There actually had never been an Iranian agreement to the fuel swap deal envisioned by the West

There is developing a commonly-held narrative that Iran agreed in principle to export most of its LEU, and then retracted that agreement. If Iran had said it agrees in principle, then that still would not have been a commitment to accept the offer presented by the West without modification. But if the Americans say that Iran said it agrees in principle, that introduces another element of doubt about the story.

Steven Erlanger and Mark Landler of the New York Times reported on October 1, 2009:

Iran agreed on Thursday in talks with the United States and other major powers to open its newly revealed uranium enrichment plant near Qum to international inspection in the next two weeks and to send most of its openly declared enriched uranium outside Iran to be turned into fuel for a small reactor that produces medical isotopes, senior American and other Western officials said.

Iran’s agreement in principle to export most of its enriched uranium for processing — if it happens — would represent a major accomplishment for the West, reducing Iran’s ability to make a nuclear weapon quickly and buying more time for negotiations to bear fruit.

Tony Karon, reporting for Time Magazine on October 2, also uses the term "agreement in principle", but indicates that details are to be negotiated later in the month

The even more significant news from Geneva was Iran's agreement, in principle, to a proposal under which it would ship most of its current stockpile of low-enriched uranium to Russia for further enrichment, and then to France to be turned into fuel rods to power a Tehran reactor used for medical research. The details are to be negotiated under IAEA auspices in Vienna on October 18, but if the scheme is implemented, it would be a major confidence-building measure: Iran's current stockpile of low-enriched uranium (LEU) has been cited as Exhibit A in dire warnings that it is drawing perilously close to bomb-making capability, on the grounds that if further enriched, that stockpile could already provide enough materiel for a single bomb. But the deal hammered out at Geneva would turn three quarters of it from its current gas form into solid fuel rods, which are extremely difficult to turn into weapons-grade material.

So we do not have word of an agreement from any Iranian source, but rather from Western sources. The first sources to report this "agreement in principle" clearly indicate that details were yet to be finalized.

While Western diplomats and journalists were claiming that Iran agreed in principle to exporting most of its uranium, Iranian officials by October 3 flatly and directly denied that claim.

Iran's Supreme National Security Council said the assumption that such an agreement had been reached with the P5+1 group consisting of the five permanent members of the UN Security Council - Russia, China, USA, France and the UK- plus Germany during the Geneva talks was untrue.

The Council's Media Secretary Peyman Jebelli made the announcement in an exclusive interview with Press TV today.

Jebelli's comments came after a number of media outlets reported that Iran had agreed to ship LEU of under 5 percent to Russia where it would be additionally enriched to about 20 percent, before being further processed in France and finally being returned to Iran.

...

Iranian officials say, however, that the offer to "purchase" 20 percent enriched uranium is what would be discussed during a meeting with the International Atomic Energy Agency (IAEA) scheduled for October 18, stressing that the session would have nothing to do with the Geneva talks.

By the October 19 meeting, David Sanger of the New York Times reports that Iran was publicly expressing reservations about the deal.

Iran opened two days of nuclear talks with the United States, Russia and France on Monday with veiled public threats that it could back away from an agreement to ship more than three-quarters of its stockpile of nuclear fuel out of the country, unless the West acceded to Iranian demands to provide it with new fuel.

At the end of a nearly four-hour session, the director general of the International Atomic Energy Agency, Mohamed ElBaradei, said little about the negotiations other than “We’re off to a good start.”

Other participants in the talks, which filled an oversize conference room at the agency’s headquarters, said that although Iran’s representatives did not reject outright the idea of sending the country’s fuel to Russia and France for further enrichment, its negotiators stopped well short of reaffirming the statements the country made in talks on Oct. 1.

Rather than an agreement to the terms put forth by El Baradei that Iran would later renege, reports of from the time indicate an agreement to the broad principle, pending details that must be determined later to Iran's satisfaction. There are no reports of any Iranian official agreeing to any deal.

It has to be mentioned that the attack on Irans' Revolutionary Guards on October 18 which killed many Iranian officers, including high-ranking ones on Iranian territory would have broken any cooperative mood that could have been developing toward the West in Iran. If this attack was aimed at creating an atmosphere that would preclude an Iranian agreement with the United States, it was successful.

By the end of the late-October meeting in Vienna, according to the BBC, El Baradei produced a plan that the West was happy about, and that Iran did not comment on - saying it would respond later:

Details are yet to be confirmed, but the plan is believed to involve Iran exporting uranium to be enriched in France and Russia.

Iran's chief negotiator has not commented on the uranium export plan.

...

[IAEA director Mohamed ElBaradei told reporters] "I have circulated a draft agreement that in my judgment reflects a balanced approach to how to move forward."

So where is this Iranian agreement, even "in principle" that the Iranians supposedly rescinded? It is the product of bad memory and an impulse to present Iranians in a negative light.