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| {{#Wiki_filter:Michael P. Gallagher Exelon Generation Vice President. | | {{#Wiki_filter:Michael P. Gallagher Vice President. License Renewal Exelon Nuclear Exelon Generation 200 Exelon Way Kennett Square, PA 19348 610 765 5958 Office 610 765 5956 Fax www.exeloncorp.com michaelp.gallagher@exeloncorp.com 10 CFR 50 10CFR51 10 CFR 54 RS-14-249 September 4, 2014 U. S. Nuclear Regulatory Commission Attention: 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 |
| License Renewal Exelon Nuclear 200 Exelon Way RS-14-249 Kennett Square, PA 19348 610 765 5958 Office 610 765 5956 Fax www.exeloncorp.com michaelp.gallagher@exeloncorp.com 10 CFR 50 10CFR51 10 CFR 54 September 4, 2014 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 | |
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| ==Subject:== | | ==Subject:== |
| | Results of Detailed Review Performed in Response to Request 1 of NRC RAI B.2.1. 7-7 from Set 17, related to the Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, License Renewal Application |
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| ==References:== | | ==References:== |
| | : 1. Letter from Michael P. Gallagher, Exelon Generation Company LLC (Exelon}, |
| | to NRC Document Control Desk, dated May 29, 2013, "Application for Renewed Operating Licenses." |
| | : 2. Letter from Lindsay R. Robinson, US NRC to Michael P. Gallagher, Exelon , |
| | dated March 20, 2014, "Request for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application, Set 17 (TAC NOS. MF1879, MF1880, MF1881, and MF1882)" |
| | : 3. Letter from Michael P. Gallagher, Exelon, to NRC Document Control Desk, dated April 14, 2014, "Response to NRC Request for Additional Information, Set 17, dated March 20, 2014, related to the Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, License Renewal Application" In Reference 1, Exelon Generation Company, LLC (Exelon) submitted the License Renewal Application (LRA) for the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2 (BBS). In Reference 2, the NRC requested additional information to support staff review of the LRA, including a request for information (RAI B.2.1. 7-7) involving the potential for Reactor Vessel Internals components to contain cold worked materials. |
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| 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 Results of Detailed Review Performed in Response to Request 1 of NRC RAI B.2.1. 7-7 from Set 17 , related to the Braidwood Station , Units 1 and 2 , and Byron Station, Units 1 and 2, License Renewal Application
| | September 4, 2014 U.S. Nuclear Regulatory Commission Page 2 In Reference 3, Exelon responded to Request 1 of RAI B.2.1.7-7 indicating that a detailed review would be performed to determine whether any BBS Reactor Vessel Internals components contain any materials that could be a concern due to cold working. Exelon stated that the results of this review would be communicated to the NRC by the end of October, 2014. |
| : 1. Letter from Michael P. Gallagher, Exelon Generation Company LLC (Exelon}, to NRC Document Control Desk , dated May 29 , 2013, "Application for Renewed Operating Licenses." 2. Letter from Lindsay R. Robinson , US NRC to Michael P. Gallagher, Exelon , dated March 20, 2014, "Request for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2 , License Renewal Application , Set 17 (TAC NOS. MF1879, MF1880 , MF1881, and MF1882)" 3. Letter from Michael P. Gallagher , Exelon, to NRC Document Control Desk, dated April 14, 2014, "Response to NRC Request for Additional Information , Set 17 , dated March 20, 2014 , related to the Braidwood Station, Units 1 and 2 , and Byron Station , Units 1 and 2 , License Renewal Application" In Reference 1, Exelon Generation Company, LLC (Exelon) submitted the License Renewal Application (LRA) for the Byron Station , Units 1 and 2, and Braidwood Station , Units 1 and 2 (BBS). In Reference 2 , the NRC r e qu e st e d additional information to support st a ff r e vi e w of th e LRA, including a request for information (RAI B.2.1. 7-7) involving the potential for Reactor Vessel Internals components to contain cold worked materials.
| | The detailed review for BBS has been completed. It is concluded that the plant-specific material fabrication and design were consistent with the MRP-191 basis and that the MRP-227-A sampling inspection aging management requirements, as related to cold work and stress corrosion cracking, are directly applicable to BBS. The Enclosure to this letter provides additional details. |
| September 4, 2014 U.S. Nuclear Regulatory Commission Page 2 In Reference 3, Exelon responded to Request 1 of RAI B.2.1.7-7 indicating that a detailed review would be performed to determine whether any BBS Reactor Vessel Internals components contain any materials that could be a concern due to cold working. Exelon stated that the results of this review would be communicated to the NRC by the end of October, 2014. The detailed review for BBS has been completed. | | There are no new or revised regulatory commitments contained in this letter. |
| It is concluded that the plant-specific material fabrication and design were consistent with the MRP-191 basis and that the MRP-227-A sampling inspection aging management requirements, as related to cold work and stress corrosion cracking, are directly applicable to BBS. The Enclosure to this letter provides additional details. There are no new or revised regulatory commitments contained in this letter. If you have any questions, please contact Mr. Al Fulvio, Manager, Exelon License Renewal, at 610-765-5936. | | If you have any questions, please contact Mr. Al Fulvio, Manager, Exelon License Renewal, at 610-765-5936. |
| I declare under penalty of perjury that the foregoing is true and correct. Executed on 'f'f' Respectfully, Vice President | | I declare under penalty of perjury that the foregoing is true and correct. |
| -License Renewal Projects Exelon Generation Company, LLC | | Executed on 'f'f' '),((~ |
| | Respectfully, Vice President - License Renewal Projects Exelon Generation Company, LLC |
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| ==Enclosure:== | | ==Enclosure:== |
| | Supplemental Information for Response to RAI B.2.1.7-7, Request 1: Results of Detailed Review Related to Potential for Cold Working of Reactor Vessel Internals Components at BBS cc: Regional Administrator- NRC Region Ill NRC Project Manager (Safety Review), NRR-DLR NRC Project Manager (Environmental Review), NRR-DLR NRC Senior Resident Inspector, Braidwood Station NRC Senior Resident Inspector, Byron Station NRC Project Manager, NRR-DORL-Braidwood and Byron Stations Illinois Emergency Management Agency - Division of Nuclear Safety |
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| Supplemental Information for Response to RAI B.2.1.7-7, Request 1: Results of Detailed Review Related to Potential for Cold Working of Reactor Vessel Internals Components at BBS cc: Regional Administrator-NRC Region Ill NRC Project Manager (Safety Review), NRR-DLR NRC Project Manager (Environmental Review), NRR-DLR NRC Senior Resident Inspector, Braidwood Station NRC Senior Resident Inspector, Byron Station NRC Project Manager, NRR-DORL-Braidwood and Byron Stations Illinois Emergency Management Agency -Division of Nuclear Safety RS-14-249 Enclosure Page 1 of 2 Enclosure Supplemental Information for Response to RAI B.2.1.7-7, Request 1:
| | RS-14-249 Enclosure Page 1 of 2 Enclosure Supplemental Information for Response to RAI B.2.1.7-7, Request 1: |
| Results of Detailed Review Related to Potential for Cold Working of Reactor Vessel Internals Components at BBS | | Results of Detailed Review Related to Potential for Cold Working of Reactor Vessel Internals Components at BBS |
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| RS-14-249 Enclosure Page 2 of 2 Byron and Braidwood Stations, Units 1 and 2 (BBS) contracted with Westinghouse Electric Company LLC (Westinghouse), through the PWR Owner's Group, to provide a detailed evaluation of the reactor vessel internals (RVI) for cold worked components.
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| Westinghouse has evaluated the BBS reactor vessel internal components according to industry guideline MRP 2013-025 [1] and the MRP-191 [2] industry generic component listings and screening criteria (including consideration of cold work as defined in MRP-175 [3], noting the requirements of Section 3.2.3). In addition to consideration of the material fabrication, forming, and finishing process, a general screening definition of a resulting reduction in wall thickness (material stock thickness) of 20 percent was applied as an evaluation limit. It was confirmed that all BBS components, as applicable for design, are included directly in the MRP-191 component lists.
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| | RS-14-249 Enclosure Page 2 of 2 Byron and Braidwood Stations, Units 1 and 2 (BBS) contracted with Westinghouse Electric Company LLC (Westinghouse), through the PWR Owners Group, to provide a detailed evaluation of the reactor vessel internals (RVI) for cold worked components. |
| | Westinghouse has evaluated the BBS reactor vessel internal components according to industry guideline MRP 2013-025 [1] and the MRP-191 [2] industry generic component listings and screening criteria (including consideration of cold work as defined in MRP-175 [3], noting the requirements of Section 3.2.3). In addition to consideration of the material fabrication, forming, and finishing process, a general screening definition of a resulting reduction in wall thickness (material stock thickness) of 20 percent was applied as an evaluation limit. It was confirmed that all BBS components, as applicable for design, are included directly in the MRP-191 component lists. |
| BBS components were categorized according to the following categories for material fabrication and cold work potential: | | BBS components were categorized according to the following categories for material fabrication and cold work potential: |
| Categories include: Cast austenitic stainless steel (CASS) (Category 1) Hot-formed austenitic stainless steel (Category 2) Annealed austenitic stainless steel (Category 3) Fasteners austenitic stainless steel (Category 4) Cold-formed austenitic stainless steel without subsequent solution annealing (Category 5) | | Categories include: |
| | | Cast austenitic stainless steel (CASS) (Category 1) |
| The evaluation, performed consistently with the industry guideline, concluded that the reactor vessel internals Categories 1, 2, and 3 components at BBS contain no cold work 20 percent or greater as a result of material specification and controlled fabrication construction. Material fabrication specifications used for BBS suggest that processes were limiting (e.g., heat treatment), which precluded the introduction of severe (greater than or equal to 20 percent) cold | | Hot-formed austenitic stainless steel (Category 2) |
| | | Annealed austenitic stainless steel (Category 3) |
| work in some of the Category 4 components. Category 4 components were already assumed to have the potential for cold work in the MRP-191 generic assessments. No Category 5 components with severe cold work were identified for BBS. | | Fasteners austenitic stainless steel (Category 4) |
| | | Cold-formed austenitic stainless steel without subsequent solution annealing (Category 5) |
| | The evaluation, performed consistently with the industry guideline, concluded that the reactor vessel internals Categories 1, 2, and 3 components at BBS contain no cold work 20 percent or greater as a result of material specification and controlled fabrication construction. Material fabrication specifications used for BBS suggest that processes were limiting (e.g., heat treatment), which precluded the introduction of severe (greater than or equal to 20 percent) cold work in some of the Category 4 components. Category 4 components were already assumed to have the potential for cold work in the MRP-191 generic assessments. No Category 5 components with severe cold work were identified for BBS. |
| The detailed evaluation for BBS concluded that the plant-specific material fabrication and design were consistent with the MRP-191 basis and that the MRP-227-A [4] sampling inspection aging management requirements, as related to cold work and stress corrosion cracking, are directly applicable to BBS. | | The detailed evaluation for BBS concluded that the plant-specific material fabrication and design were consistent with the MRP-191 basis and that the MRP-227-A [4] sampling inspection aging management requirements, as related to cold work and stress corrosion cracking, are directly applicable to BBS. |
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| ==References:== | | ==References:== |
| : 1. EPRI Letter, MRP 2013-025, "MRP-227-A Applicability Template Guideline," October 14, 2013. 2. Materials Reliability Program: Screening, Categorization, and Ranking of Reactor Internals Components for Westinghouse and Combustion Engineering PWR Design (MRP-191). EPRI, Palo Alto, CA: 2006. 1013234. 3. Materials Reliability Program: PWR Internals Material Aging Degradation Mechanism Screening and Threshold Values (MRP-175). EPRI, Palo Alto, CA: 2005. 1012081. 4. Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines (MRP-227-A). EPRI, Palo Alto, CA: 2011. 1022863.}} | | : 1. EPRI Letter, MRP 2013-025, MRP-227-A Applicability Template Guideline, October 14, 2013. |
| | : 2. Materials Reliability Program: Screening, Categorization, and Ranking of Reactor Internals Components for Westinghouse and Combustion Engineering PWR Design (MRP-191). EPRI, Palo Alto, CA: 2006. 1013234. |
| | : 3. Materials Reliability Program: PWR Internals Material Aging Degradation Mechanism Screening and Threshold Values (MRP-175). EPRI, Palo Alto, CA: 2005. 1012081. |
| | : 4. Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines (MRP-227-A). EPRI, Palo Alto, CA: 2011. 1022863.}} |
Letter Sequence Other |
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Results
Other: ML13212A367, ML14050A304, ML14071A620, ML14072A369, ML14092A346, ML14177A430, ML14238A691, ML14245A371, ML14300A218, ML14317A783, ML15027A196, ML15098A181, ML15106A736, RS-14-183, Updated Responses to NRC Set 14 Requests for Additional Information, Related License Renewal Application, RS-14-249, Results of Detailed Review Performed in Response to Request 1 of NRC RAI B.2.1.7-7 from Set 17, Related to License Renewal Application, RS-15-049, Units 1 and 2 - LRA Impact Assessment Associated with Earlier Responses to Set 29 RAI B.2.1 .5-1a, Related to the License Renewal Application, ULNRC-06118, Updated RAI Response to the License Renewal Application, Enclosures 1 and 2
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MONTHYEARML13212A3672013-08-12012 August 2013 Plan for the Aging Management Program Regulatory Audits Regarding the Byron and Braidwood Nuclear Stations License Renewal Application Review Project stage: Other ML13262A0352013-10-0707 October 2013 Requests for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application -Aging Management, Set 1 Project stage: RAI ML13281A5572013-10-28028 October 2013 Summary of Telephone Conference Call Held on September 25, 2013 Between the U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC, Concerning RAIs Pertaining to the Byron-Braidwood License Renewal Application (TAC Nos. MF187 Project stage: RAI ML13303B4632013-11-25025 November 2013 Summary of Telephone Conference Call Held on October 22, 2013, Between the U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC, Concerning RAI Set 3 for the Byron-Braidwood LRA Project stage: RAI ML13281A5742013-11-25025 November 2013 Requests for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application - Aging Management, Set 3 (TAC Nos. MF1879, MF1880, MF1881, and MF1882 Project stage: RAI ML13281A5692013-12-12012 December 2013 Request for Additional Information for the Review of the Byron Nuclear Station Units 1 and 2, and the Braidwood Nuclear Station Units 1 and 2, LRA - Aging Management, Set 4 Project stage: RAI ML13282A3692013-12-13013 December 2013 Requests for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application - Aging Management, Set 2 Project stage: RAI RS-13-273, Responses to NRC Requests for Additional Information, Set 3, Dated November 25, 2013, Related to the License Renewal Application2013-12-17017 December 2013 Responses to NRC Requests for Additional Information, Set 3, Dated November 25, 2013, Related to the License Renewal Application Project stage: Response to RAI RS-13-274, Response to NRC Requests for Additional Information, Set 5, Dated November 22, 2013, Related to License Renewal Application2013-12-19019 December 2013 Response to NRC Requests for Additional Information, Set 5, Dated November 22, 2013, Related to License Renewal Application Project stage: Response to RAI ML13317A0752014-01-13013 January 2014 Requests for Additional Information for Review of Byron, Units 1 & 2, and Braidwood, Units 1 & 2, License Renewal Applications, Set 6 Project stage: RAI RS-14-003, Bryon, Units 1 and 2, Response to NRC Requests for Additional Information, Set 2, Dated December 13, 2013, Related to the License Renewal Application2014-01-13013 January 2014 Bryon, Units 1 and 2, Response to NRC Requests for Additional Information, Set 2, Dated December 13, 2013, Related to the License Renewal Application Project stage: Response to RAI ML14017A0072014-01-16016 January 2014 Enclosure 1 to ULNRC-06072, Callaway Plant, Unit 1, Responses to Request for Additional Information (RAI) Sets 29 and 27 (RAI B2.1.6-4b) Project stage: Response to RAI ML14007A6582014-01-22022 January 2014 Requests for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 9 Project stage: RAI ML13309A9322014-01-23023 January 2014 Summary of Telephone Conference Call Held on October 31, 2013, Between the U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC, Concerning Draft Requests for Additional Information Pertaining to the Byron Station and Braid Project stage: Draft RAI ML13330A9322014-01-23023 January 2014 Bbs Record of Conference Call-Regarding-RAI Set 4 110513 Project stage: RAI ML13318A4152014-01-23023 January 2014 November 12, 2013, Summary of Telephone Conference Call Held Between the U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC, Concerning Draft Requests for Additional Information Pertaining to the Byron Station and Braidwo Project stage: Draft RAI RS-14-030, Response to NRC Requests for Additional Information, Set 6, Dated January 13, 2014, Related to License Renewal Application2014-02-0404 February 2014 Response to NRC Requests for Additional Information, Set 6, Dated January 13, 2014, Related to License Renewal Application Project stage: Response to RAI ML14006A0212014-02-0606 February 2014 Requests for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application- Aging Management, Set 8 Project stage: RAI ML14023A5642014-02-0707 February 2014 RAI for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 13 Project stage: RAI ML14030A5962014-02-10010 February 2014 Requests for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 12 Project stage: RAI ML14007A6032014-02-18018 February 2014 Request for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, LRA - Aging Management - Set 17 Project stage: RAI ML14034A0682014-02-18018 February 2014 Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 11 Project stage: RAI ML14035A5342014-02-20020 February 2014 January 22, 2014, Summary of Telephone Conference Call Held Between NRC and Exelon Generation Company, Llc., Concerning Draft Requests for Additional Information Pertaining to the Byron Station and Braidwood Station, License Renewal Applica Project stage: Draft RAI ML14035A1892014-02-20020 February 2014 Summary of Telephone Conference Call Held on January 30, 2014, Between the U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC, Concerning Draft Request for Additional Information Pertaining to the Byron Station and Braidw Project stage: Draft RAI ML14050A1222014-02-24024 February 2014 Summary of Telephone Conference Call Held on January 16, 2014, Between the U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC, Concerning RAI Set 7, Tor the Byron-Braidwood License Renewal Application (TAC Nos. MF1879, Mf Project stage: RAI ML14038A3362014-02-26026 February 2014 Request for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application - Aging Management - Set 10 Project stage: RAI RS-14-051, Response to NRC Requests for Additional Information, Set 8, Dated February 6, 2014 Related to the License Renewal Application2014-02-27027 February 2014 Response to NRC Requests for Additional Information, Set 8, Dated February 6, 2014 Related to the License Renewal Application Project stage: Response to RAI ML14063A4952014-03-0404 March 2014 Response to NRC Requests for Additional Information, Set 13, Dated February 7, 2014 Re License Renewal Application Project stage: Response to RAI ML14051A4312014-03-0404 March 2014 Summary of Telephone Conferene Call Held on January 29, 2014, Between the NRC and Exelon Generating Company, Llc., Concerning RAI Set 10, for the Byron and Braidwood Station License Renewal Application (TAC Nos. MF1879, MF1880, MF1881, and Project stage: RAI ML14036A3102014-03-0404 March 2014 Summary of Telephone Conference Call Held on January 28, 2014, Between NRC and Exelon, Concerning RAI Set 10, for the Byron and Braidwood Station, LRA Project stage: RAI ML14050A1672014-03-0404 March 2014 Summary of Telephone Conference Call on January 23, 2014, Between U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC, Concerning RAI Set 11, for Byron-Braidwood License Renewal Application (TAC Nos. MF1879, MF1880, MF1881 Project stage: RAI ML14051A4282014-03-0606 March 2014 January 13, 2014, Summary of Telephone Conference Call Held Between the NRC and Exelon RAI Set 8, for the Byron and Braidwood Station LRA Project stage: RAI ML14050A0812014-03-0707 March 2014 Correction to Request for Additional Information B.2.1.10-1, Letter Dated February 7, 2014, for the Review of the Byron Station and Braidwood Station, Units 1 and 2, LRA Set 13 Project stage: RAI ML14064A3912014-03-11011 March 2014 Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 15 Project stage: RAI ML14064A4032014-03-11011 March 2014 Summary of Telephone Conference Call on February 27, 2014, Between U.S. Nuclear Regulatory Commission & Exelon Generation Company, LLC Concerning Draft Request for Additional Information Re Byron Station & Braidwood Station License Renewal Project stage: Draft RAI ML14058B1802014-03-11011 March 2014 Summary of Telephone Conference Call on February 18, 2014, Between U.S. Nuclear Regulatory Commission & Exelon Generation Company, LLC Concerning Draft Request for Additional Information Regarding Byron & Braidwood Stations, License Renewal Project stage: Draft RAI ML14072A3692014-03-13013 March 2014 AMP Audit Enclosure (3) Project stage: Other ML14071A6202014-03-13013 March 2014 Aging Management Programs Audit Report Regarding the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2 (Tac Nos. MF1879, MF1880, MF1881, and MF1882) Project stage: Other ML14050A3042014-03-14014 March 2014 Scoping and Screening Methodology Audit Report Regarding the Byron Station, and Braidwood Station, Units 1 and 2, LRA Project stage: Other ML14058B1822014-03-18018 March 2014 Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 14 Project stage: RAI ML14051A5032014-03-20020 March 2014 Request for Additional Information for the Review of the Byron Nuclear Station Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application - Set 17 Project stage: RAI RS-14-084, Responses to NRC Requests for Additional Information, Set 10, Dated February 26, 2014 Related to the License Renewal Application2014-03-28028 March 2014 Responses to NRC Requests for Additional Information, Set 10, Dated February 26, 2014 Related to the License Renewal Application Project stage: Response to RAI ML14073A7052014-04-0303 April 2014 Summary of Telephone Conference Call Held on February 12, 2014, Between the NRC and Exelon, Concerning Drais Pertaining to the Byron and Braidwood Station, LRA Project stage: RAI ML14084A3352014-04-0303 April 2014 Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 16 Project stage: RAI ML14084A4882014-04-0707 April 2014 Summary of Telephone Conference Call Held Between NRC and Exelon Generation Company, LLC, Concerning Draft Request for Additional Information Pertaining to the Byron and Braidwood License Renewal Application Set 16 Project stage: Draft RAI ML14092A2612014-04-0707 April 2014 Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 20 Project stage: RAI ML14092A3462014-04-0707 April 2014 Project Manager Change for the License Renewal of Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2 Project stage: Other ML14094A3662014-04-0808 April 2014 Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 19 Project stage: RAI ML14093B2472014-04-10010 April 2014 Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 18 Project stage: RAI ML14099A4852014-04-17017 April 2014 Request for Additional Information for the Review of the Byron Station, Units 1 & 2, and Braidwood Station, Units 1 & 2, License Renewal Application, Set 21, Project stage: RAI 2014-02-27
[Table View] |
Text
Michael P. Gallagher Vice President. License Renewal Exelon Nuclear Exelon Generation 200 Exelon Way Kennett Square, PA 19348 610 765 5958 Office 610 765 5956 Fax www.exeloncorp.com michaelp.gallagher@exeloncorp.com 10 CFR 50 10CFR51 10 CFR 54 RS-14-249 September 4, 2014 U. S. Nuclear Regulatory Commission Attention: 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:
Results of Detailed Review Performed in Response to Request 1 of NRC RAI B.2.1. 7-7 from Set 17, related to the Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, License Renewal Application
References:
- 1. Letter from Michael P. Gallagher, Exelon Generation Company LLC (Exelon},
to NRC Document Control Desk, dated May 29, 2013, "Application for Renewed Operating Licenses."
- 2. Letter from Lindsay R. Robinson, US NRC to Michael P. Gallagher, Exelon ,
dated March 20, 2014, "Request for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application, Set 17 (TAC NOS. MF1879, MF1880, MF1881, and MF1882)"
- 3. Letter from Michael P. Gallagher, Exelon, to NRC Document Control Desk, dated April 14, 2014, "Response to NRC Request for Additional Information, Set 17, dated March 20, 2014, related to the Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, License Renewal Application" In Reference 1, Exelon Generation Company, LLC (Exelon) submitted the License Renewal Application (LRA) for the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2 (BBS). In Reference 2, the NRC requested additional information to support staff review of the LRA, including a request for information (RAI B.2.1. 7-7) involving the potential for Reactor Vessel Internals components to contain cold worked materials.
September 4, 2014 U.S. Nuclear Regulatory Commission Page 2 In Reference 3, Exelon responded to Request 1 of RAI B.2.1.7-7 indicating that a detailed review would be performed to determine whether any BBS Reactor Vessel Internals components contain any materials that could be a concern due to cold working. Exelon stated that the results of this review would be communicated to the NRC by the end of October, 2014.
The detailed review for BBS has been completed. It is concluded that the plant-specific material fabrication and design were consistent with the MRP-191 basis and that the MRP-227-A sampling inspection aging management requirements, as related to cold work and stress corrosion cracking, are directly applicable to BBS. The Enclosure to this letter provides additional details.
There are no new or revised regulatory commitments contained in this letter.
If you have any questions, please contact Mr. Al Fulvio, Manager, Exelon License Renewal, at 610-765-5936.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on 'f'f' '),((~
Respectfully, Vice President - License Renewal Projects Exelon Generation Company, LLC
Enclosure:
Supplemental Information for Response to RAI B.2.1.7-7, Request 1: Results of Detailed Review Related to Potential for Cold Working of Reactor Vessel Internals Components at BBS cc: Regional Administrator- NRC Region Ill NRC Project Manager (Safety Review), NRR-DLR NRC Project Manager (Environmental Review), NRR-DLR NRC Senior Resident Inspector, Braidwood Station NRC Senior Resident Inspector, Byron Station NRC Project Manager, NRR-DORL-Braidwood and Byron Stations Illinois Emergency Management Agency - Division of Nuclear Safety
RS-14-249 Enclosure Page 1 of 2 Enclosure Supplemental Information for Response to RAI B.2.1.7-7, Request 1:
Results of Detailed Review Related to Potential for Cold Working of Reactor Vessel Internals Components at BBS
RS-14-249 Enclosure Page 2 of 2 Byron and Braidwood Stations, Units 1 and 2 (BBS) contracted with Westinghouse Electric Company LLC (Westinghouse), through the PWR Owners Group, to provide a detailed evaluation of the reactor vessel internals (RVI) for cold worked components.
Westinghouse has evaluated the BBS reactor vessel internal components according to industry guideline MRP 2013-025 [1] and the MRP-191 [2] industry generic component listings and screening criteria (including consideration of cold work as defined in MRP-175 [3], noting the requirements of Section 3.2.3). In addition to consideration of the material fabrication, forming, and finishing process, a general screening definition of a resulting reduction in wall thickness (material stock thickness) of 20 percent was applied as an evaluation limit. It was confirmed that all BBS components, as applicable for design, are included directly in the MRP-191 component lists.
BBS components were categorized according to the following categories for material fabrication and cold work potential:
Categories include:
Cast austenitic stainless steel (CASS) (Category 1)
Hot-formed austenitic stainless steel (Category 2)
Annealed austenitic stainless steel (Category 3)
Fasteners austenitic stainless steel (Category 4)
Cold-formed austenitic stainless steel without subsequent solution annealing (Category 5)
The evaluation, performed consistently with the industry guideline, concluded that the reactor vessel internals Categories 1, 2, and 3 components at BBS contain no cold work 20 percent or greater as a result of material specification and controlled fabrication construction. Material fabrication specifications used for BBS suggest that processes were limiting (e.g., heat treatment), which precluded the introduction of severe (greater than or equal to 20 percent) cold work in some of the Category 4 components. Category 4 components were already assumed to have the potential for cold work in the MRP-191 generic assessments. No Category 5 components with severe cold work were identified for BBS.
The detailed evaluation for BBS concluded that the plant-specific material fabrication and design were consistent with the MRP-191 basis and that the MRP-227-A [4] sampling inspection aging management requirements, as related to cold work and stress corrosion cracking, are directly applicable to BBS.
References:
- 1. EPRI Letter, MRP 2013-025, MRP-227-A Applicability Template Guideline, October 14, 2013.
- 2. Materials Reliability Program: Screening, Categorization, and Ranking of Reactor Internals Components for Westinghouse and Combustion Engineering PWR Design (MRP-191). EPRI, Palo Alto, CA: 2006. 1013234.
- 3. Materials Reliability Program: PWR Internals Material Aging Degradation Mechanism Screening and Threshold Values (MRP-175). EPRI, Palo Alto, CA: 2005. 1012081.
- 4. Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines (MRP-227-A). EPRI, Palo Alto, CA: 2011. 1022863.