RS-12-046, Supplemental Information Related to License Amendment Request Regarding Measurement Uncertainty Recapture Power Uprate
| ML12093A242 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 03/30/2012 |
| From: | Borton K Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-12-046 | |
| Download: ML12093A242 (13) | |
Text
Exelon Generation Company, LLC www:exeloncorp.com Exelkn 4300 Winfield Road Generation Warrenville, IL 60555 RS-12-046 10 CFR 50.90 March 30, 201Y U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455
Subject:
Supplemental Information Related to License Amendment Request Regarding Measurement Uncertainty Recapture Power Uprate
References:
- 1. Letter from Craig Lambert (Exelon Generation Company, LLC) to U. S. NRC, "Request for License Amendment Regarding Measurement Uncertainty Recapture (MUR) Power Uprate," dated June 23, 2011
- 2. Letter from Kevin F. Borton (Exelon Generation Company, LLC) to U. S.
NRC, "Additional Information Supporting Request for License Amendment Regarding Measurement Uncertainty Recapture Power Uprate," dated February 20, 2012 In Reference 1, Exelon Generation Company, LLC (EGC) requested an amendment to Facility Operating License Nos. NPF-72, NPF-77, NPF-37 and NPF-66 for Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, respectively. Specifically, the proposed changes revise the Operating License and Technical Specifications to implement an increase in rated thermal power of approximately 1.63% based on increased feedwater flow measurement accuracy.
Subsequent to the June 23, 2011 amendment request (Reference 1), EGC has identified portions of that submittal where the NRC could benefit from several clarifications and corrections described in the following paragraphs. These clarifications and corrections pertain to the referenced sections of Attachments 5 "NRC Regulatory Information Summary 2002-03 Requested Information (Proprietary Version)," Reference 1. These changes also apply to , Reference 1, which is the Non-Proprietary version of Attachment 5.
Section 111.15, "LOCA Long Term Mass and Energy Release and Containment Response," and Section VII.6.C, "Appendix J Testing Program," indicated that the MUR reanalyzed peak containment pressure was lower than the current Technical Specification (TS) 5.5.16, "Containment Leakage Rate Testing Program," Pa value and
March 30, 2012 U.S. Nuclear Regulatory Commission Page 2 the reanalyzed value was bounded by the current TS value. In Section VII.6.C EGC stated that no changes or modifications are required to the existing Appendix J Program or procedures. Subsequent review of the Appendix J procedures by EGC identified that certain Appendix J procedures at Byron Station will be revised. As such, EGC is modifying the statement in Section VII.6.C to reflect that certain Appendix J procedures will be revised. Please note that the current Appendix J Program and the current TS Pa value remains unchanged for the MUR power uprate.
Section V.1 .D, "Grid Stability," documented that the PJM Interconnection completed a system stability analysis for Braidwood. The results of this analysis were provided in Attachment 10a, "Generator Transient Stability Study and Interim Generator Deliverability Study for Braidwood Generating Station Units 1 and 2 MUR Upgrade."
The study indicated that three of the breaker failure scenarios that were studied were unstable. The study provided remediation measures involving the adjustment of the critical clearing time (CCT). Subsequent to application submittal, PJM Interconnection provided a revised Generator Transient Stability Study and Interim Generator Deliverability Study report for the Braidwood Station Units 1 and 2 MUR power uprate.
The revised Generator Transient Stability Study and Interim Generator Deliverability Study report for the Braidwood Station Units 1 and 2 is provided in Attachment 1 to this letter. The revised study indicated that following the implementation of new ComEd criteria, all of the breaker failure scenarios, considered in this study, were found to be stable. The revised CornEd criteria included removal of a requirement that a 1-cycle margin be maintained in the delayed-cleared portion of tested fault scenarios that involved breaker failure. ComEd determined that the one-cycle margin required for the primary-cleared portion of tested faults was adequate for both primary-cleared and delay-cleared fault scenarios. The revised ComEd generator stability criteria continue to be more conservative than the related NERC Standards.
Subsequent to the February 20, 2012 EGC Request for Additional Information (RAI) response letter (Reference 2), EGC has identified corrections described in the following paragraphs.
Regarding RAI request number 12, the NRC asked that EGC discuss further information relative to, before and after uprate, the maximum stress intensity and the cumulative fatigue usage factors for the critical components of the primary and secondary sides, including nozzles, of the replacement steam generators and the respective service conditions for the replacement steam generators. EGC provided the requested information in the form of a series of tables. Subsequent to submittal of the RAI response, EGC was notified by the manufacturer of the replacement steam generators (i.e., Babcock & Wilcox Canada, Ltd.) that they had identified an error in the calculations for the MUR power uprate qualification analysis of the Braidwood and Byron replacement steam generators. It was determined that this error was carried forward in values provided to the NRC in Reference 2.
As a result of the revised calculation EGC is providing revised tables to Reference 2 in Attachment 2 to this letter. Tables EMCB R12-1, "Stress Intensity (SI) and Fatigue Usage Factors (FUF) for Level A & B Conditions," EMCB R12-2, "Primary Membrane and Bending Stresses for Level C Conditions," and EMCB R12-3, "Primary Membrane and Bending Stresses for Level D Conditions," are to replace the same referenced tables provided in the response to RAI number 12 in Reference 2 in their entirety.
Additionally, to clarify our response, the values identified as "Orig." in these tables, as well as in Table EMCB R12-4, "Average and Maximum Stresses for Studs/Bolts," in
March 30, 2012 U.S. Nuclear Regulatory Commission Page 3 Reference 2, represent values based on the original power conditions for the replacement steam generators at 3425 MWt and not the current power level of 3586.6 MWt.
Babcock & Wilcox has since entered the error into their corrective action program, performed a review of the affected engineering report and all associated calculations, and completed the necessary revisions to the calculation. The values previously provided were incorrectly taken from lower tier calculation documents instead of the correct values from the Design Reports. Babcock & Wilcox has verified that the error did not change the conclusion that the Byron and Braidwood Unit 1 replacement steam generators meet the structural requirements for Class 1 components of the ASME Code for Design, Test, Level A, B, C and D Service Levels under the MUR power uprate conditions.
EGC has reviewed the information supporting a finding of no significant hazards consideration and the environmental consideration provided to the NRC in Reference 1. The information provided in this supplement letter does not affect the previously stated bases in Reference 1 for concluding that the proposed license amendment does not involve a significant hazards consideration. In addition, the information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.
There are no regulatory commitments contained in this letter.
Should you have any questions concerning this letter, please contact Leslie E. Holden at (630) 657-3316.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 3 0 th day of March 2012.
Respectfully, Kevin F. Borton Manager, Licensing - Power Uprate Attachments: Generator Transient Stability Study and Interim Generator Deliverability Study report for the Braidwood Station Units 1 and 2 Revised Stress Intensity and Cumulative Usage Factors Tables for Braidwood and Byron Replacement Steam Generators cc: NRC Regional Administrator, Region III NRC Senior Resident Inspector - Braidwood Station NRC Senior Resident Inspector - Byron Station Illinois Emergency Management Agency - Division of Nuclear Safety
Braidwood and Byron Stations Supplemental Information Related to License Amendment Request Regarding Measurement Uncertainty Recapture Power Uprate March 30, 2012 ATTACHMENT 2 Revised Stress Intensity and Cumulative Usage Factors Tables for Braidwood and Byron Replacement Steam Generators Tables EMCB R12-1 through 3 Braidwood Station, Units 1 and 2 Byron Station Units 1 and 2 Facility Operating License Nos. NPF-72, NPF-77, NPF-37 and NPF-66
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 1 NON-PROPRIETARY Table EMCB R12 Stress Intensity (SI) and Fatigue Usage Factors (FUF) for Level A & B Conditions MUR SI Range Orig. SI MUR SI Orig. SI MUR Orig. FUF Component! Location (ksi) Range Limit Limit FUF FUF Limit (ksi) (ksi) (ksi)
Tubesheet Primary Head / Tubesheet Juncture 38.5* 82.1 80.1 87.3 0.880 0.741 1.0 Secondary Shell / Tubesheet Juncture 86.4 85.4 95.0 87.3 0.160 0.223 1.0 Tubesheet Perforated Region 90.1 90.0 95.0 93.6 0.330 0.387 1.0 Primary Nozzle Primary Nozzle 67.85 67.85 I 80.1 80.1 0.839 0.839 1.0 Primary nozzle safe end 57.37 57.37 60.3 60.3 0.096 0.096 1.0 Primary Manway Cover 30.3 30.3 80.1 80.1 0.006 0.006 1.0 Shell/flange 46 46.0 80.1 80.1 0.121 0.121 1.0 Stud See Table EMCB R12-4 for Average and 0.871 0.871 1.0 Maximum Bolt Stresses Primary Head Support Pad 79.4 79.4 80 80 0.67 0.67 1.0 Primary Divider Plate 63.9 63.9 69.9 69.9 0.905 0.904 1.0 Small Nozzles 3,4" Nozzles 13.96 11.83 26.7 26.7 0.81 0.734(1) 1.0 Steam Drum/Cone Lower Shell Assembly 74.22 62.9 80.1 80.1 0.025 0.021 1.0 8" Shell Cone Handhole Shell/cover/flange 67.3 57 80 80 0.256 0.074 1.0 Stud See Table EMCB R12-4 for Average and 0.987 0.975 1.0 Maximum Bolt Stresses 6" Feedring Handhole Shell/cover/flange 78.0 76.5 80 80 0.823 0.374 1.0 Stud See Table EMCB R12-4 for Average and 0.823 0.84 1.0 Maximum Bolt Stresses
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 2 NON-PROPRIETARY Table EMCB R12 Stress Intensity (SI) and Fatigue Usage Factors (FUF) for Level A & B Conditions MUR SI Range Orig. SI MUR SI Orig. SI MUR Orig. FUF Component / Location (ksi) Range Limit Limit L (ksi) (ksi) (ksi) FUF FUF Limit 2" Inspection Port Shell/cover/flange 77.6 65.8 80 80 0.214 0.205 1.0 Stud See Table EMCB R 12-4 for Average and 0.864 0.807 1.0 Maximum Bolt Stresses Secondary Manway Flange/Steam Drum Head 55.2 46.8 80 80 0.02 0.019 1.0 Diaphragm 60.4 60.4 69.9 69.9 0.02 0.015 1.0 Cover 25.5 21.6 80 80 0.02 0.000 1.0 Stud See Table EMCB R12-4 for Average and 0.973 0.752 1.0 Maximum Bolt Stresses Pressure Boundary Attachments Seal Skirt Transition Juncture 44.6* 44.6* 56.1 56.1 0.538 0.476 1.0 Skirt Weld 41.2* 41.2* 56.1 56.1 0.74 0.559 1.0 Steam Drum Head/Steam Drum Juncture 48.6 48.6 80.1 80.1 0.401 0.209 1.0 Steam Drum / Trunion Juncture 64.8* 80 80.0 80.0 0.688 0.239 1.0 Primary Deck Lug/Steam Drum Juncture 72 61 80 80 0.608 0.546 1.0 Shroud Lug 40.6 34.4 58.5 58.5 0.652 0.545 1.0 Shroud Lug/ Shell Juncture 54.7 46.4 80 80.1 0.652 0.545 1.0 Upper Vessel Support! Steam Drum 70.6 59.8 80.1 80.1 0.021 0.010 1.0 Juncture Main Feedwater Nozzle Shell/nozzle juncture 77.6 77.6 80 80 0.408 0.346 1.0 Nozzle 69.3 58.7 80 80 0.046 0.039 1.0 Transition Ring /Thermal Sleeve 27.2* 27.2* 69.9 69.9 0.985 0.945 1.0
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 3 NON-PROPRIETARY Table EMCB R12 Stress Intensity (SI) and Fatigue Usage Factors (FUF) for Level A & B Conditions MUR SI Range Orig. SI MUR SI Orig. SI MUR Orig. FUF Component / Location (ksi) Range Limit Limit FUF FUF Limit (ksi) (ksi) (ksi)
Steam Outlet Nozzle Nozzle/Safe End Juncture 26.8 22.7 70 70 0 0 1.0 Nozzle & Head Juncture 69.5 58.9 80 80 0.050(2) 0.035 1.0 Steam Drum Head 71.3 60.4 80 80 0.049 0.033 1.0 Perforated Zone 76.7 65 80 80 0.080 0.059 1.0 Small Nozzles 3" Blowdown Nozzle 12.02 10.19 26.7 26.7 0.85 0.928 1.0 3" Recirculation Nozzle 17.70(') 15 26.7 26.7 0.99(3) 0.938 1.0 3/4" Nozzles 13.96 11.83 26.7 26.7 0.81 0.734(1) 1.0 Acoustic Sensor Pad 54.63 46.3 56 56 0.81 0.777 1.0 Tubes 76.27(') 73.8 79.8 79.8 0.19 0.19 1.0 Notes:
- Bold/Italicizedstress range values were determined using simplified elastic-plastic analysis in accordance with NB-3228.5.
(1) Value changed from Table EMCB R12-1 in Reference A1-1. Revised due to transcription error from Reference A1-2. Revised value for Orig. FUF from 0.679.
(2) Value changed from Table EMCB R12-1 in Reference A1-1. Revised due to transcription error from Reference A1-2. Revised value for MUR FUF from 0.048.
(3) Value changed from Table EMCB R12-1 in Reference A1-1. Revised to accommodate increased external loads as reported in Reference A1-2. Revised values for MUR SI Range from 12.02 ksi and for MUR FUF from 0.5.
(4) Value changed from Table EMCB R12-1 in Reference A1-1. Reanalyzed to reflect MUR flow-induced vibration (FIV) analysis results Reference A1-3. Revised value for MUR SI Range from 73.8 ksi.
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 4 NON-PROPRIETARY Table EMCB R12 Primary Membrane and Bending Stresses for Level C Conditions MUR Orig. MUR Pm SI Orig.
PL/Pm+ MUR Pm+Pb PL, Orig.
Pm+PbPL, Component/ Location Pm/PL SI Pm/PL SIL Limit Pb Sm Pb SI SI Lmit Smit (s)(s) Limit Pb SI Pb SI SI Limit S1 Limit (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi)
Primary Head /Tubesheet 29.6 29.2 38.79 38.79 49.9 49.2 64.65 64.65 Secondary Shell Primary nozzle Bounded by design conditions Primary Manway Cover 13.33 13.33 38.8 38.8 24.39 24.39 58.2 58.2 Shell/flange 21.31 21.31 38.81 38.8 21.31 21.31 58.2 58.2 Primary Head Support Pad Bounded by design conditions Primary Divider Plate Bounded by design conditions Small Nozzles Bounded by design conditions Steam Drum/Cone/Lower Shell Bounded by design conditions Assembly 8" Shell Cone Handhole 29.3 29.02 29.37 29.37 32.6 32.2 48.06 48.06 6" Feedring Handhole 29.3 29.02 29.37 29.37 35.0(1) 34.6 48.06 48.06 2" Inspection Port 10.6 10.5 28 28 20.7 20.5 42 42 Secondary Manway Bounded by design conditions
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 5 NON-PROPRIETARY Table EMCB R12 Primary Membrane and Bending Stresses for Level C Conditions MUR Orig. MUR Pm SI Orig.
PLIPm+ MUR Pm+Pb PL, Orig.
Pm+Pb PL, Component /Location Pm/PL SI Pm/PL SI mS mS Um um mP mP Copnn I Limit Limit Pb SI Pb SI SI Limit SI Limit (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi)
Pressure Boundary Attachments Seal Skirt Transition Juncture Bounded by design conditions Skirt Weld Bounded by design conditions Steam Drum Head / Steam Drum Bounded by design conditions Juncture Steam Drum / Trunion Juncture 28.8 28.5 39.4 39.4 36 35.6 65.7 65.7 Primary Deck Lug/Steam Drum 29.8 29.8 43.8 43.8 65.2 65.2 65.7 65.7 Juncture Shroud Lug 2.32 2.3 26.37 26.37 5.8 5.73 43.95 43.95 Shroud Lug/Shell Juncture 24.9 24.63 36.9 36.9 26.9 26.61 65.7 65.7 Upper Vessel Support/ Steam Bounded by design conditions Drum Juncture Main Feedwater Nozzle Shell/nozzle juncture 29 28.7 43.8 43.8 46.6 46.1 65.7 65.7 Nozzle 28.6 28.3 43.8 43.8 28.6 28.3 65.7 65.7 Transition ring / Thermal sleeve 9.5 9.4 28 28 26.1 25.8 41.9 41.9 Steam Outlet Nozzle Bounded by design conditions Small Nozzles Bounded by design conditions Tubes 22.95 22.7 35.2 35.2 32.35 32 52.9 52.9 Tubes (external pressure) 0.1681 0.166 1.424 1.424 ........
Notes:
(1) Value changed from Table EMCB R12-2 in Reference Al-1. Revised due to transcription error from Reference A1-3. Revised value for MUR PL/Pm+ Pb SI from 34.6 ksi.
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 6 NON-PROPRIETARY Table EMCB R12 Primary: Membrane and Bending Stresses for Level D Conditions MUR Orig. MUR Orig. MUR Orig. MUR PL, Orig. PL, MR rg. Pm SI Pm SI PLIPm+ PL/Pm+ Pm+Pb Pm+Pb Component / Location Pm/PL SI Pm/PL SI P (ksi) (ksi) Limit Limit Pb SI Pb SI SI Limit SI Limit (ksi)(ksi) - (ksi) (ksi) (ksi) (ksi) (ksi) (ksi)
Primary Head / Tubesheet / 29.6 29.1 56 56 68.7 67.8 84 84 Secondary shell Primary Nozzle Primary nozzle 51.51 51.51 56 56 76.27 76.27 84 84 Primary nozzle safe end 27.7 27.7 48.9 48.9 39.93 39.93 72.36 72.36 Primary Manway Cover 13.33 13.33 56 56 24.39 24.39 84 84 Shell/flange 21.31 21.31 56 56 21.31 21.31 84 84 Primary Head Support Pad 15.9 15.9 56 56 53.9 53.9 84 84 Primary Divider Plate 35.4(1) 35.4 52.5 52.5 60.4(1) 60.4 67.5 67.5 Small Nozzles
,*," Nozzles 16.9 16.7 42.8 42.8 38 37.5 64 64 Steam Drum/Cone/Lower Shell 46.2 35.6 56 56 61.5 60.7 84 84 Assembly 8" Shell Cone Handhole 40.9 40.4 56 56 40.9 40.4 84 84 6" Feedring Handhole 35.3 34.8 56 56 35.3 34.8 84 84 2" Inspection Port 55.1 54.4 56 56 60.9 60.1 84 84 Secondary Manway 47.7 47.1 56 56 47.7 47.1 84 84
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 7 NON-PROPRIETARY Table EMCB R12 Primary: Membrane and Bending Stresses for Level D Conditions Orig. MUR Orig. MUR PL, Orig. PL, MUR MR Oi.
Orig. Pm MURSI PmS Pm PmS SI PIJPm+
u +
PLIPm+
p+
Pm+Pb Pmb Pm+Pb Pmb Component /Location Pm/PL SI Pm/PL SI Copnn I Limit Limit Pb SI Pb SI SI Limit SI Limit (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi)
Pressure Boundary Attachments Seal Skirt Transition Juncture 8.81 8.7 49 49 26.8 26.5 73.5 73.5 Steam Drum Head/Steam Drum 35.35 34.9 56 56 46.1 45.5 84 84 Juncture Steam Drum / Trunnion Juncture 35.8 35.3 56 56 42.7 42.2 84 84 Primary Deck Lug/Steam Drum 40.1 40.1 56 56 74 74 84 84 Juncture Shroud Lug 39 38.5 49 49 43.4 42.9 73.5 73.5 Shroud Lug/ Shell Juncture 33.5 33.1 56 56 39.5 39.1 84 84 Upper Vessel Support/Steam 28 27.6 56 56 63.9 63.1 84 84 Drum Juncture Main Feedwater Nozzle Shell/nozzle juncture 33.9 33.5 56 56 83.8 83.3 84 84 Nozzle 7.9 7.8 56 56 29.5 29.1 84 84 Transition ring/Thermal sleeve 12.9 12.7 49 49 53 52.3 73.5 73.5 Steam Outlet Nozzle Pipe extension 16.68 16.47 42 42 43.38 42.82 63 63 Nozzle/Safe End Juncture 14.99 14.8 49 49 40.84 40.32 73.5 73.5 Nozzle 25.43 25.1 56 56 54.82 54.12 84 84 Steam Drum Head 26.34 26 56 56 55.84 55.12 84 84 Perforated Zone 32.62 32.2 56 56 61 60.22 84 84 Small Nozzles 3" Blowdown Nozzle 31 .0(2) 30.6 42.8 42.8 62.0(2) I 61.2 64 64 3" Recirculation Nozzle 31.0(2) 30.6 42.8 42.8 62.0(2), 61.2 64 64 Acoustic Sensor Pad Bounded by shell cone/steam drum juncture
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 8 NON-PROPRIETARY Table EMCB R12 Primary: Membrane and Bending Stresses for Level D Conditions MUR Orig. MUR Orig. MUR Orig. MUR PL, Orig. PL, MUR g Pm SI Pm SI PL/Pm+ PL/Pm+ Pm+Pb Pm+Pb Copnn I Limit Limit Pb SI Pb SI SI Limit SI Limit (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi)
Tubes 31.4 31 56 56 68.68 67.8 84 84 Tubes (external pressure) 1.142 1.127 1.780 1.780 . .......
Notes:
- Value changed from Table EMCB R12-3 in Reference Al-1.
(1) Conservatism in previous analysis in Reference A1-3 removed since level D loads on divider plate are unchanged between MUR and Original power levels. Revised values for MUR Pm/PL SI from 35.9 ksi and for MUR PL/Pm+Pb SI from 61.2 ksi.
(2) Revised to accommodate increased external loads as reported in Reference A1-2. Revised values for MUR Pm/PL SI from 21.1 ksi and for MUR PL/Pm+Pb SI from 42.1 ksi.
Braidwood/Byron Stations MUR LAR Response to RAI March 30, 2012 Attachment 2, page 9 NON-PROPRIETARY References Al-1 Letter from Kevin F. Borton (Exelon Generation Company, LLC) to U. S. NRC, "Additional Information Supporting Request for License Amendment Regarding Measurement Uncertainty Recapture Power Uprate," dated February 20, 2012 Al -2 B&W Canada Report: Exelon Byron and Braidwood Stations RSG Transient Analysis Report No: 222-7720-SR-2, Rev. 6.
A1-3 B&W Canada Report: Exelon Byron and Braidwood Stations Unit 1 RSG MUR Power Uprate Structural Analysis Report No: 236R-SR-01, Rev. 1.