Last month, David Albright published screen shots of a solicitation by an Iranian company for ring magnets that may suitable for centrifuge bearings – a crucial component of Iran’s centrifuges. The question is whether the magnets, which fall below the thresholds established in the NSG “trigger list” are really suitable for Iran’s IR-1 centrifuges or not.
Ferenc Dalnoki-Veress and I have written an analysis comparing the strength of the magnets sought with an effort by Pakistan to produce P2 centrifuges in Germany in 1991. Our conclusion is that, at least on the issue of magnet strength, the magnets are consistent with a first generation centrifuge like the IR-1.
You can find our reasoning below the jump.
How Many Mega Gauss Oersteds Does It Take to Make Your World Spin?
Ferenc Dalnoki-Veress and Jeffrey Lewis
March 20, 2013
Accusing a foreign individual, entity or government of engaging in illicit commerce relating to the spread of nuclear weapons is a complex issue and must be handled carefully. Ideally, the item in question must match to the known specification of the nuclear-use item. However, buyers often purchase items that don’t precisely match these specifications to circumvent export control regulations. To prevent the sale of these items, the NSG has a “catch-all” provision under which members agree to refrain from exporting even non-controlled goods if there is a reason to believe that it is intended for a nuclear weapons program.
The recent case of an Iranian firm soliciting an order of ring magnets illustrates some of the challenges in controlling dual-use technologies.
Last month, David Albright published a report on the Institute for Science and International Security website suggesting that Iran attempted to purchase 100,000 ring magnets suitable for centrifuge bearings – a crucial component of Iran’s centrifuges (Ring Magnets for IR-1 Centrifuges, February 13, 2013). Albright posted a screenshot (Figure 3) showing a web inquiry on a Chinese website by Mr. Mohammad Tahmouresi , representing an Iranian trading company called Jahan Tech Rooyan Pars Co., regarding 100,000 ferrite barium strontium ring magnets. (In 2012, Canada sanctioned Jahan Tech Rooyan Pars Co. for supporting Iran’s “proliferation sensitive” activities.) Albright also provided a translation of the inquiry, which included some text in Chinese (Figure 4). Albright, working with an unnamed European government and an ISIS centrifuge expert, concluded that the technical specifications of the ring magnets generally matched those for Iran’s first-generation centrifuges, requiring only minor modifications to the bearing. Albright, citing concerns about proliferation-sensitive information, redacted the dimensions and other technical information that would allow outside experts to assess his conclusions.
Upon closer inspection, however, Albright inadvertently left in a key technical detail relating to the strength of the magnet – that Iran was seeking magnets with a strength (in terms of BHmax) is 3 MGOe. BHmax is an important parameter because the magnet must stabilize the rotor as it spins at hundreds of meters per second. The threshold for controlling magnet exports set by the Nuclear Suppliers Group is much higher than this – 10 mGOe – leading some commentators to question Albright’s assessment. It is important to note that the thresholds established by the Nuclear Suppliers Group are reached by negotiation and attempt to balance competing interests in restricting the spread of sensitive technologies and permitting normal commerce. This is especially challenging when dealing with technologies, like the IR-1 centrifuge, that are more than thirty years old. Whether this inquiry is plausibly linked to Iran’s centrifuge program depends in part on the possibility that the IR-1 uses ring magnets that fall below the threshold specified by the NSG. If such magnets are unsuitable for Iran’s centrifuges, then we can dismiss the allegation.
As it turns out, we have relatively detailed information about the ring magnets used in Pakistan’s P2 centrifuge because of a failed 1991 effort by Pakistan to purchase similar ring magnets in Germany. In 1995, Mark Hibbs reported that Pakistan attempted to purchase similar ring magnets from the German firm Magnetfabrik Bonn (MFB) GmbH (see: M. Hibbs, “Siemens Venture Believed Used in Pakistan Centrifuge Quest,” Nuclear Fuel, Aug. 28, 1995). Hibbs did not report the strength of the magnets, but he did state that Pakistan ordered aluminum-nickel-cobalt (Alnico)-260 S-ring magnets. The numerical suffix “260” is a designation specifically corresponding to the German standard for the technical conditions of materials of permanent magnets (DIN 17410) and corresponds to a (BH)max=18 kJ/m3 or 2.4 MGOe. In correspondence with Hibbs, we were able to confirm that the original specification of the 1991 procurement effort was 18 kJ/m3.
Our conclusion is that, at least on the issue of magnet strength, the magnets are consistent with a first generation centrifuge like the IR-1.
Hibbs also provided a detailed description of the dimensions of the ring magnets:
“Pakistan had first indicated that Telephone Industries sought magnets sized at 52 millimeters in diameter and 8 mm in height, with a ring thickness of 36 mm. It later specified a precise diameter of 52.8 mm and a thickness of 36.8 mm and defined fine tolerance requirements in the range of a few hundredths of millimeters.”
The same dimensions are given in an ISIS report by Albight, Brannan and Stricker. “For example, a P2 ring magnet sought by Iran later has dimensions of 52.8 mm x 36.8 mm x 8mm. P1 ring magnets have similar dimensions.”
It is, of course, possible that the magnets were intended for other purposes. However, we have concluded that from the point of view of the magnetic properties they can also be used for ring magnets for older generation IR-1 centrifuges, which the IAEA has reported Iran still uses in their centrifuge facilities. This is an important data point that characterizes the item in question as being appropriate for nuclear-use. Knowing the dimensions of the attempted procurement would shed further light on the issue.
An unanswered question relates to the Canadian sanctions against Jahan Tech Rooyan Pars. Although Canada stated that the sanctions are the result of Jahan Tech Rooyan Pars having provided “support” to proliferation-sensitive activities in Iran, Canada has not made public a specific allegation about what firm might have done to elicit sanctions.. Further information from the Canadian government could help understand the final end-user for any ring magnets purchased by Jahan Tech Rooyan Pars.