The U.S. Nuclear Regulatory Commission, purely as a precaution, has recommended that all nuclear power plants, non-power reactors, nuclear fuel facilities and gaseous diffusion plants go to the highest level of security. Details of the heightened security are classified.

While there has been no credible general or specific threats to any of these facilities, the recommendation was considered prudent, given the acts of terrorism in New York City and, in Washington, D.C.