Iran will resolve UN questions about suspicious aspects of its nuclear programme in phases by year-end but this will not be enough for a declaration that its activity is wholly peaceful, diplomats said on Friday.
They disclosed broad aspects of a plan Iran agreed this week with the International Atomic Energy Agency meant to clear up IAEA inquiries into indications of illicit military involvement in Iran's declared drive for peaceful nuclear energy.
Another goal is to cement regular and effective access for IAEA inspectors to Iran's underground uranium enrichment plant where it plans industrial-scale production of nuclear fuel.
Spurred by suspicions Iran is covertly trying to master the means to make atom bombs, the UN Security Council has slapped limited sanctions on Tehran over its refusal to stop enrichment. Washington is seeking wider sanctions but these may depend on how Iran's new transparency commitment to the IAEA pans out.
Diplomats said ahead of the plan's circulation to the IAEA's 35-nation board next week that it required Iran to answer questions in sequences - "easier" ones first graduating to more difficult ones, with the process finished by December.One diplomat said the IAEA had sought swifter, broader action by Iran to avoid fraying the patience of sceptical Western powers and raise pressure for more sanctions. "But Iran was adamant on sequencing, settling issues one by one.
Western diplomats assessing the transparency plan said Iran might only be trying to keep the Security Council at bay while it kept enriching uranium to perfect the fuel-production cycle.
The first batch of issues included Iran's experiments with plutonium, the commonest fissile element in nuclear warheads; re-establishing inspector access to the Arak heavy-water reactor under construction; and a legally binding accord governing inspections at the expanding Natanz enrichment complex.
The second phase in the process would lift the veil on Iran's efforts to build P-2 centrifuges, able to refine uranium 2 to 3 times as fast as the antiquated P-1 model now being used. Iran obtained centrifuge parts from the former nuclear black market network of Pakistan's A.Q. Khan, diplomats say.
Diplomats said the third phase would address the kernel of suspicions about a shadowy military character to the programme. These issues include the surfacing of a document describing how to machine uranium metal into "hemisphere" shapes suitable for the core of bombs, and particles of weapons-quality uranium on equipment sampled by inspectors.