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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 Tas fotyed Ekdrk GeneradaS,-Sta11 PO S 2820 fAd rth Teas 77483 ,n July 19, 2005 NOC-AE-05001899 File No.: G25 10CFR50.55a U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Unit 1 Docket No. STN 50-498 Request for Relief from ASME Boiler and Pressure Vessel Code, Section Xl Requirements for the Essential Cooling Water System (ECW Train 1C)
(Relief Request RR-ENG-2-40) (TAC No. MC-5192)
In accordance with the provisions of 10CFR50.55a(g)(5)(iii), the South Texas Project requests relief from IWA-5250 of Section Xl of the ASME Boiler and Pressure Vessel Code. Approval will allow deferral of code repair of flaws recently identified in the Essential Cooling Water (ECW) Class 3 piping. Repair of the flaws with a code repair at this time is impractical. In accordance with the guidance provided in Generic Letter 90-05 and subject to Nuclear Regulatory Commission approval, code repairs will be implemented no later than the next refueling outage for the affected unit.
Through-wall indications have been identified on the 30-inch pipe of the Unit 1 "C" train ECW system pipe below ECW valve EW-01 01. Several small holes and linear indications were found in the aluminum-bronze pipe; however, there is no external leakage. The flaws are on the ECW pipe inside wall in an area covered by a slip-on flange.
Operability and functionality of the system have been maintained, and deferring code repair of the flaw with application of a temporary non-code repair will not affect the health and safety of the public.
The attached relief request addresses the present condition of the pipe section, and implementation of compensatory and corrective actions in accordance with the guidelines provided in Generic Letter 90-05. A list of commitments in the request is provided.
If there are any questions, please contact either Mr. P. L. Walker at (361) 972-8392 or me at (361) 972-8922. /4 Kenneth D. House Acting Manager, Design Engineering PLW
Attachment:
Request for Relief from ASME Boiler and Pressure Vessel Code, Section Xl Requirements for the Essential Cooling Water System (ECW Train 1C)
(Relief Request RR-ENG-2-40)
AOW7 STI: 31893840 Project Manager on Behalf of the Participants in the South Texas Project
NOC-AE-05001 899 Page 2 of 2 cc:
(paper copy) (electronic copy)
Bruce S. Mallett A. H. Gutterman, Esquire Regional Administrator, Region IV Morgan, Lewis & Bockius LLP U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 David H. Jaffe Arlington, Texas 76011-8064 U. S. Nuclear Regulatory Commission Richard A. Ratliff Jack A. Fusco Bureau of Radiation Control Michael A. Reed Texas Department of Health Texas Genco, LP 1100 West 49th Street Austin, TX 78756-3189 C. Kirksey City of Austin Jeffrey Cruz Jon C. Wood U. S. Nuclear Regulatory Commission Cox Smith Matthews P. 0. Box 289, Mail Code: MN1 16 Wadsworth, TX 77483 C. M. Canady J. J. Nesrsta City of Austin R. K. Temple Electric Utility Department E. Alarcon 721 Barton Springs Road City of San Antonio Austin, TX 78704
Attachment NOC-AE-05001 899 Page 1 of 8 SOUTH TEXAS PROJECT REQUEST FOR RELIEF FROM ASME BOILER AND PRESSURE VESSEL CODE, SECTION Xl REQUIREMENTS FOR THE ESSENTIAL COOLING WATER SYSTEM (ECW TRAIN 1C) (RELIEF REQUEST RR-ENG-2-40)
Component for Which Relief is Requested (a)
Description:
Unit 1 Train C Essential Cooling Water 30-inch piping (Line Number 30" EW 1305-WT3) immediately downstream of valve EW-0101 from component cooling water heat exchanger 1C.
(b) Function:
The Essential Cooling Water (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.
(c) Class:
ASME Code Class 3 (d) Description of the flaw:
Through-wall indications have been identified on the 30-inch pipe of the C train ECW system downstream of ECW valve EW-0101. Damage consists of pitting located immediately downstream of throttle valve EW-0101 on the inside wall of the pipe in an area covered outside the pipe by a slip-on flange. Some pitting has a maximum depth of 0.78 inch with corrosion extending into the flange. The root cause of the pitting was apparent cavitation resulting from required throttling of the upstream valve. While there is some damage to the slip-on flange, the slip-on flange and the attendant welds prevent leakage from the ECW system.
In addition, linear pipe indications were identified in the pipe underneath the flange in two areas.
- The ECW pipe separated from the connecting fillet weld resulting in a gap between the pipe and the flange. The separation extends approximately 20 inches along the pipe circumference.
- The second flaw is a through-wall circumferential crack 6.5" long located 3.5" from the flange face.
The apparent cause of these linear indications is high residual stresses initiated during assembly and exacerbated by high-cycle fatigue.
The condition does not meet ASME code requirements for a Class 3 piping system.
- 2. Applicable Code Edition and Addenda ASME Boiler and Pressure Vessel Code, Section Xl, 1989 Edition
- 3. Applicable Code Requirement ASME Section Xl IWA-4310 states:
Attachment NOC-AE-05001 899 Page 2 of 8 Defects shall be removed or reduced in size in accordance with this Article. The component shall be acceptable for continued service if the resultant section thickness created by the cavity is equal to or greater than the minimum design thickness. If the resulting section thickness is reduced below the minimum design thickness, the component shall be repaired in accordance with this Article. Alternatively, the component may be evaluated and accepted in accordance with the design rules or either the Construction Code, or Section III, when the Construction Code was not Section IlIl.
Relief 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 that 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 Durinq Plant Operation While performing maintenance on May 23, 2005, aluminum-bronze piping downstream of throttle valve EW-0101 in Unit 1 ECW Train C was found to be damaged.
Implementing Code repairs within the allowed outage time for the affected train is not possible, and as a result a plant shutdown would be required to complete the repairs.
- 5. Impracticality Determination As stated in Generic Letter 90-05, the staff has determined that an ASME Code repair is required for code Class 1, 2, and 3 piping unless specific written relief has been granted by the NRC. However, the staff has determined that temporary non-code repair of Class 3 piping that cannot be isolated without a plant shutdown is justified in some instances.
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.
Performance of code repairs within the allowed outage time for the Essential Cooling Water System at the South Texas Project, as permitted by the limiting condition for operation, is not practical due to the amount of time required to implement the repair, the potential for fit-up problems during repair, and other uncertainties associated with completing the task. Therefore, the South Texas Project requests approval of this relief request on the basis of impracticality.
- 6. Proposed Alternative and Basis for Use 6.1 Temporary Non-code Repair Method Contrary to ASME Section Xl IWA-4310, defects were not removed prior to returning the affected train to service. The non-code repairs performed on the piping downstream of 1EW01 01 consist of the following:
- Area 1 (Pitting/through-wall indications on the pipe near the flange face fillet weld):
- Apply a seal weld to the pipe wall, or
Attachment NOC-AE-05001 899 Page 3 of 8
- Remove the pipe wall where pitting is excessive. The remaining pipe shall be seal welded to the carbon steel slip-on flange, or
- Remove the pipe wall where pitting is excessive. The area from which the pipe is removed may have a replacement pipe segment installed that shall be seal welded on the perimeter to the existing pipe/flange.
Welded areas were visually examined.
- Area 2 (Separation between either side of the inside diameter fillet weld and the pipe wall/flange):
- Apply seal weld between the pipe wall and flange.
Welded areas were visually examined.
- Area 3 (Minor pitting of the pipe wall wetted surfaces near the flange):
- Apply a seal weld to the pipe wall, or
- Remove the pipe wall where pitting is excessive and seal-weld the remaining pipe to the carbon steel slip-on flange, or
- Remove the pipe wall where pitting is excessive. The area from which the pipe is removed may have a replacement pipe segment installed that shall be seal welded on the perimeter to the existing pipe/flange.
Welded areas were visually examined.
- Area 4 (Linear indication in the pipe wall 3.5 inches from the flange face):
- Apply seal weld to the length of the crack. Build up seal weld to approximately 1/4-inch thickness.
The weld area was tested with dye penetrant to ensure the crack is fully seal welded.
Voids and imperfections on wetted surfaces downstream of Valve 1-EW0101 were filled with Belzona 1111 to minimize further degradation. The Belzona application is not intended to repair the pressure boundary parts to satisfy the piping minimum wall thickness requirements. Belzona will serve solely as a barrier against erosion and corrosion until code repairs can be implemented.
6.2 Basis for Use 6.2.1 Scope This relief request applies to damaged areas on the inside diameter of a 30-inch ECW pipe downstream of throttle valve EW-0101 for Component Cooling Water heat exchanger 1C. The damaged areas are covered external to the pipe by a slip-on flange where the pipe joins the throttle valve. The erosion has resulted in pitting of the aluminum-bronze pipe, to the point where the carbon steel material of the slip-on flange has experienced corrosion.
In addition, linear pipe indications were identified in the pipe underneath the flange in two areas.
- The ECW pipe separated from the connecting fillet weld resulting in a gap between the pipe and the flange. The separation extends approximately 20 inches along the pipe circumference.
Attachment NOC-AE-05001899 Page 4 of 8
- The second flaw is a through-wall circumferential crack 6.5" long located 3.5" from the flange face.
The pitting and linear pipe separations are through-wall, but underneath the pipe slip flange; consequently, there was no system leakage.
6.2.2 Specific Considerations The Essential Cooling Water System is a low-pressure system with normal operating pressures of approximately 50 psig and a design pressure of 120 psig. Therefore, the consequences associated with failure of high-energy lines are not applicable to this relief request.
Consequences of potential system interactions, including flooding, spray on equipment, and loss of flow to the system, have been evaluated and are bounded by Appendix 9A of the South Texas Project Updated Final Safety Analysis Report.
The aluminum-bronze pipe has a nominal diameter of 30 inches and a nominal thickness of 0.25 inch. The pipe material is SB 169 CA-614 rolled and welded plate (6-8 percent aluminum) fabricated to SA-155 tolerances. The slip-on flange material is SA-105 carbon steel. The slip-on flange is welded to the 30-inch aluminum bronze pipe with fillet welds at both ends. The configuration is depicted in the attached figures.
The ECW pumps and the cooling reservoir have adequate design margin and make-up capability to account for postulated small leakage and are therefore fully capable of fulfilling the design basis functions and mission times during a design basis accident (DBA).
Similar pitting of the aluminum-bronze piping at this location is expected to have occurred in the remaining ECW trains. The linear indications are considered to be unique to Unit 1 Train C. However, based on similarity in design between the ECW trains, affected ECW trains are expected to be able to continue to perform their intended design-basis function until code-based repairs can be implemented.
BeIzona coatings have been used in various components at the South Texas Project as protective coatings for erosion and corrosion control. Subsequent inspections of these components have demonstrated that Belzona coatings perform well in an immersed ECW environment. The use of BeIzona coatings does not pose a threat to the piping, downstream components, or the safety function of the ECW system.
6.2.3 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 evaluates the flaw stability by linear elastic fracture mechanics (LEFM) methodology.
Enclosure 1 to Generic Letter 90-05 details the methodology. Analysis using "Limit Load" methodology was used to determine allowed maximum critical crack size and bending loads.
To summarize the results:
s = stress at the flaw location s = 5.8 ksi K = stress intensity factor
Attachment NOC-AE-05001899 Page 5 of 8 K=57.051 Stresses Pressure + Faulted Thermal Dead Weight Stress (psi) 4769 3324 1612 Allowable Stress (psi) 18000 43200 27000 Safety Margin 3.77 12.99 16.75 The current flaw size and the bending loads are less than the respective allowed critical crack size and the bending loads determined by the limit load methodology.
Structural integrity analysis shows that at the locations of maximum stress in the piping, very large cracks would be required to cause sudden failure. Through-wall cracks are expected to be detected well before they reach a size sufficient to result in such failure.
6.2.4 Augmented Inspection The ECW piping is readily accessible; consequently, through-wall system leakage resulting from deterioration of the ECW piping can be detected during weekly VT-2 inspections. Nondestructive examination using ultrasonic or radiographic testing is not feasible due to the configuration and dimensions in the affected area.
6.2.5 Conclusion The linear indications and areas of significant damage discovered during this inspection of Train C Essential Cooling Water System (ECW) have been repaired using non-code repair methods. Defects were not removed prior to returning the affected train to service. This is acceptable for continued train operation until code-based repairs can be completed because:
- Stress safety margin without complete replacement of the flaws is at least 3.77.
- There is continued protection against system leakage from the flaws at this location because of the welded slip-on flange.
- Visual checks can determine if leaking is in progress.
These temporary repairs of the degraded piping between the two fillet welds provide added assurance that the flange and pipe are acceptable until the next available outage of sufficient duration to perform the code repair as per guidance provided in Generic Letter 90-05.
- 7. Duration of Proposed Alternative Code repair will be deferred until adequate time is available for the repair. Temporary non-code repair is applicable until the next scheduled outage exceeding 30 days, but no later than the next refueling outage, provided the condition continues to meet the acceptance criteria of Generic Letter 90-05 and is enveloped by the analysis. The next Unit 1 refueling outage is currently scheduled to begin in October 2006.
Attachment NOC-AE-05001 899 Page 6 of 8 Commitments Through-wall system leakage resulting from deterioration of the ECW piping can be detected during weekly VT-2 inspections.
Inspections are in progress and are being tracked as condition report action 05-7071-14.
Attachment NOC-AE-05001 899 Page 7of 8 SLIP-ON FLANGE SA-1 05 STEEL FLANGE
Attachment NOC-AE-05001 899 Page 8 of 8 CARBON STEEL SLIP-ON FLANGE DETAIL ALUMINUM-BRONZE TO CARBON STEEL WELD ALUMINUM-BRONZE PIPE ALUMINUM-BRONZE TO CARBON STEEL WELD r- 3/8 in.
PIPE CENTERLINE