ML070440059
| ML070440059 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/01/2007 |
| From: | Terao D NRC/NRR/ADRO/DORL/LPLIV |
| To: | Sheppard J South Texas |
| Thadani, M C, NRR/DORL/LP4, 415-1476 | |
| References | |
| RR-ENG-2-45, TAC MD3302, TAC MD3303 | |
| Download: ML070440059 (8) | |
Text
March 1, 2007 Mr. James J. Sheppard President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483
SUBJECT:
SOUTH TEXAS PROJECT, UNITS 1 AND 2 - REQUEST FOR RELIEF NO. RR-ENG-2-45 FOR REMAINDER OF SECOND 10-YEAR INSERVICE INSPECTION INTERVAL RE: USE OF PENETRAMETERS IN RADIOGRAPHIC EXAMINATION (TAC NOS. MD3302 AND MD3303)
Dear Mr. Sheppard:
The Nuclear Regulatory Commission (NRC) staff has reviewed and evaluated the information provided by South Texas Project Nuclear Operating Company (the licensee) in its letter dated June 14, 2006. The licensee requested the approval of Relief Request RR-ENG-2-45, for South Texas Project (STP), Units 1 and 2, in which the licensee requested relief from certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, pertaining to examinations in conjunction with licensees current second inservice inspection (ISI) interval. Specifically, the licensee requests use of wire-type penetrameters for radiographic examinations as provided in ASME Code,Section III, 1992 Edition with 1993 Addenda.
Based on the information provided in the licensees submittal, the NRC staff concludes that the licensee has provided an acceptable alternative to the requirements of ASME Code in relief request RR-ENG-2-45. The NRC staff concludes that the alternative proposed by the licensee provides an acceptable level of quality and safety. Therefore, pursuant to Title 10 of the Code of Federal Regulations, paragraph 50.55a(a)(3)(i), the alternative is authorized for the STP, Units 1 and 2, for the remainder of their second 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. The NRC staffs safety evaluation is enclosed.
Sincerely,
/RA/
David Terao, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
Enclosure:
Safety Evaluation cc: See next page
- No significant change to SE input.
OFFICE NRR/LPL4/PM NRR/LPL4/LA CNPB/BC OGC - NLO NRR/LPL4/BC NAME MThadani LFeizollahi TChan*
SHamrick DTerao DATE 2/16/07 2/15/07 1/16/07 2/28/07 3/1/07
March 2007 South Texas Project, Units 1 & 2 cc:
Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 289 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 J. J. Nesrsta/R. K. Temple E. Alercon/Kevin Pollo City Public Service Board P.O. Box 1771 San Antonio, TX 78296 INPO Records Center 700 Galleria Parkway Atlanta, GA 30339-3064 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Steve Winn/Christie Jacobs Eddy Daniels/Marty Ryan NRC Energy, Inc.
211 Carnegie Center Princeton, NJ 08540 Judge, Matagorda County Matagorda County Courthouse 1700 Seventh Street Bay City, TX 77414 A. H. Gutterman, Esq.
Morgan, Lewis & Bockius 1111 Pennsylvania Avenue, NW Washington, DC 20004 E. D. Halpin Site Vice President STP Nuclear Operating Company South Texas Project Electric Generating Station P.O. Box 289 Wadsworth, TX 77483 S. M. Head, Manager, Licensing STP Nuclear Operating Company P.O. Box 289, Mail Code: N5014 Wadsworth, TX 77483 C. T. Bowman General Manager, Oversight STP Nuclear Operating Company P.O Box 389 Wadsworth, TX 77483 Marilyn Kistler Sr. Staff Specialist, Licensing STP Nuclear Operating Company P.O. Box 289, Mail Code 5014 Wadsworth, TX 77483 Environmental and Natural Resources Policy Director P.O. Box 12428 Austin, TX 78711-3189 Jon C. Wood Cox, Smith, & Matthews 112 East Pecan, Suite 1800 San Antonio, TX 78205 Director Division of Compliance & Inspection Bureau of Radiation Control Texas Department of State Health Services 1100 West 49th Street Austin, TX 78756
March 2007 South Texas Project, Units 1 & 2 cc:
Mr. Ted Enos 4200 South Hulen Suite 422 Ft. Worth, TX 76109 Brian Almon Public Utility Commission William B. Travis Building P.O. Box 13326 1701 North Congress Avenue Austin, TX 78701-3326 Susan M. Jablonski Office of Permitting, Remediation and Registration Texas Commission on Environmental Quality MC-122 P.O. Box 13087 Austin, TX 78711-3087 Mr. Glenn Adler Senior Research Analyst Service Employees International Union 1313 L Street NW Washington, DC 20005 Ken Coates Plant General Manager STP Nuclear Operating Company South Texas Project Electric Generating Station P.O. Box 289 Wadsworth, TX 77483 Mr. Terry Parks, Chief Inspector Texas Department of Licensing and Regulation Boiler Division P.O. Box 12157 Austin, TX 78711
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION USE OF PENETRAMETERS IN RADIOGRAPHIC EXAMINATION STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT, UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499
1.0 INTRODUCTION
By letter dated June 14, 2006, South Texas Project Nuclear Operating Company (STPNOC, the licensee) submitted relief request RR-ENG-2-45 for South Texas Project (STP), Units 1 and 2, in which the licensee requested relief from certain requirements of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code). Specifically the licensee requested the use of an alternative to the nondestructive examination requirements applicable to repairs of ASME Class 1, 2, and 3 pipe welds. The licensee requested the use of wire-type penetrameters, or IQIs [image quality indicators] for radiographic examination as required in the ASME Code,Section III, 1992 Edition with 1993 Addenda.
2.0 REGULATORY EVALUATION
Inservice Inspections (ISI) of ASME Code Class 1, 2 and 3 components shall be performed in accordance with the requirements of Section XI of the ASME Code and applicable edition and addenda as required by Title 10 of the Code of Federal Regulations (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). Paragraph 50.55a(a)(3) of 10 CFR states in part that alternatives to the requirements of paragraph (g) may be used, when authorized by the Nuclear Regulatory Commission (NRC), if the licensee demonstrates that: (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, 3 components (including supports) shall meet the requirements, except the design and access provisions and the pre-service examination requirements, set forth in the ASME Code,Section XI, Rules for Inservice Inspection (ISI) 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 test 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) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The code of record for STP, Units 1 and 2, is the 1992 Edition of the ASME Code.
3.0 TECHNICAL EVALUATION
3.1 Component for which Relief is Requested The request for relief is applicable to ASME Code,Section XI, Class 1, 2, and 3 pipe welds.
3.2 ASME Code Requirements from which Relief is Requested (As Stated)
As noted in IWA-4120, ASME Section XI, 1989 Edition:
Repairs shall be performed in accordance with the Owner's Design Specification and the original Construction Code of the component or system. Later Editions and Addenda of the Construction Code or of Section III, either in their entirety or portions thereof, and Code Cases may be used.
In accordance with the provisions of 10 CFR 50.55a(a)(3)(i), STPNOC has been approved to use a system leakage test to detect leakage from welded repairs, fabrication welds for replacement parts and piping subassemblies, and welds for installation of replacement items in accordance with Code Case N-416-2 as an alternative to system hydrostatic testing required by IWA-4700. For a system leakage test to be used, Code Case N-416-2 requires performance of non-destructive examination in accordance with the methods and acceptance criteria of the applicable Subsection of the 1992 Edition of ASME Code,Section III, no Addenda.
ASME Section III, 1992 Edition includes the following:
Paragraph NB-5111 (ASME Class 1)
Radiographic examination shall be in accordance with Section V, Article 2, except that fluorescent screens are not permitted, the geometric unsharpness shall not exceed the limits of T-285, and the penetrameters of Table NB-5111-1 shall be used in lieu of those shown in Table T-276. [ASME Section V]
Table NB-5111-1 only refers to use of hole-type penetrameters; use of wire-type penetrameters is not addressed.
Paragraph NC-5111 (ASME Class 2) of ASME Section III, 1992 Edition Radiographic examination shall be in accordance with Section V, Article 2, except that fluorescent screens are not permitted, the geometric unsharpness shall not exceed the limits of T-285, and the penetrameters of Table NC-5111-1 shall be used in lieu of those shown in Table T-276. [ASME Section V]
Table NC-5111-1 only refers to use of hole-type penetrameters; use of wire-type penetrameters is not addressed.
3.3 Proposed Alternative Use of wire-type IQIs as incorporated into Tables NB-5111-1 (Class 1) and NC-5111-1 (Class 2) in the 1993 Addenda of the 1992 Edition of the ASME Code,Section III.
3.4 Licensees Basis for Alternative (As Stated)
Wire-type penetrameters provide the same function as hole-type penetrameters by indicating changes in thickness and spatial resolution of the image. The one-inch minimum length of the wire eliminates the problem of indicator loss due to distortion, anomalies, and part geometry that is commonly found with the target hole in plaque type penetrameters. For more complex configurations, wire-type penetrameters are superior in that placement is directly across the area of interest, encompassing the object's range of density and geometry without using shim blocks and pipe standards.
Wire-type penetrameters have shown sensitivity equivalent to that of hole-type penetrameters as documented in Table 4 of ASME Section V, Article 22, Standard SE-747. Because of its equivalent sensitivity, a wire-type penetrameter will provide results equivalent to those of a hole-type penetrameter. Therefore, the proposed alternative will maintain the quality of the examination results.
Penetrameter requirements for performing radiography are specified by Tables NB-5111-1 (ASME Class 1) and NC-5111-1 (ASME Class 2) of ASME Section III, 1992 Edition. Based on these tables, only hole-type penetrameters can be used. Wire-type penetrameters are not included in the 1992 Edition of
[ASME Code,] Section III. [In the 1992 Edition, 1993 Addenda] of ASME Section III, Tables NB-5111-1 and NC-5111-1 were revised to include wire-type penetrameter requirements. The 1992 Edition with 1993 Addenda of ASME
[Code,] Section III, includes the provision for use of equivalent wire-type penetrameters, [and] is endorsed by the NRC in 10 CFR 50.55a. Consequently, as of the 1993 Addenda to [ASME Code,] Section III. [The NRC staff has determined that] wire-type penetrameters are acceptable for use when performing radiography.
The proposed alternative to use wire-type image quality indicators for radiography examinations as provided for in ASME [Code,] Section III, 1992 Edition with 1993 Addenda, provides an acceptable level of quality and safety. Therefore, STPNOC requests that application of the proposed alternative at the South Texas Project be authorized pursuant to 10 CFR 50.55a(a)(3)(i).
4.0 EVALUATION STPNOCs use of a system leakage test in accordance with Code Case N-416-2; as an alternative to system hydrostatic testing as required by IWA-4700, ASME Code,Section XI; has been approved by the NRC staff. Code Case 416-2 requires the licensee to perform non-destructive examinations in accordance with the methods and acceptance criteria of the 1992 Edition of the ASME Code,Section III, no Addenda. The applicable subsections are NB-5111 and NC-5111, and Tables NB-5111-1 and NC-5111-1. Wire-type IQIs were not included in the ASME Code,Section III, until the 1992 Edition with 1993 Addenda. The 1992 Edition with 1993 Addenda of the ASME Code has been endorsed by the NRC in 10 CFR 50.55a, including the use of wire type IQIs.
Volume 17 of the Ninth Edition of the American Society of Materials (ASM) Handbook Series, published in 1989, states that wire-type penetrameters are widely used in Europe, and a standard design is used in the United Kingdom, Germany, the Netherlands, and Scandinavia.
The International Organization for Standardization and the International Institute of Welding have also adopted the wide use of wire-type penetrameters. Also, the handbook states that wire-type penetrameters specified in the American Society for Testing and Materials (ASTM) standard E 747-87 are widely used in the United States. The specifications in the handbook were developed in a public forum, and with public consensus. The ASTM Standard E 747-87 referenced in the ASM Handbook is identical to the 1989 Edition of ASMEs Standard SE-747-87.
Based on its previous endorsement of the1992 Edition with 1993 Addenda of the ASME Code, and the widespread use of wire-type penetrameters in industry, the NRC staff has determined that the wire-type penetrameters listed in Table NB-5111-1 (NC-5111-1) to the 1992 Edition with 1993 Addenda of the ASME Code will provide comparable density measurements; and, therefore, will provide an acceptable level of quality and safety.
5.0 CONCLUSION
Based on the above evaluation, the NRC staff concludes that the proposed alternative to use wire-type IQIs for radiography examinations as provided for in ASME Code,Section III, 1992 Edition with 1993 Addenda, provides an acceptable level of quality and safety.
Pursuant to 10 CFR 50.55a(a)(3)(i), the NRC staff authorizes the STPNOC to use the proposed alternative for the duration of the second 10-year ISI interval at South Texas Project, Units 1 and 2.
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: Isaac A. Anchondo Date: March 1, 2007