NRC warns of possible power-system design flaw

NRC warns of possible power-system design flaw
A possible design flaw involving power systems at nuclear plants could affect important safety components at the facilities, the Nuclear Regulatory Commission said in a notice to plant operators. This comes after unbalanced voltage prompted the shutdown of the Unit 2 reactor of Exelon's Byron nuclear plant in Illinois early this year. "The plant's electric power system's protection scheme was not designed to sense the loss of one of three power phases and automatically trip circuits to isolate the degraded outside power source and switch to emergency backup power," the agency said. Reuters