By Francois Murphy VIENNA (Reuters) -Iran has escalated its uranium enrichment further with the use of advanced machines at its underground Fordow plant in a setup that can more easily change between enrichment levels, the U.N. atomic watchdog said in a report on Saturday seen by Reuters. Western diplomats have long expressed concern about devices this cascade, or cluster, of centrifuges is equipped with. The use of these so-called modified sub-headers means Iran could switch more quickly and easily to enriching to higher purity levels. While Iran is required to inform the International Atomic…
