The Nuclear Regulatory Commission said security issues at the Limerick nuclear power plant warranted increased oversight of the facility.
The cause for a supplemental review of security at the plant are not revealed to the public, Mainline Media News reported. But acting Region 1 Administrator David Yew said the NRC would perform an extra inspection of the plant "to ensure Exelon fully understands the root causes of the issue and has implemented long-term corrective actions.”
The NRC, three days before the announcement, extended the operating license for 20 years for the plant's two reactors.
Yew said inspectors had confronted the security issue when they discovered it, during a June 16 to June 20 inspection. “Before our inspectors left the site after the issue had been identified, we ensured that appropriate interim compensatory actions were put in place,” Yew said.
Limerick communications manager Dana Melia said operators reacted “promptly” to address the security concerns, which are described, as a rule, as “greater than green,” in the NRC's color coding system for alerts.
Green is the color assigned to a minor problem at a nuclear power plant. In an effort to keep details of a security issue confidential, security problems are only described vaguely as “greater than green.”