ML062360072

Submittal of 30-day Report in Accordance with 10 CFR 50.46(a)(3)(ii) for a Calculated Peak Cladding Temperature (PCT) Change More That 50 Degrees for Peach Bottom Atomic Power Station (Pbaps), Units 2 and 3

ML062360072
Person / Time
Site:	Peach Bottom
Issue date:	08/22/2006
From:	Cowan P Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML062360072 (11)

Text

Exelon Nuclear www.exeloncorp.com Nucl ear 200 Exelon Way Kennett Square, PA 19348 10CFR50.46 August 22,2006 US. 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 30-Day Report

References:

1. Letter from Pamela 6. Cowan (Exelon Generation Company, LLC) to U. S. Nuclear Regulatory Commission, 10 CFR 50.46 Annual Report, dated December 1,2005

2. Letter from GE, 10 CFR 50.46 Notification Letter 2006-01, Impact of Top Peaked Power Shape for Small Break LOCA Analysis, July 28, 2006 The purpose of this letter is to submit a 30-day report in accordance with 10 CFR 50.46(a)(3)(ii) for a calculated Peak Cladding Temperature (PCT) change more that 50 degrees for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. The most recent annual 50.46 report for Peach Bottom Atomic Power Station (Reference 1) provided the cumulative PCT errors for the most recent fuel designs through November 30,2005.

As discussed in the Reference 2 letter GE identified a change in the calculated PCT more than 50 degrees. GE reported a newly discovered sensitivity to the assumed axial power shape for small break Loss-of-Coolant Accident (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 PBAPS, Units 2 and 3 was higher than the previously calculated value. The PCT impact of the new power shape sensitivity was determined to be 15O0Ffor 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.

Peach Bottom Atomic Power Station, Units 2 and 3 10 CFR 50.46 30-Day Report August 22,2006 Page 2 Two attachments are included with this letter that provide the current Peach Bottom Atomic Power Station, Units 2 and 3 10 CFR 50.46 status with this additional change. Attachments 1 and 2 (Peak Cladding Temperature Rack-Up Sheet) provide updated information regarding the PCT for the Licensing Basis event evaluations for Peach Bottom Atomic Power Station, Units 2 and 3, respectively. Attachment 3, LAssessmentNotes, contains a detailed description for each change or error reported.

If you have any questions, please contact Tom Loomis at 610-765-5510.

Respectfully, Pamela 6. Cowan Director, 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-UpSheet (Peach Bottom Atomic Power Station, Unit 3)

3) Assessment Notes (Peach Bottom Atomic Power Station, Units 2 and 3) cc: S. J. Collins, USNRC Administrator, Region I J. Kim, USNRC Project Manager, PBAPS F. L. Bower, USNRC Senior Resident Inspector, PBAPS

ATTACHMENT I 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 30-Day Report 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 30-Day Report Attachment 1 Peak Cladding Temperature Rack-Up Sheet, PBAPS U2 Page 1 of 2 PLANT NAME: Peach Bottom Unit 2 ECCS EVALUATION MODEL: SAFEWG ESTR-LOCA REPORT REVISION DATE: 08/22/06 CURRENT OPERATING CYCLE: -

16 ANALYSIS OF RECORD EvaIuation ModeI:

1. NEDC-23785-1-PA Rev. 1, The GESTR-LOCA and SAFER Models for the Evaluation of the Loss-Of-CoolantAccident Volume I I , SAFER - Long Term Inventory Model for BWR Loss-Of-CoolantAnalysis, October 1984.

2. NEDC-30996P-A, SAFER Model for Evaluation of Loss-of-CoolantAccidents for Jet Pump and Non-jet Pump Plants, Volume I, SAFER - Long Term Inventory Model for BWR Loss-of-CoolantAnalysis, October 1987.

3. NEDC-32950P, Compilation of Improvements to GENES 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-CoolantAccident Volume I I I, SAFER/GESTR Application Methodology, October 1984.

(Jet Pump Plant - SAFER)

Calculations:

1. Peach Bottom Atomic Power Station, Units 2 and 3 SAFEWGESTR-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-JI1-03716-09-02P,July 2000.

Fuel Analyzed in Calculations: P8x8R, GE9, GEI 1/13 and GE14 Limiting Fuel Type: GE14 (Note: P8x8R, GE9 and GEI llGE13 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 30-Day Report Attachment 1 Peak Cladding Temperature Rack-Up Sheet, PBAPS U2 Page 2 of 2 MARGIN ALLOCATION A. PRIOR LOCA MODEL ASSESSMENTS I 10 CFR 50.46 Report dated June 4,2001 (See Note 1) I GE14 APCT = 55°F I I 10 CFR 50.46 Report dated December 18,2002 (See Note 2) I GE14 APCT = 45°F I I 10 CFR 50.46 Report dated December 03,2004 (See Note 3) I GE14 APCT = 0°F I I 10 CFR 50.46 Report dated December 01,2005 (See Note 4) I GE14 APCT = 0°F I I Net PCT (GE14) 1550 O F

6. CURRENT LOCA MODEL ASSESSMENTS I 10 CFR 50.46 Report dated July 28,2006 (See Note 5) I GE14APCT= 150°F I I Total PCT change from current assessments (GE14)

~ ~~~~~~

I CAPCT = 150"Fl I Cumulative PCT change from current assessments (GEI 4) I C IAPCTl = 150°F I I Net PCT (GE14) 1700 O F

ATTACHMENT I!

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 30-Day Report 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 30-Day Report Attachment 2 Peak Cladding Temperature Rack-Up Sheet, PBAPS U3 Page 1 of 2 PLANT NAME: Peach Bottom Unit 3 ECCS EVALUATION MODEL: SAFEWG ESTR-LOCA REPORT REVISION DATE: 08/22/06 CURRENT OPERATING CYCLE: -

16 ANALYSIS OF RECORD Evaluation Model:

1. NEDC-23785-1-PA Rev. 1, The GESTR-LOCA and SAFER Models for the Evaluation of the Loss-Of-CoolantAccident Volume II, SAFER - Long Term Inventory Model for BW R Loss-Of-CoolantAnalysis, October 1984.

2. NEDC-30996P-A, SAFER Model for Evaluation of Loss-of-CoolantAccidents for Jet Pump and Non-jet Pump Plants, Volume I, SAFER - Long Term Inventory Model for BW R Loss-of-CoolantAnalysis, October 1987.

3. NEDC-32950P, Compilation of Improvements to GENES 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-CoolantAccident Volume III, SAFEWGESTR 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-JI1-03?16-09-02P,July 2000.

Fuel Analyzed in Calculations: P8x8R, GE9, GEI 1/13 and GE14 Limiting Fuel Type: GE14 (Note: P8x8R, GE9 and GEI llGE13 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 30-Ray Report Attachment 2 Peak Cladding Temperature Rack-Up Sheet, PBAPS U3 Page 2 of 2 MARGIN ALLOCATION A. PRIOR LOCA MODEL ASSESSMENTS I 10 CFR 50.46 Report dated June 4,2001 (See Note 1) I GE14 APCT = 55°F I I 10 CFR 50.46 Report dated December 18,2002 (See Note 2) I GE14 APCT = 45°F I I 10 CFR 50.46 Report dated December 03,2004 (See Note 3) I GE14 APCT = 0°F I I 10 CFR 50.46 Report dated December 01,2005 (See Note 4) I GE14 APCT = 0°F I Net PCT (GE141 1550 O F B. CURRENT LOCA MODEL ASSESSMENTS I 10 CFR 50.46 Report dated July 28,2006 (See Note 5) I GE14 APCT = 150°F I I Total PCT change from current assessments (GE14) I CAPCT = 150°F I I Cumulative PCT change from current assessments (GE14) I C IAPCTI =150°F I Net PCT (GE141 1700 "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 30-Day Report Attachment 3 Assessment Notes, PBAPS U2 and U3 Page 1 of 2

1. Prior LOCA Assessment 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 IOOF, 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 %OF.

[

Reference:

Letter from J. A. Hutton (PECO Nuclear) 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 5F, 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) to U.S. NRC, 10 CFR 50.46 Reporting Requirements, dated December 18, 2002.1

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 IeveI/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 3,2004.1

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 0°F.

[

Reference:

Letter from Pamela B. Cowan (Exelon Generation Company, LLC) to US.

Nuclear Regulatory Commission, 10 CFR 50.46 Annual Report, dated December 01, 2005.]

Report of the Emergency Core Cooling System Evaluation Model Changes and Errors 30-Day Report Attachment 3 Assessment Notes, PBAPS U2 and U3 Page 2 of 2

5. Current LOCA Assessment GE 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 of the new power shape sensitivity 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:

GE 10 CFR 50.46 Notification Letter, 2006-01, July 28,2006.1