Operators at the Calvert Cliffs Nuclear Power Plant in Lusby, MD, reported “an unanalyzed condition that could impact the plant’s common control room.”
The condition “involves a gap in a concrete barrier that could allow steam from a line break to enter the control room and affect plant safety operations,” said Nuclear Regulatory Commission (NRC) Spokesman Neil Sheehan.
A summary of the event, submitted to the NRC by Constellation Energy Nuclear Group (CENG) classified the situation as “non-emergency.”
Operators discovered the condition Thursday shortly before 6 p.m. Neither of the plant’s two reactors was shut down as a result of the event.
“Constellation has taken action to address the issue on an interim basis by taking the Unit 2 steam generator blow-down system out of service,” Sheehan stated. “However, the company will need to address the issue on a permanent basis.”
Sheehan said the NRC will “review the vulnerability, why it was not discovered prior to yesterday and (CENG’s) plans to remedy it.”
“Calvert Cliffs Nuclear Power Plant facility is operating safely, reliably and efficiently,” said CENG Communications Director Mark Sullivan.
“During the inspection, a small gap was found in a wall that should be solid,” Sullivan said. “Our team exhibited a good questioning attitude, leading to an evaluation that ended with the removal of the Unit 2 Steam Generator Blowdown System from service. This action removed the potential risk and corrected the condition. Additionally, it will not impact operations. The Calvert Cliffs team will perform additional analysis and this event may be retracted if the analysis shows that the condition would not have significantly impacted plant safety.”