Still, a survey of workers conducted by a commission inspector shows workers fear for their jobs if they report safety issues. The findings were included in a Feb. 3 company memo leaked this week to the environmental group San Clemente Green.
According to the memo, the commission received 63 allegations of safety concerns at the plant between 2008 and 2009, and 25 of the people making the allegations feared retaliation.
San Onofre workers report safety violations 10 times more often than the industry average, the memo states.
Ross Ridenoure, chief nuclear officer, said the plant is working on improving the safety culture, and company surveys show progress.
"We have zero tolerance for any type of retaliation," he said.
Similar allegations have previously been leveled at plant officials. In November, two plant workers filed federal whistle-blower complaints against the plant, saying managers retaliated against them after they disciplined an employee who violated regulations while welding a nuclear waste canister.
Ridenoure would not comment on pending litigation.
Gary Headrick, a founder of San Clemente Green, said a plant manager leaked the memo. Headrick said it was important to shed light on the issue because the plant is scheduled to restart a reactor that he believes may have been rushed back into service.