MARCOULE, France (Reuters) - While the world frets about uranium enrichment plants in Iran and North Korea, France is getting rid of its own plants in public to set an example. France has no plan to scrap its nuclear arms, but it has enough plutonium and highly enriched uranium to maintain its arsenal, so it is dismantling the factories where it used to make these materials. They are located at Marcoule and Pierrelatte, two sprawling industrial sites sheltered among vineyards and fields of lavender in a corner of Provence close to the Rhone river. By the time it is over, it will have taken more than 40 years and cost over 6 billion euros ($8.4 billion) to remove radioactive materials and pull apart all the complex machinery. Top secret for decades while they were still in operation, the factories at Marcoule and Pierrelatte were shown to a small group of journalists on a recent summers day in a carefully stage-managed visit that France said was the first of its kind. This is not an anodyne decision, I want to insist on that. It is the first time that a nuclear-armed state is doing this, Antoine Beaussant, a close military aide to Sarkozy, told reporters as they put on hard hats and pinned small Geiger counters to their white coats for the visit. The reporters trip was the fulfilment of a promise made in 2008 by Sarkozy to open up the two sites to show the world they were beyond use. Nuclear-armed since 1960, France has been reducing its arsenal since the end of the Cold War. It has fewer than 300 N-warheads, half the number it once had. That is enough of a deterrent to protect vital national interests, Sarkozy says. Production of new fissile materials for bombs stopped in 1996, and the destruction of the plants is at an advanced stage. Sarkozys decision to allow outsiders to see what is left of them aims to encourage the other official nuclear powers the United States, Britain, Russia and China to dismantle their equivalent facilities and to show that they are doing it. The French gesture of transparency, like recent moves by Russia and the United States to reduce their nuclear arsenals, is also a signal to Iran and North Korea. The tacit message to those countries is that mature nuclear powers are making efforts to reduce their firepower, so they should refrain from building their own nuclear arsenals. France also wants to show its support for talks towards a global cut-off treaty to halt production of nuclear bomb-making material, which have made recent progress after a long deadlock. Never one to sit quietly on the sidelines, Sarkozy wants to present France as a leader in the global disarmament process. A visit to Marcoule and Pierrelatte certainly leaves no doubt that the facilities have been irreversibly decommissioned. At Pierrelatte, three vast factories built in the 1960s to produce highly enriched uranium are quiet and empty, except for thousands of big white plastic bags and black metal drums marked with the distinctive yellow and black radioactivity symbol. These bags and drums, full of the crushed debris of machinery, await transfer to waste storage sites. A short drive away, the Marcoule site contains three graphite reactors constructed in the 1950s to produce plutonium. Reporters were shown one of these, G2, which looks like an enormous concrete cylinder lying on its side with thick metal rods sticking out of it. The concrete, 3 metres (9.8 feet) thick, serves to isolate the highly radioactive graphite heart. Outer elements of G2, such as the chutes through which the plutonium would be extracted, have been destroyed. But the graphite heart itself cannot be removed until 2020. By then, its radioactivity will have decreased sufficiently to enable technicians to work on it, and France will have a special facility for the storage of irradiated graphite waste. The complete clean-up of the facility will last until 2035. Officials said the dismantling operations at Pierrelatte and Marcoule were extremely safe, with 30 minor incidents recorded in the decade since work began, compared with about 900 a year in Frances civilian nuclear installations. Nevertheless, safety remains a concern in such sites, as workers and visitors are reminded by a message embedded in a mirror on the way into one of the facilities: THIS is the person most responsible for your safety.