ML070920029

Request for Relief from ASME Code Regarding Weld Reference System, Relief Request No. RR 4-11

ML070920029
Person / Time
Site:	Palisades
Issue date:	04/30/2007
From:	Raghavan L NRC/NRR/ADRO/DORL/LPLIII-1
To:	Harden P Nuclear Management Co
B. Singal
References
TAC MD2414
Download: ML070920029 (7)

Text

April 30, 2007 Mr. Paul A. Harden Site Vice President Nuclear Management Company, LLC Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530

SUBJECT:

PALISADES NUCLEAR PLANT - REQUEST FOR RELIEF FROM ASME CODE, SECTION XI, IWA-2600, WELD REFERENCE SYSTEM, RELIEF REQUEST NO. RR 4-11 (TAC NO. MD2414)

Dear Mr. Harden:

By letter dated June 12, 2006, Nuclear Management Company, LLC requested relief from selected American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI requirements related to the qualifications for examination of pressure retaining welds in piping at Palisades Nuclear Plant (PNP). Specifically, Nuclear Management Company, LLC proposed an alternative to the required weld reference system outlined under paragraph IWA-2600 of the ASME Code,Section XI.

The Nuclear Regulatory Commission staff has reviewed your proposed alternative to the ASME Code Section XI requirements for establishment of a weld reference system as stated in IWA-2600 of ASME Code,Section XI, and determined that compliance with the Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Further, the proposed alternative provides reasonable assurance of structural integrity. Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the alternative proposed in Relief Request No. RR 4-11 is authorized for the fourth 10-year inservice inspection interval at PNP.

Sincerely,

/RA by Thomas H. Boyce for/

L. Raghavan, Chief Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255

Enclosure:

Safety Evaluation cc w/encl: See next page

April 30, 2007 Mr. Paul A. Harden Site Vice President Nuclear Management Company, LLC Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530

SUBJECT:

PALISADES NUCLEAR PLANT - REQUEST FOR RELIEF FROM ASME CODE, SECTION XI, IWA-2600, WELD REFERENCE SYSTEM, RELIEF REQUEST NO. RR 4-11 (TAC NO. MD2414)

Dear Mr. Harden:

By letter dated June 12, 2006, Nuclear Management Company, LLC requested relief from selected American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI requirements related to the qualifications for examination of pressure retaining welds in piping at Palisades Nuclear Plant (PNP). Specifically, Nuclear Management Company, LLC proposed an alternative to the required weld reference system outlined under paragraph IWA-2600 of the ASME Code,Section XI.

The Nuclear Regulatory Commission staff has reviewed your proposed alternative to the ASME Code Section XI requirements for establishment of a weld reference system as stated in IWA-2600 of ASME Code,Section XI, and determined that compliance with the Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Further, the proposed alternative provides reasonable assurance of structural integrity. Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the alternative proposed in Relief Request No. RR 4-11 is authorized for the fourth 10-year inservice inspection interval at PNP.

Sincerely,

/RA by Thomas H. Boyce for/

L. Raghavan, Chief Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255

Enclosure:

Safety Evaluation cc w/encl: See next page DISTRIBUTION:

PUBLIC LPL3-1 R/F RidsNrrPMMChawla RidsNrrLATHarris RidsNrrDorlLpl3-1 RidsOgcRp RidsAcrsAcnwMailCenter RidsNrrDorlDpr AHiser, NRR CLipa, RGN-III RidsRgn3MailCenter RidsNrrPMBSingal TBloomer, EDO, Rgn III ADAMS Accession Number: ML070920029

• Safety Evaluation dated: April 2, 2207 OFFICE NRR/LPL2-1/PM NRR/LPL3-1/PM NRR/LPL3-1/LA DCI/CSGB OGC NRR/LPL3-1/BC NAME *BSingal:ca MChawla THarris AHiser* *JRund LRaghavan DATE 04/25/07 04/30/07 04/26/07 4/2/2007 04/23/07 04/30/07 OFFICIAL RECORD COPY

Palisades Plant cc:

Robert A. Fenech, Senior Vice President Michael B. Sellman Nuclear, Fossil, and Hydro Operations President and Chief Executive Officer Consumers Energy Company Nuclear Management Company, LLC 1945 Parnall Rd. 700 First Street Jackson, MI 49201 Hudson, MI 54016 Arunas T. Udrys, Esquire Jonathan Rogoff, Esquire Consumers Energy Company Vice President, Counsel & Secretary 1 Energy Plaza Nuclear Management Company, LLC Jackson, MI 49201 700 First Street Hudson, WI 54016 Regional Administrator, Region III U.S. Nuclear Regulatory Commission Douglas E. Cooper Suite 210 Senior Vice President and 2443 Warrenville Road Chief Nuclear Officer Lisle, IL 60532-4351 Nuclear Management Company, LLC 700 First Street Supervisor Hudson, WI 54016 Covert Township P. O. Box 35 Stephen T. Wawro, Director Covert, MI 49043 of Nuclear Assets Consumers Energy Company Office of the Governor Palisades Nuclear Plant P. O. Box 30013 27780 Blue Star Memorial Highway Lansing, MI 48909 Covert, MI 49043 U.S. Nuclear Regulatory Commission Laurie A. Lahti, Manager Resident Inspector's Office Regulatory Affairs Palisades Plant Nuclear Management Company, LLC 27782 Blue Star Memorial Highway Palisades Nuclear Plant Covert, MI 49043 27780 Blue Star Memorial Highway Covert, MI 49043 Michigan Department of Environmental Quality Waste and Hazardous Materials Division Hazardous Waste and Radiological Protection Section Nuclear Facilities Unit Constitution Hall, Lower-Level North 525 West Allegan Street P.O. Box 30241 Lansing, MI 48909-7741 Michigan Department of Attorney General Special Litigation Division 525 West Ottawa St.

Sixth Floor, G. Mennen Williams Building Lansing, MI 48913

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE WELD REFERENCE SYSTEM FOURTH 10-YEAR INSERVICE INSPECTION INTERVAL RELIEF REQUEST NO. RR 4-11 PALISADES NUCLEAR PLANT NUCLEAR MANAGEMENT COMPANY, LLC DOCKET NO. 50-255

1.0 INTRODUCTION

By letter dated June 12, 2006 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML061710216), Nuclear Management Company, LLC (the licensee),

requested relief from American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI requirements related to the establishment of the weld reference system. In Relief Request No. RR 4-11, the licensee proposed an alternative to the recommended weld reference system outlined under paragraph IWA-2600 of the ASME Code,Section XI, 2001 edition with addenda through 2003, for the fourth 10-year inservice inspection (ISI) interval for the Palisades Nuclear Plant (PNP). The fourth ISI interval started on December 13, 2006.

2.0 REGULATORY EVALUATION

Paragraph 50.55a(g) of Title 10 of the Code of Federal Regulations requires that ISI of ASME Code Class 1, 2, and 3 components be performed in accordance with Section XI of the ASME Code and applicable addenda. According to 10 CFR 50.55a(a)(3), alternatives to the requirements of paragraph 50.55a(g) may be used, when authorized by the Nuclear Regulatory Commission, if an applicant demonstrates that the proposed alternatives would provide an acceptable level of quality and safety or if the specified requirement 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 (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 ISI 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) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The ISI Code of Record for the fourth 10-year inspection interval for the PNP is the 2001 edition through the 2003 addenda of the ASME Code,Section XI.

The licensee submitted the request, pursuant to 10 CFR 50.55a(a)(3)(i), as a proposed alternative to the implementation of ASME Code Section XI, IWA-2600 for the fourth 10-year ISI interval.

3.0 TECHNICAL EVALUATION

3.1 Code Requirements for which Relief is Requested The 2001 edition through the 2003 addenda of ASME Code,Section XI, subparagraph IWA-2610 General states that a reference system shall be established for all welds and areas subject to surface or volumetric examination. Each such weld or area shall be located and identified by a system of reference points. The system shall permit identification of each weld, location of each weld centerline, and designation of regular intervals along the length of the weld. Subparagraph IWA-2620 Piping refers to requirements outlined in Article III-4300 and subparagraph IWA-2630 Vessels accepts requirements of Appendix A of Article 4 for vessels examined in accordance with Article 4 of ASME Code,Section V. With regard to ultrasonic examination of piping, Article III-4000 Examination states in paragraph III-4320 Marking that low stress stamps or vibratooling, or both may be used to permanently identify each weld.

Marking applied shall not be deeper than 3/64 inch. Paragraph III-4330 Reference System states that a reference system shall be established to locate the search unit along the seam and to determine the weld centerline. Circumferential and longitudinal welds requiring volumetric examination shall be marked once before or during the pre-service examination to establish a reference point.

The licensee requested relief from the marking requirement of the ASME Code based on the proposed alternate weld reference system.

3.2 System/Component(s) for which Relief is Requested The requested relief from the ASME Code,Section XI, IWA-2600 requirements applies to the ISI examination of piping, vessel, and component welds.

3.3 Licensees Basis for Requesting Relief The original construction code used at PNP did not require that a weld reference system be established. Establishment of a weld reference system in accordance with the ASME Code,Section XI, IWA-2600, cannot be practically attained within the scope and schedule of existing outages. Hence, the licensee has proposed the use of an alternative weld reference system in Relief Request No. RR 4-11.

3.4 Licensees Proposed Alternative At PNP, the licensee has been using isometric drawings to provide a detailed identification and location of each weld requiring examination. In addition, the licensee has proposed to perform the surface and volumetric examinations as described below:

Surface Examination - Where surface examination is specified, ASME Section XI Code requires that 100 percent of the selected weld or area be examined. Unlike the performance of volumetric examination, there is no need to indicate the direction of examination to assure uniformity of reporting results. In these cases, no marks will be placed on the weld or area.

The location of any accepted surface indications will be documented by the use of a map or photograph that permits accurate identification of areas on the examination surface.

Volumetric Examination (Manual) - If a weld containing volumetric indications is accepted for continued service under the acceptance criteria of IWX-3500 or IWX-3600, it shall be identified using appropriate reference marks to ensure that it is relocatable. These reference marks may be permanently fixed on the weld or by documentation on a map or photograph of the weld or surface that permits accurate identification of areas on the examination surface (e.g., reference points, orientation and/or proximity to other welds) to positively identify the weld or area in question and the examination starting point. The starting point is determined from the instructions provided for determining the location of the zero reference point.

Volumetric Examination (Automated Vessel) - The automated vessel tool establishes its reference point using an existing zero reference point on the reactor vessel. This point allows the device to repeat examination locations without the necessity of any other reference system.

The tool determines its location by the use of an electronic encoder system which provides for sufficient repeatability.

3.5 Staff Evaluation The weld reference system stated under subparagraph IWA-2610 of the ASME Section XI Code, 2001 edition with addenda through 2003 requires identification of each weld for ISI, location of its centerline, and designation of regular intervals along the length of the weld to ensure repeatability of the examination. The Code requires that each weld be permanently identified by marking on the weld using low stress stamps or vibratooling or both. In order to comply with the requirement of the Code, the licensee must access each and every weld within the ISI boundary to establish permanent markings. The licensee has stated that the requirement of the Code cannot be met practically, and has proposed an alternative to the weld reference system stated under paragraph IWA-2600 of the Code. In lieu of marking weld identification on each weld, PNP will provide a detailed identification and location of each weld requiring examination on isometric drawing. If a weld is found to contain an indication during ISI, appropriate reference marks shall be put on the weld to repeat future examination of the weld. The licensee will further document such indications on a weld map or with photograph(s) of the weld that will assist in identifying any indication in relation to the examination starting point and the area on the examination surface (e.g., reference points, orientation and/or proximity to other welds) of the weld. The NRC staff is aware that the majority of welds within the ISI boundary are covered under insulation and to access them for the purpose of putting the required marking would be a labor intensive effort and is associated with high radiation exposure to personnel. Therefore, the staff concludes that compliance to the Code requirement would result in hardship to the licensee. The staff further believes that the licensees proposed alternative to the weld reference system would attain the same objective of ensuring repeatability of examination if indications are found during examination and, therefore, compliance with the Code requirement would not result in an increase in the level of quality and safety. Accordingly, the staff has determined that establishment of a weld reference system in

accordance with paragraph IWA-2600, for all welds within ISI boundary would result in hardship to the licensee without a compensating increase in the level of quality and safety.

4.0 CONCLUSION

The NRC staff concludes that compliance to the ASME Code requirement to establish a weld reference system as stated under paragraph IWA-2600 of the ASME Code,Section XI would result in hardship without a compensating increase in the level of quality and safety. The staff has determined that the licensees proposed alternative to the weld reference system would attain the same objective of ensuring repeatability of examination if indications are found during examination and, therefore, provides reasonable assurance of structural integrity. Pursuant to 10 CFR 50.55a(a)(3)(ii), the proposed alternative in Relief Request No. RR 4-11 is authorized for the fourth 10-year ISI interval of PNP. All other requirements of the ASME Code,Section XI for which relief has not been specifically requested and approved remain applicable, including a third party review by the Authorized Nuclear Inservice Inspector.

Principal Contributor: Pat Patnaik Date: April 30, 2007