ML13228A306

CFR50.46 Annual Report

ML13228A306
Person / Time
Site:	Peach Bottom
Issue date:	08/16/2013
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML13228A306 (13)

Text

August 16, 2013 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

Reference:

1) Letter from Michael D. Jesse (Exelon Generation Company, 10 CFR 50.46 LLC) to U.S. Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report," dated August 17, 2012

2) Letter from GE Hitachi Nuclear Energy (GEH) to Exelon Generation Company, LLC, "1 0 CFR 50.46 Notification Letter 2012-01, Peach Bottom Atomic Power Station (Unit 2 & 3)," dated November 29, 2012 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 17, 2012.

Since the referenced report was issued, one vendor notification of an Emergency Core Cooling System (ECCS) model error/change applicable to PBAPS, Units 2 and 3 has been issued (Reference 2). Also, no ECCS-related changes or modifications have occurred at PBAPS, Units 2 and 3 that affect the assumptions of the ECCS analyses. The vendor notification is summarized below.

1) Notification 2012-01: PRIME Fuel Properties Implementation for Fuel Rod T/M Performance, replacing GESTR Fuel Properties To address inaccuracies in fuel pellet thermal conductivity as a function of exposure, commonly referred to as thermal conductivity degradation (TCD), General Electric Hitachi (GEH) replaced the GESTR-LOCA model with a newer model, PRIME. The most dominant effect impacting the PCT is the way the PRIME fuel properties treat thermal conductivity, which results in a higher fuel stored energy. The PCT impact identified in the notification reflects the difference between the existing GESTR analysis PCT and a conservatively postulated PCT if the analysis were performed with the

U.S. Nuclear Regulatory Commission Peach Bottom Atomic Power Station, Units 2 and 3 10 CFR 50.46 Annual Report August 16, 2013 Page 2 PRIME model. Notification 2012-01 impacted the GE14 PCT by 30°F. The GNF2 PCT remained unaffected. The ECCS-LOCA analysis remains GESTR based and will not be PRIME based until the ECCS-LOCA analysis is reperformed using PRIME.

Three (3) attachments are included with this letter that provide the current 10 CFR 50.46 status for PBAPS, Units 2 and 3.

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

Respectfully, James Barstow Director, Licensing & Regulatory Affairs Exelon Generation Company, LLC Attachments: 1) Peach Bottom Unit 2 I SAFER/GESTR-LOCA I GE14/GNF2 Fuel 10 CFR 50.46 Report

2) Peach Bottom Unit 31 SAFER/GESTR-LOCA I GE14/GNF2 Fuel 1 0 CFR 50.46 Report

3) Assessment Notes cc:

US NRC Region I, Regional Administrator USNRC Senior Resident Inspector, PBAPS USNRC Senior Project Manager, PBAPS R. R. Janati, Bureau of Radiation Protection S. T. Gray, State of Maryland

ATTACHMENT 1 Peach Bottom Unit 21 SAFERIGESTR-LOCA I GE14/GNF2 Fuel 1 0 CFR 50.46 Report

Peach Bottom Unit 2 I SAFER/GESTR-LOCA I GE14/GNF2 Fuel 1 0 CFR 50.46 Report PLANT NAME:

ECCS EVALUATION MODEL:

REPORT REVISION DATE:

CURRENT OPERATING CYCLE:

ANALYSIS OF RECORD (AOR)

Evaluation Model:

Peach Bottom Unit 2 SAFER/GESTR-LOCA August 16, 2013 20 Page 1 of 2

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 Ill, SAFER/GESTR Application Methodology,..

October 1984. (Jet Pump Plant-SAFER)

Calculations:

1. NEDC-32163P,.. Peach Bottom Atomic Power Station Units 2 and 3 SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis,.. January 1993.

2. GENE-J11-03716-09-02P,.. Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14,.. July 2000.

3. GENE-J11-03716-09-02P,.. Errata and Addenda Sheet for Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14,.. October 2007.

4. 0000-0100-8531-R1, "Peach Bottom Atomic Power Station Units 2 & 3 GNF2 ECCS-LOCA Evaluation,.. March 2011.

Fuels Analyzed in Calculations and in Operation: GE14 and GNF2 Limiting Fuel Type: GNF2 Limiting Single Failure-GE14/GNF2: Battery Failure Limiting Break Size/Location-GE14: 0.08 ft2 Small Break in a Recirculation Discharge Pipe Limiting Break Size/Location - GNF2: 0.06 ft2 Small Break in a Recirculation Discharge Pipe Reference PCT-GE14: 1450°F Reference PCT-GNF2: 1870°F

Peach Bottom Unit 2 I SAFER/GESTR-LOCA I GE14/GNF2 Fuel 1 0 CFR 50.46 Report MARGIN ALLOCATION A.

PRIOR LOCA MODEL ASSESSMENTS:

30-Day 10 CFR 50.46 Report dated June 4, 2001 (See Note 1)

Annual 10 CFR 50.46 Report dated December 18, 2002 (See Note 2)

Annual 10 CFR 50.46 Report dated December 3, 2004 (See Note 3)

Annual 10 CFR 50.46 Report dated December 1, 2005 (See Note 4) 30-Day 10 CFR 50.46 Report dated August 22, 2006 (See Note 5)

Annual10 CFR 50.46 Report dated August 22, 2007 (See Note 6)

Annual10 CFR 50.46 Report dated August 22, 2008 (See Note 7)

Annual 10 CFR 50.46 Report dated August 21, 2009 (See Note 8)

Annual 10 CFR 50.46 Report dated August 20, 2010 (See Note 9)

Annual 10 CFR 50.46 Report dated August 19, 2011 (See Note 1 0)

Annual 10 CFR 50.46 Report dated August 17, 2012 (See Note 11)

Net PCT (GE14)

Net PCT (GNF2)

B.

CURRENT LOCA MODEL ASSESSMENTS:

Impact of PRIME Implementation (See Note 12)

Total PCT change from current assessments (GE14)

Total PCT change from current assessments (GNF2)

Cumulative PCT change from current assessments (GE14)

Cumulative PCT change from current assessments (GNF2)

Net PCT (GE14)

Net PCT (GNF2)

Page 2 of 2 GE14 ilPCT =55°F GE14 ilPCT =45°F GE14 ilPCT =0°F GE14 ilPCT =0°F GE14 ilPCT =150°F GE14 ilPCT =0°F GE14 ilPCT=0°F GE14 ilPCT=15°F GE14 ilPCT =0°F GE14 ilPCT=50°F GNF2 ilPCT =50°F GE14 ilPCT =0°F GNF2 ilPCT =0°F 1765°F 1920°F GE14 ilPCT =30°F GNF2 ilPCT =0°F LilPCT =30°F LLlPCT=0°F LlilPCTI=30oF LlilPCTI=OoF 1795°F 1920°F

ATTACHMENT 2 Peach Bottom Unit 31 SAFERIGESTR-LOCA I GE14/GNF2 Fuel 1 0 CFR 50.46 Report

Peach Bottom Unit 3 I SAFER/GESTR*LOCA I GE14/GNF2 Fuel 1 0 CFR 50.46 Report PLANT NAME:

ECCS EVALUATION MODEL:

REPORT REVISION DATE:

CURRENT OPERATING CYCLE:

ANALYSIS OF RECORD (AOR)

Evaluation Model:

Peach Bottom Unit 3 SAFER/GESTR-LOCA August 16. 2013 19 Page 1 of 2

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 Ill, SAFER/GESTR Application Methodology,..

October 1984. (Jet Pump Plant-SAFER)

Calculations:

1. NEDC-32163P,.. Peach Bottom Atomic Power Station Units 2 and 3 SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis,.. January 1993.

2. GENE-J11-03716-09-02P,.. Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14,.. July 2000.

3. GENE-J11-03716-09-02P,.. Errata and Addenda Sheet for Peach Bottom Atomic Power Station ECCS-LOCA Evaluation for GE14,.. October 2007.

4. 0000-01 00-8531-R1,.. Peach Bottom Atomic Power Station Units 2 & 3 GNF2 ECCS-LOCA Evaluation,.. March 2011.

Fuels Analyzed in Calculations and in Operation: GE14 and GNF2 Limiting Fuel Type: GNF2 Limiting Single Failure-GE14/GNF2: Battery Failure Limiting Break Size/Location - GE14: 0.08 ft2 Small Break in a Recirculation Discharge Pipe Limiting Break Size/Location - GNF2: 0.06 ft2 Small Break in a Recirculation Discharge Pipe Reference PCT-GE14: 1450°F Reference PCT-GNF2: 1870°F

Peach Bottom Unit 3 I SAFER/GESTR-LOCA 1 GE14/GNF2 Fuel 1 0 CFR 50.46 Report MARGIN ALLOCATION A.

PRIOR LOCA MODEL ASSESSMENTS:

30-Day 1 0 CFR 50.46 Report dated June 4, 2001 (See Note 1)

Annual 10 CFR 50.46 Report dated December 18, 2002 (See Note 2)

Annual 10 CFR 50.46 Report dated December 3, 2004 (See Note 3)

Annual 1 0 CFR 50.46 Report dated December 1, 2005 (See Note 4) 30-Day 1 0 CFR 50.46 Report dated August 22, 2006 (See Note 5)

Annual 1 0 CFR 50.46 Report dated August 22, 2007 (See Note 6)

Annual 1 0 CFR 50.46 Report dated August 22, 2008 (See Note 7)

Annual 10 CFR 50.46 Report dated August 21, 2009 (See Note 8)

Annual 10 CFR 50.46 Report dated August 20, 2010 (See Note 9)

Annual 10 CFR 50.46 Report dated August 19, 2011 (See Note 1 0)

Annual 1 0 CFR 50.46 Report dated August 17, 2012 (See Note 11)

Net PCT (GE14)

PCT (GNF2)

B.

CURRENT LOCA MODEL ASSESSMENTS:

Impact of PRIME Implementation (See Note 12)

Total PCT change from current assessments (GE14)

Total PCT change from current assessments (GNF2)

Cumulative PCT change from current assessments (GE14)

Cumulative PCT change from current assessments (GNF2)

Net PCT (GE14)

Net PCT (GNF2)

Page 2 of 2 GE14 L1PCT =55°F GE14 L1PCT =45°F GE14 L1PCT =0°F GE14 L1PCT =0°F GE14 L1PCT =150°F GE14 L1PCT =0°F GE14 L1PCT =0°F GE14 L1PCT =15°F GE14 L1PCT =0°F GE14 L1PCT =50°F GE14 L1PCT=0°F GNF2 L1PCT =50° F 1765°F 1920°F GE14 L1PCT =30°F GNF2 L1PCT =0°F l:L1PCT =30°F l:L1PCT=0°F l:IL1PCTI=30°F L IL1PCTI=0° F 1795°F 1920°F

ATTACHMENT 3 Assessment Notes

Assessment Notes Peach Bottom, Units 2 and 3 1.

Prior LOCA Assessment Page 1 of 4 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 1 0°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.

Nuclear Regulatory Commission, "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.

Nuclear Regulatory Commission, "1 0 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 ooF for each error. The total PCT impact of these errors on GE14 fuel was determined to be 0°F.

[

Reference:

Letter from Michael P. Gallagher (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "1 0 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 0°F.

[

Reference:

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

Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report," dated December 1, 2005.]

Assessment Notes Peach Bottom, Units 2 and 3

5.

Prior LOCA Assessment Page 2 of 4 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.

Nuclear Regulatory Commission, "1 0 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 0°F.

[

Reference:

Letter from David P. Helker (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "1 0 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 0°F.

[

Reference:

Letter from David P. Helker (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report," dated August 22, 2008.]

8.

Prior LOCA Assessment The referenced letter provided the annual 50.46 report for Units 2 and 3. This letter reported that GE/GNF identified a Steam Flow Induced Error (SFIE, or Bernoulli 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 GE14 fuel (small break limited) due to the SFIE was reported as 15°F.

[

Reference:

Letter from David P. Helker (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report," dated August 21, 2009.]

9.

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.

Assessment Notes Peach Bottom, Units 2 and 3 Page 3 of 4

[

Reference:

Letter from David P. Helker (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report," dated August 20, 201 0.]

10.

Prior LOCA Assessment The referenced letter reported that the GNF2 fuel design had been introduced into the Peach Bottom Unit 2 core since the previous cycle. The assessment notes above are not applicable to GNF2 fuel. The referenced letter also reported that two vendor notifications of Emergency Core Cooling System (ECCS) model error/changes that were applicable to Peach Bottom were issued. No ECCS-related changes or modifications had occurred at Peach Bottom that affected the assumptions of the ECCS analyses. The errors/changes are summarized below:

The error identified in Reference 2 of the referenced letter involved the way input coefficients were used to direct the deposition of gamma radiation energy produced by the fuel. Correction of this error resulted in a PCT increase of 45°F for both the GE14 fuel and GNF2 fuel.

The error identified in Reference 3 of the referenced letter involved the contribution of heat from gamma ray absorption by the channel. The gamma ray absorption by the channel was found to have been minimized. Correction of this error resulted in a PCT increase of 5°F for both the GE14 fuel and GNF2 fuel.

[

Reference:

Letter from Michael D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report," dated August 19, 2011.]

11.

Prior LOCA Assessment The referenced letter reported that the GNF2 fuel design had been introduced into the Peach Bottom Unit 3 core since the last annual report. The Emergency Core Cooling System (ECCS) model error/changes discussed in Note 10 were applied to the GNF2 fuel in the Peach Bottom Unit 3 core which resulted in a PCT increase of 50°F, identical to the GNF2 fuel in the Unit 2 core.

[

Reference:

Letter from Michael D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report," dated August 17, 2012.]

12.

Current LOCA Assessment Subsequent to the 2012 Annual 50.46 Report (see Note 11 ), one vendor notification was received. To address inaccuracies in fuel pellet thermal conductivity as a function of exposure, commonly referred to as thermal conductivity degradation (TCD), GEH replaced the GESTR-LOCA model with a newer model, PRIME. The most dominant effect impacting the PCT is from the way the PRIME fuel properties treat thermal conductivity, which results in a higher fuel stored energy. The PCT impact identified in the notification reflects the difference between the existing GESTR analysis PCT and a conservatively postulated PCT if the analysis were performed with the PRIME model. The ECCS-LOCA analysis methodology remains GESTR based and will not be PRIME based until the ECCS-LOCA analysis is re-performed using PRIME.

Assessment Notes Peach Bottom, Units 2 and 3 Page 4 of 4 The notification resulted in a ooF PCT impact to GNF2 fuel and a 30°F PCT impact to GE14 fuel. Note that the impact to GNF2 is negligible because Peach Bottom is a small break limited plant and the higher fuel stored energy is not significant in the small break analysis. Also note that though Peach Bottom is currently small break limited, the original licensing basis PCT for GE14 was based on the large break analysis, and as such, the notification reported the impact to GE14 fuel based on the large break analysis, hence the 30°F PCT impact for GE14 fuel. It was confirmed with GEH that the GNF2 small break analysis still bounds the increased PCT for the GNF2 large break analysis including the effects discussed in this notification. GNF2 remains the limiting fuel type in the core.

[

Reference:

Letter from GE Hitachi Nuclear Energy (GEH) to Exelon Generation Company, LLC, "10 CFR 50.46 Notification Letter 2012-01, Peach Bottom Atomic Power Station (Unit 2 & 3)," dated November 29, 2012.]