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Category:Code Relief or Alternative
MONTHYEARML22245A0012022-09-12012 September 2022 Relief from the Requirements of the ASME Code ML20227A3852020-09-0303 September 2020 Nonproprietary - Proposed Alternative RR-ENG-3-24 to ASME Code Requirements for the Repair of Essential Cooling Water System Class 3 Buried Piping NOC-AE-20003702, Proposed Alternatives to ASME OM Code 2012 Edition for the Fourth Inservice Test Interval (Relief Request PRR-03)2020-01-22022 January 2020 Proposed Alternatives to ASME OM Code 2012 Edition for the Fourth Inservice Test Interval (Relief Request PRR-03) ML19142A3072019-08-13013 August 2019 Request for Relief Request RR-ENG-3-23 to Extend Volumetric Examination Interval for Reactor Vessel Closure Head Nozzles NOC-AE-19003620, Proposed Alternative for Extension of Volumetric Examination Interval for Reactor Vessel Closure Head with Alloy 690 Nozzles in Accordance with 10 CFR 50.55a(z)(1) (Relief Request RR-ENG-3-23)2019-02-28028 February 2019 Proposed Alternative for Extension of Volumetric Examination Interval for Reactor Vessel Closure Head with Alloy 690 Nozzles in Accordance with 10 CFR 50.55a(z)(1) (Relief Request RR-ENG-3-23) ML18303A2062018-11-0707 November 2018 Request for Relief from ASME Code to Extend the Inservice Inspection Interval for Category B-N-2 and B-N-3 Examinations NOC-AE-18003598, Response to Request for Additional Information Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16)2018-09-26026 September 2018 Response to Request for Additional Information Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16) ML18177A4252018-07-24024 July 2018 Relief from the Requirements of the Asme Code Regarding the Third 10-Year Inservice Inspection Interval ML18187A1492018-07-24024 July 2018 Relief Request RR-ENG-3-22 for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography NOC-AE-18003578, Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16)2018-06-25025 June 2018 Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16) NOC-AE-18003547, Proposed Alternative to Reactor Vessel Inservice Inspection Intervals (Relief Request RR-ENG-3-14)2018-02-15015 February 2018 Proposed Alternative to Reactor Vessel Inservice Inspection Intervals (Relief Request RR-ENG-3-14) ML16174A0912016-06-30030 June 2016 Relief Request RR-ENG-3-20, Use of ASME Code Case N-770-1, Reactor Vessel Cold Leg Nozzle to Safe-End Welds with Flaw Analysis, for the Third 10-Year Inservice Inspection Interval ML15218A3672015-08-21021 August 2015 Relief Request RR-ENG-17, Relief from Code Case N-770-1, Subsection 2400 and Table 1 Inspection Frequency of Reactor Vessel Cold Leg Nozzle to Safe-End Welds with Flaw Analysis, Third 10-Year ISI Interval ML13102A1262013-04-23023 April 2013 Withdrawal of Relief Request RR-ENG-3-12 from ASME Code Requirements for Periodic Inspection of Reactor Coolant Pressure Boundary Check Valve with Seal Cap, Third 10-year Inservice Inspection Interval ML13087A5172013-04-12012 April 2013 Relief Request RR-ENG-3-09, Request for Relief from ASME Code Requirements; Deferral of Code Repair of Essential Cooling Water System Piping Until April 2013 Refueling Outage ML13004A3392013-03-12012 March 2013 Relief Request RR-ENG-3-10, Reactor Pressure Vessel Head Flange O-Ring Leakoff Lines Non-Destructive Examination, for the Third 10-Year Inservice Inspection Interval NOC-AE-12002939, Request for Relief from ASME Section XI Code Requirements for Periodic Inspection of Reactor Coolant Pressure Boundary Check Valves with Seal Cap Enclosures (Relief Request RR-ENG-3-12)2013-02-0707 February 2013 Request for Relief from ASME Section XI Code Requirements for Periodic Inspection of Reactor Coolant Pressure Boundary Check Valves with Seal Cap Enclosures (Relief Request RR-ENG-3-12) NOC-AE-12002956, Response to Request for Additional Information Regarding Relief Request RR-ENG-3-09 for the Essential Cooling Water System2013-01-31031 January 2013 Response to Request for Additional Information Regarding Relief Request RR-ENG-3-09 for the Essential Cooling Water System ML12243A3432012-09-10010 September 2012 RR RE-ENG-3-04 to Apply Alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XI Requirements for Examination of Class 1 and 2 Piping Welds ML12235A3472012-08-28028 August 2012 Relief Request RR-ENG-3-06 from ASME Code Requirements for Leak Testing Boundaries of Class 1 Pressure-Retaining Components, Third 10-Year Inservice Inspection Interval (TAC ME7053-ME7054) ML12201A2562012-08-16016 August 2012 Relief Request RR-ENG-3-08, Deferral of Code Repair of Flaws in U2 Essential Cooling Water Class 3 Piping Until Restart from Current Refueling Outage Scheduled for Mid-April 2012 NOC-AE-12002837, Response to Request for Additional Information: Application of an Alternative to Requirements for Examination of Class 1 and Class 2 Piping Welds (Relief Request RR-ENG-3-04)2012-05-0909 May 2012 Response to Request for Additional Information: Application of an Alternative to Requirements for Examination of Class 1 and Class 2 Piping Welds (Relief Request RR-ENG-3-04) NOC-AE-12002807, Request for Relief from ASME Boiler and Pressure Vessel Code, Section XI Requirements for the Essential Cooling Water System (Relief Request RR-ENG-3-08)2012-03-12012 March 2012 Request for Relief from ASME Boiler and Pressure Vessel Code, Section XI Requirements for the Essential Cooling Water System (Relief Request RR-ENG-3-08) ML1118605352011-07-29029 July 2011 Relief Request RR-ENG-2-55 from ASME Code Requirements for Weld Examinations, Second 10-Year Inservice Inspection Interval ML1109803472011-04-20020 April 2011 Relief Request RR-ENG-3-01, from ASME Code Requirements for Steam Generator Main Steam Nozzle Non-Destructive Examination, Third 10-Year Inservice Inspection Interval ML1108109482011-04-0707 April 2011 Request for Relief RR-ENG-3-03 from ASME Code Requirements for Pump Casing Inservice Inspection Examination, Third 10-Year Inservice Inspection Interval ML1108400762011-04-0505 April 2011 Request for Relief RR-ENG-3-02 from ASME Code Requirements for Reactor Pressure Vessel Flange Insert Non-Destructive Examination, Third 10-Year Inservice Inspection Interval NOC-AE-10002600, Request for Relief from ASME Section XI Requirements for Ultrasonic Examination of Reactor Pressure Vessel Shell-to-Flange Welds (RR-ENG-3-05)2010-10-18018 October 2010 Request for Relief from ASME Section XI Requirements for Ultrasonic Examination of Reactor Pressure Vessel Shell-to-Flange Welds (RR-ENG-3-05) NOC-AE-10002594, Request for Relief from ASME Section XI Code Requirements for Pump Casing Inservice Inspection Examination (Relief Request RR-ENG-3-03)2010-09-20020 September 2010 Request for Relief from ASME Section XI Code Requirements for Pump Casing Inservice Inspection Examination (Relief Request RR-ENG-3-03) ML1021500772010-09-0202 September 2010 Relief Request Nos. VRR-01, PRR-03, PRR-02, and PRR-01 for Third 10-year Interval Inservice Testing Program for Pumps and Valves (TAC Nos. ME3515 Through ME3522) ML1006208692010-03-24024 March 2010 Authorization of Relief Request RR-ENG-2-53, Alternative to Inservice Inspection Requirements for Ultrasonic Exam of Reactor Pressure Vessel Shell-to-Flange Weld ML1005395882010-03-12012 March 2010 Relief Request RR-ENG-2-52 from ASME Code, Section XI Requirements for Essential Cooling Water System Code Repair NOC-AE-09002399, Request for Relief from ASME Boiler and Pressure Vessel Code Section XI Requirements for the Essential Cooling Water System (Relief Request RR-ENG-2-52)2009-03-12012 March 2009 Request for Relief from ASME Boiler and Pressure Vessel Code Section XI Requirements for the Essential Cooling Water System (Relief Request RR-ENG-2-52) ML0827502202008-12-0909 December 2008 Relief Request RR-ENG-2-30, Request for Relief to Use ASME Code Case N-516-3, Underwater Welding, Section XI, Division 1 ML0827707852008-11-12012 November 2008 Authorization of Relief Request RR-ENG-2-51 from ASME Code Case N-498-4, on 10-Year System Hydrostatic Testing for Class 1, 2, and 3 Systems ML0824901602008-09-26026 September 2008 Relief Request RR-ENG-2-49, Second 10-Year Inservice Inspection Interval, Deferral of Code Repair in the Essential Cooling Water System Piping ML0735410722008-01-10010 January 2008 Request for Relief No. RR-ENG-2-48 from ASME Code Case N-638-1 Requirements Regarding Start Time for 48-Hour Hold Period Before Non-Destructive Examination of Weld Overlay Repair ML0731204462007-11-30030 November 2007 Relief Request RR-ENG-2-47 for Approval of Temporary Non-code Repair and Deferral of Code Repair Upgraded Essential Cooling Water System Piping NOC-AE-07002211, Relief Request (RR-ENG-2-50) for the Second 10 Year ISI Interval from 10 CFR 50.55a for the Purpose of Invoking Code Case N-698, Design Stress Intensities and Yield Strength Values For...2007-10-0202 October 2007 Relief Request (RR-ENG-2-50) for the Second 10 Year ISI Interval from 10 CFR 50.55a for the Purpose of Invoking Code Case N-698, Design Stress Intensities and Yield Strength Values For... ML0708510082007-04-30030 April 2007 Relief Request No. RR-ENG-2-44 on Deferral of Code Repair of Essential Cooling Water System Indication ML0708102642007-04-0202 April 2007 Relief, Request for Relief No. RR-ENG-2-43 for Remainder of Second 10-year Inservice Inspection Interval Application of Weld Overlays in Pressurizer Nozzle Safe End Welds (TAC Nos. MD1414 - MD1423) ML0706500752007-03-15015 March 2007 Request to Use 2001 Edition Through 2003 Addenda of ASME Code for Operations and Maintenance for Remainder of Second 10-Year Inservice Testing Program Interval ML0704400592007-03-0101 March 2007 Request for Relief No. RR-ENG-2-45 for Remainder of Second 10-year Inservice Inspection Interval Use of Penetrameters in Radiography Examination ML0622303092006-10-26026 October 2006 Response to Relief Request RR-ENG-2-42 for Approval Non-Code Repair and Deferral of Code Repair of Essential Cooling Water System Piping, TAC MC8804 NOC-AE-06002031, Request for Relief from ASME Boiler and Pressure Vessel Code, Section XI Requirements for Use of Penetrameters in Radiographic Examinations2006-06-14014 June 2006 Request for Relief from ASME Boiler and Pressure Vessel Code, Section XI Requirements for Use of Penetrameters in Radiographic Examinations ML0610907542006-05-25025 May 2006 Relief, Relief Request RR-ENG-2-39 and RR-ENG-2-40 for Approval of Temporary Non-code Repair and Deferral of Code Repair of Essential Cooling Water System Piping, Trains 1B and 1C ML0609702402006-05-12012 May 2006 Relief, RR-ENG-2-41 TAC No. MC8279 NOC-AE-05001899, Request for Relief from ASME Boiler and Pressure Vessel Code, Section Xl Requirements for the Essential Cooling Water System (Ecw Train 1 C) (Relief Request RR-ENG-2-40)2005-07-19019 July 2005 Request for Relief from ASME Boiler and Pressure Vessel Code, Section Xl Requirements for the Essential Cooling Water System (Ecw Train 1 C) (Relief Request RR-ENG-2-40) ML0506205052005-03-15015 March 2005 Request for Relief from Requirements of ASME and Pressure Vessel Code RR-ENG-IWE-07 NOC-AE-04001817, Revised Request for Authorization to Use an Alternative to the ASME Boiler and Pressure Vessel Code Section XI Requirements (Relief Request VRR-05)2004-11-0909 November 2004 Revised Request for Authorization to Use an Alternative to the ASME Boiler and Pressure Vessel Code Section XI Requirements (Relief Request VRR-05) 2022-09-12
[Table view] Category:Letter type:NOC
MONTHYEARNOC-AE-230040, Supplement to Proposed Alternate Frequency to Containment Unbonded Post-Tensioning System Inservice Inspection (Relief Request RR-ENG-4-06)2023-12-14014 December 2023 Supplement to Proposed Alternate Frequency to Containment Unbonded Post-Tensioning System Inservice Inspection (Relief Request RR-ENG-4-06) NOC-AE-230039, Docket Nos. Stn 50-498, Stn 50-499 - Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/20230032023-12-12012 December 2023 Docket Nos. Stn 50-498, Stn 50-499 - Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/2023003 NOC-AE-230039, Submittal of Update Foreign Ownership, Control or Influence (FOCI)2023-07-11011 July 2023 Submittal of Update Foreign Ownership, Control or Influence (FOCI) NOC-AE-220039, Physical Security Plan, Training and Qualification Plan, Safeguards Contingency Plan, and Independent Spent Fuel Storage Installation Security Program Revision 252023-02-0606 February 2023 Physical Security Plan, Training and Qualification Plan, Safeguards Contingency Plan, and Independent Spent Fuel Storage Installation Security Program Revision 25 NOC-AE-220038, Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Cask2022-06-23023 June 2022 Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Cask NOC-AE-210038, Submittal of Operations Quality Assurance Plan Changes QA-089, QA-091, and Revision 252022-01-0404 January 2022 Submittal of Operations Quality Assurance Plan Changes QA-089, QA-091, and Revision 25 NOC-AE-21003858, 10 CFR 50.46 Thirty-Day Report of Significant ECCS Model Changes2021-12-0606 December 2021 10 CFR 50.46 Thirty-Day Report of Significant ECCS Model Changes NOC-AE-21003853, Revised Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material2021-12-0303 December 2021 Revised Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material NOC-AE-21003848, Unit 1 Cycle 24 Core Operating Limits Report2021-11-18018 November 2021 Unit 1 Cycle 24 Core Operating Limits Report NOC-AE-21003846, Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material2021-11-0404 November 2021 Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material NOC-AE-21003842, 10 CFR 50.59 Summary Report2021-09-23023 September 2021 10 CFR 50.59 Summary Report NOC-AE-21003841, Request for Relief from ASME Section Xl Code Requirements for Weld Examinations (Relief Request RR-ENG-3-25)2021-09-23023 September 2021 Request for Relief from ASME Section Xl Code Requirements for Weld Examinations (Relief Request RR-ENG-3-25) NOC-AE-21003832, Supplement to License Amendment Request to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections2021-09-0909 September 2021 Supplement to License Amendment Request to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections NOC-AE-21003812, Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections2021-08-10010 August 2021 Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections NOC-AE-21003825, Update of Foreign Ownership, Control, or Influence Information (FOCI)2021-08-0505 August 2021 Update of Foreign Ownership, Control, or Influence Information (FOCI) NOC-AE-21003824, Update Foreign Ownership, Control, or Influence (FOCI)2021-07-29029 July 2021 Update Foreign Ownership, Control, or Influence (FOCI) NOC-AE-21003823, Update Foreign Ownership Control or Influence (FOCI)2021-07-28028 July 2021 Update Foreign Ownership Control or Influence (FOCI) NOC-AE-21003820, Nuclear Insurance Protection2021-07-20020 July 2021 Nuclear Insurance Protection NOC-AE-21003819, Inservice Inspection Summary Report - 2RE212021-07-15015 July 2021 Inservice Inspection Summary Report - 2RE21 NOC-AE-21003816, Commitment Change Summary Report2021-06-30030 June 2021 Commitment Change Summary Report NOC-AE-21003814, Technical Specification Bases Control Program2021-06-24024 June 2021 Technical Specification Bases Control Program NOC-AE-21003810, Update Foreign Ownership, Control, or Influence (FOCI)- CPS Energy2021-06-17017 June 2021 Update Foreign Ownership, Control, or Influence (FOCI)- CPS Energy NOC-AE-21003811, Update Foreign Ownership, Control, or Influence (FOCI)- Nrg Energy2021-06-17017 June 2021 Update Foreign Ownership, Control, or Influence (FOCI)- Nrg Energy NOC-AE-21003806, Inservice Inspection Program Plan and Inservice Testing Program Snubber Inservice Test Plan for the Fourth Ten-Year Interval2021-05-20020 May 2021 Inservice Inspection Program Plan and Inservice Testing Program Snubber Inservice Test Plan for the Fourth Ten-Year Interval NOC-AE-21003801, Annual Dose Report for 20202021-04-26026 April 2021 Annual Dose Report for 2020 NOC-AE-21003802, 2020 South Texas Project Electric Generating Station Annual Environmental Operating Report2021-04-26026 April 2021 2020 South Texas Project Electric Generating Station Annual Environmental Operating Report NOC-AE-21003804, Operator Licensing Examination Schedule2021-04-21021 April 2021 Operator Licensing Examination Schedule NOC-AE-21003800, Radioactive Effluent Release Report2021-04-19019 April 2021 Radioactive Effluent Release Report NOC-AE-21003799, Changes to South Texas Project Electric Generating Station (STPEGS) Emergency Plan2021-04-15015 April 2021 Changes to South Texas Project Electric Generating Station (STPEGS) Emergency Plan NOC-AE-21003795, Cycle 22 Core Operating Limits Report2021-04-15015 April 2021 Cycle 22 Core Operating Limits Report NOC-AE-21003796, Update Foreign Ownership, Control, or Influence (FOCI)2021-04-15015 April 2021 Update Foreign Ownership, Control, or Influence (FOCI) NOC-AE-21003791, Financial Assurance for Decommissioning - 2021 Update2021-03-31031 March 2021 Financial Assurance for Decommissioning - 2021 Update NOC-AE-21003790, Response to Apparent Violations in NRC Inspection Report 05000498/2020401 and 05000499/2020401: (EA-20-122) (Letter)2021-03-31031 March 2021 Response to Apparent Violations in NRC Inspection Report 05000498/2020401 and 05000499/2020401: (EA-20-122) (Letter) NOC-AE-210037, STP Fire Hazards Analysis Report, Amendment 26 (Redacted)2021-03-30030 March 2021 STP Fire Hazards Analysis Report, Amendment 26 (Redacted) NOC-AE-21003792, STP Fire Hazards Analysis Report, Amendment 26 (Redacted)2021-03-30030 March 2021 STP Fire Hazards Analysis Report, Amendment 26 (Redacted) NOC-AE-200037, License Amendment Request to Revise Technical Specification 3.6.3 to Append a Note and Remove the Index from Technical Specifications2021-03-11011 March 2021 License Amendment Request to Revise Technical Specification 3.6.3 to Append a Note and Remove the Index from Technical Specifications NOC-AE-21003784, Response to Request for Additional Information Regarding 1RE22 Inspection Summary Report for Steam Generator Tubing2021-03-0808 March 2021 Response to Request for Additional Information Regarding 1RE22 Inspection Summary Report for Steam Generator Tubing NOC-AE-21003786, Annual Fitness for Duty Performance Report for 20202021-03-0101 March 2021 Annual Fitness for Duty Performance Report for 2020 NOC-AE-21003785, Evidence of Financial Protection2021-02-23023 February 2021 Evidence of Financial Protection NOC-AE-21003781, Notice Regarding Withdrawal of Funds from Nuclear Decommissioning Trust Subaccounts2021-01-27027 January 2021 Notice Regarding Withdrawal of Funds from Nuclear Decommissioning Trust Subaccounts NOC-AE-21003780, Submittal of Update Foreign Ownership, Control, or Influence (FOCI)2021-01-0707 January 2021 Submittal of Update Foreign Ownership, Control, or Influence (FOCI) NOC-AE-20003778, Changes to South Texas Project Electric Generating Station Emergency Plan2020-12-17017 December 2020 Changes to South Texas Project Electric Generating Station Emergency Plan NOC-AE-20003777, STPNOC Concerns Regarding the Proposed Change to the Evaluated Force-on-Force Inspection Guidance During the COVID-19 Public Health Emergency2020-12-10010 December 2020 STPNOC Concerns Regarding the Proposed Change to the Evaluated Force-on-Force Inspection Guidance During the COVID-19 Public Health Emergency NOC-AE-20003766, Supplement to Change Implementation Date for License Amendment Request to Revise the STPEGS Emergency Plan2020-12-0202 December 2020 Supplement to Change Implementation Date for License Amendment Request to Revise the STPEGS Emergency Plan NOC-AE-20003767, Request for a One-Time Exemption from 10 CFR 73, Appendix 8, Section VI, Subsection C.3.(1)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic2020-11-16016 November 2020 Request for a One-Time Exemption from 10 CFR 73, Appendix 8, Section VI, Subsection C.3.(1)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic NOC-AE-20003765, Inservice Testing Program Description for the Fourth Ten-Year Interval2020-10-28028 October 2020 Inservice Testing Program Description for the Fourth Ten-Year Interval NOC-AE-20003764, 1 RE22 Inspection Summary Report for Steam Generator Tubing2020-10-0707 October 2020 1 RE22 Inspection Summary Report for Steam Generator Tubing NOC-AE-20003762, Supplement to License Amendment Request to Revise Technical Specifications to Adopt TSTF-374, Revision 0, Revision to TS 5.5.13 and Associated TS Bases for Diesel Fuel Oil Using the Consolidated Line Item Improvemen2020-09-22022 September 2020 Supplement to License Amendment Request to Revise Technical Specifications to Adopt TSTF-374, Revision 0, Revision to TS 5.5.13 and Associated TS Bases for Diesel Fuel Oil Using the Consolidated Line Item Improvemen NOC-AE-20003761, Supplement to Exemption Request from 10 CFR 50 Appendix E Due to COVID-19 Pandemic2020-09-10010 September 2020 Supplement to Exemption Request from 10 CFR 50 Appendix E Due to COVID-19 Pandemic NOC-AE-20003760, Update Foreign Ownership. Control. or Influence(FOCI)- Transmittal2020-09-0808 September 2020 Update Foreign Ownership. Control. or Influence(FOCI)- Transmittal 2023-07-11
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Nuclear Operating Company South Texas ProectElectnc Genetratn Station P0. Box 289 Wadsworth. Texas 77483 March 12, 2009 NOC-AE-09002399 File No.: G25 10CFR50.55a Commission U. S. Nuclear Regulatory Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2746 South Texas Project Unit 2 Docket No. STN 50-49b Request for Relief from ASME Boiler and Pressure Vessel Code Section Xl Requirements for the Essential Cooling Water System (Relief Request RR-ENG-2-52)
In accordance with the provisions of 10 CFR 50.55a(g)(5)(iii), the South Texas Project requests relief from IWA-5250 of Section XI of the ASME Boiler and Pressure Vessel Code. Approval will allow deferral of code repair of a flaw identified in the Unit 2 Essential Cooling Water (ECW)
Class 3 piping. Repair of the flaw with a code repair at this time is impractical. In accordance with the guidance provided in NRC Generic Letter 90-05 and subject to Nuclear Regulatory Commission approval, code repairs will be implemented no later than the next scheduled Unit 2 refueling outage.
An indication of a through-wall flaw was identified on the downstream flange of ECW return throttle valve 2-EW-1004 from Essential Chiller 22B. The flaw is a linear indication (approximately 3/8-inch long) with residue buildup on the downstream flange side of a flange-to-piping weld. The root cause of the flaw is dealloying. Evaluation of the flaw using fracture mechanics methodology provided by Generic Letter 90-05 determined that the structural integrity of the ECW piping is not adversely affected.
The attached relief request addresses the piping section, and implementation of compensatory and corrective actions in accordance with the guidelines provided in Generic Letter 90-05.
Operability and functionality of the system have been maintained, and deferring repair of the flaw will not affect the health and safety of the public.
A list of commitments in the request is attached.
If there are any questions, please contact either Mr. P. L. Walker at (361) 972-8392 or me at (361) 972-7566.
G. T. Powell Vice President, Engineering PLW Attachments: 1) Request for Relief from ASME Boiler and Pressure Vessel Code Section XI Requirements for the Essential Cooling Water System (Relief Request RR-ENG-2-52)
- 2) List of Commitments 4 ---
STI No. 32433957
NOC-AE-09002399 Page 2 of 2 cc:
(paper copy) (electronic copy)
Regional Administrator, Region IV Kevin Howell U. S. Nuclear Regulatory Commission Catherine Callaway 612 East Lamar Blvd., Suite 400 Jim von Suskil Arlington, Texas 76011-8064 NRG South Texas LP Mohan C. Thadani A. H. Gutterman, Esquire Senior Project Manager Morgan, Lewis & Bockius LLP U.S. Nuclear Regulatory Commission One White Flint North (MS 7 D1) Mohan C. Thadani 11555 Rockville Pike U. S. Nuclear Regulatory Commission Rockville, MD 20852 Richard A. Ratliff J. J. Nesrsta Department of State Health Services R. K. Temple Inspection Unit - Radiation Branch E. Alarcon P.O. Box 149347 Kevin Polio Austin, TX 78714-9347 City Public Service C. M. Canady C. Kirksey City of Austin City of Austin Electric Utility Department 721 Barton Springs Road Jon C. Wood Austin, TX 78704 Cox Smith Matthews Senior Resident Inspector U. S. Nuclear Regulatory Commission P. 0. Box 289, Mail Code: MN1 16 Wadsworth, TX 77483
Attachment 1 NOC-AE-09002399 Page 1 of 7 SOUTH TEXAS PROJECT UNIT 2 REQUEST FOR RELIEF FROM ASME BOILER AND PRESSURE VESSEL CODE SECTION XI REQUIREMENTS FOR THE ESSENTIAL COOLING WATER SYSTEM (RELIEF REQUEST RR-ENG-2-52)
Component for Which Relief is Requested (a)
Description:
Aluminum-bronze flange downstream of Essential Cooling Water (ECW) return throttle valve 2-EW-1 004 from Essential Chiller 22B (b) Function:
The ECW System is designed to supply cooling water to various safety-related systems for normal plant operation, normal shutdown, and during and after postulated design-basis accidents. Valve 2-EW-1004 provides manual throttling capability and is locked in place to control the fluid flow rate through the Essential Chiller.
(c) Class:
ASME Code Class 3 (d) Description of the flaw:
An indication of a through-wall flaw is located on the downstream flange of Essential Chiller 22B ECW return throttle valve 2-EW-1004. Leakage residue buildup in a line parallel to the circumferential weld was found at the weld on the downstream flange of the valve, with an underlying flaw of approximately 3/8-inch in length. The flaw appears to be a tight crack as leakage is not readily measurable. The attached \pictures show the location (Figure 1) and the appearance (Figure 2) of the residue buildup.
- 2. Applicable Code Edition and Addenda:
ASME Boiler and Pressure Vessel Code, Section X1, 1989 Edition
- 3. Applicable Code Requirement:
ASME Section X1, IWA-5250(a)(3) requires that the source of leakage be evaluated for repair or replacement in accordance with IWA-4000 or IWA-7000. Relief from the requirements of IWA-5250(a)(3) is requested so that code repair of the through-wall flaw at this location may be deferred until the next outage of sufficient duration but not later than the next refueling outage provided the conditions of Generic Letter 90-05, "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1, 2 and 3 Piping," are met.
- 4. Flaw Detection The flaw was identified on December 2, 2008, during periodic examination of ECW large bore piping.
Attachment 1 NOC-AE-09002399 Page 2 of 7
- 5. Impracticality Determination As stated in Generic Letter 90-05, an ASME Code repair is required for Code Class 1, 2, and 3 piping unless specific written relief is granted by the NRC. Relief from ASME Code requirements is appropriate when performing the repair at the time of discovery is determined to be impractical.
A repair is considered to be impractical if:
The flaw detected during plant operation is in a section of Class 3 piping that cannot be isolated to complete a code repair within the time period permitted by the limiting condition for operation of the affected system as specified in the plant Technical Specifications, and
- Performance of code repair necessitates a plant shutdown.
STPNOC applies risk-managed Technical Specifications in accordance with the Configuration Risk Management Program. If there is a need to extend the all6wed outage time for the affected ECW loop, risk analysis techniques are applied that take into account real-time plant status to keep overall risk below 1.OE-5 up to a maximum of 30 days. However, taking an otherwise operable ECW loop out of service while at power not only increases overall risk to the plant, but also limits flexibility in dealing with other plant equipment issues that may arise in the interim.
Performance of code repairs within the allowed outage time for the ECW system, as permitted by the limiting condition for operation, is not practical due to the amount of time required to implement the repair, and the potential for fit-up problems during repair.
A plant shutdown may be necessary to complete the repair. Therefore, relief is requested on the basis of impracticality.
- 6. Proposed Alternative and Basis for Use 6.1 Proposed Alternative Repair of the defect is to be performed when adequate time is available for the repair, but no later than the next Unit 2 refueling outage. The next Unit 2 refueling outage is currently scheduled to begin in March 2010 (2RE14). Compensatory action has been implemented to detect changes in the condition of the flaw until a repair can be implemented.
6.2 Basis for Use 6.2.1 Scope Evidence of a through-wall flaw was identified on an 8-inch flange of Essential Cooling Water (ECW) return line from the essential chiller 3V1 12VCH005. There is a residue buildup that provides a linear indication located on the flange side of the flange-to-pipe weld. The flaw appears to be a tight crack approximately 3/8-inch long. This portion of pipe is subjected to normal operating pressure of the ECW system. The residue buildup suggests ongoing seepage through the flaw, although the leakage is not readily measurable.
6.2.2 Specific Considerations ASME Section XI, IWA-5250, requires that leakage be evaluated for corrective action and implies that any component with through-wall leakage must be repaired or replaced regardless of the leakage rate. The expectation of ASME Section XI is that through-wall
Attachment 1 NOC-AE-09002399 Page 3 of 7 leaks are repaired at the time of discovery. The process for repair of the affected piping requires that the affected ECW loop be made inoperable. However, repairs could not be initiated immediately upon discovery of a flaw due to time required for obtaining parts, staging materials, and repair crew preparation, with the time for actual repair beyond that. The amount of time needed for resolution will vary depending upon individual circumstances.
As stated in the South Texas Project Technical Specifications, the three independent ECW loops shall be operable in Modes 1, 2, 3, and 4. With only two of the essential cooling water loops operable, all three are to be operable within seven days. If only one loop remains in service, one loop is to be returned to service within one hour. If these requirements are not met, the affected unit is to be in Hot Standby within the next six hours, or the requirements of the Configuration Risk Management Program are to be applied.
Consequences of potential system interactions, including flooding, spray on equipment, and loss of flow to the system, are addressed in Appendix 9A of the South Texas Project Updated Final Safety Analysis Report, "Assessment of the Potential Effects of Through-Wall Cracks in ECWS Piping." The assessment assumes the effects of spray from a moderate energy line (10-inch diameter). Safety-related equipment is either designed to operate in a spray environment, or protected if sensitive to spray. Flooding in a given area due to the ECW system is enveloped by worst case flow from an opening in a local pipe due to a "critical crack," with an area equivalent to a rectangle of length one-half the pipe diameter and a width equal to one-half the pipe wall thickness.
This assessment is bounding for the condition under consideration. Flooding due to the ECW system was reviewed by NRC inspectors during an inspection conducted January 25 through February 12, 1999. This is documented in NRC Inspection Report No. 50-498/98-19; 50-499/98-19, dated March 26, 1999. Flooding is addressed in Updated Final Safety Analysis Report Appendix 9A.
Flooding calculations indicate a potential flooding rate of approximately 14.5 cu ft/min through a postulated crack in the ECW pipe. However, the maximum flood rate is approximately 80 cu ft/min due to a postulated crack in the Component Cooling Water line in Mechanical Auxiliary Building room 067E, the location of the flawed ECW pipe.
Nearby safe shutdown equipment are not affected by postulated leakage/spray effects.
The ECW pumps and the cooling reservoir have adequate design margin and make-up capability to account for postulated leakage and are therefore fully capable of fulfilling the design-basis functions and mission times during a design-basis accident.
The condition of the ECW piping and the leakage is monitored by operator/personnel rounds. Sump level alarms are available to warn operators if unanticipated, sudden leakage were to develop. Makeup capacity is available from the ECW pond inventory.
The ECW system is a low-pressure system with normal operating pressures of approximately 50 psig and a design pressure of 120 psig. Normal system temperature is 47 to 100 degrees F. Temperature following a design-basis accident is not expected to exceed 120 degrees F. Therefore, the consequences associated with failure of high-energy lines are not applicable to this relief request.
The structural integrity is monitored by the following methods:
- Monthly monitoring for qualitative assessment of leakage (quantitative if measurable leaks are observed). There is no measurable leakage at this time.
Attachment '1 NOC-AE-09002399 Page 4 of 7 Continuation of large bore ECW piping periodic walkdowns. These walkdowns are regularly scheduled VT-2 examinations at six-month intervals. These inspections have proven to be an effective means of identifying flaws in ECW components prior to deterioration of structural integrity margins below ASME Section XI requirements.
Structural integrity and the monitoring frequency are re-evaluated if significant changes in the condition of the flawed area are found during this monitoring.
6.2.3 Root Cause Determination The flaw is due to dealloying. The root cause of dealloying is a combination of corrosion and stress. The dealloying process normally initiates from a crevice such as the area behind a backing ring, a fabrication-induced flaw, or a casting flaw. Dealloying in this case is believed to be similar to dealloying seen in other susceptible aluminum-bronze components. The process by which dealloying of aluminum-bronze occurs has been described in previous communications with the NRC (Reference 8.1).
6.2.4 Flaw Evaluation The structural integrity of the flanged piping was assessed using the through-wall flaw evaluation approach in Section C-3a of NRC Generic Letter 90-05. This approach assumes a through-wall flaw and evaluates the flaw stability using Linear Elastic Fracture Mechanics (LEFM). Enclosure 1 to NRC Generic Letter 90-05 details this methodology.
To summarize the results:
s = Predicted bending stress s = 11.5 ksi K = Stress intensity factor 1/2 K = 32.239 Ksi-in For flaw stability, this methodology specifies "K" should be less than the critical stress intensity factor representing the fracture toughness of the material. Fracture toughness 1/2 for this material ranges from 63.5 to 95.1 ksi-in STRESSES PRESSURE DEAD +
WEIGHT FAULTED THERMAL STRESS (psi) 1090 4703 4804 ALLOWABLE STRESS (psi) 18000 43200 27000 SAFETY MARGIN 16.5 9.18 5.62 The calculated safety margins are adequate for the various loading conditions.
Attachment 1 NOC-AE-09002399 Page 5 of 7 6.2.5 Augqmented Inspection Normally, walkdowns of ECW piping are performed at intervals of six months. In the event a flawed area is discovered, augmented monthly inspections are performed to monitor the flaw to detect changes in the size of the discolored area or leakage rate.
Inspectors look for: change from residue buildup to active dripping; new indication at a different area on the component; or, a substantial change,(about 2x or more) in the area of the original indication. Periodic monitoring and inspection by STPNOC provide confidence in the ability to detect changes in the leakage rate before leakage becomes a safety issue. Structural integrity and the monitoring frequency are re-evaluated if monitoring identifies significant changes in the condition of the flawed area. None has shown sufficient change from the time of discovery to warrant accelerated implementation of corrective measures.
6.2.6 Conclusion The South Texas Project has analyzed through-wall flaws in ECW piping and found that degradation progresses slowly. Detectable leakage is produced before flaws reach a limiting size that would affect the operability of the Essential Cooling Water System.
Rapid or catastrophic failure is not a concern. Flaws are monitored and inspected to ensure detection of leakage. Continued inspection provides assurance that changes in the condition of the flaws will be identified and assessed for further action as needed.
Evaluation of the flaw using fracture mechanics methodology provided by NRC Generic Letter 90-05 concludes that the structural integrity of the ECW piping is not adversely affected. Operability and functionality of the system have been maintained, and deferring repair of the flaw will not affect the health and safety of the public.
- 7. Duration of Proposed Alternative Repair of the defect will be deferred until adequate time is available for the repair, but no later than the next Unit 2 refueling outage, provided the condition continues to meet the acceptance criteria of Generic Letter 90-05. The next Unit 2 refueling outage is scheduled to begin in March 2010.
- 8.
Reference:
8.1 M. A. McBurnett (Houston Lighting & Power) to NRC Document Control Desk, "Status of Corrective Actions in the ECW System," dated November 1, 1988 (ST-HL-AE-2748)
NOC-AE-09002399 Page 7 of 7
Attachment 2 NOC-AE-09002399 Page 1 of 1 LIST OF COMMITMENTS The following table identifies the actions in this document to which the STP Nuclear Operating Company has committed. Statements in this submittal with the exception of those in the table below are provided for information purposes and are not considered commitments. Please direct questions regarding these commitments to Philip!Walker at (361) 972-8392.
Commitment Expected CR Action No.
Completion Date Perform monthly walkdowns of dealloying location to detect changes in size of the discolored area or leakage until a code repair is performed. 05/04/2010 08-18477-4 Structural integrity and the monitoring frequency will be re-evaluated if significant changes in the condition of the dealloyed area are found during this monitoring.
Rework of the defect will be deferred until adequate time is available for the repair, but no 05/05/2010 08-18477-5 later than the next Unit 2 refueling outage, 2RE14.