ML080280033
| ML080280033 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 02/14/2008 |
| From: | Mark Kowal NRC/NRR/ADRO/DORL/LPLI-1 |
| To: | Balduzzi M Entergy Nuclear Operations |
| Boska J, NRR, 301-415-2901 | |
| References | |
| TAC MD4702 | |
| Download: ML080280033 (13) | |
Text
February 14, 2008 Mr. Michael A. Balduzzi Sr. Vice President & COO Regional Operations, NE Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601
SUBJECT:
INDIAN POINT NUCLEAR GENERATING UNIT NO. 2 - RELIEF REQUEST (RR) NO. RR-07 ON EMBEDDED FLAW WELD REPAIR (TAC NO. MD4702)
Dear Mr. Balduzzi:
By letter dated February 28, 2007, as supplemented by letters dated August 15, 2007 and September 19, 2007, Entergy Nuclear Operations, Inc. (the licensee), submitted a relief request for Nuclear Regulatory Commission (NRC) approval. Specifically, the licensee is proposing to use an embedded flaw repair process as described in Westinghouse Topical Report WCAP-15987-P-A, Revision 2, "Technical Basis for the Embedded Flaw Process for Repair of Reactor Vessel Head Penetrations," as an alternative to repair the reactor vessel head penetrations in lieu of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) requirements at Indian Point, Unit 2 for the fourth 10-year inservice inspection interval.
Based on the information provided in the licensees submittal, the NRC staff concludes that pursuant to Title 10 of the Code of Federal Regulations, Section 50.55a(a)(3)(i), the licensee has proposed an acceptable alternative to the ASME Code requirements. The NRC safety evaluation is provided in the enclosure.
If you have any questions regarding this approval, please contact the Indian Point Project Manager, John Boska, at (301) 415-2901.
Sincerely,
/ra/
Mark G. Kowal, Chief Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-247
Enclosure:
Safety Evaluation cc w/encl: See next page
STurk MKowal DATE 2/14/08 1/31/08 12/12/07 2/12/08 2/14/08
Indian Point Nuclear Generating Unit No. 2 cc:
Mr. Michael R. Kansler President & CEO / CNO Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Mr. John T. Herron Sr. Vice President Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Sr. Vice President Engineering & Technical Services Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Mr. Fred R. Dacimo Site Vice President Entergy Nuclear Operations, Inc.
Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, NY 10511-0249 Mr. Anthony Vitale - Acting General Manager, Plant Operations Entergy Nuclear Operations, Inc.
Indian Point Energy Center 450 Broadway P.O. Box 249 Buchanan, NY 10511-0249 Mr. Oscar Limpias Vice President Engineering Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Mr. Joseph P. DeRoy Vice President, Operations Support Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Mr. John A. Ventosa GM, Engineering Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. John F. McCann Director, Nuclear Safety & Licensing Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Ms. Charlene D. Faison Manager, Licensing Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. Ernest J. Harkness Director, Oversight Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Mr. Patric W. Conroy Director, Nuclear Safety Assurance Entergy Nuclear Operations, Inc.
Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, NY 10511-0249 Mr. Robert Walpole Manager, Licensing Entergy Nuclear Operations, Inc.
Indian Point Energy Center 450 Broadway, GSB P. O. Box 249 Buchanan, NY 10511-0249 Mr. William C. Dennis Assistant General Counsel Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601
Indian Point Nuclear Generating Unit No. 2 cc:
Mr. Paul Tonko President and CEO New York State Energy, Research, and Development Authority 17 Columbia Circle Albany, NY 12203-6399 Mr. John P. Spath New York State Energy, Research, and Development Authority 17 Columbia Circle Albany, NY 12203-6399 Mr. Paul Eddy New York State Department of Public Service 3 Empire State Plaza Albany, NY 12223-1350 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Senior Resident Inspector=s Office Indian Point 2 U. S. Nuclear Regulatory Commission P.O. Box 59 Buchanan, NY 10511 Mr. Charles Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, NY 10271 Mr. Raymond L. Albanese Four County Coordinator 200 Bradhurst Avenue Unit 4 Westchester County Hawthorne, NY 10532 Mayor, Village of Buchanan 236 Tate Avenue Buchanan, NY 10511 Mr. William DiProfio PWR SRC Consultant 48 Bear Hill Road Newton, NH 03858 Mr. Garry Randolph PWR SRC Consultant 1750 Ben Franklin Drive, 7E Sarasota, FL 34236 Mr. William T. Russell PWR SRC Consultant 400 Plantation Lane Stevensville, MD 21666-3232 Mr. Jim Riccio Greenpeace 702 H Street, NW Suite 300 Washington, DC 20001 Mr. Phillip Musegaas Riverkeeper, Inc.
828 South Broadway Tarrytown, NY 10591 Mr. Mark Jacobs IPSEC 46 Highland Drive Garrison, NY 10524 Mr. Sherwood Martinelli FUSE USA via email
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR RELIEF NO. RR-07 ENTERGY NUCLEAR OPERATIONS, INC.
INDIAN POINT NUCLEAR GENERATING UNIT NO. 2 DOCKET NO. 50-247
1.0 INTRODUCTION
By letter dated February 28, 2007, as supplemented by letters dated August 15, 2007 and September 19, 2007, (Agencywide Documents Access and Management System (ADAMS)
Accession Numbers ML070640101, ML072330472, and ML072700460, respectively) Entergy Nuclear Operations, Inc. (Entergy or the licensee) submitted a request to the Nuclear Regulatory Commission (NRC) for approval of the fourth 10-year interval inservice inspection (ISI) plan for Indian Point Nuclear Generating Unit No. 2 (IP2). In the plan, the licensee requested NRC approval of Relief Request (RR) RR-07 to use an embedded flaw repair process as described in the Westinghouse Topical Report WCAP-15987-P-A, Revision 2, "Technical Basis for the Embedded Flaw Process for Repair of Reactor Vessel Head Penetrations," as an alternative to repair the reactor vessel head penetrations in lieu of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) requirements. This relief from the ASME Code requirements was requested on the basis that the proposed alternative provides an acceptable level of quality and safety.
2.0 REGULATORY EVALUATION
As specified in Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g), ISI of nuclear power plant 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. As stated in 10 CFR 50.55a(g)(5)(iii), if the licensee has determined that conformance with certain Code requirements is impractical for its facility, the licensee shall notify the Commission and submit, as specified in 10 CFR 50.4, information to support the determinations.
The information provided by the licensee in support of its relief request has been evaluated by the NRC staff, and the bases for disposition are documented below.
3.0 TECHNICAL EVALUATION
3.1 Licensees Relief Request RR-07 3.1.1 Components for Which Relief is Requested The reactor pressure vessel head (RPVH), which includes control rod drive mechanism (CRDM) penetrations (90), In-Core Instrumentation (ICI) penetrations (7), and one head vent penetration, is an ASME Code,Section III, Class 1 component.
3.1.2. Applicable Code Edition and Addenda The Code of Record for IP2 Fourth Inservice Inspection Interval is the ASME Code,Section XI, 2001 Edition including the 2003 Addenda.
The Reactor Vessel Construction Code is the ASME Code,Section III, 1965 Edition through Summer 1965 Addenda, including Code Cases 1332, 1335, 1339, and 1359.
3.1.3 Applicable Code Requirements I.
ASME Code,Section XI, 2001 Edition, with the 2003 Addenda:
ASME Code,Section XI, 2001 Edition with 2003 Addenda, paragraph IWA-4221 Construction Code and Owners Requirements states:
(a)
An item to be used for repair /replacement activities shall meet the Owners Requirements. Owners Requirements may be revised, provided they are reconciled in accordance with IWA-4222. Reconciliation documentation shall be prepared.
(b)
An item to be used for repair/replacement activities shall meet the Construction Code specified in accordance with (1), (2), or (3) below.
(1) When replacing an existing item, the new item shall meet the Construction Code to which the original item was constructed.
(2) When adding a new item to an existing system, the Owner shall specify a Construction Code that is no earlier than the earliest Construction Code used for construction of any system of any originally installed item in that system.
(3) When adding a new system, the Owner shall specify a Construction Code that is no earlier than the earliest Construction Code used for other systems that perform a similar function.
(c)
As an alternative to (b) above, the item may meet all or portions of the requirements of different Editions and Addenda of the Construction Code, or Section III when the Construction Code was not Section III, provided the requirements of IWA-4222 through IWA-4226, as applicable, are met.
Construction Code Cases may also be used. Reconciliation required by this article shall be documented.
ASME Section XI, IWA-4420 Defect Removal Requirements:
IWA-4421 General Requirements:
Defects shall be removed or mitigated in accordance with the following requirements:
(a)
Defect removal by mechanical processing1 shall be in accordance with IWA-4462.
(b)
Defect removal by thermal methods shall be in accordance with IWA-4461.
(c)
Defect removal or mitigation by welding or brazing shall be in accordance with IWA-4411 (d)
Defect removal or mitigation by modification shall be in accordance with IWA-4340 II.
Applicable Construction Code:
The applicable Construction Code is the ASME Code,Section III, 1965 Edition through Summer 1965 Addenda, including Code Cases 1332, 1335, 1339, and 1359.
III.
Base Metal Defect Repairs:
ASME Code,Section III, 1965 Edition through Summer 1965 Addenda Requirements:
N-320 Nondestructive Examination and Repairs of Materials:
Materials shall be examined by nondestructive methods applicable to the material and product form as required by the following rules:
N-321 Nondestructive Examination of Plates:
N-321.1 Nondestructive Examination (a)
Ultrasonic Inspection - All plates for reactor vessels as defined in subarticle N-131(a) and all plates 4 in. and over in nominal thickness for all other Class A vessels shall be ultrasonically examined in accordance with Specification SA-435. In the case of clad plates conforming to SA-263 or SA-264, this examination shall include inspection of the bond between the cladding and the base plate.
(b)
Reference Specimens - A reference specimen shall be used to calibrate the test equipment. The reference specimen shall be of the same nominal thickness and composition as the plate being examined, and it shall have a flat-bottom hole 1/2 in. in diameter and a depth of 10 percent of the material thickness for thicknesses over 2 in. and a depth of 25 percent of the material thickness for thicknesses of 2 in. or less.
(c)
Acceptance Standards - A defect from which one or more ultrasonic indications cause a loss of back reflection greater than the reference defect which is monitored during movement of the transducer 2 in. in any direction is unacceptable unless the defects are removed and the plate is repaired.
1 Mechanical processing refers to metal removal by mechanical means, e.g., grinding, machining, chipping.
N-321.2 Repair of Plates by Welding - The materials manufacturer may repair defects in plates by welding provided the following requirements are met:
(a)
Prior approval is obtained from the vessel manufacturer.
(b)
The depth of the defect does not exceed 1/4 of the nominal thickness.
(c)
The welding procedure and the welders or welding operators are qualified in accordance with Section IX of the ASME Code.
(d)
The defect is removed and the area prepared for repair is examined by a magnetic particle method in accordance with N-626 or by a liquid penetrant method in accordance with N-627.
(e)
The material is heat treated after repair as required by N-532.
(f)
The repaired area is examined by radiography in accordance with N-624 and by a magnetic particle method in accordance with N-626 or a liquid method in accordance with N-627, except that for defects whose depth did not exceed the lesser of 3/8 inch or 10 percent of the nominal thickness, no radiographic examination need be made.
(g)
The location and extent of the weld repair together with the repair procedure and examination results are recorded and transmitted as a part of the certification for purposes of N-514.2.
(h)
The procedure qualification test plate receives a heat treatment which will duplicate the heating rate, the total time at maximum temperature, and the cooling rate to be employed in fabrication in accordance with the general procedure outlined in N-313.1.
ASME Code,Section III, 2001 Edition, with the 2003 Addenda Requirements:
NB-4131 Elimination and Repair of Defects:
Material originally accepted on delivery in which defects exceeding the limits of NB-2500 are known or discovered during the process of fabrication or installation is unacceptable.
The material may be used provided the condition is corrected in accordance with the requirements of NB-2500 for the applicable product form except:
(a) the limitation on the depth of the weld repair does not apply; (b) the time of examination of the weld repairs to weld edge preparations shall be in accordance with NB-5130; (c) radiographic examination is not required for weld repairs to seal membrane material when the material thickness is 1/4 in. (6 mm) or less.
NB-2538 Elimination of Surface Defects:
Surface defects shall be removed by grinding or machining, provided the requirements of (a) through (d) below are met.
(a)
The depression, after defect elimination, is blended uniformly into the surrounding surface.
(b)
After defect elimination, the area is examined by the magnetic particle method in accordance with NB-2545 or the liquid penetrant method in accordance with NB-2546 to ensure that the defect has been removed or reduced to an imperfection of acceptable size.
(c)
Areas ground to remove oxide scale or other mechanically caused impressions for appearance or to facilitate proper ultrasonic testing need not be examined by the magnetic particle or liquid penetrant test method.
(d)
When the elimination of the defect reduces the thickness of the section below the minimum required to satisfy NB-3000, the product shall be repaired in accordance with NB-2539.
NB-2539.1 Defect Removal. The defect shall be removed or reduced to an imperfection of acceptable size by suitable mechanical or thermal cutting or gouging methods and the cavity prepared for repair.
NB-2539.4 Examination of Repair Welds. Each repair weld shall be examined by the magnetic particle method (NB-2545) or by the liquid penetrant method (NB-2546). In addition, when the depth of the repair cavity exceeds the lesser of 3/8 in. (10 mm) or 10% of the section thickness, the repair weld shall be radiographed after repair in accordance with NB-5110 and to the acceptance standards of NB-5520. The penetrameter and the acceptance standards for radiographic examination of repair welds shall be based on the section thickness at the repair area.
Analysis of the 1965 Edition, Summer 1965 Addenda and the 2001 Edition, w/2003 Addenda: there is no significant difference in the ASME Code requirements.
IV.
Weld Metal Defect Repairs ASME Code Section III, 1965 Edition through Summer 1965 Addenda Requirements:
N-528 Repair of Weld Defects:
N-528.1 Unacceptable defects detected visually or by the examination described in N-624, N-625, N-626, and N-627 and defects detected by leakage tests shall be removed by mechanical means or by thermal gouging processes, and appropriate nondestructive tests shall be performed to show to the satisfaction of the Inspector that the defect has been completely and satisfactorily removed.
N-528.2 The areas to be repaired shall be rewelded using qualified welding procedures and welders and the rewelded area shall be reexamined by the methods specified for the examination of the original weld to ensure that it has been satisfactorily repaired, except that if the depth of the deposit removed does not exceed the lesser of 3/8 in. or 10 percent of the weld thickness, the examination may be made by a magnetic particle method in accordance with N-626 or a liquid penetrant method in accordance with N-627. The post-weld heat-treating rules in N-532 shall apply to all weld repairs.
ASME Code,Section III, 2001 Edition, with 2003 Addenda Requirements:
NB-4451 General Requirements:
Defects in weld metal detected by the examinations required by NB-5000, or by the tests of NB-6000, shall be eliminated and repaired when necessary.
NB-4452 Elimination of Surface Defects:
Weld metal surface defects may be removed by grinding or machining, and need not be repaired by welding, provided that the requirements of (a) through (c) below are met.
(a)
The remaining thickness of the section is not reduced below that required by NB-3000.
(b)
The depression, after defect elimination, is blended uniformly into the surrounding surface.
(c)
The area is examined by a magnetic particle or liquid penetrant method in accordance with NB-5110 after blending and meets the acceptance standards of NB-5300 to ensure that the defect has been removed or reduced to an imperfection of acceptable limit. Defects detected by visual or volumetric method and located on an interior surface need only be reexamined by the method which initially detected the defect when the interior surface is inaccessible for surface examination.
NB-4453.1 Defect Removal:
Defects may be removed by mechanical means or by thermal gouging processes. The area prepared for repair shall be examined by a liquid penetrant or magnetic particle method in accordance with NB-5110, and meet the acceptance standards of NB-5340 or NB-5350. This examination is not required where defect elimination removes the full thickness of the weld and where the backside of the weld joint is not accessible for removal of examination materials.
Analysis of the 1965 Edition through Summer 1965 Addenda compared to the 2001 Edition with the 2003 Addenda: there is no significant difference in the ASME Code requirements.
3.1.4 Reason for Request Entergy will be performing reactor vessel head inspections during future refueling outages to meet the requirements of the NRC First Revised Order EA-03-009, dated February 20, 2004 (ADAMS accession number ML040220181). Entergy is requesting this relief as a contingency in the event that flaws requiring repair are identified during these inspections. The proposed embedded flaw process as described in WCAP-15987-P-A, Revision 2, which incorporates the NRC Safety Evaluation (SE), provides an acceptable alternative to repair reactor vessel head penetrations.
3.1.5 Proposed Alternative and Basis for Use Entergy proposes that the embedded flaw process as described in WCAP-15987-P-A, Revision 2, which incorporates the NRC SE issued on July 3, 2003 (ADAMS accession number ML031840237), be used as an alternative to repair reactor vessel head penetrations in lieu of the original construction code requirements, ASME Code,Section III, 1965 Edition through Summer 1965 Addenda, Subsections N-320 and N-528, and the requirements of ASME Code,Section III, 2001 Edition with the 2003 Addenda, Subsections NB-4131, NB-2538, NB-2539.1, NB-2539.4, NB-4451, NB-4452 and NB-4453.1 to eliminate base metal and weld metal defects prior to repair welding.
Basis for Use:
In the NRC SE, incorporated in WCAP-15987-P-A, Revision 2, the NRC staff concluded that, subject to the specified conditions and limitations, the embedded flaw process proposed in the WCAP provides an acceptable level of quality and safety. The NRC staff also concluded that the WCAP is acceptable for referencing in licensing applications.
The Westinghouse Topical Report WCAP-15987-P-A, Revision 2, is based on Section XI of the ASME Code, 1989 Edition. The generic relief, as documented in the WCAP report, was based on the 1989 Edition of the ASME Code because the requirements of this edition are the most limiting of all the allowable editions now in effect (e.g.: ASME Section III, 1965 Edition, Summer 1965 Addenda through 2001 Edition, 2003 Addenda). The considerations mentioned in the generic relief are essentially independent of any particular code edition, since they stand alone.
For these reasons, it is not necessary to reconcile to any other code edition. Also, the NRC has already approved the use of the generic relief for several plants.
The embedded flaw repair process is considered a permanent repair that will last through the useful life of the vessel head. As long as a primary water stress-corrosion cracking (PWSCC) flaw remains isolated from the primary water environment, the only known mechanism for any further potential propagation is fatigue. The calculated fatigue usage in this region is very low because the reactor vessel head region is isolated from the transients that affect the hot leg or cold leg piping.
The thickness of the weld used to embed the flaw has been designed to provide a permanent embedment of the flaw. The embedded flaw process imparts less residual stresses than would a weld repair following the complete removal of the flaw.
Since Alloy 52/152 (Alloy 690) weldment is considered highly resistant to PWSCC, a new PWSCC crack should not initiate and grow through the Alloy 52/152 overlay to reconnect the primary water environment with the embedded flaw. The resistance of the Alloy 690 material has been demonstrated by laboratory testing, and in over 12 years of operational service in steam generator tubes, where no PWSCC has been found.
The design, implementation of repairs, and inspections will be consistent with the information contained in Westinghouse Topical Report, WCAP-15987-P-A, Revision 2.
The embedded flaw repair overlay welds on the penetration J-groove welds will consist of a minimum of 3 deposited layers. The embedded flaw repair overlay welds on the inside diameter (ID) and the outside diameter (OD) of the penetration tube material will consist of a minimum of 2 deposited layers of weld, consistent with WCAP-15987-P-A, Revision 2, to minimize welding induced residual stresses and material distortion. In the case of repairs on the ID surface, the 2 layer approach results in a reduced inlay excavation depth.
Flaw identification methods include eddy-current (EC) and ultrasonic examination (UT) of the penetration tube and UT of the J-groove weld from the penetration tube ID side and EC of the J-groove weld from the J-groove weld surface. These are acceptable techniques for the inspection of the J-groove welds. The embedded flaw repairs for J-groove welds will be inspected manually or remotely by qualified nondestructive examination (NDE) personnel using qualified dye penetrant inspection procedures. The inspection methodology for embedded flaw repairs will be consistent with Westinghouse letter LTR-NRC-03-61, dated October 1, 2003 "Inspection of Embedded Flaw Repair of a J-Groove Weld" (ADAMS accession number ML032810457).
3.1.6 Duration of Proposed Alternative Relief is requested for the Fourth 10-Year interval (effective from March 1, 2007 through April 3, 2016). Entergy has submitted a license renewal application, which is currently under consideration by the NRC. The end date of the 4th Interval will be controlled by the Inservice Inspection Program Plan, commensurate with the NRCs action on the Operating License Renewal Application.
3.2
NRC Staff Evaluation
The NRC staff has reviewed Westinghouse Topical Report WCAP-15987-P, Revision 2. In a letter dated July 3, 2003 (ML031840237), the NRC staff stated the topical report is acceptable for referencing in licensing applications as an alternative to the 1989 Edition of Section III of the ASME Code, NB-4453.1 to the extent specified and under the limitations delineatedin the associated NRC safety evaluation (SE) The conditions and limitations from the NRC SE are as follows:
- 1. Licensees must follow the NRC flaw evaluation guidelines (provided in the R. J. Barrett (NRC) letter to A. Marion (Nuclear Energy Institute), Flaw Evaluation Guidelines, April 11, 2003 (ML030980322)).
- 2. The crack growth rate [referenced in WCAP-15987-P, Revision 2] is not applicable to Alloy 600 or Alloy 690 weld material, i.e., Alloy 52, 82, 152, and 182 filler material.
- 3. The NDE requirements listed in the table below must be implemented for examinations of repairs made using the embedded flaw process.
Table and Notes: NDE Requirements for Embedded Flaw Repairs (copied from the NRC safety evaluation for WCAP-15987-P, Revision 2, ML031840237)
Repair Location Flaw Orientation Repair Weld Repair NDE ISI NDE of the Repair, Note 2 VHP Nozzle ID Axial Seal UT and Surface UT or Surface VHP Nozzle ID Circumferential Note 1 Note 1 Note 1 VHP Nozzle OD above J-groove weld Axial or Circumferential Note 1 Note 1 Note 1 VHP Nozzle OD below J-groove weld Axial or Circumferential Seal UT or Surface UT or Surface J-groove weld Axial Seal UT and Surface Note 3 UT and Surface Note 3 J-groove weld Circumferential Seal UT and Surface Note 3 UT and Surface Note 3 VHP refers to Vessel Head Penetration Notes:
- 1. Repairs must be reviewed and approved separately by the NRC.
- 2. Inspection consistent with the NRC Order EA-03-009 dated February 11, 2003, and any subsequent changes.
- 3. Inspect with personnel and procedures qualified with UT performance-based criteria.
Examine the accessible portion of the repaired region. The UT coverage plus surface coverage must equal 100 percent.
The licensee stated that it will use this Westinghouse topical report including the conditions and limitations identified above to repair the reactor vessel head penetrations at IP2 for the fourth 10-year ISI interval.
The licensee stated that for the inspection of repaired penetration tubes, the EC and UT of the penetration tube and UT of the J-groove weld from the penetration tube ID side and EC of the J-groove weld from the J-groove weld surface will be performed. For the repaired J-groove welds, the inspection will be performed manually or remotely by qualified NDE personnel using qualified dye penetrant inspection procedures. The licensee also stated that the inspection methodology for the embedded flaw repairs will be consistent with Westinghouse Letter LTR-NRC-03-61, dated October 1, 2003, Inspection of Embedded Flaw Repair of a J-Groove Weld.
The NRC staff finds the licensee proposed flaw inspection methods acceptable because they satisfy the requirements and guidance previously approved by the NRC staff for the inspection of the embedded flaw repairs.
Therefore, the NRC staff finds the use of the reactor vessel head penetration repair methodology as described in WCAP-15987-P-A, Revision 2, in lieu of the ASME Code requirements acceptable at IP2 for the fourth 10-year interval.
4.0 CONCLUSION
Based on the above review, the NRC staff concludes that the licensees proposed alternative as stated in relief request RR-07 provides an acceptable level of quality and safety. Therefore, pursuant to 10CFR 50.55a(a)(3)(i), the NRC staff authorizes the use of the proposed alternative in lieu of the ASME Code flaw repair requirements at IP2 for the fourth 10-year ISI interval.
All other ASME Code,Section XI, requirements for which relief was not specifically requested and authorized herein by the NRC staff remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.
Principal Contributor: William H. Koo Date: February 14, 2008