Feds cite Ginna over potential flooding problem
- The gap in floodwater protection was found during a May 2013 federal inspection
- The flood risk comes from nearby Deer Creek%2C not the lake
- The commission cited Constellation with a %22white%22 violation%2C the second-least serious of four levels
The owner of the Ginna nuclear power plant in Ontario, Wayne County, has been cited by federal regulators for failing to correct a problem that could have flooded a vital part of the facility.
The gap in floodwater protection was found during a May 2013 federal inspection driven by concern over the 2011 disaster at the Fukushima Daiichi nuclear complex in Japan. In that catastrophe, a tsunami flooded the complex and knocked out power. Operators lost control of three reactors, leading to explosions and partial meltdown of the cores.
In a violation notice released Tuesday, the U.S. Nuclear Regulatory Commission said flooding at Ginna also could have knocked out two backup sources of electricity that could be used to control the plant during an emergency.
This could have left the plant completely without power in a condition known as "station blackout," NRC spokesman Neil Sheehan said.
"At that point, there would be a limited period of time to restore power and continued cooling to the reactor core," Sheehan said. "At Fukushima, three reactors were not able to restore this power, resulting in the meltdowns of the nuclear fuel there."
The NRC noted that no such flood ever occurred at the plant, and said that plant owner Constellation Energy Nuclear Group fixed the problem in October — but only after arguing for months that no fix was needed.
Constellation spokeswoman Maria Hudson said the company has 10 days to challenge or accept the NRC's conclusions.
"We're reviewing the issue right now, and we haven't made a decision to whether we will dispute the findings," she said.
That aside, the company said it was confident the plant was and is safe.
"Ginna is a robust, fortified facility designed to withstand the most severe weather related events, including the highest recorded flood levels in the area," she said. "This potential issue was corrected, it did not affect the safe, reliable operation of the plant and we will continue to work with the NRC to make our facility even safer and more prepared for the unimaginable."
The NRC said that in fact, the flaw in Ginna's flood protection should have been found and addressed 30 years ago, when Rochester Gas and Electric Corp. owned the plant. And when the federal inspection uncovered the problem last year, Constellation failed to address it promptly, the NRC said.
The agency cited Constellation with a "white" violation, the second-least serious of four levels. The company may be subject to a fine, Sheehan said, in light of the flooding problem's "longstanding nature."
Constellation also was given two violations in the least-serious category, "green," for unrelated issues.
The Ginna plant is in the town of Ontario, on the shore of Lake Ontario. The flooding in question would not have come from the lake but from relatively small Deer Creek, which flows just south and east of the plant.
When Ginna was designed in the 1960s, it was thought that the creek could never overflow its banks to the point where the plant could be damaged. But the creek's flood potential was reassessed in 1983 and the estimated maximum flood height was increased. That was when RG&E should have realized damage was possible, the NRC said.
If flooding on the creek had been severe enough, the agency inspection report said, water could have risen to the point where it would have flowed into a large manhole on the east side of the plant.
Inspectors found the manhole contained unsealed openings for cables through which floodwater could have flowed into an adjacent below-ground room housing a large array of batteries.
Constellation officials argued that drains at the bottom of the manhole would carry away floodwater before it could pass through the unsealed openings. At the NRC's insistence, the drains were checked and found to be inadequate for that task, however.
In the flooding scenario, the batteries could have become inoperable. They are essential for operation of the plant's emergency diesel generators, Sheehan said.
Had flooding on Deer Creek been even more severe, the water would have knocked out electrical equipment on the east side of the plant that feeds the plant off-site power from the grid.
Off-site and diesel power are the two sources that would be used in the event of an emergency. Sheehan said the plant does have backup pumps with their own generators that could be brought into service to help cool the reactor.
SORR@DemocratandChronicle.com