The Nuclear Regulatory Commission (NRC) is monitoring an Alert declared this afternoon at the Susquehanna 2 nuclear power plant in Salem Township (Luzerne County), Pa. An Alert is the second-lowest of four levels of emergency classification used by the NRC.
At 4:15 a.m. today, maintenance work was initiated on a water line that is part of a reactor safety system for the plant. That work involved the use of a “freeze seal” – that is, placing a device containing nitrogen over a section of piping so that the water inside the line can be frozen. Once frozen, the line can be isolated to allow maintenance to be performed on it.
PPL, the plant’s owner and operator, declared an Alert at 12:06 p.m. when higher-than-acceptable levels of nitrogen, a toxic gas, were detected inside the room. As required by procedures, the one plant worker who was in the room at the time evacuated.