Why it’s impossible to hide nuclear work in 24 days – or 24 years

August 13, 2015
A scientist works at the International Atomic Energy Agency (IAEA) environmental sample laboratory in Seibersdorf

A scientist works at the International Atomic Energy Agency environmental sample laboratory in Seibersdorf, April 24, 2013REUTERS/Heinz-Peter Bader

One of the most misleading distortions being floated by political opponents of the Iran nuclear deal is the “24-day” loophole meme: Iran would be able to hide all  evidence of any nefarious nuclear weapons work during the 24 days it may take inspectors to gain access to a suspicious site.

For starters, International Atomic Energy Agency inspectors would have continuous daily access to all Iran’s declared nuclear facilities. If Iran does not allow anytime inspections of any declared site, it could result in the reimposition — or “snapback” — of sanctions.

The 24-day rule applies only to undeclared suspect sites anywhere in the country. Because inspections anywhere at any time can be complicated to work out, a procedure was devised to address the problem.

A security official stands in front of the Bushehr nuclear reactor

A security official stands in front of the Bushehr nuclear reactor, 1,200 km (746 miles) south of Tehran, August 21, 2010.REUTERS/Raheb Homavandi

Why 24 days? Iran and the atomic energy agency first would have a maximum of 14 days to come to an understanding about how to carry out the new inspections. In the absence of an agreement, the members of the Joint Commission – the United States, Britain, France, Germany, China, Russia and Iran — must resolve the issue, by consensus or a vote, within seven days. Tehran would have three days to implement the decision. So, the 24 days is not a gift to Tehran that would allow it to hide potential nuclear malfeasance — it is just the maximum period allowed to hammer out a way to inspect any undeclared suspicious facility in Iran.

More important, critics insist, Iran could use those 24 days to hide evidence of nuclear materials. This is not going to happen. It would be virtually impossible even in 240 days, let alone 24. Even a nanogram, or one-billionth of a gram, of leftover dust from nuclear-weapons related work — such as covert enrichment at a suspect site — could be detectable.

The main way the agency could find incriminating dust is with a “swipe sample” using a super-clean cotton cloth. The wipe would be applied to surfaces, especially where dust naturally collects, including corners of a room, cracks, bolt holes, equipment interiors and where walls meet the floor.

As the agency itself states: “Any nuclear process … will also produce particulate materials with particle dimensions in the 0.1 [to] 10 micrometer range. Such small particles are believed to be quite mobile and will travel several meters from their point of origin due to air currents or human activity. This mobility also makes it extremely difficult to clean up an area to such an extent that no particles remain available for swipe sampling.” [emphasis added]

The swipe samples from a suspect site would be taken to a laboratory, where the atomic energy agency can use a variety of highly sensitive methods to pick up any infinitesimal incriminating nuclear particles. Isotopic ratios, chemical forms or particle shapes can all provide clues about where the nuclear material came from and how it was produced.

One particularly powerful method is known as “fission track-secondary ion mass spectrometry.” Particles from a swipe sample are irradiated with neutrons on a Lexan (plastic) plate. If there are fissile materials in the sample, they would  become unstable and split apart; heavy fission-product particles would be produced. In sufficient quantities, these particles would leave tracks in the plate that can be viewed by acid etching.

A scientist conducts genetic research at the International Atomic Energy Agency (IAEA) laboratories in Seibersdorf

A scientist conducts genetic research at the International Atomic Energy Agency laboratories in Seibersdorf, some 50 kilometres (some 31 miles) southeast of Vienna, October 14, 2009. REUTERS/Herwig Prammer

The lab scientist can then focus on suspect particles and examine them further with mass spectroscopy, a powerful way to identify particles based on their charge-to-mass ratio. The process is painstaking and time consuming, but it is a highly sensitive way of identifying suspect particles.

The bottom line is that it is almost impossible to get away with messing around with nuclear materials. Nuclear fingerprints are not removable.

“You cannot get rid of them by cleaning,” Stephan Vogt, head of the atomic agency’s Environmental Sample Laboratory told Reuters in 2013. “You cannot dilute them to the extent that we will not be able to pick them up. It is just a matter of time,” he stated, before the atomic energy agency detects any incriminating residue.

In fact, one potential problem with environmental sampling is that it can often be too sensitive. Because samples are frequently collected by nuclear inspectors who are working in contaminated environments much of the time, their clothing, equipment and even their hair can introduce false positives from different locations.

Such cross-contamination may have occurred in inspections of a bombed Syrian site while Olli Heinonen was head of the safeguards department. The result was a botched analysis and invalid conclusions.

To address the possibility of cross-contamination and false positives, the atomic energy agency has devised strict procedures that require two inspectors, sterile conditions, background and control samples and procedural training. Particle samples are also supposed to be processed in multiple laboratories in different countries under a double-blind procedure to preclude any tampering with results — or the planting of evidence. This was not done in the Syria investigation.

If the procedures are followed properly, the conclusions are considered highly trustworthy.

It is imperative that official IAEA sampling procedures are adhered to scrupulously, and that the integrity of inspectors is beyond reproach. If false accusations are made based on faulty procedures, it would cast doubt on the entire international monitoring system. This is why the atomic energy agency must be extremely careful that technical mishandling of the samples, as reportedly occurred during the Syria investigation, is not repeated in Iran.

Another important consequence of the exquisite sensitivity of IAEA’s particulate- detection methods is that it is virtually impossible to hide traces of nuclear material even outside the site, for example, by partial paving of a site. Some analysts have alleged that the paving work at Iran’s Parchin military complex could sanitize it. But this is incorrect. Environmental sampling is still possible where large parts of a site remain undisturbed. As Robert Kelley, a former IAEA inspector, explained about the Parchin site: “The fact that the building’s immediate vicinity has been largely untouched on the west side strongly suggests that the purpose of the earth-moving operations was for construction and renovation work and not for ‘sanitizing’ the site by covering up contamination.”

In addition, the preferred method of sampling at the Parchin site would be to take sample swipes from inside the buildings of interest. It matters little what construction Iran does outside. If outdoor sampling were needed for some reason, it could be gathered from the large undisturbed area west of the building of interest.

Twenty-nine top U.S. scientists — including Nobel Prize winners, senior experts in arms control and former White House science advisers – wrote to President Barack Obama this past weekend to praise the Iran deal. They called it “technically sound, stringent and innovative.” Instead of listening to the complaints about the 24-day meme, Congress should pay heed to these experts.


We welcome comments that advance the story through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can flag it to our editors by using the report abuse links. Views expressed in the comments do not represent those of Reuters. For more information on our comment policy, see http://blogs.reuters.com/fulldisclosure/2010/09/27/toward-a-more-thoughtful-conversation-on-stories/

It is obvious conservatives are not scientists.

Conservatives should take the advise of scientists, and not their extremists who promote war and environmental disaster.

Posted by Flash1022 | Report as abusive

First of all this article is the “opinion” category for a reason.

Your points are fictitious. What you need to look at is the past performance of Iran adhering to the agreements. Their track record speaks for itself. All the safeguards are worthless if they never let the inspectors in anyway which is what has happened in the past. Remember perception is reality.

Posted by Opinion22 | Report as abusive

This article makes a lot of assumptions…. First that the IAEA are competent and not corrupt… Literally weapons inspectors in Iraq didn’t find thousands upon thousands of chemical weapons…

Posted by GilaFide | Report as abusive

US officials have already stated there is no provision for automatic snap-back of sanctions in the event that Iran fails to meet its commitments.

Posted by AdamMickiewicz | Report as abusive

@Flash1022: That’s quit a feat! Argumentum ad hominem, argumentum ad auctoritate, straw man, and petitio principii — four rhetorical fallacies packed into two measely sentences.

Posted by OBAFGKM | Report as abusive

You understand the Republican leaders already know this, right? They’re entire operation depends on low-information voters. They KNOW countries can’t hide nuclear activities – but those conservative voters do not. Republican politics, like corporations, have no moral or ethical compass. It’s all about marketing to you, to get what they want – which has always ever been money and power.

Posted by Thomas_CA | Report as abusive

#‎Globalize‬ NewSTART Treaty
‪#‎Extended‬ to ‪#‎NuclearWasteTransmutation‬
‪#‎25yearsHalfLife‬ nuclear waste.
Look for ‪#‎EUROTRANS_Project

Posted by givegiugio | Report as abusive

This is easily understandable, reasonable and logical. Unlike the argument against the agreement is not logical or reasonable. Why do the people against this agreement want war so badly. We have had at least 3 wars recently that we couldn’t win and that made America weaker.

Posted by denissr | Report as abusive

I’m not sure the argument in this column works. If the particles are tiny and mobile, and if we are that good at detecting them, then these trace particles could show up pretty much anywhere. Could investigators even prove that these trace particles originated from the site where they were collected? In the event of an inspection resulting in a positive test, Iran could claim that their own scientists (or anybody else, really) must have accidentally tracked these particles in from some other legitimate site. Couldn’t they?

To be clear, I don’t have strong opinions about the Iran nuclear deal itself. I’m just expressing skepticism toward the argument in this opinion column.

Posted by DaleG | Report as abusive