He agreed that the small percentage of bomb-grade material was dangerous and required great care, but insisted that it was properly looked after.

The 1994 agreement committed North Korea to freeze nuclear programs that were producing bomb-grade materials.

This change drastically moved Iran's uranium toward bomb-grade material.

He also said he believes that bomb-grade material is more likely to fall into terrorist hands from civilian rather than military sources.

Russia's system for protecting bomb-grade materials had its limitations.

Power shortages threaten to shut down electronic security systems intended to safeguard stores of bomb-grade materials.

But it has since been revealed that the physical safeguarding of bomb-grade material against theft was almost scandalously neglected.

Both could be transformed into bomb-grade material with the right equipment.

He predicted that Russia would continue with the part of the deal that requires it to blend down the bomb-grade material.

The rods would be likely to yield some bomb-grade material.