ML092330846
| ML092330846 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 08/21/2009 |
| From: | David Helker Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML092330846 (11) | |
Text
Exelon Nuclear 200 Exelon Way Kennett Square, PA 19348 August 21, 2009 www.exeloncorp.com Nuclear 10 CFR 50.46 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278
Subject:
10 CFR 50.46 Annual Report
References:
1)
Letter from David P. Helker (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "10 CFR 50.46 Annual Report," dated August 22, 2008 2)
GE 10 CFR 50.46 Notification Letter, 2008-01, "Impact of Steam Flow Induced Error on Level 3 Setpoint for Small Break LOCA Analysis," dated October 17, 2008 The purpose of this letter is to transmit the 10 CFR 50.46 reporting information for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. The previous 50.46 report for PBAPS, Units 2 and 3 (Reference 1) provided the cumulative Peak Cladding Temperature (PCT) errors for the most recent fuel designs through August 22, 2008.
Since the Reference 1 report was issued, one (1) vendor notification of an Emergency Core Cooling System (ECCS) model error/change applicable to PBAPS, Units 2 and 3 has been issued (Reference 2). GE/GNF identified a Steam Flow Induced Error (SFIE, or Bernouli Error) where water level could reach the bottom of the dryer and allow steam to bypass to* the annulus.
This bypass affects the L3 water level measurement, which relies on pressure taps in the annulus. The PCT impact for PBAPS (small break limited) due to the SFIE was determined to be 15°F. Also, no ECCS-related changes or modifications have occurred at PBAPS, Units 2 and 3 that affect the assumptions of the ECCS analyses.
u.s. Nuclear Regulatory Commission PBAPS, Units 2 and 3 10 CFR 50.46 Annual Report August 21, 2009 Three attachments are included with this letter that provide the current PBAPS, Units 2 and 3 10 CFR 50.46 status. Attachments 1 and 2, "Peak Cladding Temperature Rack-Up Sheet," provide information regarding the PCT for the limiting Loss of Coolant Accident (LOCA) analysis evaluations for PBAPS, Units 2 and 3, respectively. Attachment 3, "Assessment Notes,"
contains a detailed description for each change or error reported.
If you have any questions, please contact Tom Loomis at 610-765-5510.
Respectfully, David P. Helker Manager - Licensing & Regulatory Affairs Exelon Generation Company, LLC Attachments:
1)
Peak Cladding Temperature Rack-Up Sheet (Peach Bottom Atomic Power Station, Unit 2) 2)
Peak Cladding Temperature Rack-Up Sheet (Peach Bottom Atomic Power Station, Unit 3) 3)
Assessment Notes cc:
R. R. Janati, Commonwealth of Pennsylvania S. T. Gray, State of Maryland S. J. Collins, USNRC Administrator, Region I J. Hughey, USNRC Project Manager, PBAPS F. Bower, USNRC Senior Resident Inspector, PBAPS
ATTACHMENT 1 10 CFR 50.46 "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors" Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Peak Cladding Temperature Rack-Up Sheet Peach Bottom Atomic Power Station, Unit 2
Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Peak Cladding Temperature Rack-Up Sheet, PBAPS U2 Page 1 of 2 PLANT NAME:
ECCS EVALUATION MODEL:
REPORT REVISION DATE:
CURRENT OPERATING CYCLE:
ANALYSIS OF RECORD Evaluation Model:
Peach Bottom Unit 2 SAFER/GESTR-LOCA 08/21/09 18 1.
NEDC-23785-1-PA Rev. 1, The GESTR-LOCA and SAFER Models for the Evaluation of the Loss-Of-Coolant Accident Volume II, SAFER - Long Term Inventory Model for BWR Loss-Of-Coolant Analysis," October 1984.
2.
NEDC-30996P-A, "SAFER Model for Evaluation of Loss-of-Coolant Accidents for Jet Pump and Non-jet Pump Plants, Volume I, SAFER - Long Term Inventory Model for BWR Loss-of-Coolant Analysis," October 1987.
3.
NEDC-32950P, "Compilation of Improvements to GENE's SAFER ECCS-LOCA Evaluation Model," January 2000.
4.
NEDC-23785-1-PA Rev. 1, "The GESTR-LOCA and SAFER Models for the Evaluation of the Loss-Of-Coolant Accident Volume III, SAFER/GESTR Application Methodology,"
October 1984.
(Jet Pump Plant - SAFER)
Calculations:
1.
"Peach Bottom Atomic Power Station, Units 2 and 3 SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis," NEDC-32163P, January 1993.
2.
"Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14," General Electric Company, GENE-J11-03716-09-02P, July 2000.
3.
Errata &Addendum NO.1 to GENE-J11-03716-09-02P, "Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14," October 2007.
Fuel Analyzed in Calculations: P8x8R, GE9, GE11/13 and GE14 Limiting Fuel Type: GE14 (Note: P8x8R, GE9 and GE11/GE13 are no longer in operation and are not considered for defining the limiting fuel type)
Limiting Single Failure: Battery Failure Limiting Break Size and Location: 0.08 ft2 Small Break in a Recirculation Discharge Pipe Reference Peak Cladding Temperature (PCT) - GE14 PCT =1450°F
Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Peak Cladding Temperature Rack-Up Sheet, PBAPS U2 MARGIN ALLOCATION A.
PRIOR LOCA MODEL ASSESSMENTS Page 2 of 2 10 CFR 50.46 Report dated June 4, 2001 (See Note 1)
GE14 ~PCT =55°F 10 CFR 50.46 Report dated December 18, 2002 (See Note 2)
GE14 ~PCT =45°F 10 CFR 50.46 Report dated December 3, 2004 (See Note 3)
GE14 ~PCT =OaF 10 CFR 50.46 Report dated December 1, 2005 (See Note 4)
GE14 ~PCT =OaF 10 CFR 50.46 Report dated August 22, 2006 (See Note 5)
GE14 ~PCT =150°F 10 CFR 50.46 Report dated August 22, 2007 (See Note 6)
GE14 ~PCT =OaF 10 CFR 50.46 Report dated August 22, 2008 (See Note 7)
GE14 ~PCT =OaF Net PCT lGE14) 1700°F B.
CURRENT LOCA MODEL ASSESSMENTS GE LOCA Model error due to SFIE (See Note 8)
GE14 ~PCT =15°F Total PCT change from current assessments (GE14)
L~PCT =15°F Cumulative PCT change from current assessments (GE14)
L I~PCT I =15°F Net PCT lGE14) 1715°F
ATTACHMENT 2 10 CFR 50.46 "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors" Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Peak Cladding Temperature Rack-Up Sheet Peach Bottom Atomic Power Station, Unit 3
Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Peak Cladding Temperature Rack-Up Sheet, PBAPS U3 Page 1 of 2 PLANT NAME:
ECCS EVALUATION MODEL:
REPORT REVISION DATE:
CURRENT OPERATING CYCLE:
ANALYSIS OF RECORD Evaluation Model:
Peach Bottom Unit 3 SAFER/GESTR-LOCA 08/21/09 17 1.
NEDC-23785-1-PA Rev. 1, The GESTR-LOCA and SAFER Models for the Evaluation of the Loss-Of-Coolant Accident Volume II, SAFER - Long Term Inventory Model for BWR Loss-Of-Coolant Analysis," October 1984.
2.
NEDC-30996P-A, "SAFER Model for Evaluation of Loss-of-Coolant Accidents for Jet Pump and Non-jet Pump Plants, Volume I, SAFER - Long Term Inventory Model for BWR Loss-of-Coolant Analysis," October 1987.
3.
NEDC-32950P, "Compilation of Improvements to GENE's SAFER ECCS-LOCA Evaluation Model," January 2000.
4.
NEDC-23785-1-PA Rev. 1, "The GESTR-LOCA and SAFER Models for the Evaluation of the Loss-Of-Coolant Accident Volume III, SAFER/GESTR Application Methodology," October 1984.
(Jet Pump Plant - SAFER)
Calculations:
1.
"Peach Bottom Atomic Power Station, Units 2 and 3 SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis," NEDC-32163P, January 1993.
2.
"Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14," General Electric Company, GENE-J11-03716-09-02P, July 2000.
3.
Errata &Addendum No.1 to GENE-J11-03716-09-02P, "Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14," October 2007.
Fuel Analyzed in Calculations: P8x8R, GE9, GE11/13 and GE14 Limiting Fuel Type: GE14 (Note: P8x8R, GE9 and GE11/GE13 are no longer in operation and are not considered for defining the limiting fuel type)
Limiting Single Failure: Battery Failure Limiting Break Size and Location: 0.08 ft2 Small Break in a Recirculation Discharge Pipe Reference Peak Cladding Temperature (PCT) - GE14 PCT = 1450°F
Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Peak Cladding Temperature Rack-Up Sheet, PBAPS U3 MARGIN ALLOCATION A.
PRIOR LOCA MODEL ASSESSMENTS Page 2 of 2 10 CFR 50.46 Report dated June 4, 2001 (See Note 1)
GE14 ~PCT =55°F 10 CFR 50.46 Report dated December 18, 2002 (See Note 2)
GE14 ~PCT =45°F 10 CFR 50.46 Report dated December 3, 2004 (See Note 3)
GE14 ~PCT =OaF 10 CFR 50.46 Report dated December 1, 2005 (See Note 4)
GE14 ~PCT =OaF 10 CFR 50.46 Report dated August 22, 2006 tSee Note 5)
GE14 ~PCT =150°F 10 CFR 50.46 Report dated August 22, 2007 tSee Note 6)
GE14 ~PCT =OaF 10 CFR 50.46 Report dated August 22, 2008 tSee Note 7)
GE14 ~PCT =OaF Net PCT (GE14l 1700°F B.
CURRENT LOCA MODEL ASSESSMENTS GE LOCA Model error due to SFIE (See Note 8)
GE14 ~PCT =15°F Total PCT change from current assessments (GE14)
L~PCT =15°F Cumulative PCT change from current assessments (GE14)
L I~PCTI =15°F Net PCT (GE14l 1715°F
ATTACHMENT 3 10 CFR 50.46 "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors" Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessment Notes Peach Bottom Atomic Power Station, Units 2 and 3
Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Assessment Notes, PBAPS, Units 2 and 3 1.
Prior LOCA Assessment Page 1 of 2 The referenced letter reported two GE LOCA errors related to a SAFER condensation error and a SAFER pressure rate error. The PCT impact for the new errors was determined to be 45°F and 10°F, respectively. These PCT errors applied to all fuel types. This letter constituted a 30-Day report. The total PCT impact of these errors on GE14 fuel was determined to be 55°F.
[
Reference:
Letter from James A. Hutton (Exelon Generation Company, LLC) to U.S.
NRC, "Peach Bottom Atomic Power Station, Units 2 and 3 10 CFR 50.46 Reporting Requirements," dated June 4, 2001.]
2.
Prior LOCA Assessment The referenced letter provided the annual 50.46 report for Units 2 and 3. This letter reported GE LOCA errors related to a SAFER core spray sparger elevation error and a SAFER bulk water level error. The PCT impact for the new errors was determined to be 40°F and 5°F, respectively. These PCT errors applied to all fuel types. The total PCT impact of these errors on GE14 fuel was determined to be 45°F.
[
Reference:
Letter from Michael P. Gallagher (Exelon Generation Company, LLC) to U.S. NRC, "10 CFR 50.46 Reporting Requirements," dated December 18, 2002.]
3.
Prior LOCA Assessment The referenced letter provided the annual 50.46 report for Units 2 and 3. This letter reported GE LOCA errors related to a GESTR file interpolation error, a SAFER computer platform change, a WEVOL S1 volume error, a SAFER level/volume table error, a SAFER separator pressure drop error, and a new heat source. The PCT impact for the new errors was determined to be O°F for each error. The total PCT impact of these errors on GE14 fuel was determined to be O°F.
[
Reference:
Letter from Michael P. Gallagher (Exelon Generation Company, LLC) to U.S. NRC, "10 CFR 50.46 Annual Report," dated December 3,2004.]
4.
Prior LOCA Assessment The referenced letter provided the annual 50.46 report for Units 2 and 3. This letter reported that no vendor 50.46 change/error notifications had been received since the last annual report. Therefore, the annual PCT change for GE14 fuel was reported as O°F.
[
Reference:
Letter from Pamela B. Cowan (Exelon Generation Company, LLC) to U.S.
NRC, "10 CFR 50.46 Annual Report," dated December 1, 2005.]
Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Assessments as of August 21, 2009 Assessment Notes, PBAPS, Units 2 and 3 5.
Prior LOCA Assessment Page 2 of 2 The referenced letter provided a 30-day 50.46 report for Units 2 and 3. This letter reported a newly discovered sensitivity to the assumed axial power shape for small break LOCA cases. This sensitivity may result in higher calculated PCT values for top-peaked axial power shapes. Due to this sensitivity, the calculated PCT for Peach Bottom was higher than the previously calculated value. The PCT impact was determined to be 150°F for GE14 fuel. The 0.08 ft2 Small Break in a Recirculation Discharge Pipe is the Licensing Basis PCT event for Peach Bottom for GE14 fuel.
[
Reference:
Letter from Pamela B. Cowan (Exelon Generation Company, LLC) to U.S.
NRC, "10 CFR 50.46 30-Day Report," dated August 22, 2006.]
6.
Prior LOCA Assessment The referenced letter provided the annual 50.46 report for Units 2 and 3. This letter reported that no vendor 50.46 change/error notifications had been received since the last annual report. Therefore, the annual PCT change for GE14 fuel was reported as O°F.
[
Reference:
Letter from David P. Helker (Exelon Generation Company, LLC) to U.S.
NRC, "10 CFR 50.46 Annual Report," dated August 22, 2007.]
7.
Prior LOCA Assessment The referenced letter provided the annual 50.46 report for Units 2 and 3. This letter reported that no vendor 50.46 change/error notifications had been received since the last annual report. Therefore, the annual PCT change for GE14 fuel was reported as O°F.
[
Reference:
Letter from David P. Helker (Exelon Generation Company, LLC) to U.S.
NRC, "10 CFR 50.46 Annual Report," dated August 22, 2008.]
8.
Current LOCA Assessment GE/GNF identified a Steam Flow Induced Error (SFIE, or Bernouli Error) where water level could reach the bottom of the dryer and allow steam to bypass to the annulus. This bypass affects the L3 water level measurement, which relies on pressure taps in the annulus. Scram from the L3 level indication is conservatively modeled in the Small Break ECCS-LOCA analyses assuming Appendix K requirements. The DBA (large break) analyses are confirmed to be unaffected by the SFIE because the modeling relies on signals other than L3 for scram and ECCS response. The PCT impact for PBAPS (small break limited) due to the SFIE was determined to be 15°F.
[
Reference:
GE 10 CFR 50.46 Notification Letter, 2008-01, "Impact of Steam Flow Induced Error on Level 3 Setpoint for Small Break LOCA Analysis," dated October 17, 2008.]