Energy Northwest's nuclear power plant was back at full power at 7:30 a.m. Monday. The generating station went back on line Sunday. The 1,500 megawatt plant had been offline since July 30th, when the failure of an electronic part closed one of its eight 12-foot steam valves and triggered an automatic shutdown.

The plant was back on the grid at 20 percent power Sunday evening. During the weekend restart, plant workers replaced a smaller valve, called a bleed-steam-relief valve.