Pacific Gas & Electric Corp. said it cut the output at Unit 1 of Diablo Canyon nuclear power plant back to 50 percent to perform work on a malfunctioning feedwater pump. The company has not said when the unit will be restored.
The unit, which generates 1,122 MW at full capacity, had a malfunction in one of its two main feedwater pumps, according to PG&E. The unit also has three backup feedwater pumps.
The pumps are a part of the non-nuclear side of the plant that converts steam into electric power. The pumps manage the water pressure before it enters the unit's steam generator.