ML080390162
| ML080390162 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 02/12/2008 |
| From: | David M NRC/NRR/ADRO/DORL/LPLI-1 |
| To: | Polson K Nine Mile Point |
| david marshall NRR/DORL 415-1547 | |
| References | |
| TAC MD6620 | |
| Download: ML080390162 (4) | |
Text
February 12, 2008 Mr. Keith J. Polson Vice President Nine Mile Point Nine Mile Point Nuclear Station, LLC P.O. Box 63 Lycoming, NY 13093
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING NINE MILE POINT NUCLEAR STATION, UNIT NO. 1, ADDITIONAL ENGINEERING EVALUATION OF TWO REACTOR PRESSURE VESSEL WELD FLAWS (TAC NO. MD6620)
Dear Mr. Polson:
By letter dated August 22, 2007, Nine Mile Point Nuclear Station, LLC submitted for Nuclear Regulatory Commission (NRC) staff review additional engineering evaluations of two reactor pressure vessel weld flaws for Nine Mile Point Nuclear Station, Unit No. 1 (NMP1). The evaluations were submitted in accordance with a commitment, made in the NMP1 License Renewal Application and affirmed in the NRC staffs associated safety evaluation, to revise the previous flaw evaluations to consider additional fatigue crack growth and the effects of additional irradiation embrittlement (for beltline materials) associated with operation for an additional 20 years.
The NRC staff has reviewed the information provided in that letter and has determined that additional information is needed to complete its review. Enclosed is the NRC staffs request for additional information. On February 4, 2008, it was agreed that your response would be provided within 60 days from the date of this letter.
Sincerely,
/RA/
Marshall J. David, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-220
Enclosure:
RAI cc w/encl: See next page
February 12, 2008 Mr. Keith J. Polson Vice President Nine Mile Point Nine Mile Point Nuclear Station, LLC P.O. Box 63 Lycoming, NY 13093
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING NINE MILE POINT NUCLEAR STATION, UNIT NO. 1, ADDITIONAL ENGINEERING EVALUATION OF TWO REACTOR PRESSURE VESSEL WELD FLAWS (TAC NO. MD6620)
Dear Mr. Polson:
By letter dated August 22, 2007, Nine Mile Point Nuclear Station, LLC submitted for Nuclear Regulatory Commission (NRC) staff review additional engineering evaluations of two reactor pressure vessel weld flaws for Nine Mile Point Nuclear Station, Unit No. 1 (NMP1). The evaluations were submitted in accordance with a commitment, made in the NMP1 License Renewal Application and affirmed in the NRC staffs associated safety evaluation, to revise the previous flaw evaluations to consider additional fatigue crack growth and the effects of additional irradiation embrittlement (for beltline materials) associated with operation for an additional 20 years.
The NRC staff has reviewed the information provided in that letter and has determined that additional information is needed to complete its review. Enclosed is the NRC staffs request for additional information. On February 4, 2008, it was agreed that your response would be provided within 60 days from the date of this letter.
Sincerely,
/RA/
Marshall J. David, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-220
Enclosure:
RAI cc w/encl: See next page DISTRIBUTION:
PUBLIC RidsNrrPMMDavid RidsNrrDciCvib RidsNrrAcrsAcnw&mMailCenter LPLI-1 RidsNrrLASLittle RidsOGCRp RidsRgn1MailCenter S. Sheng Accession Number.: ML080390162 NRR-088 OFFICE LPLI-1/PM LPLI-1/LA CVIB/BC*
LPLI-1/BC NAME MDavid SLittle MMitchell MKowal DATE 2/11/08 2/11/08 01/25/08 2/12/08
- RAI transmitted by memo dated 01/25/08.
OFFICIAL RECORD COPY
Nine Mile Point Nuclear Station, Unit No. 1 cc:
Mr. Michael J. Wallace, President Constellation Energy Nuclear Group, LLC 750 East Pratt Street, 18th Floor Baltimore, MD 21202 Mr. John M. Heffley Senior Vice President and Chief Nuclear Officer Constellation Energy Nuclear Generation Group 111 Market Place Baltimore, MD 21202 Mr. Terry F. Syrell Director, Licensing Nine Mile Point Nuclear Station P.O. Box 63 Lycoming, NY 13093 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 126 Lycoming, NY 13093 Supervisor Town of Scriba Route 8, Box 382 Oswego, NY 13126 Charles Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, NY 10271 Mr. Paul D. Eddy New York State Department of Public Service 3 Empire State Plaza, 10th Floor Albany, NY 12223 Mark J. Wetterhahn, Esquire Winston & Strawn 1700 K Street, NW Washington, DC 20006 Carey W. Fleming, Esquire Sr. Counsel - Nuclear Generation 750 East Pratt Street, 17th Floor Constellation Energy Nuclear Group, LLC Baltimore, MD 21202 Mr. John P. Spath New York State Energy, Research, and Development Authority 17 Columbia Circle Albany, NY 12203-6399 Mr. Paul Tonko President and CEO New York State Energy, Research, and Development Authority 17 Columbia Circle Albany, NY 12203-6399
Enclosure REQUEST FOR ADDITIONAL INFORMATION NINE MILE POINT NUCLEAR STATION, UNIT NO. 1 ADDITIONAL EVALUATION OF TWO REACTOR PRESSURE VESSEL WELD FLAWS The Nuclear Regulatory Commission (NRC) staff has performed its initial review of your August 22, 2007, submittal of additional engineering evaluations of two reactor pressure vessel weld flaws for Nine Mile Point Nuclear Station, Unit No. 1 (NMP1). As a result of that review, the NRC staff has determined that additional information is required to adequately evaluate the acceptability of the proposed changes.
- 1. Page 7 of 22 of Attachment (1) of your August 22, 2007, submittal states, Note that any potential future increases in the leak test pressure are bounded by this evaluation since a higher leak test pressure will yield a higher temperature... The technical basis is insufficient because the submitted flaw evaluation is bounding only when the increase of fracture toughness due to a higher temperature exceeds the increase of applied stress intensity factor due to higher test pressure. Either delete this statement, or amend your basis for this statement if you can demonstrate that the increase of fracture toughness due to a higher temperature exceeds the increase of the applied stress intensity factor due to higher test pressure.
- 2. Figure 2 on Page 9 of 22 is supposed to show three curves of allowable flaw depth for flaw eccentricity ratios of -0.38, -0.22, and -0.20. However, it shows only one curve. Please confirm that the allowable flaw depth is insensitive to flaw eccentricity ratios such that the three curves become one.
- 3. Please explain why Figure 2 on Page 9 of 22 appears to show that the allowable flaw depth is insensitive to flaw eccentricity ratios while Figure 3 on Page 14 of 22 shows that the allowable flaw depth is sensitive to flaw eccentricity ratios. This serves as a check of the integrity of your computer program for flaw evaluation.
- 4. Page 12 of 22 states, Per Constellation input, the peak fluence for the upper plate from Reference [3], as used in Table 3 and this revised analysis, is 2.33 times higher than the peak fluence for the Weld @225º. Please provide relevant pages from Reference [3]
showing the fluence map of the reactor pressure vessel beltline region and mark on the map the weld location at 225º.