These four regions oversee the operation of 104 power-producing reactors, and 36 non-power-producing reactors. This oversight is done on several levels, for example:
Each power-producing reactor site has Resident Inspectors, who monitor day-to-day operations
Numerous special inspection teams, with many different specialties, routinely conduct inspections at each site
Whistleblower reports are investigated by the Office of Enforcement, specifically the Allegations branch[6]
The NRC previously had five regions. Region V was headquartered in
Walnut Creek, California and was responsible for activities in the seven far-west states: Alaska, Arizona, California, Hawaii, Nevada, Oregon and Washington. The NRC decided in September 1993 to consolidate Regions IV and V into a single Region headquartered in Arlington, Texas.[7] On April 4, 1994, NRC Region V was abolished, and the NRC Region IV office in Arlington, Texas was given expanded responsibilities to include the seven states formerly governed by Region V.[8][9] The former NRC Region V office in Walnut Creek remained open as the redesignated Walnut Creek Field Office, supporting resident inspection activities at power plants in the Pacific states of Washington, Oregon and California[8] until October 1, 1998, when the Walnut Creek Field Office was abolished to further reduce costs.[10][11][12][13]