NRC Region I Administrator Samuel Collins said the annual meeting was not a formal inspection review but instead a more freewheeling conversation about how CENG was handling reactor safety across the three nuclear plants it operates with its new French partner, EDF. Unlike a customary inquiry into a plant issue, this meeting's focus extended to corporate accountability.
"It does not take the place of our regular oversight process," Collins explained to a reporter. "It does allow us to bring these insights back into our regulatory decisionmaking, so we can understand better why things may have happened, but more important, what's being done about it across the fleet, and whether Constellation is taking away lessons learned."
"What are their standards? How are they reinforcing those rules? Where are they focusing their time, people and money?" Collins said.
Mea culpa and red flags
The meeting was an opportunity for CENG executives to highlight the reduced radiation exposures at their plants, the company's above-average record in keeping its plants online, and its standing at the high end of the performance ratings by the Institute of Nuclear Power Operations, an industry oversight organization.
But CENG's review began with a mea culpa. "We recognize our recent performance ... does not meet expectations and we are taking aggressive fleet-wide actions," the company said.
The several incidents covered during the daylong session at Nine Mile Point and the R.E. Ginna nuclear plant near Rochester, N.Y., accounted for a small fraction of the reactors' operations during 2008 and 2009, but they raised red flags nonetheless.
At Ginna, a turbine-driven auxiliary feed water pump failed in May 26, 2009, then failed again during a test run a little over a month later. While NRC concluded it did not pose a serious safety threat to the plant, it did disable one of the backup systems that would have to remove heat from the reactor in an emergency shutdown accompanied by a loss of outside power to the plant.
The pump failed because the stem of a control valve had become corroded, and the cause of the corrosion, in turn, was leakage of steam from a system involving a connected valve. The steam leak had been going on since 2005, and the NRC said the May 2009 failure should have triggered an exhaustive search for the "root cause." Ginna operators thought they had pinpointed the issue and a fix, but they did not probe deeply enough to identify the rust issue and the steam leak that was causing it, the NRC inspectors said.
"This is a critical system. This is a high safety important system," Ginna plant Vice President John Carlin told NRC officials at the January meeting. "Our performance didn't meet expectations."
"It's caused us to challenge how we were looking at the business," Carlin added. "Do you have the right mindset?"
A progression of errors
Given the stakes involved at nuclear plants, it's not enough for operators to "fix" equipment that fails, said Glenn Dentel, NRC branch chief for the three CENG plants. They have to be certain of the cause and have proved to themselves that the equipment will do its job.
The hose incident at Nine Mile Point was a progression of errors and inadequate responses, NRC inspectors concluded. Although the underwater cleaning operation had never been done before, it was not subject to a rigorous planning process, NRC inspectors said, nor was the change in the cleaning process on Nov. 4 adequately reviewed.
Contrary to expected practice, the divers did not immediately stop work when the incident occurred. Plant management was not immediately notified. An hour passed between when the first and second pumps were fouled, the NRC said.