The Nuclear Regulatory Commission on Dec. 29 issued a white inspection finding at the Diablo Canyon Power Plant, confirming that operator Pacific Gas & Electric (PG&E) failed to “adequately maintain the (plant’s) emergency core cooling system.”
Located about 12 miles southwest of San Luis Obispo, Diablo Canyon is the last operating nuclear plant in California and is scheduled to close by 2025. A white inspection finding represents a “low to moderate” safety issue.
According to the NRC, Diablo Canyon personnel discovered during a scheduled test in May that one of the plant’s Unit 2 emergency cooling systems was inoperable for a lengthy period of time, potentially dating as far back as October 2014. The reactor unit did have a backup cooling system available, as each reactor at Diablo Canyon is equipped with two emergency cooling systems in case of emergencies.
Following PG&E’s discovery in May, the NRC completed an inspection at the plant on Sept. 12 and a regulatory conference with the company on Nov. 15. The regulator said PG&E has since corrected the issue and implemented maintenance changes to ensure the problem doesn’t recur. The regulator will inspect the plant at a later, unspecified date to ensure the company has properly addressed the matter.
