We are in a makeshift ladies' changing room, putting on protective clothing for a tour of the throbbing heart of Iran's nuclear programme.
It is a welcome respite to replace a hot Islamic shawl with a shower cap. We don surgical gloves, white trousers and tops, face masks and plastic shoe covers for an hour-long trip around the Esfahan conversion plant, whose hissing vacuums and cylinders are working round the clock to produce feed material for Iran's nuclear enrichment plant at Natanz.
The Esfahan facility in central Iran, functioning under complete United Nations scrutiny, is presumed to be a likely target of any US military strike aimed at halting Iran's nuclear programme before its scientists can manufacture enough fuel for a bomb at Natanz.
With a new round of UN sanctions looming to punish Iran for its refusal to halt the Esfahan activities and uranium enrichment at Natanz, the Iranian government has launched a charm offensive designed to ensure public opinion in Europe and the US that its nuclear intentions are purely peaceful.
Western governments continue to insist that Iran must suspend enrichment as a precondition for negotiations, because of the deep mistrust stemming from the country's 18-year concealment of the most sensitive aspects of its nuclear programme.
The Independent and five other journalists from Britain, France, Germany and the US - whose governments will decide whether there can be a peaceful solution to the crisis with Iran - were invited to Iran by the government of President Mahmoud Ahmadinejad, with a promise of unprecedented access to the country's most senior officials and it's most sensitive nuclear plants. However at the last minute the Iranians set limits on the scope of the visit, cancelling trips to the critical facility at Natanz and to the controversial Arak plant under construction. The last-minute decision, put down to "technical problems", illustrated once again the opacity of the power structure in Iran, where overall decisions are made by the spiritual leader, Ayatollah Ali Khamenei, and where the Iranian Revolutionary Guard Corps holds sway in the shadows.
The conversion plant, in the shadow of jagged sandstone mountains into which tunnels have been excavated for security and the safe storage of nuclear material, is located just 15km south-east of Esfahan, one of the most beautiful cities in the Islamic world.
The facility is approached by a half-hour drive along a desert road flanked with military hardware. Here, we can see for ourselves how the Islamic republic came to raise its nuclear programme to such a level of national pride and independence that the atomic symbol is now printed on a banknote.
We are escorted into a hall where a banner proclaims: "Nuclear energy is our obvious right."
A short propaganda film, accompanied by stirring music, shows the triumph of Iranian scientists as they celebrated the production of the first vial of uranium hexafluoride from yellowcake in 2004. Since that breakthrough - according to Hamid Mohajerani, the plant's 30-year old general manager - some 200 tons of uranium hexafluoride gas have been produced. The feed material, stored in white cylinders, is dispatched, in full view of the cameras of the International Atomic Energy Agency, for enrichment to Natanz where the IAEA has confirmed Iran's claim to have mastered the technology to enrich the uranium hexafluoride to the 3.5 per cent level required for civil purposes.
If the uranium was enriched to 93 per cent or more, Iran would have weapons grade fuel. However Western experts say the country is still between five and 10 years away from producing a bomb.
The West's need for objective guarantees of Iran's peaceful intentions has been further reinforced with the election of President Mahmoud Ahmadinejad.
A fierce critic of the West, he has raised tensions with Israel through his repeated references to the disappearance of the Jewish state. He is also a firm believer in the prophesied return of the Shia "hidden imam". According to some scholars, a nuclear holocaust may be needed to hasten the promised reappearance of the 12th imam who disappeared into a cave in 878.
But the Esfahan conversion plant's public relations general manager, Hossein Simorg, stresses: "All our activities are completely peaceful, and all activities are applied for peaceful, industrial and agricultural work."
We are led through chambers where chemical processes purify the yellowcake and convert it into a variety of compounds that can be used for enrichment or fuel production. Mr Mohajerani says that the main purpose at present of the plant, which is still being expanded, is to produce hexafluoride gas for enrichment as part of a civilian programme to meet the burgeoning demand for electricity, with Iran's oil exports predicted to dry up in 20 years. Mr Simorg appeals to us to "write about what you see, not about political matters".
But Iran's nuclear programme is inseparable from international politics. Hence the Iranian government's attempts to end UN Security Council involvement in order to clarify outstanding "technical" issues with the IAEA which has been unable to guarantee the programme's "exclusively peaceful nature". America has successfully pressured European, Chinese and Russian governments over the years into restricting nuclear cooperation with Iran.
The next stop on our nuclear tour, at Bushehr in steamy southern Iran, illustrates the Iranian difficulties. The "safe" light-water power plant on the Persian Gulf has been under construction with Russian cooperation for the past 12 years. The contract is now restricted to construction of a single nuclear reactor which is supposed to produce 3,000 megawatts of electricity for the national grid.
To guarantee that no nuclear fuel will be diverted for military purposes, Iran has agreed to receive uranium from Russia and to export the spent fuel back to Russia for reprocessing.
The Bushehr scientists, who were sent for three-year training spells in Russia, say the reactor is 93 per cent complete and will be ready to operate in six months. They remain resolutely optimistic that the first delivery of 80 tons of uranium for the reactor core will soon be on its way.
But after we ram white hard hats over our headscarves to tour the facility in humidity that soon drenches our clothes, it is clear that the huge steel reactor core and adjacent turbine chamber are still a giant construction site.
The Iranian government is convinced that the long delays in completing the plant are the result of political pressure.
The Russians suspended cooperation last March, officially citing payment issues. And on the day of our visit to Bushehr last Wednesday, the Russian government announced that the plant would not begin operating until the second half of next year.
Iran's invitation to Western journalists shows that the government is reaching out to the outside world.
Yet the PR campaign has been accompanied by officially backed attempts to intimidate Iranians from contact with foreigners, amid fears that the Bush administration is trying to generate a "velvet revolution" that would bring down the country's clerical rulers.
When the British embassy held its annual garden party on 14 June to mark the Queen's birthday, Iranian guests were pelted with eggs and tomatoes. And efforts have been made to discourage contact between Iranians and froeigners following demonstrations over the award of a knighthood to the author Salman Rushdie, who in 1989 was the target of a death threat in a religious fatwa for his book the Satanic Verses.
With a Bush administration weakened by the war in Iraq, it is difficult to predict where the nuclear stand-off is heading.
President Bush does not want to hand over an unresolved nuclear crisis with Iran to his successor and continues to declare that all options, including military, remain on the table.
This is a game of chicken played for the highest stakes, involving national pride. It holds the risk of regional conflagration and a potential nuclear arms race in the Middle East if Iran continues on its present course. But seen from here, the Iranians will not be the ones to blink first.Reuse content