ML040640499
| ML040640499 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/04/2004 |
| From: | Hopkins J NRC/NRR/DLPM/LPD3 |
| To: | Myers L FirstEnergy Nuclear Operating Co |
| Hopkins J, DLPM/NRR, 415-3027 | |
| References | |
| TAC MC1642 | |
| Download: ML040640499 (6) | |
Text
March 4, 2004 Mr. Lew W. Myers Chief Operating Officer FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RE: ROOT CAUSE ANALYSIS (TAC NO. MC1642)
Dear Mr. Myers:
Recently, concerns were raised regarding the Davis-Besse root cause analysis which FirstEnergy Nuclear Operating Company submitted to the NRC concerning the reactor pressure vessel head degradation. To resolve the concerns, the NRC staff will need additional information. Enclosed is a request for additional information The enclosed questions were provided to your staff on February 25, 2004, and the questions were discussed with members of your staff on that date. It is our understanding that FirstEnergy Nuclear Operating Company will respond to the questions by May 25, 2005. If our understanding is not correct, please contact me at (301) 415-3027 at the earliest opportunity.
Sincerely,
/RA/
Jon B. Hopkins, Sr. Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosure:
Request for Additional Information cc w/enclosure: See next page
Davis-Besse Nuclear Power Station, Unit 1 cc:
Mary E. OReilly FirstEnergy Corporation 76 South Main St.
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 Director, Ohio Department of Commerce Division of Industrial Compliance Bureau of Operations & Maintenance 6606 Tussing Road P.O. Box 4009 Reynoldsburg, OH 43068-9009 Regional Administrator U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60523-4351 Michael A. Schoppman Framatome ANP 1911 N. Ft. Myer Drive Rosslyn, VA 22209 Resident Inspector U.S. Nuclear Regulatory Commission 5503 North State Route 2 Oak Harbor, OH 43449-9760 Randel J. Fast, Plant Manager FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State - Route 2 Oak Harbor, OH 43449-9760 Dennis Clum Radiological Assistance Section Supervisor Bureau of Radiation Protection Ohio Department of Health P.O. Box 118 Columbus, OH 43266-0118 Carol OClaire, Chief, Radiological Branch Ohio Emergency Management Agency 2855 West Dublin Granville Road Columbus, OH 43235-2206 Zack A. Clayton DERR Ohio Environmental Protection Agency 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 General 30 East Broad Street Columbus, OH 43216 President, Board of County Commissioners of Ottawa County Port Clinton, OH 43252 President, Board of County Commissioners of Lucas County One Government Center, Suite 800 Toledo, OH 43604-6506 David Lochbaum, Nuclear Safety Engineer Union of Concerned Scientists 1707 H Street NW, Suite 600 Washington, DC 20006 The Honorable Dennis J. Kucinich United States House of Representatives Washington, D.C. 20515 The Honorable Dennis J. Kucinich, Member United States House of Representatives 14400 Detroit Avenue Lakewood, OH 44107 Mr. James P. Riccio Nuclear Policy Analyst Greenpeace 702 H. Street, NW, Suite 300 Washington, DC 20001 Paul Gunter Director Nuclear Watchdog Project Nuclear Information & Resource Service 1424 16th Street NW Suite 401 Washington, DC 20009
March 4, 2004 Mr. Lew W. Myers Chief Operating Officer FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RE: ROOT CAUSE ANALYSIS (TAC NO. MC1642)
Dear Mr. Myers:
Recently, concerns were raised regarding the Davis-Besse root cause analysis which FirstEnergy Nuclear Operating Company submitted to the NRC concerning the reactor pressure vessel head degradation. To resolve the concerns, the NRC staff will need additional information. Enclosed is a request for additional information The enclosed questions were provided to your staff on February 25, 2004, and the questions were discussed with members of your staff on that date. It is our understanding that FirstEnergy Nuclear Operating Company will respond to the questions by May 25, 2005. If our understanding is not correct, please contact me at (301) 415-3027 at the earliest opportunity.
Sincerely,
/RA/
Jon B. Hopkins, Sr. Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosure:
Request for Additional Information cc w/enclosure: See next page DISTRIBUTION:
PUBLIC OGC PDIII-2 r/f ACRS AMendiola CLipa, RIII THarris SReynolds, RIII JHopkins ADAMS Accession Number: ML040640499 OFFICE PM:PDIII-2 LA:PDIII-2 SC:PDIII-2 NAME JHopkins THarris AMendiola DATE 03/04/04 03/04/04 03/04/04 OFFICIAL RECORD COPY
ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION DAVIS-BESSE NUCLEAR POWER STATION ROOT CAUSE ANALYSIS TAC NO. MC1642 1.
The purpose of the vent line that runs from nozzle14 to the steam generator number 2 upper primary hand hole is to vent non-condensible gases from the Davis Besse reactor pressure vessel (RPV) head during a loss of coolant accident. The head vent configuration at Davis Besse is unique from other Babcock and Wilcox (B&W) designs in that reactor coolant flows continuously through it during power operations. Given the proximity of the cracked nozzles in the old RPV head to the vent line nozzle, a phenomenon may exist wherein the continuous flow through the vent line impacts the potential for cracking of nearby nozzles. This same phenomenon, if real, could impact the cracking assumptions for the new RPV head.
Confirm whether or not you considered this potential phenomenon in the April 2002 root cause analysis that was performed as a result of the degradation of the old RPV head.
If an evaluation was performed, provide the results of the technical analysis that would demonstrate that the phenomenon either did or did not impact cracking in adjacent nozzles. If this potential phenomenon was not considered, provide the technical basis for discounting it. If it was not discounted, but it was never considered, provide a technical basis for why it will or will not play a role in the operation of the new RPV head.
If your analysis results show that there is a potential impact on the new RPV head penetrations, discuss the actions that would be taken to ensure the integrity of the head penetrations. Consider whether an update to your root cause analysis report is needed.
2.
You used 605F for the time-at-temperature calculations for the old RPV head. This value is apparently an average value of hot leg temperatures. Use of this temperature, given that you have hot leg resistance temperature detectors (RTDs) with higher temperature values, does not appear to result in a conservative effective degradation year (EDY) calculation.
A.
Inform the staff as to which temperature value you will use in determining the EDY of your new RPV head, i.e., the average of hot leg temperatures or the highest hot leg temperature. If you do not plan to use the highest hot leg temperature, then respond to items B and C below.
B.
Provide an explanation for the differences in temperature readings for the RTDs used in determining the average value used in the EDY calculation.
C.
Provide a technical basis for not using the highest hot leg temperature measurement as input to the EDY calculation.