KEY POINTS:
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 visit of 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 on any list of targets for possible US military strikes which would aim to halt 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 targeting public opinion in Europe and the US to demonstrate 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.
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 President Mahmoud Ahmadinejad's government with a promise of unprecedented access to the country's most senior Iranian officials and it's most sensitive nuclear plants.
However at the last minute the Iranians set limits on the transparency, cancelling visits to the critical facility at Natanz and to the controversial Arak plant under construction. The last-minute decision was put down to "technical problems" by the foreign minister, Manouchehr Mottaki. But it illustrated once again the opacity of the power structure in Iran, where the overall decision-making rests in the hands of the spiritual leader, Ayatollah Ali Khamenei, and where the Iranian Revolutionary Guard Corps holds sway in the shadows with its parallel forces.
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 southeast of Esfahan, one of the most beautiful cities in the Islamic world.
Less than half an hour's drive away along a desert road flanked by military hardware, we are seeing 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. Since that breakthrough in 2004, according to the plant's 30-year old general manager, Hamid Mohajerani, 200 tonnes of uranium hexafluoride gas has been produced.
The feed material, stored in white cylinders, is dispatched in full view of the cameras of the International Atomic Energy Agency.
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."
He appeals to us to "write about what you see, not about political matters". But Iran's nuclear programme is inseparable from international politics.
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 Gulf has been under construction under co-operation with Russia for the last 12 years.
The contract is now restricted to construction of a single nuclear reactor, which is supposed to produce 3000MW 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 routinely spend three years training in Russia, say that the reactor is 93 per cent complete and ready to operate "in six months".
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.
On the very 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.
The invitation to western journalists shows that Iran is reaching out to the outside world. But the nation's nuclear ambitions are a game of chicken played for the highest stakes, involving national pride.
It holds the risk of regional conflagration in case of US military strikes 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.
- INDEPENDENT