VIENNA - Iran is increasing the number of advanced uranium enrichment centrifuges installed at its Natanz underground plant, despite tightening international sanctions aimed at stopping Tehran's nuclear progress, diplomats said on Wednesday.
Iran has for years been trying to develop centrifuges more efficient than the erratic 1970s era IR-1 machines it now uses, but introducing new models has been dogged by technical hurdles and difficulty in obtaining key parts abroad.
If launched and operated successfully, the new machines would enable the Islamic state to sharply speed up sensitive atomic activity which it says is for peaceful energy purposes but which the West fears may be aimed at building nuclear bombs.
"It is clear Iran can build them. The question is how many and how good are they," one Western envoy said.