Representatives from the Nuclear Regulatory Commission (NRC) recently held a public forum to answer questions related to a recent special inspection of the Diablo Canyon power plant.

The meeting, held early in the evening Jan. 26 at the Embassy Suites in San Luis Obispo, specifically addressed an Oct. 23 incident during which plant maintenance workers discovered a set of misaligned switches. When properly aligned, the switches allow control room operators to remotely open water valves to cool the reactor.

The discovery prompted an on-site inspection by regulators from Nov. 30 to Dec. 3.

NRC officials said at the meeting the mishap was discovered in time and never posed a significant safety threat. Even if the valves couldn’t be opened remotely, officials said, operators would have been able to manually open them or use a different system to provide cooling water for the reactor.

“After extensive review of the data from the inspection, we have determined this probably had a very low safety impact,” said NRC’s senior resident inspector for Diablo Canyon, Michael Peck.

Peck was joined by a number of NRC officials and Pacific Gas & Electric’s site vice president for Diablo, Jim Becker.

The NRC did, however, find three violations of NRC requirements during its inspection, including inadequate design elements, testing, and safety evaluations.

Roughly 50 people attended the session and grilled NRC and PG&E staffers with tough safety questions about scenarios ranging from human error to earthquakes to terrorist attacks. NRC seismologist Annie Kammerer said studies are currently underway regarding the newly discovered Shoreline Fault and will likely be released to the public later this year.

The Q&A became politely heated after the official meeting ended, when members of the SLO-based, anti-nuclear nonprofit group Mothers for Peace reiterated their concerns with restrained regulators.

According to senior NRC spokesman Victor Dricks, a second meeting—which will specifically address PG&E’s relicensing efforts—is set for Feb. 10, though an exact time has yet to be determined because of a scheduling conflict with yet another local environmental meeting.