ML13135A069

Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02

ML13135A069
Person / Time
Site:	Byron, Braidwood
Issue date:	05/14/2013
From:	Gullott D Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-04-002, RS-13-134
Download: ML13135A069 (7)

Text

4300 Winfield Road Warrenville. IL 60555 630 657 2000 Office 10 CFR 50.54(f)

Exelon Generation, RS-13-134 May 14, 2013 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:

Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02

References:

(1)

Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,"

dated September 13, 2004 (2)

SECY-12-0093: R. W. Borchardt, U.S. Nuclear Regulatory Commission, to The Commissioners, U.S. Nuclear Regulatory Commission, 'Closure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance," dated July 9, 2012 (3)

Letter from W. H. Ruland (NRC) to J. C. Butler (NEI), "Nuclear Regulatory Commission Review of Generic Safety Issue-191 Nuclear Energy Institute Revised Schedule for Licensee Submittal of Resolution Path,' dated November 21, 2012 (4)

Letter from S. Bahadur (NRC) to W. A. Nowinowski (PWR Owners Group),

"Final Safety Evaluation for Pressurized Water Reactor Owners Group Topical Report WCAP-1 6793-NP, Revision 2, 'Evaluation of Long-Term Cooling Considering Particulate Fibrous and Chemical Debris in the Recirculating Fluid,"' dated April 8, 2013 Generic Safety Issue (GSI)-191, "Assessment of Debris Accumulation on Pressurized-Water Reactor (PWR) Sump Performance," remains a long-standing open issue. GSI-191 concluded that debris could clog the containment sump strainers in pressurized water reactors (PWRs),

leading to the loss of net positive suction head for the emergency core cooling system (ECCS) and containment spray system (CSS) pumps. The Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated September 13, 2004, (Reference 1) requesting that licensees address the issues raised by GSI-1 91. GL 2004-02 was focused on demonstrating compliance with 10 CFR 50.46.

1 4300 Winfield Road Warrenville, IL 60555 Exelon Generation 630 657 2000 Office RS-13-134 May 14, 2013 10 CFR 50.54(f)

U. S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555-0001

Subject:

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 Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02

References:

(1)

Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors, II dated September 13, 2004 (2)

SECY-12-0093: R. W. Borchardt, U.S. Nuclear Regulatory Commission, to The Commissioners, U.S. Nuclear Regulatory Commission, "Closure Options for Generic' Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance'" dated July 9, 2012 (3)

Letter from W. H. Ruland (NRC) to J. C. Butler (NEI), "Nuclear Regulatory Commission Review of Generic Safety Issue-191 Nuclear Energy Institute Revised Schedule for Licensee Submittal of Resolution Path," dated November 21, 2012 (4)

Letter from S. Bahadur (NRC) to W. A. Nowinowski (PWR Owners Group),

"Final Safety Evaluation for Pressurized Water Reactor Owners Group Topical Report WCAP-16793-NP, Revision 2, 'Evaluation of Long-Term Cooling Considering Particulate Fibrous and Chemical Debris in the Recirculating Fluid,'" dated April 8, 2013 Generic Safety Issue (GSI)-191, "Assessment of Debris Accumulation on Pressurized-Water Reactor (PWR) Sump Performance," remains a long-standing open issue. GSI-191 concluded that debris could clog the containment sump strainers in pressurized water reactors (PWRs),

leading to the loss of net positive suction head for the emergency core cooling system (ECCS) and containment spray system (CSS) pumps. The Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors, II dated September 13, 2004, (Reference 1) requesting that licensees address the issues raised by GSI-191. GL 2004-02 was focused on demonstrating compliance with 10 CFR 50.46.

May 14, 2013 U. S. Nuclear Regulatory Commission Page 2 Since the issuance of GL 2004-02, the industry, through extensive testing has made significant strides in understanding the effects of post-LOCA debris generation, debris transport, sump screen effectiveness, and, most recently, in-vessel effects of the debris that bypasses the sump screens. Large scope modifications have been implemented to increase the surface area of the sump strainers and reduce the debris quantities that reach the sump strainers.

On July 9, 2012, the NRC staff issued SECY-12-0093, "Closure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance," (Reference 2). SECY-12-0093 presents three options to the Commission; each considered a viable path for resolving GSI-1 91.

The options are:

Option 1:

Compliance with 10 CFR 50.46 based on approved models; Option 2:

Mitigative measures and alternate methods approach; and Option 3:

Different regulatory treatment for suction strainer and in-vessel effects.

Although a licensee may choose to pursue any option to achieve closure, specific options may lend themselves optimally to a plant's fiber status. Based on the low fiber status, Braidwood Station, Units 1 and 2; and Byron Station, Units 1 and 2, have chosen Option 1.

In a letter from W. H. Ruland (NRC) to J. C. Butler (NEI), "Nuclear Regulatory Commission Review of Generic Safety Issue-191 Nuclear Energy Institute Revised Schedule for Licensee Submittal of Resolution Path," dated November 21, 2012 (Reference 3), the NRC extended the date for the GSI-1 91 submittal. The revised schedule permits the licensee to submit their chosen resolution option and associated resolution implementation schedule to the NRC, 30 days following the NRC making the final safety evaluation associated with the review of WCAP-1 6793, Revision 2, "Evaluation of Long-Term Cooling Considering Particulate, Fibrous and Chemical Debris in the Recirculating Fluid," (Reference 4), and the Staff Requirements Memorandum associated with SECY-12-0093, "Closure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance,", publicly available. The final safety evaluation was made publicly available April 16, 2013; therefore, the due date for this submittal is May 16, 2013. to this letter provides the Braidwood Station and Byron Station plant-specific path and schedule for resolution of GSI-1 91. Attachment 2 provides a summary of the regulatory commitments made in this submittal.

If you have any questions or require additional information, please contact Joseph A. Bauer at (630) 657-2804.

May 14, 2013 U. S. N.uclear Regulatory Commission Page 2 Since the issuance of GL 2004-02, the industry, through extensive testing has made significant strides in understanding the effects of post-LOCA debris generation, debris transport, sump screen effectiveness, and, most recently, in-vessel effects of the debris that bypasses the sump screens. Large scope modifications have been implemented to increase the surface area of the sump strainers and reduce the debris quantities that reach the sump strainers.

On July 9, 2012, the NRC staff issued SECY 0093, "Closure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance," (Reference 2). SECY 0093 presents three options to the Commission; each considered a viable path for resolving GSI-191.

The options are:

Option 1: Compliance with 10 CFR 50.46 based on approved models; Option 2: Mitigative measures and alternate methods approach; and Option 3: Different regulatory treatment for suction strainer and in-vessel effects.

Although a licensee may choose to pursue any option to achieve closure, specific options may lend themselves optimally to a planfs fiber status. Based on the low fiber status, Braidwood Station, Units 1 and 2; and Byron Station, Units 1 and 2, have chosen Option 1.

In a letter from W. H. Ruland (NRC) to J. C. Butler (NEI), "Nuclear Regulatory Commission Review of Generic Safety Issue-191 Nuclear Energy Institute Revised Schedule for Licensee Submittal of Resolution Path, II dated November 21, 2012 (Reference 3), the NRC extended the date for the GSI-191 submittal. The revised schedule permits the licensee to submit their chosen resolution option and associated resolution implementation schedule to the NRC, 30 days following the NRC making the final safety evaluation associated with the review of WCAP-16793, Revision 2, "Evaluation of Long-Term Cooling Considering Particulate, Fibrous and Chemical Debris in the Recirculating Fluid, II (Reference 4), and the Staff Requirements Memorandum associated with SECY-12-0093, IIClosure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance"', publicly available. The final safety evaluation was made publicly available April 16, 2013; therefore, the due date for this submittal is May 16, 2013. to this letter provides the Braidwood Station and Byron Station plant-specific path and schedule for resolution of GSI-191. Attachment 2 provides a summary of the regulatory commitments made in this submittal.

If you have any questions or require additional information, please contact Joseph A. Bauer at (630) 657-2804.

May 14, 2013 U. S. Nuclear Regulatory Commission Page 3 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 14th day of May 2013.

Respectfully, David M. Gullott Manager - Licensing Exelon Generation Company, LLC Attachments: 1. Braidwood Station and Byron Station, Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02 2.

Summary of Regulatory Commitments cc:

USNRC Region III, Regional Administrator USNRC Senior Resident Inspector, Braidwood Station USNRC Senior Resident Inspector, Byron Station May 14, 2013 U. S. Nuclear Regulatory Commission Page 3 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 14th day of May 2013.

Respectfully, David M. Gullott Manager - Licensing Exelon Generation Company, LLC Attachments: 1. Braidwood Station and Byron Station, Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02

2. Summary of Regulatory Commitments cc:

USNRC Region III, Regional Administrator USNRC Senior Resident Inspector, Braidwood Station USNRC Senior Resident Inspector, Byron Station

ATTACHMENT 1 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02 Introduction Exelon Generation Company (EGC) has selected Option 1 from Reference 2 for Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2. It has been determined these units meet the requirements of 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors," based on approved models for analyses, strainer head loss testing, and in-vessel effects.

Current Resolution Status As of May 2013, Braidwood and Byron Stations have completed the following Generic Letter 2004-02 (Reference 1) actions, analyses and modifications:

Latent debris walkdowns and analysis Debris generation analysis Debris transport analysis Hydraulic analysis of the Emergency Core Cooling System (ECCS) and Containment Spray (CS) systems (taking suction from the containment recirculation sump)

Net Positive Suction Head (NPSH) analysis for CS and Residual Heat Removal (RH) pumps (taking suction from the containment recirculation sump)

Head loss testing for containment recirculation sump strainers Bypass testing for containment recirculation sump strainers Wear and blockage analysis for components downstream of containment recirculation sump strainer Chemical effects testing (bench top and head loss testing)

Wear and blockage testing for ECCS throttle valves Debris blockage testing for CS pump cyclone separator Installation of trash rack upstream of containment recirculation sump strainers Structural analysis of containment recirculation sump strainers and trash rack Removal of fiber insulation in the zone-of-influence at Braidwood Unit 1 and Byron Unit 1 (Note that Braidwood Unit 2 and Byron Unit 2 have no fiber insulation)

Installation of new containment recirculation sump strainers at Braidwood Units 1 and 2 and Byron Units 1 and 2 Installation of new ECCS throttle valves Braidwood Units 1 and 2 and Byron Units 1 and 2 Documentation of the resolution for GL 2004-02 for Braidwood Station and Byron Station has been provided to the NRC in References 3 through 8. As of May 2013, EGC has no existing open regulatory commitments for Braidwood Station and Byron Station related to the above documentation. The only remaining open issue is related to in-vessel downstream effects (see new regulatory commitment in Attachment 2).

In order to address in-vessel downstream effects, Braidwood Station and Byron Station plan to use the criteria of 15 grams/fuel assembly established by WCAP-1 6793-NP Revision 2, "Evaluation of Long-Term Cooling Considering Particulate, Fibrous and Chemical Debris in the Recirculating Fluid," including any limitations and conditions associated with the use of the WCAP based on the associated NRC Safety Evaluation (SE) (Reference 10). From the debris Page 1 of 3 ATTACHMENT 1 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02 Introduction Exelon Generation Company (EGC) has selected Option 1 from Reference 2 for Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2. It has been determined these units meet the requirements of 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors, II based on approved models for analyses, strainer head loss testing, and in-vessel effects.

Current Resolution Status As of May 2013, Braidwood and Byron Stations have completed the following Generic Letter 2004-02 (Reference 1) actions, analyses and modifications:

Latent debris walkdowns and analysis Debris generation analysis Debris transport analysis Hydraulic analysis of the Emergency Core Cooling System (ECCS) and Containment Spray (CS) systems (taking suction from the containment recirculation sump)

Net Positive Suction Head (NPSH) analysis for CS and Residual Heat Removal (RH) pumps (taking suction from the containment recirculation sump)

Head loss testing for containment recirculation sump strainers Bypass testing for containment recirculation sump strainers Wear and blockage analysis for components downstream of containment recirculation sump strainer Chemical effects testing (bench top and head loss testing)

Wear and blockage testing for ECCS throttle valves Debris blockage testing for CS pump cyclone separator Installation of trash rack upstream of containment recirculation sump strainers Structural analysis of containment recirculation sump strainers and trash rack Removal of fiber insulation in the zone-of-influence at Braidwood Unit 1 and Byron Unit 1 (Note that Braidwood Unit 2 and Byron Unit 2 have no fiber insulation)

Installation of new containment recirculation sump strainers at Braidwood Units 1 and 2 and Byron Units 1 and 2 Installation of new ECCS throttle valves Braidwood Units 1 and 2 and Byron Units 1 and 2 Documentation of the resolution for GL 2004-02 for Braidwood Station and Byron Station has been provided to the NRC in References 3 through 8. As of May 2013, EGC has no existing open regulatory commitments for Braidwood Station and Byron Station related to the above documentation. The only remaining open issue is related to in-vessel downstream effects (see new regulatory commitment in Attachment 2).

In order to address in-vessel downstream effects, Braidwood Station and Byron Station plan to use the criteria of 15 grams/fuel assembly established by WCAP-16793-NP Revision 2, IIEvaluation of Long-Term Cooling Considering Particulate, Fibrous and Chemical Debris in the Recirculating Fluid, II including any limitations and conditions associated with the use of the WCAP based on the associated NRC Safety Evaluation (SE) (Reference 10). From the debris Page 1 of 3

ATTACHMENT 1 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02 generation and debris transport analysis, Braidwood Station and Byron Station have determined that 22.5 Ibm of fibrous debris can be transported to the strainers. As Braidwood Station and Byron Station have no fibrous material installed in the zone-of-influence, the fibrous debris is completely from latent debris quantity inside containment. The fibrous debris quantity is documented in Reference 6 (see "EGC response to Issue 3f6," on page 39 of 102). Based on previously performed strainer bypass testing, the total quantity of fiber conservatively assumed to bypass the strainer is 5% (i.e., 1.125 Ibm). Of this quantity, 100% is conservatively assumed to reach the reactor fuel. Considering 193 fuel assemblies in the Braidwood Station and Byron Station reactor cores, this equates to an approximate loading of 2.6 grams/fuel assembly.

The required actions for the resolution plan include documenting the quantity of fibrous debris that reaches the sump strainers and documenting compliance with the limitations and conditions of the NRC SE for WCAP-1 6793-NP Revision 2.

Licensing Basis Commitments EGC does not have open commitments within the Braidwood Station and Byron Station commitment management system to provide additional updates or information to the NRC regarding GL 2004-02.

Resolution Schedule EGC does not have any open issues related to the resolution of GSI-1 91 except for in-vessel downstream effects. EGC will complete resolution of the in-vessel downstream effects for all four Braidwood Station and Byron Station units within two refueling outages after January 1, 2013, for the final Braidwood and Byron unit; i.e., upon startup of Braidwood Station, Unit 2, Cycle 19 in the fall of 2015. At this time, no physical modifications are anticipated to be required for any of the four units. The final resolution will be documented in a submittal to the NRC. This submittal will also include documentation of compliance with the limitations and conditions of the NRC SE for WCAP-16793-NP Revision 2.

If the NRC has follow-up questions regarding this submittal, EGC will hold discussions with the NRC in order to establish a mutually acceptable timeline for resolution.

References

1. Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated September 13, 2004

2. NRC Document SECY-12-0093, "Closure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance,"

dated July 9, 2012

3. Letter from K. R. Jury (Exelon Generation Company, LLC and AmerGen Energy Company, LLC) to U. S. Nuclear Regulatory Commission, "Exelon/AmerGen Response to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,"' dated March 7, 2005 Page 2 of 3 ATTACHMENT 1 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic LeHer 2004-02 generation and debris transport analysis, Braidwood Station and Byron Station have determined that 22.5 Ibm of fibrous debris can be transported to the strainers. As Braidwood Station and Byron Station have no fibrous material installed in the zone-of-influence, the fibrous debris is completely from latent debris quantity inside containment. The fibrous debris quantity is documented in Reference 6 (see "EGC response to Issue 3f6," on page 39 of 102). Based on previously performed strainer bypass testing, the total quantity of fiber conservatively assumed to bypass the strainer is 50/0 (Le., 1.125 Ibm). Of this quantity, 100

% is conservatively assumed to reach the reactor fuel. Considering 193 fuel assemblies in the Braidwood Station and Byron Station reactor cores, this equates to an approximate loading of 2.6 grams/fuel assembly.

The required actions for the resolution plan include documenting the quantity of fibrous debris that reaches the sump strainers and documenting compliance with the limitations and conditions of the NRC SE for WCAP-16793-NP Revision 2.

Licensing Basis Commitments EGC does not have open commitments within the Braidwood Station and Byron Station commitment management system to provide additional updates or information to the NRC regarding GL 2004-02.

Resolution Schedule EGC does not have any open issues related to the resolution of GSI-191 except for in-vessel downstream effects. EGC will complete resolution of the in-vessel downstream effects for all four Braidwood Station and Byron Station units within two refueling outages after January 1,

2013, for the final Braidwood and Byron unit; Le., upon startup of Braidwood Station, Unit 2, Cycle 19 in the fall of 2015. At this time, no physical modifications are anticipated to be required for any of the four units. The final resolution will be documented in a submittal to the NRC. This submittal will also include documentation of compliance with the limitations and conditions of the NRC SE forWCAP-16793-NP Revision 2.

If the NRC has follow-up questions regarding this submittal, EGC will hold discussions with the NRC in order to establish a mutually acceptable timeline for resolution.

References

1. Generic Letter 2004-02, IIPotential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors, II dated September 13, 2004

2. NRC Document SECY 0093, "Closure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance,"

dated July 9, 2012

3. Letter from K. R. Jury (Exelon Generation Company, LLC and AmerGen Energy Company, LLC) to u. S. Nuclear Regulatory Commission, "Exelon/AmerGen Response to NRC Generic Letter 2004-02, IPotentiallmpact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors, III dated March 7, 2005 Page 2 of 3

ATTACHMENT 1 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02 4.

Letter from P. B. Cowan (Exelon Generation Company, LLC and AmerGen Energy Company, LLC) to U. S. Nuclear Regulatory Commission, "Exelon/AmerGen Response to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized -Water Reactors,"' dated September 1, 2005 5.

Letter from K. R. Jury (Exelon Generation Company, LLC) to U. S. Nuclear Regulatory Commission, "Supplement to Exelon Response to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,"' dated May 31, 2006 6.

Letter from Patrick R. Simpson (Exelon Generation Company, LLC), "Supplemental Response to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,'"

dated December 31, 2007 7.

Letter from Patrick R. Simpson (Exelon Generation Company, LLC), "Response to Request for Additional Information Related to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors,"' dated September 19, 2008 8.

Letter from Patrick R. Simpson (Exelon Generation Company, LLC), "Response to Request for Additional Information Related to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors,"' dated May 29, 2009 9.

Letter from W. H. Ruland (NRC) to J. C. Butler (NEI), "Nuclear Regulatory Commission Review of Generic Safety Issue-191 Nuclear Energy Institute Revised Schedule for Licensee Submittal of Resolution Path," dated November 21, 2012

10. Letter from S. Bahadur (NRC) to W. A. Nowinowski (PWR Owners Group), "Final Safety Evaluation for Pressurized Water Reactor Owners Group Topical Report WCAP-1 6793-NP, Revision 2, 'Evaluation of Long-Term Cooling Considering Particulate Fibrous and Chemical Debris in the Recirculating Fluid,"' dated April 8, 2013 Page 3of3 ATTACHMENT 1 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02

4. Letter from P. B. Cowan (Exelon Generation Company, LLC and AmerGen Energy Company, LLC) to u. S. Nuclear Regulatory Commission, IIExelon/AmerGen Response to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors, III dated September 1, 2005

5. Letter from K. R. Jury (Exelon Generation Company, LLC) to u. S. Nuclear Regulatory Commission, "Supplement to Exelon Response to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,1I1 dated May 31,2006

6. Letter from Patrick R. Simpson (Exelon Generation Company, LLC), "Supplemental Response to NRC Generic Letter 2004-02, IPotentiallmpact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,'"

dated December 31,2007

7. Letter from Patrick R. Simpson (Exelon Generation Company, LLC), IIResponse to Request for Additional Information Related to NRC Generic Letter 2004-02, IPotentiallmpact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors,'" dated September 19, 2008

8. Letter from Patrick R. Simpson (Exelon Generation Company, LLC), IIResponse to Request for Additional Information Related to NRC Generic Letter 2004-02, IPotentiallmpact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors,'" dated May 29, 2009

9. Letter from W. H. Ruland (NRC) to J. C. Butler (NEI), IINuclear Regulatory Commission Review of Generic Safety Issue-191 Nuclear Energy Institute Revised Schedule for Licensee Submittal of Resolution Path,1I dated November 21,2012

10. Letter from S. Bahadur (NRC) to W. A. Nowinowski (PWR Owners Group), "Final Safety Evaluation for Pressurized Water Reactor Owners Group Topical ReportWCAP-16793-NP, Revision 2, 'Evaluation of Long-Term Cooling Considering Particulate Fibrous and Chemical Debris in the Recirculating Fluid,1II dated April 8, 2013 Page 3 of 3

ATTACHMENT 2 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02 Summary of Regulatory Commitments The following table identifies those actions committed to by Exelon Generation Company, LLC (EGC) in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.

COMMITMENT COMMITTED DATE OR "OUTAGE" COMMITMENT TYPE ONE-TIME PROGRAMMATIC ACTION (Yes/No)

(Yes/No)

EGC will submit a letter addressing the final resolution of GSI-1 91 in-vessel downstream effects for all Upon Startup of Braidwood Station and Byron Braidwood Station, Yes No Station units; and will document Unit 2, Cycle 19 compliance with the limitations and (Fall 2015) conditions of the NRC SE for WCAP-16793-NP, Revision 2.

Page 1 of 1 ATTACHMENT 2 Braidwood Station and Byron Station Plant-Specific Path and Schedule for Resolution of Generic Letter 2004-02 Summary of Regulatory Commitments The following table identifies those actions committed to by Exelon Generation Company, LLC (EGC) in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.

COMMITMENT COMMITTED DATE COMMITMENT TYPE OR "OUTAGE" ONE-TIME PROGRAMMATIC ACTION (Yes/No)

(Yes/No)

EGC will submit a letter addressing the final resolution of GSI-191 in-vessel downstream effects for all Upon Startup of Braidwood Station and Byron Braidwood Station, Yes No Station units; and will document Unit 2, Cycle 19 compliance with the limitations and (Fall 2015) conditions of the NRC SE for WCAP-16793-NP, Revision 2.

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