Inside Iran's nuclear nerve centre: halfway house to an atomic bomb

In the bowels of Iran's uranium conversion facility in Isfahan strands of black and red wire stretch from the concrete wall to giant white tanks full of a volatile uranium compound. It is by these slender cords that the international community hopes to hold Iran's atomic ambitions in check. The wires pass through a brass seal that has been soldered and marked in such a way that any attempt to divert the fuel to making a bomb would be spotted by UN inspectors. It is a nuclear trigger the world hopes will never be pulled. With global tensions rising over Iran's nuclear intentions, the doors of the Isfahan plant were opened last week to a small group of journalists from Europe and America in a rare bid for transparency by the embattled but determined government in Tehran. Ten miles south-east of the tiled mosques of Isfahan, Persia's old capital, the conversion plant is a cluster of squat yellow-brick buildings at the foot of some weathered sandstone crags, and ringed by anti-aircraft batteries dug into the surrounding semi-desert. Inside the plant, a dense network of shining vats, pipes and gauges perform the alchemy of turning processed uranium ore, "yellow cake", into uranium hexafluoride (UF6), an elusive gas which is a halfway house to making both nuclear fuel and nuclear bombs. As far as the much of the outside world is concerned, however, Isfahan is a nuclear flashpoint. Almost exactly two years ago, the seals on the tanks of uranium hexafluoride were broken in front of inspectors from the UN's International Atomic Energy Agency (IAEA), in an act of defiance by the Iranian government - a blunt signal Tehran was not going to halt its nuclear progress in return for the incentives Europe was offering. The order was given for uranium conversion to resume at Isfahan after a two-year gap. That decision, in August 2005, marked the start of a crisis that has been steadily worsening ever since, to the point where Washington is said to be studying potential bombing targets, the Iranian leadership is spouting apocalyptic rhetoric, and Europe - once more caught in between - is scrambling to salvage a peaceful solution.