At its much larger enrichment complex at Natanz, the country already has produced enough low-enriched fuel to build one or two weapons, though it would need to be further enriched to weapons-grade material.

Nordion, to its credit, has converted to low-enriched fuel for two reactors.

The Energy Department is joined by United States university research reactor operators, who are resisting an order by the Nuclear Regulatory Commission to convert to the low-enriched fuel.

Amongst the topics of the study will be a domestic uranium enrichment plant for supplying low-enriched fuel for nuclear power reactors, either domestic or foreign.

"It's outrageous that they're still doing this," said Victor Gilinsky, who was an early advocate for switching to low-enriched fuel as a member of the Nuclear Regulatory Commission from 1975 to 1984.

Power reactors in this country use uranium fuel in which the proportion of U-235 has been raised to 3 to 5 percent, which is low-enriched fuel.

Last year, Russia agreed to ship low-enriched fuel to the plant by March 2007 and start it in September, with electricity generation to start by November.

Some operate with high-enriched uranium fuel, and international efforts are underway to substitute low-enriched fuel.

The Paducah plant produces low-enriched nuclear fuel for nuclear power plants.

That institute is also involved in a American-financed program to develop a low-enriched fuel for research reactors, thereby rendering fuel unsuitable for bomb making.