ML090920046
| ML090920046 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 04/20/2009 |
| From: | Pickett D Plant Licensing Branch 1 |
| To: | Entergy Nuclear Operations |
| Boska J, NRR, 301-415-2901 | |
| References | |
| TAC ME0413 | |
| Download: ML090920046 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 20, 2009 Vice President, Operations Entergy Nuclear Operations, Inc.
Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, NY 10511-0249
SUBJECT:
INDIAN POINT NUCLEAR GENERATING UNIT NO.3 - RELIEF REQUEST (RR) NO. RR-3-47(1) FOR REACTOR VESSEL WELD EXAMINATION (TAC NO.
ME0413)
Dear Sir or Madam:
By letter dated January 22, 2009, as supplemented by letter dated February 6, 2009, Entergy Nuclear Operations, Inc. (the licensee) submitted Relief Request No. RR 3-47(1) to the Nuclear Regulatory Commission (NRC) on the reactor vessel shell-to-flange weld examination applicable to Indian Point Nuclear Generating Unit NO.3 (IP3) for the third 1O-year inservice inspection (lSI) interval. The relief pertains to the method and equipment used to inspect this weld. The applicable version of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) requires ultrasonic examination of the weld in accordance with ASME Code,Section V, Article 4, as supplemented by Section XI, Appendix I. In lieu of this, the licensee has proposed an alternative to perform the ultrasonic examination of the weld with equipment, procedures, and personnel qualified to the requirements of the ASME Code,Section XI, Appendix VIII, supplements 4 and 6,1995 Edition with the 1996 Addenda, as amended by Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a. To support the licensee's outage schedule, verbal authorization of the subject relief request was granted on March 3, 2009.
Based on the information provided in the licensee's submittal, the NRC staff concludes that the licensee's use of an ultrasonic examination which complies with the ASME Code,Section XI, Appendix VIII, supplements 4 and 6, 1995 Edition with the 1996 Addenda, as amended by 10 CFR 50.55a, would be equivalent to the required examination. Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), the NRC staff authorizes the alternative weld examination proposed in RR 3-47(1) for the third 10-year lSI interval at IP3, which ends in July 2009, as the alternative examination will provide an acceptable level of quality and safety. The NRC safety evaluation is provided in the enclosure.
- 2 If you have any questions regarding this approval, please contact the Indian Point Project Manager, John Boska, at (301) 415-2901.
Sincerely, Douglas V. Pickett, Chief, Acting Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-286
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 REQUEST FOR RELIEF RR-3-47(1)
ENTERGY NUCLEAR OPERATIONS, INC.
INDIAN POINT NUCLEAR GENERATING UNIT NO.3 DOCKET NO. 50-286
1.0 INTRODUCTION
By letter dated January 22,2009, Agencywide Documents Access and Management System (ADAMS) accession number ML090420062, as supplemented by letter dated February 6,2009, ADAMS Accession No. ML090570506, Entergy Nuclear Operations, Inc. (the licensee) submitted Relief Request No. RR 3-47(1) to the Nuclear Regulatory Commission (NRC) on the reactor vessel shell to flange weld examination applicable to Indian Point Nuclear Generating Unit NO.3 (IP3) for the third 1O-year inservice inspection (lSI) interval. The relief pertains to the method and equipment used to inspect this weld. The applicable version of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) requires ultrasonic examination of the weld in accordance with the ASME Code,Section V, Article 4, as supplemented by Section XI, Appendix I. In lieu of this, the licensee has proposed an alternative to perform the ultrasonic examination of the weld with equipment, procedures, and personnel qualified to the requirements of the ASME Code,Section XI, Appendix VIII, supplements 4 and 6, 1995 Edition with the 1996 Addenda, as amended by Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a. To support the licensee's outage schedule, verbal authorization of the subject relief request was granted on March 3, 2009.
2.0 REGULATORY REQUIREMENTS As specified in 10 CFR 50.55a(g), inservice inspection of ASME Code Class 1, 2, and 3 components shall be performed in accordance with the requirements of ASME Code,Section XI, except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Pursuant to 10 CFR 50.55a(a)(3), alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed alternatives would provide 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, 2, and 3 components (including supports) shall 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 of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The Enclosure
- 2 regulations require that inservice examination of components and system pressure tests conducted during the first 10-year 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 in paragraph (b) of that section. The lSI Code of Record for the third 10-year lSI interval for IP3 is the 1989 Edition of the ASME Code,Section XI. The third 10-year lSI interval for IP3 started on July 21, 2000, and is scheduled to end on July 21, 2009.
3.0 TECHNICAL EVALUATION
Components for Which Relief is Requested ASME Code,Section XI, Table IWB-2500-1, Examination Category B-A, Item B1.30, Reactor Pressure Vessel (RPV) Shell-to-Flange Weld.
ASME Code Requirements ASME Code,Section XI, Table IWB-2500-1, Examination Category B-A, Item B1.30, requires essentially 100 percent volumetric examination, as defined by ASME Code,Section XI, Figure IWB-2500-4. "Essentially 100%", as clarified by ASME Code Case N-460, "Alternative Examination Coverage for Class 1 and Class 2 Welds," is greater than 90 percent coverage of the examination volume, or surface area, as applicable. ASME Code Case N-460 has been approved for use by the NRC in Regulatory Guide (RG) 1.147, Revision 15, "Inservice Inspection Code Case Acceptability." The 1989 Edition of the ASME Code,Section XI, Subsection IWA-2232, requires ultrasonic (UT) examination of the RPV shell-to-flange weld to be in accordance with ASME Code,Section V, Article 4, as supplemented by Appendix I of Section XI.
Licensee's Request for Relief (As Stated by the Licensee)
Pursuant to 10CFR50.55a(a)(3)(i), relief is requested from the requirements of
[ASME Code,Section XI,] Subsection IWA-2232 since the vendor performing the inspection has qualified their equipment, procedures and personnel to the requirements of ASME [Code,] Section XI, 1995 Edition with 1996 Addenda, Appendix VIII, Supplements 4 and 6 as amended by 10 CFR 50.55a. Performing the inspection in accordance with the requirements of IWA-2232 would require the inspection vendor to qualify their equipment, procedures and personnel to the requirements of [ASME Code,Section XI,] Article 4 of Section V, as supplemented by Appendix I of ASME [Code, Section] XI. Since the inspection methods provided in
[ASME Code,Section XI,] Appendix VIII have been proven to be more effective in detecting and sizing flaws, the use of [ASME Code,] Section V techniques would require additional resources and result in a less effective inspection.
- 3 Licensee's Proposed Alternative Examination (As Stated by the Licensee)
Pursuant to 10CFR50.55a(a)(3)(i), Entergy requests authorization to utilize the alternative requirements in ASME [Code,] Section XI, 1995 Edition with 1996 Addenda, Appendix VIII, Supplements 4 and 6 as amended by 10 CFR 50.55a in lieu of the requirements of IWA-2232, that requires UT examination of the RPV shell-to-flange weld to be in accordance with ASME Code, Article 4 of Section V, as supplemented by Appendix I of Section XI.
[ASME Code,Section XI,] Appendix VIII requirements were developed and adopted to ensure the effectiveness of ultrasonic examinations within the nuclear industry by means of a rigorous, item specific performance demonstration containing flaws of various sizes, locations, and orientations. The performance demonstration process has established with a high degree of confidence, the capability of personnel, procedures, and equipment to detect and characterize flaws that could be detrimental to the structural integrity of the RPV. The PDI
[performance demonstration initiative] approach has demonstrated that for detection and characterization of flaws in the RPV the ultrasonic examination techniques are equal to or better than the requirements of the ASME [Code,]
Section V, Article 4 ultrasonic examination requirements.
Though [ASME Code,Section XI,] Appendix VIII is not required for the RPV shell to-flange weld examination, the use of [ASME Code,Section XI,] Appendix VIII, Supplements 4 and 6 criteria for detection and sizing of flaws in this weld will be equal to or exceed the requirements of ASME [Code,] Section V, Article 4.
Therefore, the use of the proposed alternative will continue to provide an acceptable level of quality and safety, and approval is requested pursuant to 10 CFR 50.55a(a)(3)(i).
NRC Staff Evaluation
The 1989 Edition of ASME Code,Section XI, IWA-2232 states, "[UT] examination shall be conducted in accordance with Appendix I." ASME Code,Section V, Article 4 provides a prescriptive process for qualifying UT procedures and the scanning requirements for examinations. The UT performed to ASME Code,Section V, Article 4 uses detailed criteria for setting up and calibrating equipment, calculating coverage, and detecting indications. The capability of an ASME Code,Section V, Article 4 UT examination is demonstrated with calibration blocks made from representative material containing holes and notches.
The licensee proposes, in lieu of the ASME Code,Section V, Article 4 angle beam examination to use an exarnination that will be performed using examination procedures, personnel, and equipment qualified in accordance with ASME Code,Section XI, Appendix VIII, Supplements 4 and 6, as modified by 10 CFR 50.55a. 10 CFR 50.55a limits the use of ASME Code,Section XI, Appendix VIII to the 2001 Edition of the ASME Code with no Addenda. ASME Code,Section XI, Appendix VIII is a performance-based UT method. Performance-based UT requires that detailed criteria be used for performance demonstration tests. The results of 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. The
- 4 performance-based tests demonstrate the effectiveness of UT personnel and procedures.
Examinations are performed with the scanning requirements for ASME Code,Section XI, Appendix VIII, Supplements 4 and 6 that 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. The scanning requirements are: (1) for the examination of the inner 15 percent through-wall volume, scanning will be performed in four orthogonal directions to the maximum extent possible with procedures and personnel qualified to with ASME Code,Section XI, Appendix VIII, Supplement 4 or; (2) if the inner 15 percent through-wall volume examination is not possible as required above, the inner 15 percent through-wall volume is 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 ASME Code,Section XI, Appendix VIII, Supplement 4 and 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 procedures, equipment, and personnel qualified to ASME Code,Section XI, Appendix VIII have shown a high probability of flaw detection, and have increased the reliability of examinations of weld configurations within the scope of the POI program. Therefore, the NRC staff concludes that the proposed alternative will provide an acceptable level of quality and safety.
4.0 CONCLUSION
The NRC staff has reviewed the licensee's proposed alternative to apply ASME Code,Section XI, Appendix VIII examination requirements when volumetrically examining the RPV Shell-to Flange Weld by UT and concludes that the procedures, equipment, and personnel qualified to ASME Code,Section XI, Appendix VIII have shown a high probability of flaw detection, and have increased the reliability of examinations of weld configurations within the scope of the POI program. Therefore, the NRC staff finds that the proposed alternative will provide an acceptable level of quality and safety and authorizes the proposed alternative pursuant to 10 CFR 50.55a(a)(3)(i) for the IP3 third 10-year lSI interval.
All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in the subject requests for relief remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
Principal Contributor: T. McLellan Date:
April 20, 2009
- 2 If you have any questions regarding this approval, please contact the Indian Point Project Manager, John Boska, at (301) 415-2901.
Sincerely, IRA!
Douglas V. Pickett, Chief, Acting Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-286
Enclosure:
Safety Evaluation cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC LPL1-1 Reading File RidsNrrDciCsgb RidsOGCMailCenter RidsNrrDorlDpr RidsNrrDorlLpl1-1 RidsRgn1MailCenter RidsAcrsAcnw_MailCTR RidsNrrPMJBoska RidsNrrLASLittle (hard copy)
TMcLelian ADAMS ACCESSION NUMBER ML090920046 See memo dated 3/23/09 OFFICE LPL1-1/PM LPL1-1/LA CVIB/BC OGC LPL1-1/BC(A)
NAME JBoska SLittie MMitchell*
DRoth DPickett DATE 4/15/09 4/6/09 3/23/09 4/15/09 4/20/09 OFFICIAL RECORD COpy