The Parchin Puzzle

by Robert Kelley

In the seemingly never-ending debate over Iran’s nuclear program, specifically the “possible military dimensions,” or PMD, of its past work, much has been made over the thus-far frustrated demands by the International Atomic Energy Agency (IAEA) to inspect a building at the sprawling Parchin military complex near Tehran. It has repeatedly been alleged by Iran’s critics that there is an explosive containment chamber in that building and that a visit there would go far toward establishing that Iran has nuclear-weapons ambitions.

However, before anyone gets overly excited about this alleged chamber, it may be useful to assess the evidence that has been put forward to prove its existence and, if it does exist, what relevance it might have to a nuclear weapons program.

The alleged chamber is said by the critics to be part of a program to test simulated internal components of a nuclear weapon using natural uranium with explosives. Such simulations are an ordinary part of nuclear weapons development, although they have not normally been conducted in a chamber and certainly never in the United States’ nuclear weapons program. According to the critics, Iran is using the chamber to hide these experiments in order to avoid detection.

With Iran’s permission, the IAEA inspected facilities in the Parchin complex twice in 2005. Since 2012, it has repeatedly asked to return, precisely to look into this particular building, but Iran has consistently declined, noting that the agency had pledged after its last visit that it would not ask again. The resulting controversy has become a key obstacle to resolving the PMD issue between the IAEA and Tehran and is repeatedly cited by critics as evidence of Iran’s bad intentions. It is also brought up as a major reason why the P5+1 (US, UK, Russia, China, France, plus Germany) should not sign a comprehensive accord with Iran without first clearing the issue up (even though weaponization is explicitly not on the table in the current P5+1 talks).

Officially, the claim that such a chamber exists boils down to one paragraph (Paragraph 49 in the Annex) on weaponization in an IAEA Board report issued in November 2011. According to that paragraph, an anonymous source asserts that such a chamber may exist and that it was installed at Parchin in the year 2000. Included in the paragraph is a carefully crafted sentence that suggests that the IAEA has satellite imagery of the actual chamber. But a closer reading of the text finds that the image to which it is referring is consistent only with the existence of a building (in which the chamber is presumably housed). Three years after its existence was first postulated, however, there is still no publicly available satellite image of the chamber—and no internal photos, either. Only a cartoon drawing from a newspaper that includes by way of substantiation only this reference:

A former senior International Atomic Energy Agency official said he believes the drawing is accurate. Olli Heinonen, until last year the U.N. nuclear agency’s deputy director general in charge of the Iran file, said it was “very similar” to a photo he recently saw that he believes to be the pressure chamber the IAEA suspects is at Parchin.

He said even the colors of the computer-generated drawing matched that of the photo he had but declined to go into the origins of the photo to protect his source. (Emphasis added)

Given the massive amount of information that has leaked out of the IAEA in the past few years, it seems reasonable to ask why no photos of the chamber have yet materialized.

Those who have insisted that such a chamber indeed exists often cite as corroboration the assertion in a book by an Ukrainian/Russian engineer named Vyacheslav Danilenko that he was designing a chamber for nanodiamond experiments between 1990 and 2000. Danilenko, who has been interviewed by the IAEA, did not assert that he was designing it for Iran, but we do know that he worked in Iran during the period in question. That information enables us to build a simple timeline.

The chamber in question is reported to be about 18 meters long and 4.5 meters in diameter. It is allegedly designed to contain 70 kg of high-explosive yield, which is a very large quantity for any containment chamber. A chamber of that size would weigh 100 tons or more and would be extremely difficult to fabricate. It would also be difficult to move such a large object without detection. If it is made in pieces, then the offset in weight would be complicated by the need for massive welds and flanges. It is also noteworthy that the cartoon version of the chamber shows a person-sized door presumably to permit entry and exit.

If Danilenko was still designing the chamber in 2000, it is very hard to believe that it could be fabricated and delivered in that same year. It would have required massive castings and forgings and considerable assembly work. Based on real-world experience, however, the notion that design, construction, and installation could all be completed in one year’s time is simply not credible. Moreover, assuming that planning for the chamber would have preceded its design, funding and engineering work for the project would need to have begun in the mid- to late-1990’s at the latest. In other words, even a simple timeline begs significant questions.

But a more fundamental question: Why would Iran want such a chamber? The answer, according to the critics, is that its purpose is to contain traces of uranium from high-explosive experiments related to nuclear weapons development. That implies that, already in the mid-1990’s, Iran was anticipating that the IAEA or some other organization was going to be looking for traces of uranium. However, according to Gareth Porter’s recently published Manufactured Crisis, Iran was taken completely by surprise in 2003 when the IAEA first took environmental samples at the Kalaye electric company where centrifuges were being developed. The sampling process was so sensitive that it detected tiny traces of uranium, which unmasked part of a uranium enrichment program. Iranian scientists apparently failed to appreciate just how sensitive environmental sampling would be in the late 1990s when planning for the chamber would have begun. Without such an understanding, why would they have commissioned such an expensive chamber to hide traces of alleged uranium at a sensitive conventional military factory where IAEA nuclear inspections were, in any case, unlikely to take place?

There’s an additional problem with this version of events. Would conducting tests in a chamber actually succeed in hiding traces of uranium? The answer is no. When explosives and uranium are detonated together, they produce large amounts of soot and debris, as well as finely divided uranium particles. There would be other materials in the chamber—for example, railroad ties to absorb shrapnel and protect the chamber walls—and they would inevitably be damaged and burnt. The chamber’s interior would look like your fireplace after a few frigid winter evenings when your furnace is on the fritz. Unless the experimenters are very careful, bits of debris, fine soot and ash will go everywhere. And if the entry door is opened, soot and uranium will be released into the light metal building that allegedly houses the chamber. This would concentrate the uranium evidence in a single building, making it easy for the hypothetical inspectors to find and sample. Performing the tests in a chamber is frankly a monumentally stupid idea. Indeed, once it was identified, it would be a veritable magnet for inspections and a sure-fire way to get caught.

A much better way to conduct any experiments with uranium and explosives is to perform them outdoors at a temporary firing site. The site could be reused, or experiments could be moved around from place to place to frustrate satellite surveillance. Given Iran’s vast desert areas, the chances of conducting tests undetected are good. And while uranium traces would remain, if the site were used and then quickly bulldozed flat again, the chances of discovery would be vanishingly small.

If the experimenters were concerned that they might still be detected, however, they can also move to a mine or a cave, making it yet more difficult for spy satellites to find, so long as basic security precautions are observed. This is what Pakistan did in its nuclear-weapons development program. A mined room at the back of an adit (a cave or tunnel with one entrance) is much cheaper than a multi-million-dollar steel vessel and can effectively contain unlimited chemical explosions. After all, full-scale thermo-nuclear tests with vastly higher yields—not little simulations, as allegedly conducted in the Parchin chamber—have been contained in similar locations in all nuclear-armed nations except India and Israel.

But, aside from the obviously far more attractive and difficult-to-detect alternatives, there are still more problems with the critics’ contentions that the suspected building contains a steel chamber for testing uranium and explosives. Is its location, for example, compatible with the high security, safety (given the use of high explosives inside), and remoteness that are needed to prevent uranium from being detected? Again, the answer is a pretty clear no.

The building in fact is located some 200 meters from the site boundary, with a low wire fence next to a major highway inside just the first level of security within the Parchin complex—a huge area which has many and far more secure and hidden sites. It is easily accessible to anyone who simply has business to conduct there without the kind of high-security clearances one might expect to approach the potentially sensitive chamber site. Moreover, the building sits a mere six meters from a security fence on the west side, while a support building that resembles a control room is located just one meter from the fence. A long-armed foreign agent can literally reach across the fence to attach a spying device to its wall. It seems reasonable to ask why, if the site is so sensitive, wouldn’t one expect a much higher level of security?

A satellite image of the compound of buildings in the Parchin Military Complex near Tehran. One allegedly holds a containment explosive chamber. Credit: Google Maps

A satellite image of the compound of buildings in the Parchin Military Complex near Tehran. One allegedly holds a containment explosive chamber (north is to the right).

As to safety, there is a very small—in contrast to its description as “large” in the 2011 IAEA report—earthen wall, or berm, separating the mystery building from two other support buildings. It protects only a very small angle of hazard. While such a berm is consistent with a radiation beam stop for an industrial x-ray machine, it offers very little protection from the kinds of explosives that it is purportedly designed to test.

The critics, however, have not been deterred by these observations and have pointed to what they insist has been an effort by the Iranians to “sanitize” the building and its surroundings as additional evidence that the site has been used for nefarious purposes.

Unfortunately, if coincidentally, when the IAEA first asked to visit the building in 2011, Iran had already begun what appears to be a major renovation project at the site. This project has at various times involved a workforce of dozens, judging from the number of cars and trucks photographed at the site. Several small structures in the area were renovated and some minor structures removed. The project involved tearing up paving, repaving some areas, and re-roofing the remaining buildings with modern insulation (which some analysts called the “pretty-in-pink” phase)—all consistent with renewed interest in an area that had looked virtually unused for years. All of this activity, however, was interpreted by the critics as part of a sanitization operation designed to both hide what was going on inside the buildings or eliminate any detectable traces of what happened there.

On at least one occasion, water was observed in the parking lot, although traces of water there had been visible for a number of years before. Indeed, the vegetation at the run-off point is visible and abundant compared to other areas in the complex. While the critics cited this as evidence of sanitization, they neglected to mention that any wash-down would actually have concentrated contamination in a ditch, making it easier for inspectors or anyone else to sample.

Occasional satellite photos depicting equipment stacked up next to the building have also been cited as evidence that items are being removed from the site, presumably as part of the alleged sanitization operation. But, in the absence of precisely identifying the equipment and establishing that it is actually being removed—as opposed to delivered—such a conclusion testifies only to the amateurism of this kind of analysis.

A large area up to one kilometer northeast of the site was also bulldozed and flattened, and new roads were laid out, apparently in anticipation of an expansion of a nearby explosives plant. This, too, has been characterized by some as part of a sanitization effort. But that interpretation fails to account for why there has been no clean-up effort whatsoever just six meters west of the suspect building. That’s where a steep, rocky bluff unsuitable for any construction juts up from the surface, making it a perfect site for sampling for uranium.

Of course, if the wind always blows from west to east at Parchin, then perhaps the Iranians believed that it was unnecessary to sanitize the bluff because any contamination that may have been produced by the alleged experiments over the years would only have been blown east. But that is not typical of fallout patterns. In fact, we know that sometimes the wind at Parchin blows east to west because, on the night of October 5, 2014, an explosion at another factory about four kilometers away sent burning debris almost entirely to the west.

In other words, the bull-dozing and clean-up story is highly questionable.

Nevertheless, according to the critics, in the mid- to late-1990’s, Iran’s nuclear planners:

  • had foreseen the need to defend their illicit operations from the kind of sophisticated environmental sampling that they did not yet know existed;
  • finished the design and actual construction—both in the space of just one year—of a massive, very expensive, entirely unnecessary, and arguably counter-productive chamber to contain nuclear weapons development tests that would concentrate any contamination at one site, such that, if there were ever any inspections, all of the inculpatory evidence could be conveniently found in the one place allegedly designed by Danilenko;
  • were ignorant about the fact that a chamber filled with soot and debris would produce fine particles that would almost certainly contaminate the building in which the chamber was housed and would also likely be tracked outside into the open environment, including any disposal sites, as well as the unsanitized bluff just six meters to the west;
  • chose to place the chamber in a building located in plain sight of the surrounding hills, next to a well-travelled highway, and within arm’s length of a security fence protecting a purportedly contaminated experimental compound—making it easy pickings for any clandestine approach by hostile intelligence personnel or local workmen in their hire—when they had 50 square kms of better-secured land of hills and valleys available to hide it within the Parchin complex.

Is this credible?

Robert Kelley

Robert Kelley is a licensed professional nuclear and mechanical engineer in California. He spent his career in nuclear weapons development activities such as plutonium metallurgy, survivability of U.S. nuclear warheads in ABM intercepts and isotope separation by gas centrifuge and lasers. He later used these hands-on skills to lead intelligence analysis of foreign nuclear weapons systems for the U.S. government and then as a director at the International Atomic Energy Agency, particularly in weapons related non-proliferation analysis in Iraq, South Africa and Libya. Along the way, he has been a research reactor supervisor, a plutonium facility manager and director of the DOE Remote Sensing Laboratory at Nellis Air Force Base. He currently writes on non-proliferation for a number of publications and is an associate research fellow at the Stockholm International Peace Research Institute.



  1. Kudos to Bob Kelley for his factual exposition on Parchin and PMD. The IAEA Chief Yukiya Amano recently told CNN “Iran is not fully cooperating with the Agency to clarify the information that may have military aspects” and Kelley’s work certainly clarifies the information beyond any reasonable doubt..

    We ought to keep in mind that the IAEA is not a UN agency as widely reported and it is not a “UN watchdog” as also reported. It’s only regulatory function under the NPT is “for the exclusive purpose of verification of the fulfillment of its obligations assumed under this Treaty with a view to preventing diversion of nuclear energy from peaceful uses to nuclear weapons or other nuclear explosive devices.”

    The IAEA has no organic organization concerned with nuclear weapons and has nobody on its staff qualified in this area. It is not a function of the IAEA, except in its role of implementing US policy on Iran, which has been and is oriented toward regime change. The “Iran nuclear crisis” is entirely fabricated and Kelley’s work is proof of that.

  2. It is a well recorded phenomenon, that when a sailor misreads his charts and ends up in the wrong harbor, he will tend to take note of the evidence that supports his expectations and ignore buoys, lights and geographical features that he does not expect to see.
    Sounds like exactly the same sort of thing is happening here. If you are sufficiently paranoid, you will find conspiracy everywhere.

  3. Reading this article brings to mind that I’ve read it before, though I can’t recall where. Perhaps it was attached to the “famous Yellow Cake hoax” bush used, or perhaps another of the many Israel has used too. Needless to say, the so-called critics will continue, even if Iran ceased to exist.

  4. Very interesting and informative article.Sadly though, no matter how much “credible” evidence is provided by qualified people so support the fact that Iran could not be developing & testing nuke weapons at Parchin, those with hidden agenda’s will still defy and ignore the facts and insist on painting a different picture by falsifying information and misleading the politicians & public opinion with allegations without any evidence to prove them. I wish some our so called :Representatives” in the government would read this work/assessment by Bob Kelly. Good work Bob.

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