Publication

If terrorists could steal 25 kg to 50 kg of highly enriched uranium fuel to be used for one or more large research reactors, they might be able to make a nuclear weapon from it. The same is not true of unburned fuel from power reactors because the uranium is not highly enriched and therefore not useful for making such weapons without a difficult uranium enrichment process. If terrorists could steal radioactive fuel that has been burned in either kind of reactor, they could probably make a radioactive dispersal device or "dirty bomb."