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Category:Letter type:RS
MONTHYEARRS-24-104, Nuclear Radiological Emergency Plan Document Revision2024-11-0101 November 2024
Nuclear Radiological Emergency Plan Document Revision
RS-24-098, Units 1 and 2 - Supplement to License Amendment Request to Revise Technical Specifications 3.7.15, Spent Fuel Pool Boron Concentration, 3.7.16, Spent Fuel Assembly Storage, 4.3.1, Fuel Storage, Criticality2024-10-23023 October 2024
Units 1 and 2 - Supplement to License Amendment Request to Revise Technical Specifications 3.7.15, Spent Fuel Pool Boron Concentration, 3.7.16, Spent Fuel Assembly Storage, 4.3.1, Fuel Storage, Criticality
RS-24-095, Relief Request I4R-19 and I4R-26, Associated with the Fourth and Fifth Inservice Inspection Intervals2024-10-10010 October 2024
Relief Request I4R-19 and I4R-26, Associated with the Fourth and Fifth Inservice Inspection Intervals
RS-24-093, Response to Request for Additional Information - Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests2024-10-10010 October 2024
Response to Request for Additional Information - Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests
RS-24-088, Relief Requests Associated with the Fifth Inservice Inspection Interval2024-09-13013 September 2024
Relief Requests Associated with the Fifth Inservice Inspection Interval
RS-24-064, Nuclear Radiological Emergency Plan Document Revisions2024-06-28028 June 2024
Nuclear Radiological Emergency Plan Document Revisions
RS-24-066, Inservice Testing Interval Extension for Essential Service Water Valves Due to Required Use of Containment Chiller2024-06-25025 June 2024
Inservice Testing Interval Extension for Essential Service Water Valves Due to Required Use of Containment Chiller
RS-24-061, Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations2024-06-14014 June 2024
Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations
RS-24-057, License Amendment to Technical Specification 3.7.9, Ultimate Heat Sink2024-06-0404 June 2024
License Amendment to Technical Specification 3.7.9, Ultimate Heat Sink
RS-24-044, License Amendment to Transition to Framatome Gaia Fuel and Exemptions to 10 CFR 50.46 and 10 CFR 50 Appendix K. Attachments 1 to 11 Enclosed2024-05-28028 May 2024
License Amendment to Transition to Framatome Gaia Fuel and Exemptions to 10 CFR 50.46 and 10 CFR 50 Appendix K. Attachments 1 to 11 Enclosed
RS-24-043, Application to Remove Power Distribution Monitoring System (Pdms) Details from Technical Specifications2024-05-24024 May 2024
Application to Remove Power Distribution Monitoring System (Pdms) Details from Technical Specifications
RS-24-055, 2023 Corporate Regulatory Commitment Change Summary Report2024-05-17017 May 2024
2023 Corporate Regulatory Commitment Change Summary Report
RS-24-041, Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests2024-04-30030 April 2024
Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests
RS-24-026, License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, Technical Specifications 5.6.5, Core Operating Limits Report (COLR)2024-04-25025 April 2024
License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, Technical Specifications 5.6.5, Core Operating Limits Report (COLR)
RS-24-034, Annual 10 CFR 50.46 Report of Emergency Core Cooling System Evaluation Model Changes and Errors2024-04-10010 April 2024
Annual 10 CFR 50.46 Report of Emergency Core Cooling System Evaluation Model Changes and Errors
RS-24-002, Constellation Energy Generation, LLC - Annual Property Insurance Status Report2024-04-0101 April 2024
Constellation Energy Generation, LLC - Annual Property Insurance Status Report
RS-24-024, Response to Request for Additional Information Regarding Proposed Alternative for Examination of Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds2024-03-22022 March 2024
Response to Request for Additional Information Regarding Proposed Alternative for Examination of Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds
RS-24-013, Response to Request for Additional Information Regarding Proposed Alternative to Distribution Requirements of ASME Code Table IWC-2411-1 for the Steam Generators2024-02-13013 February 2024
Response to Request for Additional Information Regarding Proposed Alternative to Distribution Requirements of ASME Code Table IWC-2411-1 for the Steam Generators
RS-24-004, Proposed Alternative to the Distribution Requirements of ASME Code Table IWC-2411-1 for the Steam Generators2024-01-11011 January 2024
Proposed Alternative to the Distribution Requirements of ASME Code Table IWC-2411-1 for the Steam Generators
RS-23-118, Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information2023-11-10010 November 2023
Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information
RS-23-117, Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information2023-11-10010 November 2023
Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information
RS-23-114, Proposed Alternative for Examination of Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds2023-11-0101 November 2023
Proposed Alternative for Examination of Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds
RS-23-100, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-10-13013 October 2023
Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation
RS-23-097, Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans2023-10-12012 October 2023
Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans
RS-23-108, Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator Pressure Retaining Welds and Full Penetration Welded Nozzles2023-10-11011 October 2023
Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator Pressure Retaining Welds and Full Penetration Welded Nozzles
RS-23-105, Proposed Alternative for Examinations of Examination Category C-B Steam Generator Nozzle-to-Shell Welds and Nozzle Inside Radius Sections2023-10-10010 October 2023
Proposed Alternative for Examinations of Examination Category C-B Steam Generator Nozzle-to-Shell Welds and Nozzle Inside Radius Sections
RS-23-094, Relief Request I4R-24, Alternative for Post-Peening Reexamination Frequency for Reactor Pressure Vessel Head Penetration Nozzle Number 752023-09-29029 September 2023
Relief Request I4R-24, Alternative for Post-Peening Reexamination Frequency for Reactor Pressure Vessel Head Penetration Nozzle Number 75
RS-23-093, License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, Technical Specifications 3.7.15, Spent Fuel Pool Boron Concentration, 3.7.16, Spent Fuel.2023-09-29029 September 2023
License Amendment to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, Technical Specifications 3.7.15, Spent Fuel Pool Boron Concentration, 3.7.16, Spent Fuel.
RS-23-091, Relief Request I4R-25, Alternative Requirements for Reactor Pressure Vessel Inservice Inspection Intervals2023-09-26026 September 2023
Relief Request I4R-25, Alternative Requirements for Reactor Pressure Vessel Inservice Inspection Intervals
RS-23-083, Withdrawal - Proposed Alternatives Related to the Steam Generators2023-06-27027 June 2023
Withdrawal - Proposed Alternatives Related to the Steam Generators
RS-23-077, Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-06-16016 June 2023
Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations
RS-23-074, Supplement to Application for License Amendment to Braidwood Station, Units 1 and 2, Technical Specification 3.7.9, Ultimate Heat Sink2023-06-0909 June 2023
Supplement to Application for License Amendment to Braidwood Station, Units 1 and 2, Technical Specification 3.7.9, Ultimate Heat Sink
RS-23-075, Application for Technical Specification Improvement to Extend the Completion Time for Condition B of Technical Specification 3.5.1, Accumulators, Using the Consolidated Line Item Improvement Process2023-06-0707 June 2023
Application for Technical Specification Improvement to Extend the Completion Time for Condition B of Technical Specification 3.5.1, Accumulators, Using the Consolidated Line Item Improvement Process
RS-23-050, Supplement to Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube.2023-05-22022 May 2023
Supplement to Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube.
RS-23-056, Response to Request for Additional Information to Braidwood Station, Unit 1, and Byron Station, Unit 1, for Steam Generator License Renewal Response to Commitment 102023-04-20020 April 2023
Response to Request for Additional Information to Braidwood Station, Unit 1, and Byron Station, Unit 1, for Steam Generator License Renewal Response to Commitment 10
RS-23-055, Annual 10 CFR 50.46 Report of Emergency Core Cooling System Evaluation Model Changes and Errors2023-04-10010 April 2023
Annual 10 CFR 50.46 Report of Emergency Core Cooling System Evaluation Model Changes and Errors
RS-23-052, License Amendment to Braidwood Station, Units 1 and 2, Technical Specification 3.7.9, Ultimate Heat Sink2023-03-24024 March 2023
License Amendment to Braidwood Station, Units 1 and 2, Technical Specification 3.7.9, Ultimate Heat Sink
RS-23-049, Constellation Energy Generation, LLC, Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations2023-03-23023 March 2023
Constellation Energy Generation, LLC, Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations
RS-23-045, Constellation Energy Generation, LLC Submittal of Fitness for Duty Performance Data Reports for 2022 Per 10 CFR 26.717(c) & 10 CFR 26.2032023-02-28028 February 2023
Constellation Energy Generation, LLC Submittal of Fitness for Duty Performance Data Reports for 2022 Per 10 CFR 26.717(c) & 10 CFR 26.203
RS-23-038, Response to Request for Additional Information for the Byron Proposal to Reinsert an Accident Tolerant Fuel Lead Test Assembly2023-02-27027 February 2023
Response to Request for Additional Information for the Byron Proposal to Reinsert an Accident Tolerant Fuel Lead Test Assembly
RS-23-040, Constellation Energy Generation, LLC, Supplemental Information - Proposed Alternatives Related to the Steam Generators2023-02-21021 February 2023
Constellation Energy Generation, LLC, Supplemental Information - Proposed Alternatives Related to the Steam Generators
RS-23-003, Constellation Energy Generation, LLC, Summary of Changes to Quality Assurance Topical Report, NO-AA-10, and Decommissioning Quality Assurance Program, NO-DC-102023-01-31031 January 2023
Constellation Energy Generation, LLC, Summary of Changes to Quality Assurance Topical Report, NO-AA-10, and Decommissioning Quality Assurance Program, NO-DC-10
RS-22-123, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator2022-12-0707 December 2022
Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator
RS-22-126, Constellation Energy Generation, LLC - Request to Use Provisions of a Later Edition of the ASME Boiler and Pressure Vessel Code, Section XI2022-11-30030 November 2022
Constellation Energy Generation, LLC - Request to Use Provisions of a Later Edition of the ASME Boiler and Pressure Vessel Code, Section XI
RS-22-118, Withdrawal of License Amendment Request to Revise Braidwood Station, Units 1 and 2, Technical Specification 3.7.9, Ultimate Heat Sink2022-10-31031 October 2022
Withdrawal of License Amendment Request to Revise Braidwood Station, Units 1 and 2, Technical Specification 3.7.9, Ultimate Heat Sink
RS-22-110, Supplemental Information - Proposed Alternatives Related to the Steam Generators and Request.2022-09-20020 September 2022
Supplemental Information - Proposed Alternatives Related to the Steam Generators and Request.
RS-22-097, License Amendment Request to Reinsert an Accident Tolerant Fuel Lead Test Assembly2022-08-31031 August 2022
License Amendment Request to Reinsert an Accident Tolerant Fuel Lead Test Assembly
RS-22-093, Advisement of Leadership Changes for Constellation Energy Generation, LLC and Submittal of Updated Standard Practice Procedures Plans2022-08-18018 August 2022
Advisement of Leadership Changes for Constellation Energy Generation, LLC and Submittal of Updated Standard Practice Procedures Plans
RS-22-086, R. E. Ginna Nuclear Power Plant - Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam.2022-08-10010 August 2022
R. E. Ginna Nuclear Power Plant - Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam.
RS-22-084, Response to Request for Additional Information Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator .2022-06-17017 June 2022
Response to Request for Additional Information Proposed Alternative for Examinations of Examination Categories B-B, B-D, and C-A Steam Generator .
2024-09-13
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Exelokn Exelon Generation www.exeloncorp.com Nuclear 4300 Winfie]d Road Warrenville, IL60555 RS-02-072 April 11, 2002 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington. D.C. 20555 - 0001
Subject:
Response to Request for Additional Information Regarding Risk Informed Inservice Inspection Relief Requests for Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2 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
References:
(1) Letter from K. A. Ainger (Exelon Generation Company, LLC) to U.S.
NRC, "Response to Request for Additional Information Regarding Risk Informed Inservice Inspection Relief Requests for Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2," dated September 5, 2001 (2) Letter from G. F. Dick, Jr. (U.S. NRC) to 0. D. Kingsley (Exelon Generation Company, LLC), "Request for Additional Information Regarding Inservice Inspection Relief Requests for Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2," dated May 23, 2001 (3) Letter from T. J. Tulon (Commonwealth Edison Company) to U.S. NRC, "Braidwood Station Interval 2 Inservice Inspection Program: Relief Request 12R-39, Alternative to the ASME Boiler and Pressure Vessel Code,Section XI, Requirements for Class 1 and Class 2 Piping Welds",
dated October 16, 2000 (4) Letter from William Levis (Commonwealth Edison Company) to U.S.
NRC, "Byron Station Interval 2 Inservice Inspection Program, Relief Request 12R-40, Alternative to the ASME Boiler and Pressure Vessel Code,Section XI, Requirements for Class 1 and Class 2 Piping Welds,"
dated November 17, 2000
April 11, 2002 U. S. Nuclear Regulatory Commission Page 2 In References 3 and 4, Commonwealth Edison Company, now Exelon Generation Company, LLC, requested approval of an alternative to the existing 1989 edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV)
Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Compornents,"
requirements for the selection and examination of Class 1 and 2 piping welds. This alternative utilizes the "risk-informed" inservice inspection (RI ISI) program methodology discussed in Electric Power Research Institute (EPRI) Topical Report (TR) 112657, "Revised Risk-Informed Inservice Inspection Evaluation Procedure," Revision B-A, December 1999. In Reference 2, the NRC requested additional information regarding our Reference 3 and 4 submittals. Exelon subsequently provided the requested information in Reference 1.
This letter is being submitted to the NRC to clarify one issue presented in Reference 1. In Reference 1, Attachment C, "Response to Request for Additional Information [RAI],
Braidwood Station, Units 1 and 2, RAI Question Br. 12, and Byron Station, Units 1 and 2, RAI Question By. 18," a detailed discussion is presented regarding the risk impact of implementing the RI ISI program. Page C-1 6 describes the "frequency of flaws" term (i.e.,
p), which is a mathematical term used in the Markov model. Attachment C states the following:
"Estimates of the frequency of flaws are determined from the same service data that is used to develop the failure rates and rupture frequencies."
The service data that were used to develop the failure rates and rupture frequencies are based on the Electric Power Research Institute (EPRI) database (i.e., T.J. Mikschl and K.N.
Fleming, "Piping System Failure Rates and Rupture Frequencies for Use in Risk Informed Inservice Inspection Applications," EPRI TR-1 11880, September 1999). The above statement would imply that 0 was developed solely using the EPRI database; however, 0 is actually a function of multiple variables not all provided in the EPRI database. Therefore, based on informed engineering judgement, data from SKI - Pipe, "SKI Piping Failure Database," dated May 1, 2000, in combination with the EPRI database were used to determine the value of 0. Using engineering judgement to determine 0 is consistent with the guidance in EPRI Topical Report, TR-110161, "Piping System Reliability and Failure Rate Estimation Models for Use in Risk-Informed In-Service Inspection Applications."
TR-1 10161, Table 3-2, "Strategies for Estimation of Markov Model Parameters," states that, "Data from results of NDE inspections can be used to estimate [0] directly as a multiple of the rate of leaks." Further, TR-1 10161, Table 6-2, Definition of Markov Model Parameters,"
states that 0 is, "Assumed to be 3 4F [where XF is the occurrence rate of a leak from a flaw state] for all segments and all degradation mechanisms, i.e., for each flaw that develops a leak there will be on the average 3 detectable flaws in the same location that do not develop leaks; based on engineering judgement."
The base value for p used in the RI ISI analysis for Byron and Braidwood Stations is 4.39 XF. It is worthy to note that the resultant core damage frequency (CDF) is relatively insensitive to a wide range of values for p. A sensitivity study was performed where 0 was varied from 1.0 to 20.0. Given this range for 0, the resultant reactor coolant system CDF varied from 9.16E-08 to 9.15E-08.
April 11, 2002 U. S. Nuclear Regulatory Commission Page 3 Given the above discussion, the results of the Byron Station and Braidwood Station RI ISI analyses are unaffected and remain valid. The basis upon which the NRC previously approved the use of the RI ISI approach is also unaffected.
Please direct any questions you may have regarding this submittal to Mr. J. A. Bauer at (630) 657-2801.
Respectfully,
/C6& aax-for Keith R. Jury Director - Licensing Mid-West Regional Operating Group cc: Regional Administrator - NRC Region III NRC Senior Resident Inspector - Braidwood Station NRC Senior Resident Inspector - Byron Station
