While the Nuclear Regulatory Commission (NRC) has bolstered security at nuclear plants since 9-11, the GAO cannot yet say whether each plant "has taken reasonable and appropriate steps to address the new design-basis threat," which establishes the maximum terrorist threat that a facility must defend against. Security plans reviewed by GAO lacked "important site-specific information," including where responding guards were to be stationed. Moreover, the GAO noted that the NRC isn't sharing with plants lessons learned from inspections at those plants.