US has a plot to invade Iran but Iranians should seek to mend ties with US in my view. There is no Saddam out there to draw American attention away from Iran this time.

The Americans understand Iran is a major key to that region. If they could have, they would have dealt with Iran many years ago.

I think you greatly overestimate these Americans my friend. Perhaps you are in awe of them because of your own imagination of their perceived capability. The America that we see, is clearly different to what you're seeing.
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If Iran could make nuke it will trigger nuke posesion through all ME.

S.A and Turkiye will be first.

Pakistan may sell nukes to S.A.
If Iran could make nuke it will trigger nuke posesion through all ME.

S.A and Turkiye will be first.

Pakistan may sell nukes to S.A.
Europeans won't let a country like Turkey become nuclear

Same as SA

Trump is still paying for minor nuclear help that he did to Saudis
Europeans won't let a country like Turkey become nuclear

Same as SA

Trump is still paying for minor nuclear help that he did to Saudis
Europeans won't be able to do anything to stop Türkiye and KSA from developing nuclear weapons if Iran officially becomes a nuclear power.

this is exegration of the Influnce of EU. Turkiye tested 1000km ranged MRB missiles last week. Longer ones in development phases.

IMHO possibility of nuked Iran scares Turkiye and pushing for balance. Atleast Turkiye wanna to be ready for worst scenario.

Currently no Nuke power directly threats SA . But If Iran got nukes who will provide counter protection for S.A ? USA ?
this is exegration of the Influnce of EU. Turkiye tested 1000km ranged MRB missiles last week. Longer ones in development phases.

IMHO possibility of nuked Iran scares Turkiye and pushing for balance. Atleast Turkiye wanna to be ready for worst scenario.

Currently no Nuke power directly threats SA . But If Iran got nukes who will provide counter protection for S.A ? USA ?

Why should Iran nuke SA and Turkey to begin with ?

Its against Islam and humidity and great honor of our country and our religious leaders are against using nukes even against israelis

But deterrence against europeans Americans and israelis is another story
This is not a discussion about who will win a full on war. It's about whether Iran can inflict enough damage to them.

Like what damage? I don't think there's going to be 100,000 US troops running around the streets of Iran.
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Where do you think Pakistan got that?
i knew exactly the blueprint for that come to Pakistan , i wonder if you guys also knew it.

Let just say in Iran we have a proverb about a thief who enter the house with lamp

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