Letter Sequence Approval |
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EPID:L-2020-LLR-0158, Proposed Alternative Requests RR-05-04 and IR-4-02, Use of Alternative Pressure/Flow Testing Requirements for Service Water System Supply Piping (Approved, Closed) |
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MONTHYEARML20352A3342020-12-17017 December 2020 Proposed Alternative Requests RR-05-04 and IR-4-02, Use of Alternative Pressure/Flow Testing Requirements for Service Water System Supply Piping Project stage: Request ML21012A0442021-01-12012 January 2021 1/12/2021 E-mail Acceptance Review Determination, Alternative Requests RR-05-04 and IR-4-02 Project stage: Acceptance Review ML21284A0062021-10-29029 October 2021 Authorization and Safety Evaluation for Alternative Request No. RR-05-04 and IR-4-02 Project stage: Approval 2021-01-12
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Category:Code Relief or Alternative
MONTHYEARML23188A0432023-07-31031 July 2023 Authorization and Safety Evaluation for Alternative Request No. IR-04-11 ML22201A5082022-07-28028 July 2022 Authorization and Safety Evaluation for Alternative Request No. IR-04-09 ML21284A0062021-10-29029 October 2021 Authorization and Safety Evaluation for Alternative Request No. RR-05-04 and IR-4-02 ML21174A0202021-08-0202 August 2021 Relief Request for Limited Coverage Examinations Performed in the Fourth 10-Year Inservice Inspection Interval ML21167A3552021-07-16016 July 2021 Authorization and Safety Evaluation for Alternative Request No. RR-05-06 ML20312A0012020-12-10010 December 2020 Relief Requests for Limited Coverage Examinations Performed in the Fourth 10-Year Inservice Inspection Interval ML20312A0022020-12-10010 December 2020 Relief Request for Limited Coverage Examinations Performed in the Third 10-Year Inservice Inspection Interval (EPID L-2020-LLR-0027 Through L-2020-LLR-0032) ML20287A4712020-10-20020 October 2020 Proposed Alternative RR-05-05 to the Requirements of the ASME Code Containment Unbonded Post-Tensioning System Inservice Inspection Requirements ML20189A2062020-07-16016 July 2020 Relief Request IR-4-03 Concerning Non-Code Methodology to Demonstrate Structural Integrity of Class 3 Moderate-Energy Piping ML20080K5082020-03-24024 March 2020 Alternative Request RR-05-03 for the Fifth 10-Year Inservice Inspection Interval ML19340A0012019-12-18018 December 2019 Proposed Alternative Request IR-4-01 Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography ML19338G3722019-12-18018 December 2019 Alternative Requests RR-05-01 and RR-05-02 for the Fifth 10-Year Inservice Inspection Interval ML19340A0002019-12-13013 December 2019 Relief Request IR-3-39, Proposed Alternative to ASME Code Weld Preheat Requirements ML19275D2522019-09-24024 September 2019 Alternative Request RR-05-03, Extension of ASME Code Case N-770-2 Volumetric Inspection Frequency for Reactor Coolant Pump Inlet and Outlet Nozzle Dissimilar Metal Butt Welds ML19098A0342019-04-30030 April 2019 Units 1 and 2; Limerick, Units 1 and 2; Peach Bottom, Units 2 and 3, and Quad Cities, Units 1 and 2 - Revision to Approved Alternative to Use BWR Vessel and Internal Proj Guidelins ML18290A6022018-11-13013 November 2018 Alternative Requests Related to the Fifth and Fourth 10-Year Interval Pump, Valve, and Snubber Inservice Testing Programs, Respectively (EPID L-2018-LLR- 0012 Through EPID L-2018-LLR-0022) ML18252A0032018-09-17017 September 2018 Alternative Requests RR-04-27 and IR-3-38 for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography ML18066A5222018-02-28028 February 2018 Proposed Alternative Requests RR-04-27 and IR-3-38 Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography in Accordance with 10 CFR 50.55(z)(1) ML17132A1872017-05-25025 May 2017 Alternative Relief Requests RR-04-24 and IR-3-30: Reactor Pressure Vessel Threads in Flange ML17135A2962017-05-25025 May 2017 Alternative Relief Request RR-04-25 Boric Acid Pump P-19B Stuffing Box Cover ML17122A3742017-05-0303 May 2017 Alternative Relief Request RR-04-26 Boric Acid Pump P-19B Stuffing Box Cover ML17125A2522017-04-28028 April 2017 ASME Section XI Relief Request RR-04-26 ML17090A1102017-03-29029 March 2017 ASME Section XI Relief Request RR-04-25 ML16363A0892017-01-23023 January 2017 Alternative Relief RR-04-23 and IR-3-28 from the Requirements of ASME Code Section XI Regarding Radiographic Examinations ML16277A6782016-10-18018 October 2016 Alternative Request RR-04-22 to Implement Extended Reactor Vessel Inservice Inspection Interval ML16172A1352016-07-13013 July 2016 Relief Requests for Limited Coverage Examinations Performed in the Fourth 10-Year Inservice Inspection Interval ML16038A0012016-02-16016 February 2016 Alternative Request IR-3-27 for Implementation of Extended Reactor Vessel Inservice Inspection Interval ML15257A0052015-09-21021 September 2015 Relief from the Requirements of ASME Code Section XI Regarding Radiographic Examinations ML15216A3632015-07-30030 July 2015 ASME Section XI Inservice Inspection Program Relief Requests for Limited Coverage Examinations Performed in the Fourth 10-Year Inspection Interval ML15216A3592015-07-30030 July 2015 ASME Section XI Inservice Inspection Program Relief Requests for Limited Coverage Examinations Performed in the Fourth 10-Year Inspection Interval ML15082A4092015-04-24024 April 2015 Alternative Use of Weld Overlay as Repair and Mitigation Technique ML14217A2032014-09-0404 September 2014 Relief from the Requirements of the ASME Code Section XI, Requirements for Repair/Replacement of Class 3 Service Water Valves (Tac No. MF1314) ML14163A5862014-07-10010 July 2014 Relief from the Inservice Testing Requirements of American Society of Mechanical Engineers Code for Operation and Maintenance of Nuclear Power Plants ML14091A9732014-04-0404 April 2014 Issuance of Relief Request RR-04-16 Regarding Use of Encoded Phased Array Ultrasonic Examination in Lieu of Radiography ML1130001002011-11-0909 November 2011 Issuance of Relief Request RR-04-12 Regarding the Temporary Non-Code Compliant Condition of the Class 3 Service Water System 10 Inch Emergency Diesel Generator Supply Piping Flange ML11234A0772011-08-19019 August 2011 Relief Request RR-04-12 for the Temporary Non-Code Compliant Condition of the Class 3 Service Water System 10 Inch Emergency Diesel Generator Supply Piping Flange ML1118810292011-07-27027 July 2011 Issuance of Relief Request RR-04-04 Regarding Use of Alternative Pressure Testing Requirements ML1118706002011-07-22022 July 2011 Issuance of Relief Request RR-04-05 Regarding Use of Alternative Pressure Testing Requirements ML1106800802011-03-24024 March 2011 Issuance of Relief Request lR-3-14 -- Use of Risk-Informed Inservice Inspection Program Plan ML1014700992010-06-11011 June 2010 Issuance of Relief Request IR-3-05 Regarding Use of American Society of Mechanical Engineering Code, Section XI, Appendix Viii ML1012412192010-05-13013 May 2010 Relief Request IR-3-02 Regarding Use of American Society of Mechanical Engineering Code, Section XI, 2004 Edition ML1010400422010-04-29029 April 2010 Issuance of Relief Request lR-3-11 Regarding Use of American Society of Mechanical Engineering Code, Section XI, 2004 Edition ML0935702372010-04-26026 April 2010 Issuance of Relief Request RR-89-67 Regarding the Repair of Reactor Coolant Pump Seal Cooler Return Tubing and Weld ML1011301872010-04-19019 April 2010 ASME Section XI Inservice Inspection Program Relief Request for Limited Coverage Examinations Performed in the Second 10-Year Inspection Interval ML1008407382010-04-15015 April 2010 Issuance of Relief Requests IR-3-13 Regarding Use of American Society of Mechanical Engineering Code, Section XI, 2004 Edition ML1006801182010-04-0606 April 2010 Issuance of Relief Request IR-3-01 Regarding Use of American Society of Mechanical Engineering Code, Section XI, Appendix Viii ML1009002002010-03-30030 March 2010 Relief Requests RR-04-02, Alternative VT-2 Pressure Testing Requirements for the Lower Portion of the Reactor Pressure Vessel, and RR-04-03, Alternative Evaluation Criteria for Code Case N-513-2, Temporary Acceptance of Flaws in ML1006404462010-03-12012 March 2010 Issuance Relief ML1005402202010-02-19019 February 2010 Relief Request IR-3-01 Supplemental Information Re Snubber Inspection and Testing for Third 10-Year Interval ML0923901412009-08-24024 August 2009 Relief Request for Millstone Power Station, Unit 3, Relief Request IR-3-04, Response to Request for Additional Information for Alternative Brazed Joint Assessment Methodology 2023-07-31
[Table view] Category:Safety Evaluation
MONTHYEARML25014A2862025-01-21021 January 2025 Alternative Request to Defer ASME Code Section XI Inservice Inspection Examinations for Pressurizer and Steam Generator Pressure-Retaining Welds and Full Penetration Welded Nozzles ML24351A2412024-12-19019 December 2024 Reactor Vessel Internals Inspections Aging Management Program Submittal Related to License Renewal Commitment No. 13 ML24351A2422024-12-19019 December 2024 Reactor Coolant System Alloy 600 Inspection Program for License Renewal Commitment No. 15 ML24128A2772024-06-0404 June 2024 Issuance of Amendment No. 290 to Revise TSs for Reactor Core Safety Limits, Fuel Assemblies, and Core Operating Limits Report for Use of Framatome Gaia Fuel (EPID L-2023-LLA-0074) (Non-Proprietary) ML24109A0032024-05-21021 May 2024 Issuance of Amendment No. 289 to Revise Technical Specifications to Use Framatome Loss of Coolant Accident Evaluation Methodologies for Establishing Core Operating Limit (EPID L-2023-LLA-0065) (Non-Proprietary) ML23341A0172024-01-12012 January 2024 Issuance of Amendment No. 288 Revision to Applicability Term for Reactor Coolant System Heatup and Cooldown Pressure-Temperature Limitations Figures ML23283A3052023-12-20020 December 2023 Review of Appendix F to DOM-NAF2, Qualification of the Framatome ORFEO-GAIA and ORFEO-NMGRID CHF Correlations in the Dominion Energy VIPRE-D Computer Code (EPID L-2022-LLT-0003) (Nonproprietary) ML23230A0502023-10-0202 October 2023 5 of the Quality Assurance Topical Report - Review of Program Changes ML23226A0052023-09-26026 September 2023 Issuance of Amendment No. 287 Supplement to Spent Fuel Pool Criticality Safety Analysis ML23188A0432023-07-31031 July 2023 Authorization and Safety Evaluation for Alternative Request No. IR-04-11 ML23175A0052023-07-12012 July 2023 Alternative Request P-07 for Pump Periodic Verification Testing Program for Containment Recirculation Spray System Pumps ML23072A0892023-05-0101 May 2023 (Amendments 346 & 286), North Anna 1 & 2 (Amnds 294 & 277), Surry 1 & 2 (Amnds 311 & 311), and Summer 1 (Amd 225) - Issuance of Amendments to Revise TSs to Adopt TSTF-554 Revise Reactor Coolant Leakage Requirements ML23058A4542023-03-16016 March 2023 Issuance of Amendment Nos. 345 and 285 Regarding Adoption of Technical Specification Task Force-359, Increase Flexibility in Mode Restraints ML21320A0072022-09-0707 September 2022 Review of Appendix E to DOM-NAF-2, Qualification of the Framatome BWU-I CHF Correlation in the Dominion Energy VIPRE-D Computer Code (EPID L-2021-LLT-0000) (Non-Proprietary) ML22201A5082022-07-28028 July 2022 Authorization and Safety Evaluation for Alternative Request No. IR-04-09 ML22095A1072022-07-11011 July 2022 Issuance of Amendment Nos. 120, 344, & 284, 293 & 276, & 307 & 307 to Relocate Requirements to the QAPD ML22039A3392022-03-0303 March 2022 Request for Alternative Frequency to Supplemental Valve Position Verification Testing Requirements in the Fourth 10-year Valve Inservice Testing Program ML22041A0102022-03-0101 March 2022 V.C. Summer 1, Issuance of Amendment Nos. 283 (Millstone), 291 and 274 (North Anna), and 221 (Summer) to Revise TSs to Adopt TSTF-569 Revision of Response Time Testing Definition ML22007A1512022-02-16016 February 2022 Issuance of Amendment No. 282 Regarding Shutdown Bank Technical Specification Requirements and Alternate Control Rod Position Monitoring Requirements ML21326A0992022-01-0707 January 2022 Issuance of Amendment No. 281 Regarding Revised Reactor Core Safety Limit to Reflect Topical Report WCAP-177642-P-A, Revision 1 ML21262A0012021-11-0909 November 2021 Issuance of Amendment No. 280 Regarding Measurement Uncertainty Recapture Power Uprate ML21284A0062021-10-29029 October 2021 Authorization and Safety Evaluation for Alternative Request No. RR-05-04 and IR-4-02 ML21227A0002021-10-0505 October 2021 Issuance of Amendment No. 279 Regarding Addition of Analytical Methodology to the Core Operating Limits Report for a Large Break Loss-of-Coolant Accident ML21222A2302021-09-0909 September 2021 Issuance of Amendment No. 343 Revision to Technical Specifications for Steam Generator Inspection Frequency (L-2020-LLA-0227) ML21174A0202021-08-0202 August 2021 Relief Request for Limited Coverage Examinations Performed in the Fourth 10-Year Inservice Inspection Interval ML21167A3552021-07-16016 July 2021 Authorization and Safety Evaluation for Alternative Request No. RR-05-06 ML21167A2112021-06-30030 June 2021 Relief Request for Limited Coverage Examinations Performed in the Third 10-Year Inservice Inspection Interval (EPID L-2020-LLR-0081 Through L-2020-LLR-0088) ML21075A0452021-03-26026 March 2021 Request to Utilize Code Case N-885 ML21043A1622021-03-25025 March 2021 Issuance of Amendment No. 278 Regarding Revision to Battery Surveillance Requirements ML21026A1422021-02-23023 February 2021 Issuance of Amendment No. 342 Revision to Technical Specification Table 3.3-11, Accident Monitoring Instrumentation ML20312A0022020-12-10010 December 2020 Relief Request for Limited Coverage Examinations Performed in the Third 10-Year Inservice Inspection Interval (EPID L-2020-LLR-0027 Through L-2020-LLR-0032) ML20312A0012020-12-10010 December 2020 Relief Requests for Limited Coverage Examinations Performed in the Fourth 10-Year Inservice Inspection Interval ML20287A4712020-10-20020 October 2020 Proposed Alternative RR-05-05 to the Requirements of the ASME Code Containment Unbonded Post-Tensioning System Inservice Inspection Requirements ML20275A0002020-10-14014 October 2020 Issuance of Amendment No. 277 to Revise Technical Specification 6.8.4.g to Allow a One-Time Deferral of the Steam Generator Inspections ML20237H9952020-09-29029 September 2020 Issuance of Amendment No. 341 Revision to Technical Specification 6.25, Pre-Stressed Concrete Containment Tendon Surveillance Program ML20252A0072020-09-15015 September 2020 Request to Use a Provision of a Later Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XI ML20191A0042020-08-0707 August 2020 Issuance of Amendment No. 340 Revised Technical Specification Limits for Primary and Secondary Coolant Activity ML20189A2062020-07-16016 July 2020 Relief Request IR-4-03 Concerning Non-Code Methodology to Demonstrate Structural Integrity of Class 3 Moderate-Energy Piping ML20161A0002020-07-15015 July 2020 Issuance of Amendment No. 276 Regarding Revision to the Integrated Leak Rate Type a and Type C Test Intervals ML20140A3692020-06-24024 June 2020 Issuance of Amendment No. 339 Extension of Technical Specification 3.8.1.1, A.C. Sources - Operating, Allowed Outage Time ML20027B9702020-03-26026 March 2020 Issuance of Amendment No. 338 Regarding Adoption of TSTF-522, Revision 0, Revise Ventilation System Surveillance Requirements to Operate for 10 Hours Per Month, Using CLIIP ML20080K5082020-03-24024 March 2020 Alternative Request RR-05-03 for the Fifth 10-Year Inservice Inspection Interval ML19340A0252020-01-30030 January 2020 Issuance of Amendment No. 337 Regarding Adoption of 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structure, Systems, and Components of Nuclear Power Reactors ML19305D2482019-12-31031 December 2019 Issuance of Amendments Adoption of Emergency Action Level Schemes Per NEI 99-01, Rev. 6 ML19338G3722019-12-18018 December 2019 Alternative Requests RR-05-01 and RR-05-02 for the Fifth 10-Year Inservice Inspection Interval ML19340A0012019-12-18018 December 2019 Proposed Alternative Request IR-4-01 Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography ML19340A0002019-12-13013 December 2019 Relief Request IR-3-39, Proposed Alternative to ASME Code Weld Preheat Requirements ML19126A0002019-05-28028 May 2019 Issuance of Amendment No. 273 Regarding Technical Specification Changes for Spent Fuel Storage and New Fuel Storage ML19098A0342019-04-30030 April 2019 Units 1 and 2; Limerick, Units 1 and 2; Peach Bottom, Units 2 and 3, and Quad Cities, Units 1 and 2 - Revision to Approved Alternative to Use BWR Vessel and Internal Proj Guidelins ML19042A2772019-03-21021 March 2019 Issuance of Amendment No. 272 Regarding Revision to Technical Specification Action Statement for Loss of Control Building Inlet Ventilation Radiation Monitor Instrumentation Channels 2025-01-21
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MILLSTONE POWER STATION, UNIT NOS. 2 AND 3 - AUTHORIZATION AND SAFETY EVALUATION FOR ALTERNATIVE REQUEST NO. RR-05-04 AND IR-4-02 (EPID L-2020-LLR-0158)
LICENSEE INFORMATION Recipients Name and Address: Mr. Daniel G. Stoddard Senior Vice President and Chief Nuclear Officer Dominion Energy Nuclear Connecticut, Inc.
Millstone Power Station Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, VA 23060-6711 Licensee:
Dominion Energy Nuclear Connecticut, Inc.
Plant Name and Units:
Millstone Power Station, Unit Nos. 2 and 3 Docket Nos.:
50-336 and 50-423 APPLICATION INFORMATION Application Date: December 17, 2020 Application Agencywide Documents Access and Management System (ADAMS)
Accession No.: ML20352A334 Supplement Date: N/A Applicable Inservice Inspection (ISI) Program Interval and Interval Start/End Dates: For RR-05-04, the alternative is requested for the fifth 10-year ISI interval for Millstone Power Station, Unit No. 2 (MPS2). The MPS2 fifth 10-year ISI interval began April 1, 2020, and is currently scheduled to end on March 31, 2030. For IR-4-02, the alternative is requested for the fourth ten-year ISI interval for Millstone Power Station, Unit No. 3 (MPS3). The MPS4 fourth 10-year ISI interval began February 23, 2019, and is currently scheduled to end on February 22, 2029.
Alternative Provision: The applicant requested an alternative under Title 10 of the Code of Federal Regulations (10 CFR), paragraph 50.55a(z)(2).
ISI Requirements: Section XI, Table IWD-2500-1, Examination Category D-B and IWD-5220 require Class 3 piping receive a system leakage test at the pressure obtained while the system is performing its normal function and a VT-2 visual examination once per inspection period.
Applicable Code Edition and Addenda: 2013 Edition of the American Society of Mechanical Engineers (ASME) Code,Section XI.
ASME Code Components Affected:
Unit 2 MPS2s Service Water System (SWS) supply piping located in the intake structure bays designated as line numbers 24-JGD-1 and 24-KE-1 as shown in the December 17, 2020, submittal.
Unit 3 MPS3s 30 SWS supply piping located in the intake structure bays designated as B train line number 3-SWP-030-3-3 as shown in the December 17, 2020, submittal.
Brief Description of the Proposed Alternative:
The licensee proposes to use a verification of unimpaired flow performed during quarterly SWS flow testing along with internal visual inspection of the piping to be performed every other refueling outage in lieu of the ASME Code-required system leakage test and VT-2 examination for the subject piping. The licensee requested the use of these alternatives for the duration of the MPS2s fifth and MPS3s fourth ten-year interval.
For additional details on the licensees request, please refer to the documents located at the ADAMS Accession Nos. identified above.
STAFF EVALUATION The NRC staff has evaluated Alternative Requests RR-05-04 and IR-4-02 pursuant to 10 CFR 50.55a(z)(2). Specifically, the U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the affected pipe segments, flow test procedures, and internal visual examinations to determine if the alternatives provide reasonable assurance of structural integrity. The NRC staff also reviewed whether complying with the specified requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Affected Piping Segments Unit 2 The subject piping is the 24 SWS train A and B supply piping located in normally inaccessible confined space areas of the intake structure bays. The nominal wall thickness of the 24"-JGD-1 piping is 0.375 inches. The nominal wall thickness of the 24"-KE-1 piping is 0.410 inches. The normal operating pressure is 45 pounds per square inch gauge (psig). The normal operating temperature range is 33 °F to 80 °F.
The A train piping includes approximately 75 feet of piping running through four intake structure bays. The majority of this piping is A-106, Grade B carbon steel piping which has been internally lined with a cured in-place pipe, epoxy-impregnated material (lnsituform), and externally coated with an epoxy coal tar material (Carbomastic 14), in order to enhance its long-term life. Approximately 10.5 feet of this piping has been upgraded to 6 percent molybdenum stainless steel (UNS N08367), also known as AL6XN.
The B train piping consists of approximately 22 feet of piping running through one intake structure bay. This piping has been upgraded to AL6XN.
The VT-2 visual examination of this piping requires entry into each of the four MPS2 intake structure bays (A, B, C, and D) that are designated as confined spaces.
Unit 3 The subject piping is the 30 common B train SWS header piping located in the normally inaccessible confined space areas of the MPS3 intake structure bays. The nominal wall thickness of the subject piping is 0.375 inches. The normal operating pressure is 44 psig. The normal operating temperature range is 33 °F to 80 °F. The piping material is SB-127 (Monel).
The inaccessible piping consists of approximately 99 feet of piping running through the five MPS3 intake structure bays. The licensee stated that no repairs or upgrades to this piping section have been performed and the service history of this piping has shown no significant degradation.
The staff notes the required VT-2 visual examinations would continue to be performed on the remaining accessible portions of the MPS2 and MPS3 SWS piping not covered by this alternative request, when conducting the system leakage test in accordance with ASME Code,Section XI, IWD-5000 and IWA-5244(b)(2) for buried components.
Additionally, the intake structure is walked down once per shift during plant equipment operator rounds. Any significant leakage in the inaccessible piping would likely be audible to the operators during these rounds.
Flow Test Procedures The flow testing of the MPS2 and MPS3 SWS pumps is performed quarterly and uses an established minimum flow rate specified in the IST procedures as the acceptance criteria for the pressure testing of the subject piping segments. Once the reference flow rate is established, pump performance parameters are recorded (e.g., suction pressure, discharge pressure, and flow). If the flow rate cannot be achieved or the associated differential pressure at the reference conditions is not achieved, the test is considered to be unsatisfactory. The Corrective Action Program (CAP) would be used to determine the cause and return the pumps to operable status.
The CAP would initiate additional activities, such as pump maintenance and additional system walkdowns/inspections, to determine the cause of the issue. If during the investigation it is suspected that there may be leakage occurring from the subject piping addressed by this request, actions would be taken to gain access to this normally inaccessible piping for visual inspection, as necessary.
The NRC staff finds that the licensee's flow testing program is adequate to determine potential through wall leakage from the affected pipe segments because the licensee's CAP contains procedures requiring corrective actions to be performed to determine the source of the leakage, regardless of the source. Additionally, the plant equipment operator performs walkdowns of accessible areas of the intake structure once each shift. Any significant flow from leakage of the subject piping would likely be audible to the operator during these rounds. Therefore, the NRC staff finds that the licensee will properly identify the pipe through wall leakage, if it occurred, and take corrective actions in accordance with its CAP.
Piping Internal Inspections The licensee stated that each of the subject piping segments inside surface is visually inspected using a robotic crawler at an approximately 3-year frequency. The robotic crawler is fitted with a high-resolution camera. The licensee stated that any identified conditions such as erosion corrosion, fouling or any other degraded piping conditions are evaluated for acceptance or corrective action. Inspections performed over the last two MPS2 and MPS3 refueling outages have identified no unsatisfactory conditions.
The NRC staff notes that the 3-year frequency for performing the internal visual inspection is essentially equivalent to the timing of the ASME Code-required system leakage test and, therefore, is acceptable. The NRC staff finds that, in addition to the flow test, the periodic internal visual inspection will provide additional assurance on the structural integrity of the affected piping.
Hardship Justification In the December 17, 2020, submittal, the licensee described that personnel entry into the confined space of the intake bays with equipment operational is considered a personnel safety hazard. Therefore, equipment is required to be removed from service and tagged out prior to entry. Additionally, due to the physical configuration of the intake structure, seven of the nine bays require draining to erect the scaffolding needed to access these bays. Draining the bays also requires equipment to be removed from service to preclude damage to the service water pumps that could occur with the bays drained. The licensee explained that unavailability of safety-related service water pumps places the station at a greater operational risk since it removes the availability of redundant equipment, introducing a reduction in the safety margin of the plant. Placing the plant in a condition where safety-related service water is out of service for an extended period of time, resulting in increased operational risk, is considered a hardship without a compensating increase in the level of quality and safety.
The NRC staff finds that the licensee has provided valid arguments to demonstrate that complying with the specified ASME Code requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Based on information provided, the NRC staff finds that the proposed alternatives RR-05-04 and IR-4-02 will provide reasonable assurance of the structural integrity and leak tightness of the affected SWS piping segments because: (1) the flow test procedures will be able to detect potential leakage in the affected pipe segments in the intake structure bays; (2) the licensee performs visual examinations on the inside surface of the affected pipe segments approximately every three years which would detect potential pipe degradation; and (3) the plant operator walkdowns of the accessible areas of the intake structure during every shift which will identify significant leakage in the inaccessible areas. The NRC staff also finds the licensees hardship justification is acceptable and that complying with the specified ASME Code requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
CONCLUSION The NRC staff has determined that complying with the specified ASME Code requirements described in the licensees request referenced above would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
The proposed alternative provides reasonable assurance of structural integrity of the subject piping segments.
The NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(2).
The NRC staff authorizes the use of proposed alternatives RR-05-04 and IR-4-02 at Millstone Power Station, Units 2 and 3, for the fifth and fourth 10-year intervals, respectively.
All other ASME Code,Section XI, requirements for which an alternative was not specifically requested and authorized remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
Principal Contributor: Keith Hoffman Date: October 29, 2021 James G. Danna, Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation cc: Listserv James G.
Danna Digitally signed by James G. Danna Date: 2021.10.29 13:45:20 -04'00'
ML21284A006 OFFICE NRR/DORL/LPL1/PM NRR/DO - L/LPL1/LA NRR/DNRL/NPHP/BC NAME RGuzman KEntz MMitchell DATE 10/13/2021 10/12/2021 8/9/2021 OFFICE NRR/DORL/LPL1/PM NAME JDanna DATE 10/29/2021