Diablo Canyon nuclear power plant operated safely in 2016, the Nuclear Regulatory Commission found, even after being cited for a broken switch in December.
The federal oversight agency examines the power plant each year and issues a report card to PG&E detailing how safely it operated in the year prior.
In 2016, the NRC gave the the plant’s Unit 1 nuclear reactor the highest performance rating possible because all inspection findings had a “very low” risk to public health and safety and all performance indicators were good.
Unit 2, however, was bumped down to the second highest performance rating, largely because of a broken switch that left one aspect of the reactor cooling system temporarily inoperable last year.
The NRC issued a “white finding” in December, claiming the plant failed to adequately maintain an aspect of its emergency core cooling system, resulting in a low-to-moderate safety risk. The NRC evaluates regulatory performance at nuclear plants by color-coding inspection findings as green, white, yellow or red in order of increasing safety significance.
The switch was fixed, and operations resumed as normal.
“Diablo Canyon is a safe, clean and reliable energy resource for our customers and our state,” said Ed Halpin, PG&E senior vice president of generation and chief nuclear officer. “The NRC’s assessment places Diablo Canyon among the higher performing plants in the U.S. nuclear industry.”