Terrorism concerns and threats thumb|right|NRC headquarters outside Rockville, Maryland Terrorist attacks such as those executed by al-Qaeda on New York City and Washington, D.C., on September 11, 2001, and in London on July 7, 2005, have prompted fears that extremist groups might use radioactive dirty bombs in further attacks in the United States and elsewhere.Averting Catastrophe p. 338. In March 2007, undercover investigators from the Government Accountability Office set up a false company and obtained a license from the Nuclear Regulatory Commission that would have allowed them to buy the radioactive materials needed for a dirty bomb. According to the GAO report, NRC officials did not visit the company or attempt to personally interview its executives. Instead, within 28 days, the NRC mailed the license to the West Virginia postal box. Upon receipt of the license, GAO officials were able to easily modify its stipulations and remove a limit on the amount of radioactive material they could buy. A spokesman for the NRC said that the agency considered the radioactive devices a "lower-level threat"; a bomb built with the materials could have contaminated an area about the length of a city block but would not have presented an immediate health hazard.
Terrorism concerns and threats thumb|right|NRC headquarters outside Rockville, Maryland Terrorist attacks such as those executed by al-Qaeda on New York City and Washington, D.C., on September 11, 2001, and in London on July 7, 2005, have prompted fears that extremist groups might use radioactive dirty bombs in further attacks in the United States and elsewhere.Averting Catastrophe p. 338. In March 2007, undercover investigators from the Government Accountability Office set up a false company and obtained a license from the Nuclear Regulatory Commission that would have allowed them to buy the radioactive materials needed for a dirty bomb. According to the GAO report, NRC officials did not visit the company or attempt to personally interview its executives. Instead, within 28 days, the NRC mailed the license to the West Virginia postal box Upon receipt of the license, GAO officials were able to easily modify its stipulations and remove a limit on the amount of radioactive material they could buy. A spokesman for the NRC said that the agency considered the radioactive devices a "lower-level threat"; a bomb built with the materials could have contaminated an area about the length of a city block but would not have presented an immediate health hazard.