NRC to inspect Grand Gulf Nuclear Station in Mississippi following shut down

The Nuclear Regulatory Commission (NRC) recently began a special inspection at the Grand Gulf Nuclear Station to examine the circumstances surrounding the plant’s suspension of service.

The plant, operated by Entergy Operations Inc., is located in Port Gibson, Mississippi, and has been shut down since Sept. 8.

Maintenance discovered that a misalignment of valves rendered the plant’s alternate decay heat removal system unavailable on Sept. 23. When one of the plant’s two residual heat removal systems is out of service, technical specifications require that an alternate system be available. The following day, operators caused an unexpected increase in reactor vessel water level due to the value misalignment when preparing to start the reactor.

“The purpose of this special inspection is to better understand the circumstances surrounding several recent operational events to determine if operator response was appropriate,” Kriss Kennedy, administrator for NRC Region IV, said. “We will also review the licensee’s corrective actions to ensure that their causes, including associated equipment problems and any contributing operator actions, have been effectively addressed.”

Three NRC inspectors will spend approximately one week at the station evaluating causes of the problems as well as the adequacy of corrective actions to address reliability issues. A report will be publicly available approximately 45 days at the end of the inspection.