Iranian technicians have tripled the number of uranium enrichment centrifuges they have installed over the past three months to 600, diplomats warned Wednesday.The high-tech machines arenÂ’t yet producing enrichment uranium, the diplomats said in a CBS report, and some are only partly installed. But the report is worrisome, in that it is another sign of IranÂ’s move to develop nuclear weaponry, as the West fears.