LR-N07-0282, Response to Request for Additional Information, Relief Request HC-RR-I2-W02
| ML073100791 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 10/30/2007 |
| From: | Fricker C Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| HC-RR-I2-W02, LR-N07-0282 | |
| Download: ML073100791 (7) | |
Text
PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, New Jersey 08038-0236 OCT 3 0 21OD 10CFR50.55a LR-N07-0282 C PSEG Nuclear LLC United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 HOPE CREEK GENERATING STATION FACILITY OPERATING LICENSE NO. NPF-57 DOCKET NO. 50-354
Subject:
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION, RELIEF REQUEST HC-RR-12-W02 PROPOSED ALTERNATIVE REPAIR METHOD
References:
(1) PSEG Letter LR-N07-0273 RELIEF REQUEST HC-RR-12-W02 PROPOSED ALTERNATIVE REPAIR METHOD Dated: October 19, 2007 In Reference 1, PSEG Nuclear LLC (PSEG) proposed an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section Xl, Rules for Inservice Inspection of Nuclear Power Plant Components. This proposed alternative would permit the use of a full structural weld overlay repair for an indication identified in the N2A recirculation inlet nozzle safe-end to nozzle weld joint.
On October 29, 2007, the NRC provided PSEG a draft Request for Additional Information (RAI) on the Reference 1 submittal. The response to the RAI is provided in the attachment to this letter.
If you have any questions or require additional information, please contact Mr. Philip J.
Duca at (856) 339-1640.
Sin~cerel arl dicker Vice President - Operations Support Attachment 44Y7 95-2168 REV. 7/99
Document Control Desk LR-N07-0282 CC Mr. S. Collins, Administrator - Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. R. Ennis, Licensing Project Manager - Hope Creek U. S. Nuclear Regulatory Commission Mail Stop 08B1 Washington, DC 20555 Mr. P. Mulligan Bureau of Nuclear Engineering P. O. Box 415 Trenton, NJ 08625 USNRC Senior Resident Inspector - Hope Creek (X24)
Attachment LR-N07-0282 RESPONSE TO RAI #3 FOR RELIEF REQUEST HC-RR-12-W02 NRC RAI #3:
This relief request references Code Case N-504-3 and on page 11 of 13 of the relief request, it states that this code case has been conditionally accepted in Regulatory Guide (RG) 1.147, Revision 15. It is correct that Code Case N-504-3, has been conditionally accepted in Regulatory Guide 1.147, Revision 15; however, 10 CFR 50.55a(b)(5) currently incorporates by reference RG 1.147, Revision 14. Revision 14 of RG 1.147 states that Code Case N-504-2 is conditionally acceptable. Therefore, based on the current regulations, the licensee may use Code Case N-504-2. If the licensee still desires the use of Code Case N-504-3, a detailed basis for use of all of the parts of Code Case N-504-3 must be submitted.
PSEG RESPONSE:
PSEG has already completed the weld overlay (WOL) repair on the weld identified as RPV1-N2ASE. The repair was performed in accordance with a Design Change Package (DCP) prepared in accordance with the relief request submitted on October 19, 2007.
Additionally, related procedures, the weld traveler, and repair/replacement activities were conducted in accordance with the relief request, as submitted. All weld overlay documentation has been completed in accordance with the submitted relief request.
The welding vendor's National Board (NR) Repair program was utilized for this repair, resulting in issuance and approval of a NR-1 report. All of these documents invoked Code Case N-504-3.
The use of Code Case N-504-3 was based on the conditional approval contained within Revision 15 of Regulatory Guide 1.147, which was made available on the NRC website on or before October 19, 2007. Additionally, a notice of the issuance and availability of this Regulatory Guide was published in the Federal Register (72 FR 60695).
PSEG provides the following evaluation of the changes and the basis for those changes between Code Case N-504-2, which has already been conditionally approved within Regulatory Guide 1.147, Revision 14, and Code Case N-504-3, which has already been conditionally approved within Regulatory Guide 1.147, Revision 15.
Based upon the evaluation that follows, PSEG has confirmed that the weld overlay repair satisfies the technical provisions of both revisions of the Code Case, and has elected to retain use of N-504-3 as it is referenced in the repair documentation for the completed weld overlay. It would pose an undue burden to revise said documentation without any increase in technical merit or margins for safety.
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Attachment LR-N07-0282 Hope Creek N2A Nozzle Weld Overlay Relief Request HC-RR-12-WO2 RAI#4 Response - N-504-3 vs N-504-2 Evaluation of Changes and Basis for Their Use Rev 3 changes in italicized bold underlined font, Basis in bold font N-504-2 N-504-3 Reply: It is the opinion of the Committee that, in lieu of the requirements of IWA-4120 in Editions and Addenda up to and including the 1989 Edition with the 1990 Addenda, in IWA-4170(b) in the 1989 Edition with the 1991 Addenda up to and including the 1995 Edition, and in IWA-4410 in the 1995 Edition with the 1995 Addenda and later Editions and Addenda, defect in austenitic stainless steel piping may be reduced to a flaw of acceptable size in accordance with IWB-3640 from the 1983 Edition with the Winter 1985 Addenda, or later Editions and Addenda, by deposition of weld reinforcement (weld overlay) on the outside surface of the pipe, provided the following requirements are met.
Reply: It is the opinion of the Committee that, in lieu of the requirements of IWA-4120 in Editions and Addenda up to and including the 1989 Edition with the 1990 Addenda, in IWA-4170(b) in the 1989 Edition with the 1991 Addenda up to and including the 1995 Edition, and in IWA-4410 in the 1995 Edition with the 1995 Addenda up to and including the 1996 Addenda, and in IWA-4420 in the 1995 Edition with the 1997 Addenda and later Editions and Addenda, in IWA-4810(a) in the 1992 Edition with the 1994 Addenda throuah the 1995 Edition, and in IWA-4520(a) in the 1995 Edition with the 1995 Addenda and later Editions and Addenda, a defect in austenitic stainless steel piping may be reduced to a flaw of acceptable size in accordance with IWB-3640 from the 1983 Edition with the Winter 1985 Addenda, or later Editions and Addenda, by deposition of weld reinforcement (weld overlay) on the outside surface of the pipe, provided the following requirements are met.
Basis: These changes were intended to make the case usable to all versions of Section Xl from Summer 1978 Addenda through 2004 Edition. This updated Case now refers to applicable paragraphs of ASME Xl, 1998 Edition including Addenda through 2000 applicable to the Nozzle N2A weld overlay activities.
(b) Reinforcement weld metal shall be low carbon (0.035% max.) austenitic stainless steel applied 3600 around the circumference of the pipe, and shall be deposited in accordance with a qualified welding procedure specification identified U
(b) Reinforcement weld metal shall be low carbon (0.035% max.) austenitic stainless steel applied 3600 around the circumference of the pipe, and shall be deposited in accordance with a qualified welding procedure specification identified I~
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Attachment LR-N07-0282 N-504-2 N-504-3 in the Repair Program.
in the Repair Program. The submerged arc method shall not be used for weld overlay.
Basis: The machine GTAW process was used so this change is not pertinent to the Nozzle N2A overlay activities.
(0(1) For circumferentially oriented flaws (0(1) For circumferentially oriented flaws greater than 10% of the pipe greater than 10% of the pipe circumference, axial flaws greater than 1.5 circumference, axial flaws equal to or in., in length, or more than 5 axial flaws of greater than 1.5 in. in length, 5 or more any length, the weld reinforcement shall axial flaws of any length, the weld provide the necessary wall thickness to reinforcement shall provide the necessary satisfy the flaw evaluation procedures of wall thickness to satisfy the flaw evaluation IWB-3640 from the 1983 Edition with the procedures of IWB-3640 from the 1983 Winter 1985 Addenda, or later Editions and Edition with the Winter 1985 Addenda, or Addenda...
later Editions and Addenda.
Basis: Revision to eliminate the oversight of the case of an axial flaw exactly 1.5 in. long, and exactly five axial flaws of any length.
(g)(2) For repaired welds the evaluation (g)(2) For repaired welds the evaluation shall consider residual stresses produced shall consider residual stresses produced by the weld overlay with other applied by the weld overlay with other applied loads on the system. The effects of water loads on the system. The effects of water backing on the repair weld shall be backing on the repair weld shall be considered. The evaluation shall considered. The evaluation shall demonstrate that the requirements of IWB-demonstrate that the requirements of IWB-3640 from the 1983 Edition with the Winter 3640 from the 1983 Edition with the Winter 1985 Addenda, or later Editions and 1985 Addenda, or later Editions and Addenda, are satisfied for the design life of Addenda, are satisfied for the design life of the repair, considering potential flaw the repair, considering potential flaw growth due to fatigue and the mechanism growth due to fatigue and the mechanism believed to have caused the flaw. The flaw believed to have caused the flaw. The flaw growth evaluation shall be performed in growth evaluation shall be performed in accordance with Appendix C. When accordance with Appendix C. When structural credit is taken for SAW or SMAW structural credit is taken for SAW or weld metal in the original pipe weldment or SMAW weld metal in the original pipe the weld overlay, the evaluation weldment or SMAW weld metal in the requirements of Tables IWB-3641-5 and weld overlay, the evaluation requirements IWB-3641-6 shall be applied, of IWB-3640 for SAW or SMAW welds, as applicable, shall be applied.
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Attachment LR-N07-0282 N-504-2 N-504-3 Basis: The applicable requirements in N-504-3 now refer to IWB-3640 rather than referring to each applicable table therein as previously done prior to 1996 Addenda.
(i) Preservice examination of the completed repair shall be performed in accordance with IWB-2200. For all classes of components, liquid penetrant and ultrasonic examination of the completed weld repair shall be performed.
Examination procedures shall be specified in the Repair Program. The acceptance standards of Table IWB-3514-2 shall apply. Ultrasonic examinations shall verify the integrity of the newly applied weld reinforcement. Examinations shall also be performed to identify the original flaws in the outer 25% of the underlying pipe wall as a benchmark for subsequent examinations of the overlay. Grinding and machining of the as-welded overlay surface may he used to improve the surface finish for such examinations, when the overlay thickness is not reduced below design requirements.
(i) Preservice examination of the completed repair shall be performed in accordance with IWB-2200. For all classes of components, liquid penetrant and ultrasonic examination of the completed weld repair shall be performed.
Examination procedures shall be specified in the Repair Program. The acceptance standards of Table IWB-3514-2 shall apply for Planar flaws. The acceptance standards of Table IWB-3514-3 shall apply for laminar flaws provided the reduction in coverage of the examination volume is less than 10%.
The dimensions of the uninspectable volume are dependent on the coverage achieved with the anale beam examination. Additionally, any uninspectable volume in the weld overlay shall be assumed to contain the largest radial planar flaw that could exist within that volume. The assumed planar flaw shall meet the inservice examination acceptance standards of Table IWB-3514-2. Both axial and circumferential flaws shall be assumed.
As an alternative to the assumed Planar flaw radiography in accordance with the Construction Code shall be used to examine the uninspectable volume in the weld overlay. The radio-graphic acceptance criteria of the Construction Code shall apply. Ultrasonic examinations shall verify the integrity of the newly applied weld reinforcement.
Examinations shall also be performed to identify the original flaws in the outer 25%
of the underlying pipe wall as a benchmark for subsequent examinations of the overlay. Grinding and machining of the as-4 of 5
Attachment LR-N07-0282 N-504-2 N-504.3 welded overlay surface may he used to improve the surface finish for such examinations, when the overlay thickness is not reduced below design requirements.
Basis: The revision here clarifies which acceptance criteria applies to the different types of flaws and should have been included in previous revision of the Case.
(m) Use of this Case shall be documented (m) Use of this Case shall be documented on an NIS-2 form.
on Form NIS-2.
Basis: Editorial change Footnote 1 When applying this Case to Footnote 1 When applying this Case to Editions and Addenda later than the 1989 Editions and Addenda later than the 1989 Edition, reference to Repair Program shall Edition, reference to Repair Program shall be read as Repair Plan.
be read as Repair Plan or Repair/Replacement Plan as applicable.
Basis: Editorial change to update terminology included in later versions of Section XI.
Ref: ASME Section Xl, 1998 Edition, including Addenda through 2000 5 of 5