Iranian Detonators: Big News?

Nov 10, 2011

By Eli Jacobs

A recent Washington Post article identifies Iranian possession of design information for an R265 generator as not yet “publically described.” Such a device allows for simultaneous detonation to compress a plutonium or enriched uranium core, producing a chain reaction. According to the article, Vyacheslav Danilenko, a former Soviet nuclear scientist, provided Iran with this information. Crucially, their continued work in this field suggests that their nuclear weapons program “never really stopped.”

The recent IAEA report about Iran does describe the Iranian development of such a device, with the assistance of a “foreign expert.” Although it calls the device an “exploding bridgewire detonator,” or EBW (and not an “R265 generator”), it’s clear from the description of function that Albright and the IAEA are describing the same device.

This claim has been the subject of much contention since the publication of the Post’s article. One critic, Robert Dreyfuss, pointed out that the detonator information was exchanged in the 1990s and does not speak to Iran’s current capabilities or intentions. A piece in The Hindu reports that the IAEA fabricated Danilenko’s knowledge of nuclear physics and his work remained limited to its ostensibly civilian purpose: the production of nanodiamonds as part of their substantial nanotechnology industry.

To the extent that these claims are criticisms of the IAEA’s conclusions, they are unpersuasive. Such arguments resemble Iran’s dismissal of the report as “politicized". A more interesting question, and one raised by these critiques, is whether the information about detonators in the recent report, despite not being previously “publically described,” adds anything fundamentally new to the case that Iran is pursuing nuclear weapons. After reviewing this and previous IAEA reports, I think the answer is no, it did not introduce much that is truly new, with a couple of exceptions of ambiguous importance.

The issue of Iran’s work on detonators is decisively not revolutionary. The IAEA report on Iran released this May, for example, contains the following “areas of concern”:

Exploding bridgewire (EBW) detonator studies, particularly involving applications necessitating high simultaneity: possible nuclear significance of the use of EBW detonators.

Multipoint explosive initiation and hemispherical detonation studies involving highly instrumented experiments: integrating EBW detonators in the development of a system to initiate hemispherical high explosive charges and conducting full scale experiments, work which may have benefitted from the assistance of foreign expertise.

Similar suspicion exists as far back as the February 2008 report:

[The] Agency made available documents for examination by Iran and provided additional technical information related to: the testing of high voltage detonator firing equipment; the development of an exploding bridgewire detonator (EBW); the simultaneous firing of multiple EBW detonators…

Although the recent report describes Iran’s work on detonators in far more detail than previous reports, that it has done such work should, at this point, be unsurprising. Of course, that fact does not make this revelation inconsequential; a major barrier to Iran credibly fielding nuclear weapons is their ability to make a warhead small enough to be mounted on their missiles – a problem that effective detonators would help resolve. But, as far as considering the current report goes, the devil’s in the details: three clarifications in the new report introduce potentially significant new wrinkles to the situation.

The first of these wrinkles is the most recent report’s contention that Iran used the detonator’s specifications in developing the Shahab-3’s re-entry vehicle. It says:

It should be noted that the dimensions of the initiation system and the explosives used with it were consistent with the dimensions for the new payload which, according to the alleged studies documentation, were given to the engineers who were studying how to integrate the new payload into the chamber of the Shahab 3 missile re-entry vehicle (Project 111).

This seems like big news, until one looks a little closer. It is relatively uncontroversial that Iran maintained a nuclear weapons program until 2003; Project 111 refers to work done as part of this program that the report clarifies to have consisted of “a structured and comprehensive programme of engineering studies to examine how to integrate a new spherical payload into the existing payload chamber which would be mounted in the re-entry vehicle of the Shahab 3 missile.” It is unclear that Iran has resumed work on re-entry vehicles since 2003. Thus, prior investigations may not characterize Iran’s nuclear present.

This new detail does establish, however, that Iran views detonators at least in part through the lens of nuclear weapons delivery, which leads to the second wrinkle in the new IAEA report: the conclusion that these detonators are likely part of a weapons rather than civilian program.

Notwithstanding, given their possible application in a nuclear explosive device, and the fact that there are limited civilian and conventional military applications for such technology, Iran’s development of such detonators and equipment is a matter of concern, particularly in connection with the possible use of the multipoint initiation system referred to below.

The report takes a similar approach in two other areas of weapons development, arguing that Iran needs to explain itself in light of the importance of hydrodynamic experiments and a neutron initiator for nuclear weapons. However, in these two cases the IAEA implicitly leaves open the possibility that this work was done for some as yet unknown civilian purpose. The decision to go a step further in assessing detonators suggests a higher degree of confidence in the IAEA’s assessment of Iran’s nuclear intent. Although Danilenko’s work may have been purely related to nanodiamonds, it seems highly likely that Iran used his or similar expertise to support their nuclear weapons endeavor.

Of course, the marginal difference between these two levels of confidence seems small enough to affect the ultimate conclusions of only the most dedicated Iran apologists. Further, much like the IAEA’s assessment of Iran’s attempts to fit the detonator on the Shahab-3, it matters much less without the new report’s third wrinkle: that Iran has continued work on these detonators post-2003.

Furthermore, the Agency has received information from two Member States that, after 2003, Iran engaged in experimental research involving a scaled down version of the hemispherical initiation system and high explosive charge referred to in paragraph 43 above, albeit in connection with non-nuclear applications.

This probably means that Iran has continued work on nanodiamonds. It does not mean that nanodiamonds were always the sole focus of its work on detonators. The IAEA distinguishes between the EBWs themselves and Iranian work on simultaneous initiation – perhaps on the basis of the higher voltage of the EBWs – and concludes that the EBWs have few plausible civilian applications.

It is hard to say what these conclusions add up to. It’s fairly easy to conclude that, prior to 2003, Iran was interested in building nuclear weapons and, after 2003, Iran remained (or became) interested in constructing nanodiamonds. It’s also clear that Iran realized the connections between these two realms of inquiry. The applicability of their scaled-down work on hemispherical initiation to an EBW for nuclear use is unclear to me; it would be more obvious to a specialist.

However, the relevant point here remains Iranian intentions. Should we understand their history as pointing to a continued desire to build nukes? Or a desire to create a nuclear hedge similar to Japan’s? Or are they simply working on nanotechnology, nuclear weapons aspirations safely behind them?

The rest of the report suggests that they’re pursuing a hedge at the very least. But the new facts presented regarding nuclear detonators are not decisive in reaching this conclusion. The Washington Post article is commendable for focusing on components of nuclear weapons development beyond uranium enrichment, but it drastically overstates the importance of new revelations emerging from evidence related to nuclear detonators in constructing a case for a nuclear weapons-seeking Iran.

Eli Jacobs is a research intern for the Project on Nuclear Issues. The views expressed above are his own and do not necessarily reflect those of the Center for Strategic and International Studies or the Project on Nuclear Issues.