ML053470091

Relief, Boiler and Pressure Vessel Code, MC6528 and MC6529

ML053470091
Person / Time
Site:	Hatch
Issue date:	01/03/2006
From:	Marinos E C Plant Licensing Branch III-2
To:	Sumner H L Southern Nuclear Operating Co
Gratton C, NRR/DLPM 415-1055
References
TAC MC6528, TAC MC6529
Download: ML053470091 (7)

Text

January 3, 2006Mr. H. L. Sumner, Jr.

Vice President - Nuclear Hatch Project Southern Nuclear Operating Company, Inc.

P.O. Box 1295 Birmingham, AL 35201-1295

SUBJECT:

EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS 1 AND 2 (HATCH), REQUESTFOR RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME), BOILER AND PRESSURE VESSELCODE (CODE) (TAC NOS. MC6528 AND MC6529).

Dear Mr. Sumner:

By letter dated March 30, 2005, as supplemented by letters dated August 3, October 5, andOctober 24, 2005, Southern Nuclear Operating Company, Inc. (the licensee), submitted aproposed request for relief, ISI-ALT-1, for Hatch. The licensee proposed an alternative to the ASME Code requirements. Specifically, the licensee proposed using ASME Code,Section XI, Appendix VIII, Supplements 4 and 6, qualified procedures and personnel, and the criteria fromTitle 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 50.55a applicable to theexamination of the reactor pressure vessel (RPV) shell-to-flange and RPV head-to-flange welds. The letter dated October 24, 2005, included Version 4.0 of the relief request and superceded the letters dated March 30, August 3, and October 5, 2005, for relief requestISI-ALT-1. The request is for the fourth 10-year inservice inspection interval. The Nuclear Regulatory Commission (NRC) staff found the proposed alternative, ISI-ALT-1,Version 4.0, acceptable in accordance with 10 CFR 50.55a(a)(3)(I) because the licensee's proposed alternative provides an acceptable level of quality and safety. The NRC staffauthorizes the proposed alternative for the fourth 10-year inservice inspection interval for Hatch.The NRC staff's safety evaluation is enclosed.Sincerely,/RA/Evangelos C. Marinos, ChiefPlant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-321 and 50-366

Enclosure:

Safety Evaluation cc w/encl: See next page January 3, 2006Mr. H. L. Sumner, Jr.

Vice President - Nuclear Hatch Project Southern Nuclear Operating Company, Inc.

P.O. Box 1295 Birmingham, AL 35201-1295

SUBJECT:

EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS 1 AND 2 (HATCH), REQUESTFOR RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME), BOILER AND PRESSURE VESSELCODE (CODE) (TAC NOS. MC6528 AND MC6529).

Dear Mr. Sumner:

By letter dated March 30, 2005, as supplemented by letters dated August 3, October 5, andOctober 24, 2005, Southern Nuclear Operating Company, Inc. (the licensee), submitted aproposed request for relief, ISI-ALT-1, for Hatch. The licensee proposed an alternative to the ASME Code requirements. Specifically, the licensee proposed using ASME Code,Section XI, Appendix VIII, Supplements 4 and 6, qualified procedures and personnel, and the criteria fromTitle 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 50.55a applicable to theexamination of the reactor pressure vessel (RPV) shell-to-flange and RPV head-to-flange welds. The letter dated October 24, 2005, included Version 4.0 of the relief request and superceded the letters dated March 30, August 3, and October 5, 2005, for relief requestISI-ALT-1. The request is for the fourth 10-year inservice inspection interval. The Nuclear Regulatory Commission (NRC) staff found the proposed alternative, ISI-ALT-1,Version 4.0, acceptable in accordance with 10 CFR 50.55a(a)(3)(I) because the licensee's proposed alternative provides an acceptable level of quality and safety. The NRC staffauthorizes the proposed alternative for the fourth 10-year inservice inspection interval for Hatch.The NRC staff's safety evaluation is enclosed.Sincerely,/RA/

Evangelos C. Marinos, ChiefPlant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-321 and 50-366

Enclosure:

Safety Evaluation cc w/encl: See next pageDISTRIBUTION:

PublicRidsOgcRpLPL2-1ReadingDNaujock RidsAcrsAcnwMailCenterRidsNrrLAMO'BrienBWetzel, EDO RIIRidsNrrPMGrattonRidsAcrsRgn2MailCenter(MWidmann)RidsNrrDorlLplc(EMarinos)RidsNrrDciCpnb(TChan)RidsNrrDprAccession No. ML053470091NRR_028OFFICENRR/LPL2-1/PMNRR/LPL2-1/LANRR/CPNB/BCOGC NRR/LPL2-1/BCNAMECGratton:kgMO'BrienTChanS. HamrickEMarinosDATE12/22/0501/03/06SE dated 12/12/0512/16/0501/03/06OFFICIAL RECORD COPY SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST ISI-ALT-1, VERSION 4.0SOUTHERN NUCLEAR OPERATING COMPANY, INC.EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS. 1 AND 2 (HATCH)DOCKET NOS. 50-321 AND 50-36

61.0 INTRODUCTION

By letter dated March 30, 2005, as supplemented by letters dated August 3, October 5, andOctober 24, 2005, Southern Nuclear Operating Company, Inc. (the licensee) submitted arequest for relief, ISI-ALT-1, for Hatch. The licensee proposed an alternative to the requirements of the American Society of Mechanical Engineers (ASME), Boiler and PressureVessel Code (Code). Specifically, the licensee proposed using ASME Code,Section XI,Appendix VIII, Supplements 4 and 6 qualified procedures and personnel, and the criteria fromthe Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 50.55a that areapplicable to the examination of the reactor pressure vessel (RPV) shell-to-flange and RPV head-to-flange welds. The letter dated October 24, 2005, included Version 4.0 of the relief request and superceded the letters dated March 30, August 3, and October 5, 2005, for reliefrequest ISI-ALT-1. The request is for the fourth 10-year inservice inspection (ISI) interval which begins January 1, 2006, and ends December 31, 2015. 2.0 REGULATORY REQUIREMENTSThe ISI of ASME Code Class 1, Class 2, and Class 3 components will be performed inaccordance with Section XI of the ASME Code and applicable edition and addenda as required by 10 CFR 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Section 50.55a(a)(3) states in part that alternatives to therequirements of paragraph (g) may be used, when authorized by the Nuclear Regulatory Commission (NRC), if the licensee demonstrates that: (i) the proposed alternatives wouldprovide 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.Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, Class 2, and Class 3 components(including supports) will meet the requirements, except the design and access provisions andthe preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection 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 com ponents and system pressure testsconducted during the first 10-year ISI 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) twelve months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The ASME Code of record for Hatchfor the fourth 10-year ISI interval is the 2001 edition through the 2003 addenda of the ASME Code. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein and subject to Commission approval.

3.0 TECHNICAL EVALUATION

3.1Component for Which Relief is RequestedThe applicable vessel welds are ASME Code Class 1, Category B-A pressure retaining welds inthe RPV, Item No. B1.30, shell-to-flange weld, and Item No. B1.40, head-to-flange weld.3.2Applicable ASME Code RequirementsThe applicable requirement is the 2001 edition through the 2003 addenda of Section XI of theASME Code, Appendix I, I-2120, which states that vessels greater than 2 inches in thicknessshall be examined in accordance with Section V, Article 4, as supplemented by Table I-2000-1.3.3Licensee's Proposed AlternativeThe licensee proposed performing ultrasonic test (UT) examinations of the subject welds inaccordance with the 2001 edition with the 2003 addenda of ASME Code,Section XI, with the modifications and limitations listed in the 10 CFR 50.55a. The licensee will use personnel andprocedures qualified to the 2001 edition with no addenda,Section XI, Appendix V III,Supplement 4, "Qualification Requirements for the Clad/Base Metal Interface of ReactorVessel," and Supplement 6, "Qualification Requirements for Reactor Vessel Welds other thanClad/Base Metal Interface," as administered by the Energy Power Research Institute -

Performance Demonstration Initiative (PDI) Program. 3.4Licensee's Basis for ReliefAppendix VIII requirements were developed with a rigorous, item-specific performancedemonstration to ensure the effectiveness of UT examinations. The performance demonstration administered by PDI was conducted on RPV mockups containing flaws of various size and allocations. The demonstration established the capability of equipment,procedures, and personnel to find flaws that could be detrimental to the integrity of the RPV. The performance demonstration showed that for the detection of flaws in RPV welds, the UT techniques were equal to or surpassed the requirements of the Section V, Article 4 of the ASME Code. Additionally, the PDI qualified sizing techniques are considered to be more accurate than the techniques used in Section V, Article 4.Although Appendix VIII is not required for the RPV shell-to-flange and RPV head-to-flangewelds, the use of Appendix VIII, Supplements 4 and 6 criteria for detection of flaws in thesewelds will be equal to or will exceed the requirements established by Section V, Article 4. 3.5NRC Staff EvaluationThe 2001 edition, 2003 addenda of ASME Code,Section XI, IWA-2232 states, "Ultrasonicexamination shall be conducted in accordance with Appendix I." Subarticle I-2120 states that vessels greater than 2 inches in thickness shall be examined in accordance with Section V, Article 4, as supplemented by Table I-2000-1.Section V, Article 4 provides a prescriptive-based process for qualifying UT of procedures and the scanning requirements for examinations. The prescriptive-based UT uses detailed criteria for setting up and calibrating equipment, calculating coverage, and detecting indications. The capability of aprescriptive-based UT examination is demonstrated with calibration blocks made fromrepresentative material containing holes and notches. Performance-based UT requires that detailed criteria be used for performance demonstration tests. The results for the tests are compared against statistically developed screening criteria. The tests are performed on representative mockups containing flaws similar to those found in operating plants. Theperformance-based tests demonstrate the effectiveness of UT personnel and procedures.In lieu of Subarticle I-2120, the licensee proposed performing UT examinations of the subjectwelds in accordance with the 2001 edition, 2003 addenda of ASME Code,Section XI, Appendix VIII, Supplements 4 and 6, as modified by 10 CFR 50.55a. Section 50.55a limits the use ofAppendix VIII to the 2001 edition with no addenda. Appendix VIII is a performance-based UTmethod. Examinations are performed with the scanning requirements for Supplements 4 and 6that are provided in 10 CFR 50.55a(b)(2)(xv)(G), and the scanning volume identified in the ASME Code,Section XI, Figure IWB-2500-4 for the shell-to-flange weld and Figure IWB-2500-5 for the head-to-flange weld. The scanning requirements are: (1) for the examination of the inner 15 percent through-wall volume, scanning will be performed in fourorthogonal directions to the maximum extent possible with procedures and personnel qualified to Appendix VIII, Supplement 4; (2) the remainder of the inner 15 percent through-wall volumeis considered fully examined if coverage is obtained in at least one parallel and one perpendicular direction using personnel and procedures qualified for single side examination in accordance with Supplement 6; and (3) the remaining 85 percent through-wall volume is considered fully examined if coverage is obtained in one parallel and one perpendicular direction using procedures and personnel qualified for single side examination. Single side qualification criteria are provided in 10 CFR 50.55a(b)(2)(xv)(G)(2) and 10 CFR 50.55a(b)(2)(xvi).The licensee will follow 10 CFR 50.55a(b)(2)(xv)(G) for the vessel-to-flange and head-to-flangewelds. Because the head-to-flange weld has no cladding, the licensee will use Code Case N-664, "Performance Demonstration Requirements for Examination of Unclad Reactor Pressure Vessel Welds, Excluding Flange Welds," that permits using Appendix V III,Supplement 4 in lieu of the requirements of Appendix VIII, Supplement 6 for the inner10 percent performance demonstration. Code Case N-664 is endorsed in Regulatory Guide, 1.147, Revision 14, "Inservice Inspection Code Case Acceptability, ASME Section XI,Division 1." There are no specific performance demonstration requirements from 10 percent through 15 percent through-wall thickness. The scanning of the uncladded head-to-flange weld would be applied according to the requirements of 10 CFR 50.55a(b)(2)(xv)(G).The procedures, equipment, and personnel qualified to Appendix VIII through the PDI programhave shown a high probability of flaw detection, and have increased the reliability of examinations of weld configurations within the scope of the PDI program. Therefore, theproposed alternative will provide an acceptable level of quality and safety. 4.0 ConclusionBased on the above evaluation, the NRC staff concludes that the licensee's proposedalternative, ISI-ALT-1, Version 4.0, to use the 2001 edition of the ASME Code,Section XI,Appendix VIII, Supplements 4 and 6 as modified by 10 CFR 50.55a(b)(2)(xv) and 10 CFR50.55a(b)(2)(xvi) for the RPV shell-to-flange and head-to-flange welds will provide anacceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), the proposed alternative is authorized for Hatch for the fourth 10-year inservice inspection interval.All other requirements of the ASME Code for which relief has not been specifically requestedremain applicable, including third party review by the Authorized Nuclear Inservice Inspector.Principal Contributor: Donald Naujock, NRR Date: January 3, 2006

Edwin I. Hatch Nuclear Plant, Units 1 & 2 cc:

Laurence BergenOglethorpe Power Corporation 2100 E. Exchange Place P.O. Box 1349 Tucker, GA 30085-1349Mr. R.D. BakerManager - Licensing Southern Nuclear Operating Company, Inc.

P.O. Box 1295 Birmingham, AL 35201-1295Resident InspectorPlant Hatch 11030 Hatch Parkway N.

Baxley, GA 31531Harold Reheis, DirectorDepartment of Natural Resources 205 Butler Street, SE., Suite 1252 Atlanta, GA 30334Steven M. JacksonSenior Engineer - Power Supply Municipal Electric Authority of Georgia 1470 Riveredge Parkway, NW Atlanta, GA 30328-4684Mr. Reece McAlisterExecutive Secretary Georgia Public Service Commission 244 Washington St., SW Atlanta, GA 30334Arthur H. Domby, Esq.Troutman Sanders Nations Bank Plaza 600 Peachtree St, NE, Suite 5200 Atlanta, GA 30308-2216ChairmanAppling County Commissioners County Courthouse Baxley, GA 31513Mr. Jeffrey T. GasserExecutive Vice President Southern Nuclear Operating Company, Inc.

P.O. Box 1295 Birmingham, AL 35201-1295Mr. G. R. Frederick, General ManagerEdwin I. Hatch Nuclear Plant Southern Nuclear Operating Company, Inc.

U.S. Highway 1 North P.O. Box 2010 Baxley, GA 31515Mr. K. RosanskiResident Manager Oglethorpe Power Corporation Edwin I. Hatch Nuclear Plant P.O. Box 2010 Baxley, GA 31515