ML080240029
| ML080240029 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Kewaunee, Surry, North Anna  |
| Issue date: | 02/25/2008 |
| From: | Melanie Wong NRC/NRR/ADRO/DORL/LPLII-1 |
| To: | Grecheck E Dominion Resources Services, Virginia Electric & Power Co (VEPCO) |
| Jervey, Richard 301-415-2728 | |
| References | |
| TAC MD6144, TAC MD6145, TAC MD6146, TAC MD6147, TAC MD6148, TAC MD6149, TAC MD6150 | |
| Download: ML080240029 (10) | |
Text
February 25, 2008 Mr. Eugene S. Grecheck Vice President - Nuclear Support Services Dominion Resources Services, Inc.
5000 Dominion Boulevard Glen Allen, VA 23060
SUBJECT:
RELIEF REQUEST FOR KEWAUNEE POWER STATION; MILLSTONE POWER STATION, UNIT NOS. 2 AND 3; NORTH ANNA POWER STATION, UNIT NOS.
1 AND 2; AND SURRY POWER STATION, UNIT NOS. 1 AND 2; REGARDING THE USE OF ASME CODE, SECTION III, DIVISION 1, CODE CASES N-756 AND N-757 (TAC NOS. MD6144, MD6145, MD6146, MD6147, MD6148, MD6149 AND MD6150)
Dear Mr. Grecheck:
By letter dated July 25, 2007, and supplemented by letters dated November 9, 2007, and January 24, 2008, Dominion Energy Kewaunee, Inc., Dominion Nuclear Connecticut, Inc., and Virginia Electric and Power Company (the licensees), submitted a request for U.S. Nuclear Regulatory Commission (NRC) approval to use the alternative rules of American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code (Code),Section III, Division 1, Code Cases N-756 and N-757 for Kewaunee Power Station, Millstone Power Station, Unit Nos.
2 and 3, North Anna Power Station, Unit Nos. 1 and 2, and Surry Power Station, Unit Nos. 1 and
- 2. The licensees agreed to withdraw the request for Code Case N-756 in their letter of January 24, 2008.
The use of Code Case N-757 is authorized subject to conditions identified in the enclosed safety evaluation. If you have any questions regarding this matter, I may be reached at 301-415-2911.
Sincerely,
/RA/
Melanie C. Wong, Acting Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-305, 50-336, 50-423, 50-338, 50-339, 50-280, and 50-281 cc w/encl: See next page
- transmitted by memo dated OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRR/DE/EMCB/BC OGC NRR/LPL2-1(A)BC NAME RJervey MO=Brien KManoly*
DRoth MWong DATE 02/ 20/08 02/ 20/08 01/18/2008 02/13 /08 02/ 25/08 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING PROPOSED USE OF ASME CODE CASES N-756 AND N-757 KEWAUNEE POWER STATION MILLSTONE POWER STATION, UNIT NOS. 2 AND 3 NORTH ANNA POWER STATION, UNIT NOS. 1 AND 2 SURRY POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-305, 50-336, 50-423, 50-338, 50-339, 50-280 AND 50-281
1.0 INTRODUCTION
By letter dated July 25, 2007 (Agencywide Documents Acess and Management System (ADAMS) Accession No. ML072070354), Dominion Resources Services, Inc., representing Dominion Energy Kewaunee, Inc., Dominion Nuclear Connecticut, Inc., and Virginia Electric and Power Company (the licensees), requested approval to use American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code (ASME Code),Section III, Division 1, Code Cases N-756 and N-757. The licensees responded to the Nuclear Regulatory Commission (NRC) staffs request for additional information (RAI) by letters dated November 9, 2007 (ADAMS Accession No. ML073170675), and January 24, 2008 (ADAMS Accession No. ML080240322). The request involves small replacement valves at Kewaunee Power Station, Millstone Power Station, Unit Nos. 2 and 3, North Anna Power Station, Unit Nos. 1 and 2, and Surry Power Station, Unit Nos. 1 and 2. The request was to allow the use of the two code cases which have recently been approved by ASME, but have not yet been endorsed by the NRC in Regulatory Guide (RG) 1.84. These code cases allow for replacement of small (one-inch nominal pipe size (NPS) and smaller) welded end valves with non-welded end valves.
2.0 REGULATORY REQUIREMENTS The inservice inspection (ISI) of the ASME Code Class 1, 2, and 3 components in operating nuclear plants is to be performed in accordance with the ASME Code,Section XI and applicable edition and addenda as required by Part 50, Section 50.55a(g) Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 50.55a(g), except where specific relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i).
The regulation at 10 CFR 50.55a(a)(3) states:
Proposed alternatives to the requirements of paragraphs (c), (d), (e), (f), (g), and (h) of this section or portions thereof may be used when authorized by the Director of the Office of Nuclear Reactor Regulation. The applicant shall demonstrate that: (i)The proposed alternatives would provide an acceptable level of quality and safety, or (ii) Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Section 50.55a(b) provides ASME Code editions and addenda approved for design and construction of components in nuclear power plants. Section 50.55a(b)(4) states that licensees may apply the ASME Boiler and Pressure Vessel Code cases listed in NRC Regulatory Guide 1.84, Revision 33, without prior approval subject to the conditions listed in that section. RG 1.84 is periodically updated to accommodate new code cases and revisions to existing code cases, but has not yet endorsed Code Cases N-756 and N-757.
3.0 TECHNICAL EVALUATION
Code Cases N-756, Alternate Rules for Acceptability for Class 1 Valves NPS 1 (DN 25) and Smaller With Nonwelded End Connections Other Than FlangesSection III, Division 1, and N-757, Alternative Rules for Acceptability for Class 2 and 3 Valves, NPS1 (DN 25) and Smaller With Welded and Nonwelded End Connections Other Than FlangesSection III, Division 1, provide alternative rules to determine the acceptability of one inch and smaller NPS with end connections such as compression fittings. The licensees indicated that the reason for the request was to reduce personnel radiation exposure for applicable Class 1 valve replacements and for some Class 2 valve replacements. Installation of valves with compression fittings could be performed much more quickly than installation of welded end valves.
The ASME Code requirements for the design of valves are contained in Articles NB-3500, NC-3500 and ND-3500 for ASME Class 1, 2 and 3 valves, respectively. The standard design rules require that the minimum wall thickness satisfies the thickness requirements specified in the valve standard ASME B16.34, Valves - Flanged, Threaded, and Welding End. Articles NB-3500, NC-3500 and ND-3500 provide two alternative design procedures. The alternative design procedures allow a detailed evaluation of the valve body stresses to demonstrate that the ASME Code allowable stress limits have been satisfied. However, these alternate rules only apply to valves with welded end connections. Code Cases N-756 and N-757 specify the use of the alternate rules of Articles NB-3500, NC-3500 and ND-3500 for non-welded end connections in the design of small valves. As an alternate, the ASME Code provides design rules for use of non-welded connections, such as compression fittings, in Articles NB-3600, NC-3600 and ND-3600 for piping design. Code Cases N-756 and 757 require that the valve ends meet the requirements in Articles NB-3600, NC-3600 and ND-3600.
ASME Code Case N-757 applies to both ASME Class 2 and Class 3 valves. These valves are typically qualified using the minimum thickness requirements in the design standard ASME B16.34. The code case provides three options for a more detailed design of Class 2 and 3 valves that do not meet the minimum thickness requirements in ASME B16.34. These options include the pressure design rules of NC/ND-3324, experimental stress analysis in Section III, Appendix II; or design based on stress analysis in Section III, Appendix XIII. The staff finds that the first option provides an acceptable alternative basis for the design of ASME Code Class 2 and 3 valves because it provides adequate design margin by using the vessel design rules accepted by the staff in 10 CFR 50.55a. The staff also finds the second option provides an acceptable basis for the design of ASME Code Class 2 and 3 valves because it allows the designer to use experimental stress analysis techniques to establish that the design provides acceptable ASME Code margin for parts in which theoretical stress analysis might not be possible or practical. The third option allows the designer to use criteria provided in Section III, Division 1, Appendix XIII. Appendix XIII provides for design based on stress analysis which uses criteria similar to those used for the design of ASME Code Class 1 components, including the ASME Code Class 1 stress intensity allowable limits. However, as defined by the scope, Appendix XIII is only applicable to the design of Code Class 2 vessels meeting the requirements of NC-3200. Appendix XIII uses ASME Code Class 1 design stress intensity values in the acceptance criteria which are greater than the allowable stress values specified for the design of ASME Code Class 3 components. As a consequence, the staff concludes that the Appendix XIII criteria are not intended for the design of ASME Code Class 3 components, including the valves within the scope of N-757. In telephone discussions related to RAI on December 19, 2007, the licensees agreed to this limitation within their request.
In the NRC staffs RAI dated September 4, 2007, (ADAMS Accession No. ML072480014) the staff requested that the licensees: (1) describe the procedures that will be used for the installation of these non-welded valves, and, (2) provide a certified design report for the use of a typical Class 1 replacement valve. In its response of November 9, 2007 (ADAMS Accession No. ML073170675), the licensees identified that training and/or procedures were used for the installation of the non-welded valves that address the operating experience described in Information Notice (IN) 92-15 and IN 84-55 except at Kewuanee Power Station, which only had applicable training. The specific provisions addressed in the procedures include: a) not mixing the parts from one manufacturer to another, b) following manufacturer=s recommended instructions for installing compression fittings, and c) the training or familiarity with the procedure(s) for personnel doing the work. The licensees also committed to develop procedures for Kewuanee prior to the use of non-welded valves with end connections other than flanges. The staff finds that the licensee=s use of procedures, and/or training is adequate to address the operating experience described in IN 92-15 and IN 84-55.
The licensees also provided a design report template for the Code Class 1 application which was the topic of discussion during a conference call with the staff on January 10, 2008. The licensees discussed that a certified design report currently was not available for the Code Class 1 application. The licensees agreed to withdraw the request for approval of Code Case N-756 until such time as the code case is needed or the staff endorses the code case in its update of RG 1.84. The licensees withdrawal of the Class 1 alternative (Code Case N-756) was made by letter dated January 24, 2008.
4.0 CONCLUSION
On the basis of the above evaluation, the NRC staff concludes that the proposed use of ASME Code Case N-757 provides an acceptable level of quality and safety, and is acceptable for use, subject to the condition that the design provisions of ASME Code,Section III, Division 1, Appendix XIII not be used for the design of Code Class 3 valves. Therefore, subject to the condition stated above, the proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i). The use of Code Case N-757 is authorized until such time as the code case is published in a future version of RG 1.84. At that time, if the licensees intend to continue implementing this code case, it must follow all provisions of Code Case N-757 with conditions as specified in RG 1.84 and limitations as specified in 10 CFR 50.55a(b)(4).
Principal Contributor: John Fair Date: February 25, 2008
Kewaunee Power Station, Millstone Power Station, Units 2 and 3, North Anna Power Station, Unit Nos. 1 and 2, and Surry Power Station, Unit Nos. 1 & 2 cc:
Mr. David A. Christian President and Chief Nuclear Officer Virginia Electrical and Power Company Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711 Ms. Lillian M. Cuoco, Esq.
Senior Counsel Dominion Resources Services, Inc.
120 Tredegar Street, RS-2 Richmond, VA 23219 Mr. Donald E. Jernigan Site Vice President Surry Power Station Virginia Electric and Power Company 5570 Hog Island Road Surry, Virginia 23883-0315 Senior Resident Inspector Surry Power Station U. S. Nuclear Regulatory Commission 5850 Hog Island Road Surry, Virginia 23883 Chairman Board of Supervisors of Surry County Surry County Courthouse Surry, Virginia 23683 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23218 Dr. Robert B. Stroube, MD, MPH State Health Commissioner Office of the Commissioner Virginia Department of Health Post Office Box 2448 Richmond, Virginia 23218 Office of the Attorney General Commonwealth of Virginia 900 East Main Street Richmond, Virginia 23219 Mr. Chris L. Funderburk, Director Nuclear Licensing & Operations Support Dominion Resources Services, Inc.
Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, Virginia 23060-6711 Mr. C. Lee Lintecum County Administrator Louisa County Post Office Box 160 Louisa, Virginia 23093 Old Dominion Electric Cooperative 4201 Dominion Blvd.
Glen Allen, Virginia 23060 Senior Resident Inspector North Anna Power Station U. S. Nuclear Regulatory Commission P. O. Box 490 Mineral, Virginia 23117 Mr. Daniel G. Stoddard Site Vice President North Anna Power Station Virginia Electric and Power Company Post Office Box 402 Mineral, Virginia 23117-0402 Mr. Mark D. Sartain, Director Nuclear Safety & Licensing Virginia Electric and Power Company North Anna Power Station P. O. Box 402 Mineral, VA 23117
Kewaunee Power Station, Millstone Power Station, Units 2 and 3, North Anna Power Station, Unit Nos. 1 and 2, and Surry Power Station, Unit Nos. 1 & 2 cc:
Edward L. Wilds, Jr., Ph.D.
Director, Division of Radiation Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 First Selectmen Town of Waterford 15 Rope Ferry Road Waterford, CT 06385 Charles Brinkman, Director Washington Operations Nuclear Services Westinghouse Electric Company 12300 Twinbrook Pkwy, Suite 330 Rockville, MD 20852 Senior Resident Inspector Millstone Power Station c/o U.S. Nuclear Regulatory Commission P. O. Box 513 Niantic, CT 06357 Mr. J. W. "Bill" Sheehan Co-Chair NEAC 19 Laurel Crest Drive Waterford, CT 06385 Ms. Nancy Burton 147 Cross Highway Redding Ridge, CT 00870 Mr. Evan W. Woollacott Co-Chair Nuclear Energy Advisory Council 128 Terrys Plain Road Simsbury, CT 06070 Mr. Joseph Roy Director of Operations Massachusetts Municipal Wholesale Electric Company P.O. Box 426 Ludlow, MA 01056 Mr. William D. Bartron Licensing Supervisor Dominion Nuclear Connecticut, Inc.
Building 475, 5th Floor Roper Ferry Road Waterford, CT 06385 Mr. J. Alan Price Site Vice President Dominion Nuclear Connecticut, Inc.
Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385 Ms. Leslie N. Hartz Dominion Energy Kewaunee, Inc.
Kewaunee Power Station N 490 Highway 42 Kewaunee, WI 54216 Resident Inspectors Office U. S. Nuclear Regulatory Commission N490 Highway 42 Kewaunee, WI 54216-9510 Mr. Thomas L. Breene Dominion Energy Kewaunee, Inc.
Kewaunee Power Station N490 Highway 42 Kewaunee, WI 54216 Mr. David H. Peace Swagelok Company 29450 F. A. Lennon Drive Solon, Ohio 44139