A reactor at the Balakovskaya nuclear power plant (NPP) in central Russia was restarted and reconnected to power grid early on Sunday after a safety shutdown, a spokesman for the plant said. \"The reactor was reconnected to the power grid and restarted in compliance with regulations for safety operation,\" the source said. \"Radiation levels at the station and surrounding territories remain unchanged, at the normal level.\" The plant\'s fourth reactor shut down automatically late on Thursday, when a thunderstorm on the border of the Saratov and the Samara regions damaged two power supply lines serving the reactor. The lines were fixed shortly after midnight on Sunday. Nuclear specialists earlier said such safety shutdowns are a routine occurrence.