How many centrifuges did IAEA think were installed and/or in operation? Good question. In October 2003, Iran finalized the installation of the first 164-centrifuge cascade at the PFEP – presumably what Rouhani refers to as Iran having “150 centrifuges” when he took over the nuclear-negotiating job.
IAEA was able to verify the installation of a second 164-centrifuge cascade at the PFEP by October 2006 – an event indicating a much, much lower centrifuge total than 1,700 or 3,000.
In its February 2006 report, linked above, IAEA regretted the lack of transparency in the Iranian nuclear program, which made it difficult to resolve questions about its nature (emphasis added):
Without full transparency that extends beyond the formal legal requirements of the Safeguards Agreement and Additional Protocol — transparency that could only be achieved through Iran’s active cooperation — the Agency’s ability to reconstruct the history of Iran’s past programme and to verify the correctness and completeness of the statements made by Iran, particularly with regard to its centrifuge enrichment programme, will be limited, and questions about the past and current direction of Iran’s nuclear programme will continue to be raised.
IAEA basically had its November 2004 baseline for centrifuges at the PFEP to work with during this period. It did not have a good handle on what was going on in the larger FEP, nor did it have the slightest idea what was going on in the underground facilities at Esfahan, where extensive tunneling activities were revealed in late 2004. IAEA visited an underground chamber at Esfahan in November 2004, but it was empty at the time. IAEA has not visited Esfahan’s underground complex since, nor has it ever been allowed to visit the vast underground network identified at Natanz by 2007.
Tunnels at Esfahan, Feb 2005 (Annotations: Institute for Science and International Security/ISIS)
IAEA’s lack of information continued throughout 2006. Another Safeguards report refers to centrifuge operations on 23 May 2007, 21 months after August 2005. In May 2007, IAEA registered this lament (emphasis added):
Since early 2006, the Agency has not received the type of information that Iran had previously been providing, including pursuant to the Additional Protocol, for example information relevant to the assembly of centrifuges, the manufacture of centrifuge components or associated equipment and research and development of centrifuges or enrichment techniques.
But in this report, at least, IAEA was finally able to give some numbers on the centrifuge cascades in the FEP at Natanz:
On 13 May 2007, eight 164-machine cascades were operating simultaneously and were being fed with UF6; two other similar cascades had been vacuum tested and three more were under construction.
The centrifuge total from this layout would come to 1,312, operational and being fed with UF6. That’s below the total Rouhani cites for a timeframe of 21 months earlier, although it is not fully clear from the translation what status Rouhani assigns to the centrifuges he talks about. Does he mean the 1,700 were installed and operational by August 2005, when he departed his nuclear-negotiating job? Or does he mean their manufacture and delivery were completed? What about the 3,000 by the end of 2005? If his starting number – 150 – means the same thing as his ending numbers, then he is, in fact, referring to operational centrifuges, and not just the number of finished machines on-hand. But we can’t conclude that as an indisputable interpretation.
The long march of gaps in knowledge
In any case, IAEA can’t help us with this question, because it just didn’t know. The May 2007 observation concludes a period in which the comprehensive timeline looks like this:
Oct 2003 – 164 centrifuges begin operating at the PFEP
Oct 2004 – Suspicious tunneling begins at Esfahan
Nov 2004 – IAEA’s last baseline inventory of Iranian UF6 and centrifuges/parts
Nov 2004 – Last/only IAEA visit to underground chamber at Esfahan
Aug 2005 – NCRI announces Iran has produced approximately 4,000 centrifuges and plans to install them in secret
Aug 2005 – According to Rouhani, the nuclear program had 1,700 centrifuges
Dec 2005 – According to Rouhani, the nuclear program had 3,000 centrifuges