ML053480358
| ML053480358 | |
| Person / Time | |
|---|---|
| Site: | North Anna  (NPF-004, NPF-007) |
| Issue date: | 12/13/2005 |
| From: | Hartz L Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 05-834 | |
| Download: ML053480358 (11) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY
- RICHMOND, VIRGINIA 23261 December 13, 2005 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Serial No.05-834 NL&OS/ETS RO Docket Nos.
50-338 License Nos. NPF-4 50-339 N PF-7 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNITS 1 AND 2 UPDATE TO REACTOR VESSEL INTEGRITY DATABASE TO REFLECT LICENSE RENEWAL PERIOD Dominion recently implemented new Reactor Coolant System Pressureflemperature Limit Curves and Low Temperature Overpressure Protection System (LTOPS) setpoints which are valid to the end of the 60-year license renewal period. These changes were submitted to the NRC by letter dated July 1, 2004. The revised P/T limits and LTOPS setpoints are based on reactor vessel neutron fluence projections for the period of license renewal, corresponding to cumulative core burnups of 50.3 Effective Full Power Years (EFPY) for North Anna Unit 1, and 52.3 EFPY for North Anna Unit 2. NRC approval of the revised PA-limits and LTOPS setpoints was granted in a letter dated July 8, 2005.
In the submittal of July 1, 2004, Dominion made a commitment to provide an update to the NRCs Reactor Vessel Integrity Database to reflect license renewal values (60-year license period) for North Anna Power Station. The information contained herein is provided in fulfillment of this commitment.
Dominion has previously provided updates to the NRCs Reactor Vessel Integrity Database (RVID) by letters dated November 19, 1999, September 19, 2000, and most recently April 27, 2001. These updates considered available reactor vessel materials surveillance data, including data obtained from the North Anna Units 1 and 2 plant-specific surveillance program as well as from other utilities surveillance programs.
However, these RVlD updates were limited to the period of the original 40-year operating license, and did not apply to the renewed license period (i.e. 60-year operation).
The attachment to this letter provides revised North Anna Unit 1 and Unit 2 data tables for the NRCs Reactor Vessel Integrity Database (RVID) and a discussion of changes relative to the previous RVlD update for North Anna Units 1 and 2. The RVlD update provided herein is based on peak fast neutron fluence (E > 1.0 MeV) values for North Anna Unit 1 and Unit 2 reactor pressure vessels at the end of the license renewal period.
These evaluations consider the impact of the peak fast neutron fluence values for North Anna Unit 1 and Unit 2 reactor pressure vessels at the end of the license renewal period on (a) licensing basis reactor coolant system (RCS) pressurehemperature (Pn) limit curves, (b) the associated Low Temperature Overpressure Protection System (LTOPS) setpoints and enabling temperature, (c) 10 CFR 50.61 Pressurized Thermal Shock (PTS) screening calculations, and (d) 10 CFR 50 Appendix G requirements for Upper Shelf Energy. The evaluation is performed in a manner consistent with applicable regulatory guidance. Evaluation results are presented in a format consistent with the data requirements of the NRC's Reactor Vessel Integrity Database (RVID).
As documented in the attached evaluation, the RTPT~
reference temperature calculation results for North Anna Unit 1 and Unit 2 continue to meet the applicable PTS screening criteria in 10 CFR 50.61. The Upper Shelf Energy values for North Anna Units 1 and 2 beltline materials meet the 50 ft-lb acceptance criteria of 10 CFR 50 Appendix G at end of the current 60-year license period. Further, the RTNDT value used in the development of the current North Anna Unit 1 and Unit 2 Technical Specification Pressure/Temperature limits, LTOPS setpoints, and LTOPS enabling temperature remains valid and conservative for cumulative core burnups up to 50.3 EFPY for North Anna Unit 1, and 52.3 EFPY for North Anna Unit 2, corresponding to the end of the current 60-year license period.
If you should have any questions regarding this submittal, please contact Mr. Thomas Shaub at (804) 273-2763.
Sincerely, U
L. N. Hartz Vice President - Nuclear Engineering
Attachment:
Reactor Vessel Integrity Database Updates for the 60-Year License Period Commitments made in this letter: None
cc:
U. S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. J. T. Reece NRC Senior Resident Inspector North Anna Power Station Mr. J. E. Reasor, Jr. (without attachment)
Old Dominion Electric Cooperative lnnsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 Mr. S. R. Monarque NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 11 555 Rockville Pike Mail Stop 8-HI 2 Rockville, Maryland 20852 Mr. R. E. Martin NRC Lead Project Manager - North Anna and Surry U. S. Nuclear Regulatory Commission One White Flint North 11 555 Rockville Pike Rockville, Maryland 20852
Attachment Serial No.05-834 UPDATE TO REACTOR VESSEL INTEGRITY DATABASE TO REFLECT LICENSE RENEWAL PERIOD Virginia Electric and Power Company (Dominion)
North Anna Power Station Units 1 and 2
UPDATE TO REACTOR VESSEL INTEGRITY DATABASE TO REFLECT LICENSE RENEWAL PERIOD NORTH ANNA, UNITS 1 AND 2 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
DOCKET NOS. 50-338 AND 50-339 BACKGROUND Dominion recently implemented new Reactor Coolant System Pressure/Temperature Limit Curves and Low Temperature Overpressure Protection System (LTOPS) setpoints which are valid to the end of the 60-year license renewal period. These changes were submitted to the NRC by letter dated July 1, 2004 (Reference 1). The revised P/T limits and LTOPS setpoints are based on reactor vessel neutron fluence projections for the period of license renewal, corresponding to cumulative core burnups of 50.3 Effective Full Power Years (EFPY) for North Anna Unit 1, and 52.3 EFPY for North Anna Unit 2.
NRC approval of the revised P/T limits and LTOPS setpoints was granted in a letter dated July 8, 2005 (Reference 2).
In the submittal of July 1, 2004, Dominion made a commitment to provide an update to the NRCs Reactor Vessel Integrity Database to reflect license renewal values (60-year license period) for North Anna Power Station. The information contained herein is provided in fulfillment of this commitment.
Dominion has previously provided updates to the NRCs Reactor Vessel Integrity Database (RVID) by letters dated November 19, 1999 (Reference 4), September 19, 2000 (Reference 5), and most recently April 27, 2001 (Reference 6). These updates considered available reactor vessel materials surveillance data, including data obtained from the North Anna Units 1 and 2 plant-specific surveillance program as well as from other utilities surveillance programs. However, these RVlD updates were limited to the period of the original 40-year operating license, and did not apply to the renewed license period (i.e. 60-year operation).
This evaluation provides revised North Anna Unit 1 and Unit 2 data tables for the NRCs Reactor Vessel Integrity Database (RVID) and a discussion of changes relative to the previous RVlD update for North Anna Units 1 and 2. The RVlD update provided herein is based on peak fast neutron fluence (E > 1.O MeV) values for North Anna Unit 1 and Unit 2 reactor pressure vessels at the end of the license renewal period, as previously submitted to the NRC via Reference 7.
The evaluation documented herein considers the impact of the peak fast neutron fluence values for North Anna Unit 1 and Unit 2 reactor pressure vessels at the end of the license renewal period on (a) licensing basis reactor coolant system (RCS) pressure/temperature (PIT) limit curves, (b) the associated Low Temperature Overpressure Protection System (LTOPS) setpoints and enabling temperature, (c) 10 Page 1 of 4
CFR 50.61 Pressurized Thermal Shock (PTS) screening calculations, and (d) 10 CFR 50 Appendix G requirements for Upper Shelf Energy. The evaluation is performed in a manner consistent with applicable regulatory guidance. Specifically, the calculation of the Reference Temperature for the Nil Ductility Transition (RTNDT) is performed in accordance with Regulatory Guide 1.99 Revision 2 (Reference 8), and the regulatory guidance provided in the meeting minutes from the November 12, 1997 NRC/lndustry meeting on reactor vessel integrity (Reference 9). PTS screening calculations were performed in accordance with 10 CFR 50.61 (Reference1 0). Evaluation results are presented in a format consistent with the data requirements of the NRCs Reactor Vessel Integrity Database (RVID).
DISCUSSION OF CHANGES TO PREVIOUSLY REPORTED INFORMATION The RVID update provided herein is based on peak fast neutron fluence (E > 1.O MeV) values for North Anna Unit 1 and Unit 2 reactor pressure vessels at the end of the license renewal period, as previously submitted to the NRC via Reference 7. The peak reactor vessel inner surface fluence (E> 1.0 MeV) values at the end of the current 60 year operating license (EOL) are:
North Anna Unit 1 North Anna Unit 2 5.90 E l 9 n/cm2 5.91 E l 9 n/cm2 EVALUATION OF EXISTING PTT LIMITS AND LTOPS SETPOINTS RTNDT calculations have been performed for all North Anna Unit 1 and Unit 2 reactor vessel beltline materials at the end of the current 60 year operating license (EOL) with neutron fluence values corresponding to 50.3 EFPY for Unit 1 and 52.3 EFPY for Unit 2 (References 1 and 2). The results are presented in Appendix A. After consideration of the EOL fluence values, the most limiting 1/4-T RTNDT value of 218.5 OF bounds the end-of-license renewal limiting material for both North Anna Units 1 and 2 (Unit 2 Lower Shell Forging 990533/297355). This value is unchanged from that previously provided in Reference 1.
EVALUATION OF PTS SCREENING CALCULATIONS PTS screening calculations have been performed for all North Anna Unit 1 and Unit 2 reactor vessel beltline materials at the end of the current 60 year operating license (EOL) neutron fluence values. The results of these calculations are presented in Appendix A. After consideration of the EOL fluence values, it is concluded that all North Anna Unit 1 and Unit 2 reactor vessel beltline materials continue to meet the 10 CFR 50.61 PTS screening criteria (270 OF for plates, forgings, and axial welds, and 300 O F for circumferential welds).
The limiting RTPTs value of 227.7 OF applies to Unit 2 Lower Shell Forging 990533/297355, Page 2 of 4
as shown in Appendix A. This limiting material is unchanged from that provided in Reference 1.
EVALUATION OF UPPER SHELF ENERGY CALCULATIONS The decrease in Charpy Upper Shelf Energy due to peak end-of-license fluence at the
%-T location is calculated from Regulatory Guide 1.99, Rev. 2 Figure 2 trend curves.
The %-T Upper Shelf Energy values for North Anna Units 1 and 2 beltline materials meet the 50 ft-lb acceptance criteria of 10 CFR 50 Appendix G at end of the current 60-year license period.
CONCLUSIONS The R T ~ T ~
reference temperature calculation results for North Anna Unit 1 and Unit 2 continue to meet the applicable PTS screening criteria in 10 CFR 50.61. The Upper Shelf Energy values for North Anna Units 1 and 2 beltline materials meet the 50 ft-lb acceptance criteria of 10 CFR 50 Appendix G at the end of the current 60-year license period. Further, the RTNDT value used in the development of the current North Anna Unit 1 and Unit 2 Technical Specification Pressure/Temperature limits, LTOPS setpoints, and LTOPS enabling temperature remains valid and conservative for cumulative core burnups up to 50.3 EFPY for North Anna Unit 1, and 52.3 EFPY for North Anna Unit 2, corresponding to the end of the current 60-year license period.
NRC REACTOR VESSEL INTEGRITY DATABASE Dominion requests that information presented in Appendix A be used to update the NRC Reactor Vessel Integrity Database (RVID).
Page 3 of 4
References
- 1. Letter from W. R. Matthews (Dominion) to USNRC, Virginia Electric and Power Company, North Anna Power Station Units 1 and 2, Proposed Technical Specifications Change Request, Reactor Coolant System Pressurenemperature Limits, LTOPS Setpoints and LTOPS Enable Temperatures, Serial No.04-380, dated July 1, 2004; supplemented by letters dated October 28, 2004 and November 16, 2004.
- 2. Letter from John Honcharik (USNRC) to D. A. Christian (Dominion), North Anna Power Station Units 1 and 2 - Issuance of Amendments on Reactor Coolant System Pressure and Temperature Limits (TAC Nos. MC3705 and MC3706), Dominion Serial No.05-460, dated July 8, 2005.
- 3. Letter from John Honcharik (USNRC) to D. A. Christian (Dominion), Correction to Amendment Nos. 242 and 223, for North Anna Power Station (TAC Nos. MC3705 and MC3706), Dominion Serial No.05-594, dated August 23, 2005.
- 4. Letter from L. N. Hartz (Dominion) to USNRC, Virginia Electric and Power Company, North Anna Power Station Units 1 and 2, Surry Power Station Units 1 and 2, Evaluation of Reactor Vessel Materials Surveillance Data, Serial No. 99-452A, dated November 19, 1999.
- 5. Letter from L. N. Hartz (Dominion) to USNRC, Virginia Electric and Power Company, North Anna Power Station Unit 2, Evaluation of Reactor Vessel Materials Surveillance Data, Serial No.00-463, dated September 19,2000.
- 6. Letter from L. N. Hartz (Dominion) to USNRC, Virginia Electric and Power Company, North Anna Power Station Unit 2, Application of Sequoyah 2 Surveillance Data to North Anna Unit 2 Reactor Vessel Weld Material Fabricated from Weld Wire Heat 4278, Serial No. 01 -262, dated April 27,2001.
- 7. Letter from L. N. Hartz (Dominion) to USNRC, Virginia Electric and Power Company (Dominion), Surry and North Anna Power Stations Units 1 and 2, Response to Request for Supplemental Information License Renewal Applications, Serial No.02-601, dated October 15, 2002.
- 8. Regulatory Guide 1.99 Revision 2, Radiation Embrittlement of Reactor Vessel Materials, dated May, 1988.
- 9. Memorandum from K. R. Wichman to E. J. Sullivan, Meeting Summary for November 12, 1997 Meeting with Owners Group Representatives and NEI Regarding Review of Responses to Generic Letter 92-01, Revision 1, Supplement 1 Responses, dated November 19, 1997.
Requirements for Protection Against Pressurized Thermal Shock Events.
1O.Title 10, Code of Federal Regulations, Part 50.61, Fracture Toughness Page 4 of 4
APPENDIX A REACTOR VESSEL MATERIALS DATA TABLES FOR NORTH ANNA UNIT 1 AND UNIT 2
Facility: North Anna Unit 1 Vessel Manufacturer: Rotterdam Dockyard Best-Best-Assigned Estimate Estimate EOL ID Material Inner Surf ART o( RT(PTS) at RPV Weld Wire Heat or Comer Nickel Fluence Chemistry Method of Initial Current Licensing Basis 114-T Lccation Best-Best-Assigned Estimate Estimate EOL ID Material Initial RPV Weld Wire Heat or Copper Nickel Fluence Chemistry Method of
- 1/4-T ART value of 218 5 F was used in the determinatim of PTT limits Current Inner Surf ART Licensing OT RT(PTS) at Basis 114-T Facility: North Anna Unit 2 Vessel Manufacturer: Rotterdam Dockyard
- 114-T ART value of 21 8 5 F was used in the determination of PfT limits Nde Shaded cdk indcate a cnanged value rdative to values prevlwsly submrted in LElter from L N Ham to USNRC. Virginia Electric and Power Company. Nmth Anna Power Statlcm Unlt 2. Appllcatrm d Seq-Survelbnce Data to Nonh Anna Unit
- 2. Reactor Vessd Wela Mated Fabrlcated lrcm Wdd Wire Heal 4278,' dated Apnl27.2001 Page 1 of 2
Facility: North Anna Unit 1 Vessel Manufacturer: Rotterdam Dockyard RPV Weld Wire Heat or Facility: North Anna Unit 2 Vessel Manufacturer: Rotterdam Dockyard Page 2 of 2