United States Nuclear Regulatory Commission - Protecting People and the Environment

Loss Of Offsite Power

The availability of ac power to commercial nuclear power plants is essential for safe operations and accident recovery. A loss of offsite power (LOOP) event, therefore, is an important contributor to total risk at nuclear power plants. In 1988, the NRC published NUREG-1032 to report on an evaluation of the risk from actual LOOP events that had occurred at nuclear power plants within the United States up through 1985. NUREG/CR-5496 documents a similar study whose primary objective was to update the LOOP model parameters, frequency, and recovery time, using plant event data from 1980 - 1996. An additional objective was to re-examine the engineering insights concerning LOOP events. These studies were followed by NUREG/CR-6890 which evaluated data from 1986 through 2004. The update studies provided here represent annual updates to NUREG/CR-6890.

Current Results:

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Historical Results:

Page Last Reviewed/Updated Monday, March 27, 2017