It is also important to secure nuclear materials in countries that enrich uranium for fuel.

VOA: standard.2010.08.06

"Last November,Iran announced that it would build In February, Iran said that it would begin to enrich uranium to nearly 20 percent-moving,closer to weapons-grade material."

VOA: standard.2010.06.09

Under the scheme, Russia would further enrich the uranium to the 20 per cent purity needed for use in a research reactor in Tehran which produces medical isotopes but is running out of fuel.

VOA: standard.2009.10.24