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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
MONTHYEARML24029A2752024-01-29029 January 2024 Request to Reschedule Evaluated Force-on-Force Drill IR 05000498/20230042024-01-29029 January 2024 Integrated Inspection Report 05000498/2023004 and 05000499/2023004 ML24024A1162024-01-24024 January 2024 STP Unit 2 Request for Information IR 05000498/20244042024-01-18018 January 2024 Information Request for the Cyber-Security Baseline Inspection, Notification to Perform Inspection 05000498/2024404; 05000499/2024404 IR 05000498/20230032023-12-28028 December 2023 Acknowledgment of Reply to a Notice of Violation (NRC Inspection Report 05000498/2023003 and 05000499/2023003) ML23360A1692023-12-26026 December 2023 FEMA, Submittal of Radiological Emergency Preparedness Final Report for the South Texas Project Medical Services Drill Evaluated on August 31, 2023 NOC-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 ML23326A2592023-12-0505 December 2023 Review of the Fall 2022 Steam Generator Tube Inspection Report ML23339A1902023-12-0505 December 2023 Update Foreign Ownership, Control, or Influence (FOCI) IR 05000498/20234012023-12-0404 December 2023 Security Baseline Inspection Report 05000498/2023401 and 05000499/2023401 ML23324A0102023-11-16016 November 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23310A2282023-11-13013 November 2023 Integrated Inspection Report 05000498/2023003 and 05000499/2023003, and Notice of Violation ML23311A2082023-11-0909 November 2023 Reassignment of U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch IV ML23298A0002023-11-0101 November 2023 the Associated Independent Spent Fuel Storage Installation - Issuance of Amendment Nos. 226 and 211 Related to Order Approving Indirect Transfer of Licenses and Conforming License Amendments ML23303A0782023-10-30030 October 2023 Submittal of Supplemental Information in Response to Order Consenting to License Transfers and Approval of Draft Conforming License Amendments ML23279A0342023-10-30030 October 2023 Associated Independent Spent Fuel Storage Installation - Order Approving Indirect Transfer of Licenses and Draft Conforming License Amendments (EPID L-2023-LLM-0004) (Letter) IR 05000498/20234032023-10-26026 October 2023 Material Control and Accounting Program Inspection Report 05000498/2023403 and 05000499/2023403 (Cover Letter) ML23317A1262023-10-12012 October 2023 South. Texas Project Physical Security Plan, Training and Qualification Plan, Safeguards Contingency Plan, and Independent Spent Fuel Storage Installation Security Program Revision 26 ML23279A1382023-10-0505 October 2023 Responses to Requests for Additional Information Related to Application for Order Approving Indirect Transfer of Control of Licenses ML23271A1942023-10-0303 October 2023 Notification of Commercial Grade Dedication Inspection (05000498/2024013 and 05000499/2024013) and Request for Information ML23270B2592023-09-27027 September 2023 Update Foreign Ownership, Control, or Influence ML23263B1132023-09-20020 September 2023 Operator Licensing Examination Schedule Revision 1 IR 05000498/20243012023-09-0707 September 2023 Notification of NRC Initial Operator Licensing Examination 05000498/2024301; 05000499/2024301 IR 05000498/20233012023-09-0101 September 2023 NRC Examination Report 05000498/2023301 and 05000499/2023301 ML23243B0562023-08-31031 August 2023 Supplemental Information to Application for Order Approving Indirect Transfer of Control of Licenses ML23236A6042023-08-24024 August 2023 Annual Dose Report for 2022 IR 05000498/20230052023-08-22022 August 2023 Updated Inspection Plan for South Texas Project Electric Generating Station, Units 1 and 2 (Report 05000498/2023005 and 05000499/2023005) - Mid Cycle Letter ML23229A5262023-08-17017 August 2023 Inservice Inspection Summary Report - 1 RE24, ML23229A5892023-08-17017 August 2023 Voluntary Response to Regulatory Issue Summary (RIS) 2023-02, Scheduling Information for the Licensing of Accident Tolerant, Increased Enrichment, and Higher Burnup Fuels ML23229A4992023-08-17017 August 2023 Supplement to Proposed Alternate Frequency to Containment Unbonded Post-Tensioning System Inservice Inspection (Relief Request RR-ENG-4-06) ML23228A2102023-08-15015 August 2023 Closure of Investigation (OI 4-22-19) ML23222A0322023-08-10010 August 2023 Report of Changes Made to Quality Assurance Program for Radioactive Material Packages ML23221A3002023-08-0909 August 2023 RE22 Inspection Summary Report for Steam Generator Tubinq, Rev. 1 (Epld L-2023-LRO-0029) ML23222A2792023-08-0909 August 2023 Submittal of Update Foreign Ownership, Control, or Influence (FOCI) IR 05000498/20230022023-07-28028 July 2023 Integrated Inspection Report 05000498/2023002 and 05000499/2023002 ML23198A0532023-07-24024 July 2023 Request for Withholding Information from Public Disclosure ML23188A1612023-07-14014 July 2023 the Associated ISFSI - Notice of Consideration of Approval of Indirect Transfer of Licenses and Conforming Amendments and Opportunity to Request a Hearing (EPID L-2023-LLM-0004) - Letter ML23193A9932023-07-11011 July 2023 Submittal of Update Foreign Ownership, Control or Influence (FOCI) ML23192A0482023-07-11011 July 2023 NRC Initial Operator Licensing Examination Approval 05000498/2023301; 05000499/2023301 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) ML23180A2822023-06-29029 June 2023 Operator Licensing Examination Schedule ML23177A2522023-06-26026 June 2023 Units 1, 2 & Independent Spent Fuel Storage Installation - Biennial Submittal of Technical Specification Bases Changes, Commitment Changes, 10 CFR 50.59 Evaluation Summary, and 10 CFR 72.48 Evaluation Summary ML23166B0802023-06-14014 June 2023 Update Foreign Ownership, Control, or Influence (FOCI) ML23163A1762023-06-12012 June 2023 Application for Order Approving Indirect Transfer of Control of Licenses 2024-01-29
[Table view] Category:Safety Evaluation
MONTHYEARML23279A0342023-10-30030 October 2023 Associated Independent Spent Fuel Storage Installation - Order Approving Indirect Transfer of Licenses and Draft Conforming License Amendments (EPID L-2023-LLM-0004) (Letter) ML23279A0482023-10-30030 October 2023 Associated Independent Spent Fuel Storage Installation - Enclosure 4 -Order Approving Indirect Transfer of Licenses and Draft Conforming License Amendments (EPID L-2023-LLM-0004) (Nonproprietary Safety Evaluation) ML23015A0012023-02-0606 February 2023 Issuance of Amendment Nos. 225 and 210 to Revise Technical Specifications to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements ML22300A2492022-12-0606 December 2022 Approval for Alternate Disposal Procedures for Very Low-Level Radioactive Material (EPID: L?2021?LLL?0022) ML22245A0012022-09-12012 September 2022 Relief from the Requirements of the ASME Code ML21319A3552021-12-0909 December 2021 Issuance of Amendment Nos. 224 and 209 to Revise Technical Specifications to Adopt TSTF-577, Revision 1, Revised Frequencies for Steam Generator Tube Inspections ML21320A0022021-12-0808 December 2021 Issuance of Amendment Nos. 223 and 208 to Revise Technical Specification 3.6.3 and to Remove the Technical Specifications Index NUREG-0654, Correction to Amendment Nos. 221 and 206 to Authorize Revision of the Emergency Plan Based on NUREG-0654/FEMA-REP-1, Revision 22021-05-11011 May 2021 Correction to Amendment Nos. 221 and 206 to Authorize Revision of the Emergency Plan Based on NUREG-0654/FEMA-REP-1, Revision 2 ML21033A2392021-04-0808 April 2021 Issuance of Amendment Nos. 222 and 207 to Revise Technical Specifications to Adopt TSTF-374, Revision to TS 5.5.13 and Associated TS Bases for Diesel Fuel Oil ML20253A0462020-09-29029 September 2020 Issuance of Amendment Nos. 220 and 205 to Revise Technical Specifications to Adopt TSTF-490, Deletion of E-Bar Definition and Revision to RCS Specific Activity Tech Spec 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 ML20199M1622020-07-21021 July 2020 Proposed Alternatives PRR-01, PRR-02, PRR-03, and PRR-04 to the Requirements of the ASME OM Code (Epids L-2020-LLR-0007 to L-2020-LLR-0010) ML20141L6122020-05-28028 May 2020 Issuance of Amendment No. 219 to Revise Technical Specifications to Reduce Safety Injection Accumulators Minimum Pressures (Exigent Circumstances) ML19322A7192019-12-0909 December 2019 Issuance of Amendment Nos. 218 and 204 to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules ML19217A0602019-10-24024 October 2019 Issuance of Amendment Nos. 217 and 203 Revision to Technical Specification Tables to Change Terminology for the P-13 Permissive Interlock Description ML19213A1472019-08-20020 August 2019 Issuance of Amendment Nos. 216 and 202 Standby Diesel Generator Surveillance Requirements ML19142A3072019-08-13013 August 2019 Request for Relief Request RR-ENG-3-23 to Extend Volumetric Examination Interval for Reactor Vessel Closure Head Nozzles ML19067A2222019-06-0606 June 2019 Issuance of Amendment Nos. 215 and 201 Adoption of TSTF-522 Revise Ventilation System Surveillance Requirements to Operate for 10 Hours Per Month 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 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 ML18159A2122018-07-19019 July 2018 Issuance of Amendment Nos. 214 and 200 Emergency Response Organization Time Augmentation and Staffing Chances to the Emergency Plan (CAC Nos. MG0024 and MG0025; EPID L-2017-LLA-0265) ML18128A3422018-06-0707 June 2018 Issuance of Amendment Nos. 213 and 199 to Revise TSs for Administrative Changes and to Relocate Fxy Exclusion Zones to the Colrs(Cac Nos. MG0253 and MG0254, EPID-L-2017-LLA-0300) ML17038A2232017-07-11011 July 2017 Issuance of Amendment Nos. 212 and 198 - Risk-Informed Approach to Resolve Generic Safety Issue 191 ML17019A0022017-07-11011 July 2017 Safety Evaluation, Enclosure 3 to Amendment Nos. 212 and 198 - Risk-Informed Approach to Resolve Generic Safety Issue 191 ML16319A0102016-12-21021 December 2016 Issuance of Amendment No. 211, Revise Technical Specification 5.3.2 to Allow Operation with 56 Full-Length Control Rod Assemblies 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 ML16116A0072016-04-29029 April 2016 Issuance of Amendment Nos. 210 and 197, Revise Technical Specification 6.8.3.j, Containment Leakage Rate Testing Program, to Extend Integrated Leak Rate Test Interval from 10 to 15 Years ML15342A0032015-12-28028 December 2015 Issuance of Amendment Nos. 209 and 196, Adopt Technical Specification Task Force (TSTF)-510-A, Revision 2, Revision to Steam Generator Program Inspection Frequencies and Tube Sample Selection (CAC MF6178-MF6179) ML15343A1282015-12-11011 December 2015 Issuance of Amendment No. 208, Revise Technical Specification 5.3.2 to Allow Operation with 56 Full-Length Control Rod Assemblies for Unit 1 Cycle 20 (Emergency Circumstances) ML15209A6412015-09-22022 September 2015 Issuance of Amendment Nos. 207 and 195, Revise Updated Final Safety Analysis Report Table 15.6-17 to Correct Radiological Doses Resulting from Calculation Error Performed in Support of Amendments 182 and 169 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 ML15201A1952015-08-20020 August 2015 Issuance of Amendment Nos. 206 and 194, Revise the Emergency Action Level Scheme to the NRC-endorsed Scheme Contained in NEI-99, Revision 6 ML15075A1462015-04-29029 April 2015 Issuance of Amendment Nos. 205 and 193, Request to Revise Technical Specification 3.3.1, Functional Unit 20, Reactor Trip Breakers, for Required Actions and Allowed Outage Times ML15049A1292015-02-27027 February 2015 Issuance of Amendment Nos. 204 and 192, Revise Technical Specification 6.9.1.6, Core Operating Limits Report, with Respect to Analytical Methods Used to Determine Core Operating Limits ML14339A1702015-02-13013 February 2015 Issuance of Amendment Nos. 203 and 191, Revise Fire Hazards Analysis Report and Fire Protection Program License Conditions Related to Alternate Shutdown Capability ML14281A0652015-01-29029 January 2015 Issuance of Amendment Nos. 202 and 190, Revise Operating License Conditions Related to Cyber Security Plan Milestone 8 Full Implementation Date ML13221A0042013-09-0909 September 2013 Issuance of Amendment Nos. 201 and 189, Revise TS 5.0, Design Features, to Reflect Removal of Visitor'S Center Building and References to Emergency Operations Facility ML13142A1602013-06-0606 June 2013 Safety Assessment in Response to Information Request Pursuant to 10 CFR 50.54(f) - Recommendation 9.3 Communications Assessment ML13008A5282013-04-25025 April 2013 Issuance of Amendment Nos. 200 and 188, Revise Technical Specification 3.3.3.6, Accident Monitoring Instrumentation 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 ML13007A1362013-01-31031 January 2013 Review of Operations Quality Assurance Plan, Revision 20 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 ML12152A2452012-08-14014 August 2012 Issuance of Amendment Nos. 199 and 187, Revise Applicability of Risk-Managed Technical Specifications (TS) to TS 3.7.7, Control Room Makeup and Cleanup Filtration System ML1124402222011-11-17017 November 2011 Issuance of Amendment Nos. 198 and 186, Revise Technical Specifications 5.3.1 and 6.9.1.6 to Allow Fuel Assemblies with Optimized Zirlo Cladding ML1126500712011-10-14014 October 2011 Relief Request RR-ENG-3-05, from Requirements for Ultrasonic Examination of Reactor Pressure Vessel Shell-to-Flange Welds for Third 10-Year Inservice Inspection ML1118605352011-07-29029 July 2011 Relief Request RR-ENG-2-55 from ASME Code Requirements for Weld Examinations, Second 10-Year Inservice Inspection Interval 2023-02-06
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 12, 2010 Mr. Edward D. Halpin President and Chief Executive Officer STP Nuclear Operating Company South Texas Project P. O. Box 289 VVadsworth,TX 77483 SUB..IECT: SOUTH TEXAS PRO..IECT, UNIT 2 - RELIEF REQUEST RR-ENG-2-52 FOR THE ESSENTIAL COOLING VVATER SYSTEM (TAC NO. ME0899)
Dear Mr. Halpin:
By letter dated March 12, 2009, as supplemented by letter dated December 9, 2009, STP Nuclear Operating Company (the licensee) requested approval of Relief Request RR-ENG-2-52 from the requirements of IVVA-5250 of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) at South Texas Project, Unit 2 (STP-2). Relief Request No. RR-ENG-2-52 will allow deferral of the code repair of a flaw identified in the Unit 2 Essential Cooling VVater (ECVV) Class 3 piping. The licensee stated that an ASME Code repair of the flaw at the time was impractical. In accordance with the guidance provided in U.S. Nuclear Regulatory Commission (NRC) Generic Letter 90-05, "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1,2, and 3 Piping," dated June 15, 1990, and subject to NRC approval, the licensee stated that a code repair would be implemented no later than the next scheduled Unit 2 refueling outage. However, the licensee repaired the degraded flange in accordance with the ASME Code on April 24, 2009.
Although the flange was repaired in accordance with the ASME Code on April 24, 2009, the NRC needs to review the proposed alternative to ensure that the plant would have been in compliance with 10 CFR 50.55a from December 2, 2008 to April 24, 2009. Operability and functionality of the system was maintained and deferring the repair did not affect the health and safety of the public.
The NRC staff has reviewed the licensee's submittal and determined that conformance with ASME Code requirements to repair the degraded flange during the period from December 2, 2008, to April 24, 2009, was impractical. Pursuant to paragraph 50.55a(g)(6)(i) of Title 10 of the Code of Federal Regulations (10 CFR), the NRC grants the use of Relief Request No. RR-ENG-2-52, as revised by letter dated December 9, 2009, for the repair of a through-wall flaw on the downstream flange of ECVV return throttle valve 2-EVV-1 004 from Essential Chiller 22B at STP-2 for the period from December 2, 2008, to April 24, 2009.
E. Halpin -2 A copy of the Safety Evaluation is enclosed. All other ASME Code,Section XI, requirements for which relief has not been specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
Sincerely, Michael T. Markley, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-499
Enclosure:
Safety Evaluation cc w/encl: Distribution via Listserv
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO ESSENTIAL COOLING WATER SYSTEM RELIEF REQUEST NO. RR-ENG-2-52 STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT, UNIT 2 DOCKET NO. 50-499
1.0 INTRODUCTION
By letter dated March 12, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090830517), STP Nuclear Operating Company (STPNOC, the licensee) requested approval of Relief Request No. RR-ENG-2-52 from IWA-5250 of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) at South Texas Project (STP), Unit 2. Relief Request No. RR-ENG-2-52 will allow deferral of code repair of a flaw identified in STP, Unit 2 Essential Cooling Water (ECW) Class 3 piping at STP, Unit 2. The licensee stated that an ASME Code repair of the flaw at the time was impractical. In accordance with the guidance provided in U.S. Nuclear Regulatory Commission (NRC) Generic Letter 90-05, "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1, 2, and 3 Piping," dated June 15, 1990, and subject to NRC approval, the ASME Code repair will be implemented no later than the next scheduled STP, Unit 2 refueling outage.
On December 2, 2008, the licensee detected a through-wall flaw 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 was determined by the licensee to be 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 reasonable assured.
On April 24, 2009, the licensee repaired the degraded component in accordance with the ASME Code.
Although the flange was repaired in accordance with the ASME Code on April 24, 2009, the NRC needs to review the proposed alternative to ensure that the plant would have been in compliance with 10 CFR 50.55a from December 2, 2008 to April 24, 2009. Operability and functionality of the system was maintained and deferring the repair did not affect the health and safety of the public.
Enclosure
-2 The NRC staff requested additional information by email dated August 25,2009 (ADAMS Accession No. ML100540530). The licensee responded to the NRC staff's request by letter dated December 9, 2009 (ADAMS Accession No. ML093560366) and updated Relief Request No. RR-ENG-2-52. The staff's evaluation is based on the relief request dated December 9, 2009.
2.0 REGULATORY EVALUATION
Pursuant to paragraph 50.55a(g)(4) of Title 10 of the Code of Federal Regulations (10 CFR),
ASME Code Class 1,2, and 3 components (including supports) will meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection (lSI) of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 1O-year lSI interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein.
Pursuant to 10 CFR 50.55a(a)(3), alternatives to requirements may be authorized by the NRC if the licensee demonstrates that: (i) the proposed alternative provides an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
The lSI Code of record for the second 1O-year lSI interval at STP-2 is the ASME Code,Section XI, the 1989 Edition.
3.0 TECHNICAL EVALUATION
3.1 Components Affected By the Relief Request The affected component is an ASME Code Class 3, aluminum-bronze flange downstream of Essential Cooling Water (ECW) return throttle valve 2-EW-1004 from Essential Chiller 22B.
In its letter dated December 9, 2009, the licensee states:
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.
3.2 Applicable Code Edition and Addenda (as stated by the licensee)
ASME Boiler and Pressure Vessel Code,Section XI, 1989 Edition
- 3 3.3 Applicable Code Requirements (as stated by the licensee)
ASME [Code] Section XI, 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 for deferral of code repair of the through-wall flaw at this location until the following 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.
3.4 Reason for Request (as stated by the licensee)
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.
Requesting relief from ASME Code requirements is appropriate when performing the repair at the time of discovery is determined to be impractical.
Generic Letter 90-05 defines a repair as being 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 allowed 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 1.0E-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.
Isolating the subject pipe for a code repair makes the affected ECW train unavailable for service for the duration of the repair. Assigning a specific amount of time to complete a flaw repair when a flaw is first identified and using that as a criterion for initiating a train outage is not appropriate. At the time of discovery of a flaw, an estimate of the amount of time needed to complete the repair would be a rough approximation. Flaw repairs are added to the tasks to be performed during a scheduled train outage of sufficient duration to accommodate the repairs with minimal impact on plant operations. Lengthening or initiating a train outage to perform repairs when it has not already been scheduled may conflict with other train outages or disrupt the schedule for activities such as surveillances that must be performed at set intervals. Delays in the preparation process if a train has already been taken out of service may result in a train outage that exceeds the limiting condition for operation defined in the Technical Specifications. Prior to
-4 the train outage scheduled for the repair, preparations prior to the actual repair would be put in place while the train is in service. Preparation activities are not necessarily performed in series, and may be performed in parallel, and the time to be used for preparation would be determined by the train outage schedule.
In this instance, a replacement flange was ordered. A purchase order was issued January 29, 2009, with a due date of April 17, 2009.
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.
3.5 Proposed Alternative (as stated by the licensee)
Repair of the defect would be performed when adequate time is available for the repair, but no later than the following Unit 2 refueling outage. The next Unit 2 refueling outage is currently scheduled to begin in March 2010 (2RE 14).
Compensatory actions were implemented to detect changes in the condition of the flaw until a repair could be implemented.
3.6 Duration of Proposed Alternative (as stated by the licensee)
Rework of the defect to restore the flange to its design condition was deferred until sufficient time was available. The flange was replaced in accordance with the ASME Code on April 24, 2009.
3.7 NRC Staff Evaluation 10 CFR 50.55a(a)(2) requires that systems and components of boiling and pressurizer water reactors meet the ASME Code specified in paragraphs (b), (c), (d), (e), (f), and (g) of 10 CFR 50.55a. 10 CFR 50.55a(a)(2) requires that if a component is degraded, it must be repaired in accordance with the ASME Code,Section XI. However, 10 CFR 50.55a(a)(3) permits licensees to apply alternatives to the requirements of the ASME Code,Section XI, when authorized by the NRC.
Although the flange was repaired in accordance with the ASME Code on April 24, 2009, the NRC needs to review the proposed alternative to ensure that the plant would be in compliance with 10 CFR 50.55a from December 2, 2008 to April 24, 2009.
During the period from the discovery of the flaw in the flange on December 2, 2008 to April 24, 2009 when the flange was repaired, operability and functionality of the system was maintained and deferring the repair did not affect the health and safety of the public.
The staff evaluated the structural integrity of the pipe/flange during the period while it was degraded from December 2, 2008 to April 24, 2009.
-5 3.7.1 Flaw Characterization On December 2, 2008, during periodic examination of ECW large bore piping, the licensee found an indication of a through-wall flaw on the downstream flange of Essential Chiller 22B ECW return throttle valve 2-EW-1004.
In its letter dated December 9, 2009, the licensee states, in part, that:
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. Nominal ECW pipe diameter is 8 inches with a pipe wall thickness of 0.322 inch.
In its December 9, 2009, letter the licensee also states that:
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.
In its email dated August 25,2009, the NRC staff requested the licensee to describe the flaw size that would cause a leak rate such that the ECW system could not provide sufficient make-up to fulfill its intended function. In its response dated December 9, 2009, the licensee states:
Flooding calculations indicate a potential flooding rate of approximately 14.5 cu ft/min [cubic feet per minute] through a postulated crack in the ECW pipe.
However, this is enveloped by the maximum flood rate of 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.
There is no effect on nearby safe shutdown equipment 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. Conservatism in the assumed seepage losses from the Essential Cooling Pond (ECP) and ECP inventory margin bounds water loss that would occur due to a crack 15 inches by 1/8 inch.
The NRC staff has determined that the ECW system has sufficient make-up capacity to compensate for leakage from a crack size/area of 15 inches by 1/8 inch. The staff further determined that dealloying flaw size is much smaller than the postulated crack size/area.
Therefore, there was reasonable assurance that the ECW system was adequate in performing its intended function during the period of degradation from December 2, 2008, to April 24, 2009.
The NRC staff also requested the licensee to discuss the changes to the flaw size and leakage since the discovery.
- 6 In its December 9, 2009 letter, the licensee states:
The experience at the South Texas Project is that the dealloying process progresses very slowly. Changes observed in flaw conditions over a period of months have been inconsequential or non-existent. Any changes in flaw parameters would be identified well before the affected ECW train would be put at risk.
The licensee evaluated the subject flaw using the methodology in NRC Generic Letter 90-05 and determined that the degraded pipe/flange has adequate structural safety margin. The NRC staff has determined that the ECW piping is subject to relatively low loads. The licensee states that the normal operating pressure and temperature are 50 pounds per square inch gauge (psig) and 47 to 100 degrees Fahrenheit (OF), respectively. The design pressure is 120 psig and design-basis accident is not expected to exceed 120 oF. Based on the low pressure and temperature, the NRC staff concludes that the degraded pipe/flange should have sufficient fracture toughness to reasonably assure adequate structure integrity.
3.7.2 Inspection and Monitoring In its email dated August 25,2009, the NRC staff requested the licensee to describe the sensitivity of the sump level alarms (Le., how low of a leak rate would the alarm annunciate) and at what leak rate will the operator take corrective actions.
In its response dated December 9,2009, the licensee states:
Leakage from ECW piping in [the degraded] location would end up at the Mechanical Auxiliary Building (MAB) sumps. Sump level alarms are available to warn operators if leakage exceeds the sump pump capacity.
In its letter dated December 9, 2009, the licensee states that 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.
- Continuation of large bore ECW piping periodic walkdowns. Walkdowns of all ECW train piping are regularly scheduled VT-2 examinations at six-month intervals to identify areas of dealloying. 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. The dealloying process proceeds very slowly. Despite the increased frequency of inspection following identification of a flaw, changes observed in flaw conditions over a period of months have been inconsequential or non-existent. Dealloying flaws are only detectable by visual examination once they have reached the
-7 piping surface. Dealloying flaws are addressed under the station condition reporting program.
The licensee's proposed monthly walkdown as stated above is contrary to the recommended frequency in NRC Generic Letter 90-05 which recommends that weekly walkdowns be performed to determine any degradation of structural integrity of the affected component. In its email dated August 25, 2009, the NRC staff requested the licensee to justify the proposed monthly monitoring and to demonstrate that the proposed augmented inspection schedule will provide reasonable assurance that the operator has sufficient time to take corrective actions prior to the flaw in the flange growing uncontrollably to challenging operability of the affected ECWtrain.
By letter dated December 9, 2009, the licensee states:
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. A flaw caused by dealloying is not detectable by either ultrasonic testing or radiography. The extent of the linear indication was determined by use of dye penetrant.
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.
By the time of the repair, there were no changes evident in the flaw compared to its appearance at the time of discovery. No dealloyed area has shown sufficient change from the time of discovery to warrant accelerated implementation of corrective measures.
The NRC staff has determined that a monthly visual examination is acceptable for the routine inspection of the ECW piping that contains no flaws. However, the NRC staff does not agree with a monthly inspection frequency when a flaw is detected in the ECW piping. NRC Generic Letter 90-05 and ASME Code,Section XI, Code Case N-513, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1," both require shorter inspection intervals. However, the licensee has repaired the flaw; therefore, the inspection frequency issue is moot.
The Code Case N-513-2 paragraph (f) requires that for through-wall leaking flaws, leakage shall be observed by daily walkdowns to confirm that the analysis conditions used in the flaw evaluation remain valid. In its email dated August 25, 2009, the NRC staff requested the licensee to discuss whether a daily walkdown will be performed if the subject flaw starts to leak.
By letter dated December 9, 2009, the licensee states:
- 8 The ASME Section XI Code of record for the South Texas Project is the 1989 Edition. Code Case N-513 is applicable to the 1998 Edition. Code Case N-513-2 is applicable to the 2004 Edition. Consequently, this code case is not applicable to [STP, Unit 2].
The NRC staff has determined that the licensee's response is acceptable.
The staff requested the licensee to discuss whether examinations were performed on other ECW trains to identify similar flaws.
In its December 9, 2009 letter, the licensee states that examinations of all ECW train piping are performed every 6 months. No other areas of dealloying were found during the December 2, 2008, periodic examination. In addition, the licensee states that if identified, dealloying flaws are addressed under the station condition reporting program. The NRC staff has determined that the licensee has examined all ECW piping and no flaws were found other than the subject flaw.
NRC Generic Letter 90-05, Enclosure 1, Section 3 specifies that the integrity of the temporary non-code repair of Code Class 3 piping should be assessed at least every 3 months by either ultrasonic testing (UT) or radiographic testing (RT). The NRC staff questioned the reason these inspection methods were not specified in the proposed relief request.
By letter dated December 9, 2009, the licensee revised Section 6.2.5 of its relief request to state that a flaw caused by dealloying is not detectable by either ultrasonic testing or radiography.
The extent of the linear indication was determined by use of dye penetrant. The NRC staff understands the difficulties of detecting the dealloying-initiated flaw by qualified UT and RT in terms of technology and piping configuration. Besides visual examination, dye penetrant or eddy current technique would be the preferred inspection method that could be used.
3.7.3 Impracticality In its March 12, 2009, letter, the licensee used impracticality defined in Generic Letter 90-05 as the basis for the relief request. Generic Letter 90-05 defines impracticality as that the pipe cannot be isolated to complete a code repair within the time period permitted by the limiting condition for operation in the technical specifications and a plant shutdown may be necessary to complete the code repair. The NRC staff questioned the reason the subject pipe could not be isolated to complete an ASME Code repair. By letter dated December 9,2009, the licensee states that isolating the subject pipe for a code repair makes the affected ECW train unavailable for service for the duration of the repair. Removing an operable ECW train from service while at power increases overall risk to the plant. Scheduled train work periods are rarely of sufficient duration to allow an ASME Code repair of this nature during the train outage without lengthening the outage, which will disrupt scheduled work activity to follow in work periods for other trains.
The NRC staff concludes that the licensee has satisfactorily demonstrated impracticality of repair from December 2, 2008, to April 24, 2009.
-9
4.0 CONCLUSION
The NRC staff has determined that conformance with ASME Code requirements to repair the degraded pipe/flange during the period from December 2, 2008, to April 24, 2009, is impractical.
The NRC concludes that granting relief pursuant to 10 CFR 50.55a(g)(6)(i) is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the licensee. Therefore, the NRC staff authorizes the use of Relief Request No. RR-ENG-2-52, as described in the licensee's letter dated December 9, 2009, for the repair of a through-wall flaw on the downstream flange of ECW return throttle valve 2-EW-1004 from Essential Chiller 228 at STP, Unit 2. Relief Request No. RR-ENG-2-52 is granted for the period from December 2,2008, to April 24,2009.
All other ASME Code,Section XI, requirements for which relief was not specifically requested and approved in the subject request for relief remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
Principal Contributor: J. Tsao Date: March 12. 2010
E. Halpin -2 A copy of the Safety Evaluation is enclosed. All other ASME Code,Section XI, requirements for which relief has not been specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
Sincerely, IRN Michael 1. Markley, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-499
Enclosure:
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