ML051010196

ASME Section XI Relief Request Alternative Acceptance Criteria for Surface Examinations

ML051010196
Person / Time
Site:	Surry
Issue date:	04/11/2005
From:	Grecheck E Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
05-225
Download: ML051010196 (7)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND,VIRGINIA 23261 A p r i l 11, 2005 U.S. Nuclear Regulatory Commission Serial No.05-225 Attention: Document Control Desk NL&OS/GDM R1 Washington, D.C. 20555 Docket No. 50-281 License No. DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

SURRY POWER STATION UNIT 2 ASME SECTION XI RELIEF REQUEST ALTERNATIVE ACCEPTANCE CRITERIA FOR SURFACE EXAMINATIONS The ASME Section XI Code permits required inservice inspection (ISI) interval examinations to be completed within a grace period of one-year beyond the end of the interval to accommodate outage scheduling. Surry Power Station Unit 2 is presently in the one year extension period of the third ten-year IS1 interval and uses the 1989 Edition of ASME Section XI as the basis for the IS1 Program.

The ASME Code includes surface examination requirements for pump casing welds.

The Outside Recirculation Spray (ORS) pumps and the Low Head Safety Injection (LHSI) pumps are subject to these requirements. However, the ORS and LHSl pumps casing design is atypical. These pumps are vertical, two-stage, centrifugal pumps with extended shafts and casings. These pump casings extend subgrade for more than 40 feet, and the pump column casings consist of bolted flange sections made from austenitic stainless steel pipe. Due to the unique pump design, the specified code examination acceptance criteria are not appropriate. Therefore, a relief request for the Surry Unit 2 ORS and LHSl pumps is attached that requests the use of alternative examination acceptance criteria that are more suitable for the pump casing welds.

In accordance with 10 CFR 50.55a(a)(3)(i), Dominion submits herein for NRC review and approval Surry Unit 2 Relief Request SR-38 for the ORS and LHSI pumps.

If you have any questions or require additional information, please contact Mr. Gary D.

Miller at (804) 273-2771.

Very truly yours, n

E. S. Grecheck Vice President - Nuclear Support Services Attachment

Serial No.05-225 Docket No. 50-281 Page 2 of 2 Commitments made by this letter: None cc: U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23 T85 Atlanta, GA 30303-3415 Mr. S. R. Monarque U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 8H12 Rockville, MD 20852 Mr. N. P. Garrett NRC Senior Resident Inspector Surry Power Station Mr. R. A. Smith Authorized Nuclear Inspector Surry Power Station

Attachment Serial No.05-225 Third Ten Year Interval Relief Request SR-38 Alternative Requirements for the Acceptance Criteria for Surface Examinations on Class 2 Austenitic Stainless Steel Pump Casing Welds Virginia Electric & Power Company (Dominion)

Surry Power Station Unit No. 2

Serial No.05-225 Docket No. 50-281 Relief Reauest SR-38 (Unit 21 Surrv Power Station Third Ten Year Interval Alternative Requirements for the AcceDtance Criteria of Surface Examinations on Class 2 Austenitic Stainless Steel PumD Casina Welds I. ldentification of Components Systems: Recirculation Spray (RS) and Safety Injection (SI)

Components: ASME Class 2 Austenitic Stainless Steel Pump Casing Welds Surrv ComDonent Drawinq Weld Number 2- RS-P-2A 11548-WMKS-RS-P-2A Pump shaft casing welds*

2- RS-P-26 11548-WMKS-RS-P-26 Pump shaft casing welds*

2-SI-P-1A 11548-WMKS-SI-P-1A Pump shaft casing welds*

2-SI-P-1B 11548-WMKS-SI-P-16 Pump shaft casing welds*

• Welds will be visually identified and assigned weld numbers upon inspection.

Drawings will be changed accordingly.

II. Applicable Code Edition and Addenda Unit 2: Third 10-Year Interval/l989 Edition Ill. Code Requirement Table IWC-2500-1, Category C-G, Item C6.10 for Class 2 pump casing welds requires a surface examination on 100% of the pump casing welds in the 1989 Edition of ASME Section XI.

For Category C-G welds, this table requires the use of acceptance standard IWC-3515. In the referenced Code Edition, IWC-3515, Standards for Examination Category C-G, Pressure Retaining Welds in Pumps and Valves, states that the standards are in the course of preparation and the standards of IWB-3518 may be applied. IWB-3518, Standards for Examination Category B-L-1 and B-M-1, Pressure Retaining Welds in Pump Casings and Valve Bodies, states that the size of allowable planar flaws shall not exceed the limits in Tables IWB-3518-1 and IWB-3518-2 as applicable. Table IWB-3518-2, Allowable

Serial No.05-225 Docket No. 50-281 Planar Flaws, is applicable for austenitic stainless steel material with a thickness range of 2 inches or greater.

IV. Basis for Relief The pumps specified in this relief request are vertical, two-stage, centrifugal pumps with an extended shaft and casing that allows suction from the containment sump. This pump casing extends subgrade for more than 40 feet.

The pump column consists of bolted flange sections made from austenitic stainless steel pipe. Circumferential welds exist at the pipe to flange locations.

Verification of longitudinal welds cannot be made, but will be determined when the pump is disassembled and inspected. See Figure 1 for typical view.

The inspection standard specified in the Code for Class 1 and 2 pump casing welds, Table IWB-3518-2, is only for 2 inches or greater thickness. Dominion believes the pump columns were manufactured from schedule 40 pipe, which gives a nominal wall thickness of 0.365 inches. Therefore, the figures in Table IWB-3518-2 do not apply. However, the standards for austenitic piping provided in Table IWB-3514-2 are appropriate.

V. Proposed Alternative In accordance with the provisions of 10CFR50.55a(a)(3)(i), approval is requested to use Table IWB-3514-2, Allowable Planar Flaws (which is applicable to austenitic stainless steel piping) from the 1989 Edition of ASME Section XI as an alternative to the evaluation requirements of Table IWC-2500-1 for examination of category C-G pump column casing welds. The pump column is fabricated from bolted flange sections of austenitic stainless steel pipe with circumferential welds at the pipe to flange locations and possible long seam welds. Therefore, using acceptance criteria for austenitic stainless steel pipe would be more appropriate than the acceptance criteria intended for much thicker pump casings and would provide an acceptable level of quality and safety.

VI. Duration of Proposed Alternative This relief is necessary to complete the Third IS1 Interval for Surry Unit 2.

Serial No.05-225 Docket No. 50-281 VII. References

1. Letter from Virginia Electric and Power Company to the USNRC dated June 29, 2004, (Serial No.04-337), Virginia Electric and Power Company (Dominion), Revision to Surry Power Station Unit 2 Third Interval Relief Request No. SR-004 Rev. 2, Withdrawal of Surry Unit 1 Fourth Interval Relief Request No. CMP-002.

2. Letter from Virginia Electric and Power Company to the USNRC dated October 12, 2004, (Serial No. 04-337A), Virginia Electric and Power Company (Dominion), Surry Power Station Unit 2, lnservice Inspection Third Interval Relief Request No. SR-004 Rev. 2, Response to Request for Additio naI Inf o rmatio n.I

3. Letter from the USNRC to Virginia Electric and Power Company dated January 13, 2005, Surry Power Station, Unit 2 - American Society of Mechanical Engineers lnservice Inspection Program Third 1O-Year Interval Request for Relief SR-004, Revision 2 (TAC No. MC3693).

Suction Can I

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Figure 1 Typical Low Head Safety Injection and Recirculation Spray Pump