OAK HARBOR — The Nuclear Regulatory Commission plans to hold a public meeting regarding its acceptance of FirstEnergy Nuclear Operating Corp.’s “root cause” report concerning cracks discovered last year in the Davis-Besse nuclear power plant’s concrete shell structure.
Exactly when that meeting might be held was not disclosed, but the intent was reported in a cover letter to FENOC that accompanied NRC’s transmission of its “inspection report” today to the utility.
The letter stated that the meeting would be convened “in the near future to allow the opportunity for FirstEnergy Nuclear Operating Company to describe its root cause activities and planned actions going forward and NRC staff to discuss the related NRC inspection.”
It did not state if public comments will be received as well.
FirstEnergy blamed the cracks — first observed in October when a hole was cut through the plant’s Shield Building for access to replace its nuclear reactor — on moisture penetration and freezing during the Blizzard of 1978. The utility’s researchers found that wind-whipped rain during the storm penetrated the concrete, then froze when the temperature plunged during the blizzard’s peak.
The utility pledged to develop a monitoring program and to coat the concrete structure with a weatherproofing material that was not applied when the plant was built during the mid-1970s.
In its inspection report NRC found, among other things, that the absence of waterproofing during the original construction did not constitute a design failure, because other aspects of the Shield Building’s design made it compliant with durability design standards.
“The SB [Shield Building] provided for a design that minimized the uptake of moisture into the SB wall, but these measures were not effective at precluding the moisture intrusion associated with the 1978 blizzard event,” NRC wrote in the inspection report.
The agency found that FirstEnergy’s practices for monitoring Davis-Besse’s aging concrete was consistent with federal standards, and that its plan to apply weatherproofing, “if properly implemented would preclude moisture intrusion and hence preclude recurrence of the conditions that caused the SB laminar cracking.”
The cracking issue has arisen as FirstEnergy seeks a 20-year renewal of Davis-Besse’s operating license, which expires in 2017. Re-licensing opponents’ request that the hairline cracks be made a factor to be considered in the re-licensing process is pending NRC review.
— David Patch