In June 2003, the IAEA's Director General (DG) Mohamed ElBaradei first reported to the Board of Directors (the representatives of member countries) that Kalaye was connected to Iran's nuclear program, having housed centrifuges used to "enrich" uranium to the point that it would be useful for bombs. (The preferred level of enrichment for bombs is about 90%. Uranium at lower levels of enrichment could still be used, but would be much bulkier and less easily moved or mated to a missile or bomb.)

At Kalaye, ElBaradei wrote, Iran's policy of voluntary transparency suddenly turned opaque.

8. During the discussions in Iran in February between DDG-SG [Deputy Director General for Safeguards Pierre Goldschmidt] and the Iranian authorities, reference was made by the Agency to information in open sources on the possible conduct of enrichment activities at the workshop of the Kalaye Electric Company in Tehran. The Iranian authorities acknowledged that the workshop had been used for the production of centrifuge components, but stated that there had been no operations in connection with its centrifuge enrichment development programme involving the use of nuclear material, either at the Kalaye Electric Company or at any other location in Iran. According to the Iranian authorities, all testing had been carried out using simulation studies. While a centrifuge component production facility is not a nuclear facility required to be declared to the Agency under Iran's NPT Safeguards Agreement, Iran was requested, in light of its stated policy of transparency, to permit the Agency to visit the workshop and to take environmental samples there to assist the Agency in verifying Iran's declaration and confirming the absence of undeclared nuclear material and activities. The request was initially declined. The Iranian authorities told the Agency that Iran considered such visits, and the requested environmental sampling, as being obligatory only when an Additional Protocol was in force. [Underlining added for emphasis]

However, they subsequently agreed to permit access to the workshop (to limited parts of the location in March, and to the entire workshop in May), and have recently indicated that they would consider permitting the taking of environmental samples during the visit of the Agency's enrichment experts to Iran scheduled to take place between 7 and 11 June 2003...

43. In March 2003, during an Agency visit to the workshop at the Kalaye Electric Company, the Iranian authorities refused Agency access to one of the workshop buildings, claiming that the building was used for storage and that no keys to the building were available.

11. During a meeting between the Vice President and the Director General on 5 May 2003, the Director General reiterated the Agency's earlier request for permission to send Agency inspectors to the workshop of the Kalaye Electric Company in Tehran, and to take environmental samples. The Director General also referred to an earlier proposal the Agency had made in April for a group of Agency experts to visit Iran to discuss the centrifuge research and development programme to seek to assess how the current status of the project could have been achieved without using any nuclear material during tests. Iran agreed to consider the proposal for an expert mission, and subsequently agreed that the mission could take place from 7 to 11 June 2003.

Enrichment under cover of secrecy would be highly suspicious, and difficult to explain as anything but a step towards acquiring a nuclear weapon. But neither the DG's reports, which called Kalaye "suitable for pilot scale" efforts, nor news accounts, which described a secret space hidden behind a wall of boxes, indicated that Kalaye was nearly big enough to be the center of a full-scale enrichment effort.

Still, the awkward and unexplained delays suggested the presence of some level of secret enrichment activities. They also suggest either an internal debate about how much to admit to the IAEA, or an attempt to play for time while the facility was "sanitized," or both.

In September, the DG delivered a follow-up report touching on several problem areas. Among other difficulties, the Iranians had continued to delay environmental sampling at Kalaye until August.

7. During the follow-up technical discussions, which were held from 10 to 13 July 2003 in Iran, the Agency... reiterated the Agency's request that, in fulfilment of Iran's stated commitment to full transparency, Iran permit the Agency to take environmental samples at the workshop of the Kalaye Electric Company in Tehran... The Iranian authorities indicated that they were not yet... willing at this stage to permit the Agency to take environmental samples at the workshop of the Kalaye Electric Company... The Iranian authorities indicated that they would like to propose a comprehensive solution to all of the enrichment related issues, but that it would take some time on their side. During the discussions, the specific issues that needed to be resolved were identified, and the Iranian side agreed to propose at an early date a timetable for resolving those issues...

9. On 23 July 2003, the Agency received from the AEOI [Atomic Energy Organization of Iran] Vice President of Nuclear Safety and Safeguards a letter proposing a timetable for actions to be taken by 15 August 2003 in relation to urgent outstanding issues. In its reply of 25 July 2003, the Agency agreed to send to Iran a team of technical experts, with the understanding that the team would... take environmental samples at the workshop of the Kalaye Electric Company... This mission took place from 9 through 12 August 2003. [emphasis added]

44. During their 9-12 August 2003 visit to Iran, Agency inspectors were permitted to take environmental samples at the Kalaye Electric Company workshop, with a view to assessing the role of that company in Iran's enrichment research and development programme. During that visit, the inspectors noted that there had been considerable modification of the premises since their visits in March and May 2003, which the Iranian authorities attributed to the transformation of the workshop from use as a storage facility to its use as a laboratory for non-destructive analysis. As reflected in the Director General's previous report to the Board, this could impact on the accuracy of the environmental sampling and the Agency's ability to verify Iran's declarations about the types of activities previously carried out there. [emphasis added]

The third IAEA report, issued in late November, provided more details on what was found at both Kalaye and the "pilot fuel enrichment plant" (PFEP) in Natanz, where, oddly, two different types of highly enriched uranium (HEU) traces were discovered, in addition to the low enriched uranium (LEU) traces that might have resulted from small-scale centrifuge testing. But even these traces suggested the presence of a uranium supply that Iran had failed to acknowledge.

(At Natanz, the inspectors also found "other particles, not of a type on Iran's inventory." Don't ask me to explain this part, at least not yet.)

9. On 16 September 2003, the Agency met representatives of Iran to discuss the results of the analysis of the environmental samples taken at the Kalaye Electric Company in August 2003, which had revealed the presence of high enriched uranium (HEU) particles and low enriched uranium (LEU) particles which were not consistent with the nuclear material in the declared inventory of Iran. Also discussed were the results of the environmental sampling taken at PFEP, which had revealed the presence of other types of HEU particles, as well as LEU and other particles, not of a type on Iran's inventory. [emphasis added]

12. Between 13 and 22 October 2003, an Agency inspection team conducted safeguards inspections at PFEP and other facilities in Esfahan and Tehran. These inspections included follow-up activities related to the HEU and LEU particles found at the Kalaye Electric Company and at Natanz...

13. On 16 October 2003, at the invitation of the Iranian Government, the Director General met in Tehran with H.E. Dr. H. Rohani, Secretary of the Supreme National Security Council of Iran, to discuss the open issues requiring urgent resolution. These issues related to the use of nuclear material in the testing of centrifuges (including the presence of LEU and HEU particles at the Kalaye Electric Company and at Natanz)... At this meeting, Dr. Rohani stated that a decision had been taken to provide the Agency, in the course of the following week, with a full disclosure of Iran's past and present nuclear activities. He also expressed Iran's readiness to conclude an Additional Protocol and, pending its entry into force, to act in accordance with the Protocol and with a policy of full transparency.

15. As a follow-up to the 16 October 2003 meeting, in a letter to the Director General dated 21 October 2003 and received on 23 October 2003, H.E. Mr. R. Aghazadeh, Vice President of the Islamic Republic of Iran and President of the AEOI, reaffirmed that "the Islamic Republic of Iran ha(d) decided to provide a full picture of its nuclear activities, with a view to removing any ambiguities and doubts about the exclusively peaceful character of these activities and commencing a new phase of confidence and co-operation in this field at the international level." Mr. Aghazadeh stated further in his letter that Iran was prepared "to provide, in full transparency, any additional clarifications that the Agency may deem necessary."

16. In that letter, Iran acknowledged that: between 1998 and 2002 it had carried out some testing of centrifuges at the Kalaye Electric Company using [uranium] imported in 1991... [emphasis added]

The HEU especially was probably setting off all sorts of alarms at the IAEA, which continued to press the matter.

17. Between 27 October and 1 November 2003, a technical team from the Agency, led by DIR-SGOB [Olli Heinonen, Director of Safeguards Operations Division B] and including centrifuge technology experts, visited Iran to follow up on these and other issues, including, in particular, the source of HEU and LEU contamination...

32. In its letter of 21 October 2003, Iran acknowledged that "a limited number of tests, using small amounts of [uranium], (had been) conducted in 1999 and 2002" at the Kalaye Electric Company. In a meeting with enrichment technology experts held during the 27 October-1 November 2003 visit, Iranian authorities explained that the experiments that had been carried out at the Kalaye Electric Company had involved the 1.9 kg of imported [uranium], the absence of which the State authorities had earlier attempted to conceal by attributing the loss to evaporation due to leaking valves on the cylinders containing the gas...

34. As mentioned above, environmental samples taken by the Agency at... the Kalaye Electric Company revealed particles of HEU and LEU indicating the possible presence in Iran of nuclear material that had not been declared to the Agency. The Iranian authorities attributed the presence of these particles to contamination originating from centrifuge components which had been imported by Iran. In connection with its efforts to verify that information, the Agency requested, and Iran provided in October 2003, a list of imported and domestically produced centrifuge components, material and equipment, and an indication of the batches of items that Iran claims to have been the source of the contamination. The Agency carried out another sample-taking campaign in October 2003, at which time all major imported and domestically produced components, as well as various pieces of manufacturing equipment, were sampled.

35. In a meeting on 1 November 2003, the Iranian authorities stated that all nuclear material in Iran had been declared to the Agency, that Iran had not enriched uranium beyond 1.2% U-235 using centrifuges and that, therefore, the contamination could not have arisen as a result of indigenous activities. The Agency has now obtained information about the origin of the centrifuge components and equipment which Iran claims to be the source of HEU contamination. The Agency will continue its investigation of the source of HEU and LEU contamination, including through follow up with other relevant parties. [emphasis added]

41. Agency inspectors were told in early October 2003 that all of the centrifuges from the Kalaye Electric Company had been scrapped, and therefore were not available for inspection, whereas it became clear later that the centrifuges had in fact been stored at another location in Tehran and were finally shown to the inspectors at Natanz on 30-31 October 2003, at which time Agency experts examined the centrifuges and associated equipment, and took environmental samples. All major imported and domestically produced components, as well as various pieces of manufacturing equipment have now been sampled. The results of the sample analyses are not expected to be available before December 2003. The nuclear material held in this equipment will be verified during the forthcoming inspections. The Agency has now also obtained information about the source of the components that Iran claims to have been contaminated. [emphasis added]

51. No new information was provided by Iran with respect to the issue of testing of centrifuges using nuclear material until October 2003. In its letter of 21 October 2003, Iran acknowledged that, in order to ensure the performance of centrifuge machines, a limited number of tests using small amounts of [uranium] imported in 1991 had been carried out at the Kalaye Electric Company. According to Iran, the first test of the centrifuges was conducted in 1998 using an inert gas (xenon). Series of tests using [uranium] were performed between 1999 and 2002. In the course of the last series of tests, an enrichment level of 1.2% U-235 was achieved...

53... In the course of these investigations and interviews of individuals involved in the nuclear programme, the Agency has obtained information on the origin of the centrifuge components and equipment which Iran claims to be the source of HEU, LEU and other particle contamination at the Kalaye Electric Company and at PFEP. The Agency will continue to investigate this matter.

35. As described [previously], environmental samples taken by the Agency at Natanz and at the Kalaye Electric Company workshop have revealed particles of natural uranium, LEU and high enriched uranium (HEU) that called into question the completeness of Iran's declarations about its centrifuge enrichment activities.

36. As part of its efforts to resolve the issue of contamination, the Agency has continued to take environmental samples of the imported and domestically manufactured centrifuge components and equipment located at Natanz. The Agency has also recently requested another State to provide access for environmental sampling at locations from which the imported centrifuges are believed to have originated. Taking environmental samples at such locations is indispensable for the Agency to arrive at conclusions regarding the issue of contamination...

But the kicker was the presence of a very particular grade of HEU found almost exclusively at "one room in the Kalaye Electric Company workshop."

39. On the basis of environmental sample analysis thus far, there remain a number of discrepancies and unanswered questions:

• Analysis of samples taken from domestically manufactured centrifuge components show predominantly LEU contamination, while analysis of samples from imported components show both LEU and HEU contamination. It is not clear why the components would have different types of contamination if, as Iran states, the presence of uranium on domestically manufactured components is due solely to contamination originating from imported components.
  
• The types of uranium contamination found at the Kalaye Electric Company workshop differ from those at Natanz, even though Iran states that the source of contamination in both cases is the imported centrifuge components.
  
• Environmental samples showing uranium enriched to 36% U-235 have come almost entirely from one room in the Kalaye Electric Company workshop, which seems to be predominantly contaminated with that material. Only negligible traces of 36% enriched uranium have been found on imported centrifuge components. The level of contamination suggests the presence of more than just trace quantities of such material. [emphasis added]

The footnote coyly alludes to a Soviet "swimming pool" reactor design present in Russia and several former Soviet Republics and Eastern European states, as well as Vietnam and North Korea. The HEU used in these reactors has been produced in Russia (and in the case of Bulgaria, recently returned there).

An article by William Broad in Saturday's New York Times spells out the significance of finding this very specialized sort of uranium at Kalaye.

Inspectors have found evidence that some of the highly enriched uranium found on nuclear machinery in Iran came from Russia, European diplomats and American experts said Friday. The nuclear fuel appears to have come through the global black market, the experts added, and not with the blessings of Moscow...

In a report on Tuesday, the International Atomic Energy Agency said that its inspections had found that centrifuge equipment made indigenously in Iran - but not imported gear - showed many traces of the concentrated fuel, leading experts to doubt the Iranian explanation and suggest that Iran had enriched the uranium itself. Its purity was 36 percent U-235 - short of the 90 percent needed for most nuclear bomb designs but greater than that needed for most nuclear reactors.

On Friday, however, European diplomats said the agency's laboratory at Seibersdorf, Austria, had discovered a likely match between the atomic signatures of Russian uranium and samples agency inspectors had gathered from Iranian centrifuges.

In its sleuthing, the lab studies such things as a sample's isotopes - atoms of the same element that have different numbers of neutrons. A distinctive mix of such isotopes can amount to a fingerprint that experts check against atomic databanks.

As an expert quoted in the New York Times story explains, there is a long distance between trying to enrich uranium to weapons-grade levels from "natural" feed and starting from a base of 36%:

Michael A. Levi, a science fellow at The Brookings Institution in Washington who has studied the recent I.A.E.A. report, said yesterday that he had independently deduced that the Iranian uranium originated in Russia. The strong clue, he said, was its 36 percent enrichment, a level that matches a kind of fuel used in certain Russian submarines and research reactors. Globally, he added, he knew of no other nuclear technology that used 36 percent enrichment.

"There's no reason for Iran to enrich to 36 percent," he said. 'The only place that does that is Russia."

He added that it was highly unlikely that the Russian government sold Iran the uranium because its scientists could have easily concealed the telltale signature.

Rather, he argued, thieves probably stole the material either from Russia proper or elsewhere in the former Soviet Union and sold it on the black market...

Poor security over such materials has been the rule rather than the exception since the collapse of the Soviet Union, Mr. Levi said. For instance, in 1993, two Russian naval servicemen stole nearly four pounds of 36 percent enriched uranium from a naval base at Andreyeva Guba, Russia. They were caught and the material recovered.

Mr. Levi said Iran might have wanted a supply of 36 percent uranium because it could ease the production of bomb-grade uranium, making the process much faster and easier.

He estimated, for instance, that enriching one bomb's worth of material would take one year of running 66 pounds of 36 percent enriched uranium through just 25 centrifuges. A set of such centrifuges, known as a cascade, incrementally concentrates the U-235 isotope.

In contrast, if Iran started with natural, unenriched uranium, Mr. Levi said, the same production run would require 13,200 pounds of raw material running through 750 centrifuges. Such a cascade, he noted, "would be far harder to hide than the 15 centrifuge arrangement."

In a May 2002 report sponsored by the Federation of American Scientists, Robert L. Civiak wrote:

Russia and other nations of the Former Soviet Union (FSU) present a serious risk that a nuclear weapon or nuclear material could be diverted for malevolent purposes. The economic and political collapse of the Soviet Union created a formidable challenge to keeping its nuclear weapons and materials under adequate control. Individuals and groups have attempted to steal uranium or plutonium from sites in the FSU dozens of times during the past ten years, and in several incidents, a kilogram or more of weapons-usable material has been stolen or lost. In January 2001, a bipartisan task force chaired by former Senate majority leader, Howard Baker, and former White House counsel, Lloyd Cutler concluded:

The most urgent unmet national security threat to the United States today is the danger that weapons of mass destruction or weapons-usable material in Russia could be stolen, sold to terrorists or hostile nation states, and used against American troops abroad or citizens at home.

There have been no confirmed reports of successful thefts of a complete nuclear weapon or sufficient nuclear material to make one. However, given the inadequate Soviet-era record keeping for nuclear material stocks, there is no way to know for sure that significant diversions have not already occurred. If they have not, without prompt action, it may only be a matter of time before they do.

To discover the truth, several questions must be answered. When did activities actually commence at Kalaye? When did they end? How many centrifuges were involved, and were more than one type involved? How much uranium entered the cascade? And where is the uranium now?

Until these questions are answered, no one should sleep too easily.

Analyst

The IAEA's Iran page, with links to the first three reports referenced above, is here. The fourth report is here. My previous assessments of Iran's nuclear program are here and here. Earlier, Ami Isseroff asked whether Iran really needs nuclear power.

My comments on Libya's nuclear program, including its multiple sources of uranium, are here and here.