In one method, the ore is burned and then reacted with nitric acid to convert uranium into a dissolved state.

James Graham, the president of Converdyn, a company that converts uranium to gaseous form for enrichment, puts it bluntly.

Diplomats said the six nations had agreed to let Iran continue to convert uranium.

They say Iran would also want to convert uranium at Isfahan and to continue making centrifuges.

He led the way in finding how to convert uranium into energy, and how to produce and use plutonium for the same purpose.

Indeed, Iraqi scientists have made great strides in developing centrifuges, which can convert natural uranium to nuclear weapon grade.

The case concerned pollution at Fernald, the Government's plant for converting uranium from gaseous to metal form, an early step in weapons production.

They have demanded that Iran stop its program to convert raw uranium into uranium tetrafluoride.

Last year, the West warned Iran not to convert raw uranium into uranium hexaflouride gas.

At present Iran is converting raw uranium in a form known as yellowcake into a gas, which it could in theory enrich to weapons grade.