The Nuclear Regulatory Commission (NRC) has launched a special inspection at the Quad Cities Generating Station to review two events caused by battery issues at the two-unit plant, in Cordova, Illinois. It’s operated by Constellation Energy.
A Wednesday, June 4, NRC news release said the first event involved a Unit 1 scram – or rapid emergency reactor shutdown – caused by a degraded condition on a Unit 2 battery. The second event involved an Notice of Unusual Event, the lowest of the NRC’s emergency level classifications, due to a brief fire on the same Unit 2 battery.
Neither of last month’s events impacted public health or plant workers.
According to a statement released by Paul Dempsey, manager of Generation Communications at Constellation Energy:
“On May 22, Quad Cities Clean Energy Center operators quickly extinguished a small fire on a battery located in a Unit 2 electrical room outside of the reactor building. This event was unrelated to an electrical issue that caused Unit 1 to lose power to plant equipment and safely shut down three days prior.
“Each incident was handled correctly by plant personnel and resulted in no injuries to employees or impact to the public. Quad Cities’ two reactors are both online and continue producing reliable, carbon-free electricity for more than 1 million homes and businesses in the region.”
The NRC release said it had determined a special inspection was warranted because of multiple unexpected system interactions and failures during the scram, the unknown cause of the fire and a possible connection between the two events.
‘Plant remained safe’
Batteries supply power to plant systems during routine plant operation and are an important back-up power source in case of an emergency, the NRC said.
“While the plant remained safe during these occurrences, an independent review by the regulator is warranted, given questions related to battery problems at the root of both events,” Region III NRC Administrator Jack Giessner said.
“Our inspectors will independently assess the issues, evaluate Constellation’s understanding of events and causes, and assess operator actions, the scope of the plant’s assessment and the development of corrective actions.”
Once the inspection is completed, NRC inspectors will document their findings in a report, which will be distributed electronically to listserv subscribers and available on the NRC website.
The NRC recently completed a special inspection at the plant to review the inoperability of safety-related vacuum breakers. That inspection, unrelated to the battery issues, will also be documented in a publicly available inspection report.
