VIENNA - Iran is preparing to install centrifuges for higher-grade uranium enrichment in an underground bunker, diplomatic sources say, a development that is likely to add to Western worries about Tehran's atomic aims.
Preparatory work is under way at the Fordow facility, tucked deep inside a mountain to protect it against any attacks, and machines used to refine uranium could soon be moved to the site near the clerical city of Qom, the sources said.
Tehran only disclosed the existence of Fordow two years ago after Western intelligence detected it and said it was evidence of covert nuclear activities. The facility has yet to start operating.
Refined uranium can be used to fuel nuclear power reactors and also, if enriched to much higher levels, provide material for atomic arms.