ML022400295
| ML022400295 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/27/2002 |
| From: | Sands S NRC/NRR/DLPM |
| To: | Campbell G FirstEnergy Nuclear Operating Co |
| References | |
| BL-01-001, FOIA/PA-2002-0229, TAC MB2626 | |
| Download: ML022400295 (4) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION 0
WASHINGTON, D.C. 20555-0001 Mr. Guy G. Campbell, Vice President - Nuclear FirstEnergy Nuclear Operating Company 5501 North State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1 - DOCUMENTATION OF CONFERENCE CALL OF NOVEMBER 15,2001, RE: RESPONSE TO BULLETIN 2001-01 (TAC NO. MB2626)
Dear Mr. Campbell:
On November 15, 2001, a conference call was held between the staff and representatives of FirstEnergy Nuclear Operating Company concerning the staff's assessment of the Davis-Besse response to Nuclear Regulatory Commission (NRC)Bulletin 2001-01, "Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles." This conference call reflected recent meetings held with your staff at the NRC offices in Rockville, MD, on November 8, 9, and 14, 2001. The purpose of this letter is to document the staff's findings as discussed during the conference call.
As discussed in the bulletin, the Davis-Besse facility is considered to have a high susceptibility to primary water stress corrosion cracking (PWSCC) at reactor pressure vessel head penetration (VHP) nozzles. Thirteen reactor facilities have been categorized as having a high susceptibility to PWSCC at the VHP nozzles. To date, eleven of these facilities have performed inspections as recommended in the bulletin and ten of these have identified cracking in VHP nozzles. With respect to the seven operating Babcock and Wilcox (B&W) facilities, the other six facilties (Davis-Besse excluded) have performed inspections as recommended in the bulletin and all six facilities have identified cracking in VHP nozzles. More significantly, three of these B&W facilities have identified circumferential cracking.
The staff believes there is a reasonable likelihood that the Davis-Besse facility currently has multiple cracks in the VHP nozzles and that one or more of these cracks could be circumferential. The staff has viewed the photographs provided of the Davis-Besse reactor vessel head and videotapes taken from previous refueling outages and is unable to make an independent assessment of the structural integrity of the VHP nozzles.
During the conference call, your staff asked how the NRC had factored the probabilistic safety assessment (PSA) included in your submittal of November 1, 2001. The staff has reviewed the risk assessment included in your submittal and finds the methodology employed to be reasonable. However, the inspection credits for the 1996, 1998, and 2000 inspections and the probabilistic fracture mechanics on crack initiation-propagation are unresolved due to inadequate data and ambiguity to support the risk numbers presented in your submittal.
Based on our review of the information you have provided in your bulletin responses (which includes the staff's request for additional information), the videotapes from previous outages, the PSA included in your submittal of November 1, 2001, and the information provided in the
meetings identified above, the staff is unable to reconcile the inspection results described above. The staff has not identified any mitigating factors which would distinguish Davis-Besse from the other high susceptible facilities that have previously shut down and identified cracking in the VHP nozzles.
As discussed in the conference call, the staff does not envision a success path using traditional analyses or risk arguments. The staff believes that based on the information available, inspections as recommended in the bulletin are the only means to provide reasonable assurance of the structural integrity of the reactor vessel head. Therefore, any future discussions or submittals on this subject should focus on how Davis-Besse is unique or can be distinguished from the inspection results from the other, high susceptible facilities.
Sincerely, Stephen P. Sands, Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-346 cc: See next page G. Campbell
meetings identified above, the staff is unable to reconcile the inspection results described above. The staff has not identified any mitigating factors which would distinguish Davis-Besse from the other high susceptible facilities that have previously shut down and identified cracking in the VHP nozzles.
As discussed in the conference call, the staff does not envision a success path using traditional analyses or risk arguments. The staff believes that based on the information available, inspections as recommended in the bulletin are the only means to provide reasonable assurance of the structural integrity of the reactor vessel head. Therefore, any future discussions or submittals on this subject should focus on how Davis-Besse is unique or can be distinguished from the inspection results from the other, high susceptible facilities.
Sincerely, Stephen P. Sands, Project Manager, Section 2 Project Directorate Ill Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-346 cc: See next page Distribution PUBLIC JZwolinski WBateman DPickett LPD3-2 R/F AMendiola KWichman RBarrett SSands AHiser JStrosnider MReinhart A
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Mr. Guy G. Campbell FirstEnergy Nuclear Operating Company cc:
Mary E. O'Reilly FirstEnergy 76 South Main Street Akron, OH 44308 Manager - Regulatory Affairs FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State - Route 2 Oak Harbor, OH 43449-9760 Jay E. Silberg, Esq.
Shaw, Pittman, Potts and Trowbridge 2300 N Street, NW.
Washington, DC 20037 Regional Administrator U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60523-4351 Michael A. Schoppman Framatome ANP 1700 Rockville Pike, Suite 525 Rockville, MD 20852 Resident Inspector U.S. Nuclear Regulatory Commission 5503 North State Route 2 Oak Harbor, OH 43449-9760 Plant Manager FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State - Route 2 Oak Harbor, OH 43449-9760 Davis-Besse Nuclear Power Station, Unit 1 Dennis Clum Radiological Assistance Section Supervisor Bureau of Radiation Protection Ohio Department of Health P.O. Box 118 Columbus, OH 43266-0118 Carol O'Claire, Chief, Radiological Branch Ohio Emergency Management Agency 2855 West Dublin Granville Road Columbus, OH 43235-2206 Director Ohio Department of Commerce Division of Industrial Compliance Bureau of Operations & Maintenance 6606 Tussing Road P.O. Box 4009 Reynoldsburg, OH 43068-9009 Ohio Environmental Protection Agency DERR--Compliance Unit ATTN: Zack A. Clayton P.O. Box 1049 Columbus, OH 43266-0149 State of Ohio Public Utilities Commission 180 East Broad Street Columbus, OH 43266-0573 Attorney General Department of Attorney 30 East Broad Street Columbus, OH 43216 President, Board of County Commissioners of Ottawa County Port Clinton, OH 43252