CPSES-200400045, Relief Request C-2 for the Second 10-Year ISI Interval for Unit 1 and C-7 for the First 10-Year ISI Interval for Unit 2 from 10CFR50.55a for the Purpose of Invoking Code Case N-661
| ML040150729 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/08/2004 |
| From: | Blevins M TXU Electric, TXU Generation Co, LP |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CPSES-200400045, TAC MB7947, TAC MB7948, TXX-04009 | |
| Download: ML040150729 (11) | |
Text
V0 TXU TXU Energy Mike Blevins Comanche PeakSteam Senior Vice President & Principal Nuclear Officer Electric Station P.O. Box 1002 (EO1)
Glen Rose,TX 76043 Ref: 10 CFR 50.55a(3)(i)
Tel: 254 897 5209 10 CFR 50.55a(g)(4)(iv)
Fax: 254 897 6652 mike.blevins@txu.com CPSES-200400045 Log # TXX-04009 January 8, 2004 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446; RELIEF REQUEST C-2 FOR THE SECOND 10 YEAR ISI INTERVAL FOR UNIT 1 AND C-7 FOR THE FIRST 10 YEAR ISI INTERVAL FOR UNIT 2 FROM 10 CFR 50.55a FOR THE PURPOSE OF INVOKING CODE CASE N-661 (UNIT 1 SECOND INTERVAL START DATE AUGUST 2000 UNIT 2 FIRST INTERVAL END DATE: AUGUST 2004)
(TAC NOS. MB7947 AND MB7948)
REFERENCE:
TXU Energy Letter logged TXX-03046 dated March 5, 2003 from C. Lance Terry to the NRC TXU Energy Letter logged TXX-03159 dated September 11, 2003 from Fred W. Madden to the NRC Via the referenced letters TXU Generation Company LP (TXU Energy) requested relief from the ASME Code pursuant to 10CFR50.55a. TXU Energy requests to invoke ASME Code Case N-661 instead of ASME Code Case 562-1 as suggested by your staff during several conversations. The changes are clearly identified by the revision bars in the attachment to this letter.
- DLfq A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- South Texas Project
- Wolf Creek
@TXU to TXX-04009 Page 1 of 4 This communication contains no new licensing basis commitments regarding CPSES.
TXU Energy requests approval of this relief request by March 5, 2004. The approval date was selected to allow use of this relief request during the tenth refueling outage for Unit 1, scheduled to start later in March 2004. If you have any questions regarding this request, please contact Douglas Snow at (254) 897-8448 or Jack Hicks at (254) 897-6725.
Sincerely, TXU Generation Company LP By: TXU Generation Management Company LLC, Its General Partner Mike Blevins Senior Vice President and Principal Nuclear Officer By: _AJ) -) g
/Fred W. Madden Nuclear Licensing Manager DWS/dws Attachment/Enclosure c- B. S. Mallet, Region IV W. D. Johnson, Region IV M. C. Thadani, NRR Resident Inspectors, CPSES Terry Parks, Chief Inspector, TDLR J.C. Hair ANII, CPSES to TXX-04009 Page 1 of 4 TXU GENERATION COMPANY LP COMANCHE PEAK STEAM ELECTRIC STATION UNIT 1 SECOND TEN-YEAR INTERVAL ISI RELIEF REQUEST NO. C-2 AND UNIT 2 FIRST TEN YEAR INTERVAL FOR ISI RELIEF NO. C-7 PROPOSED USE OF SUBSEQUENT ASME CODE EDITION AND ADDENDA PURSUANT TO 10 CFR 50.55a(g)(4)(iv) AND INVOKING CODE CASE N-661 I. ASME System/Component(s) Affected:
All ASME Class 2 and 3 carbon steel plant raw water piping systems.
II. Applicable Code Edition and Addenda:
ASME Code 1986 Edition (No Addenda),Section XI.
I. Proposed Subsequent Code Edition and Addenda and Code Case:
ASME Code,Section XI, IW A-4120 (a) requires that repairs be performed in accordance with the Owner's Design Specification and the original Construction Code of the component or system.
ASME Code,Section XI, IW A-43 I 0 requires that the defect be removed or reduced in size in accordance with Article IW A-4000.
TXU Energy proposes to use 1998 Edition, ASME Section XI IWA 4000 and invoke Code Case N-661, to repair defects found in Class 2 and 3 carbon steel plant raw water piping systems during the corrosion monitoring program (CPSES procedure STA-730, "Corrosion Monitoring Program").
Relief is requested from replacement or internal weld repair of wall thinning conditions resulting from various wall thinning degradation mechanisms such as erosion, corrosion, cavitation, and pitting in Class 2 and 3 carbon steel raw water piping systems in accordance with the design specification and the original construction code. The primary reason for this request is to provide adequate time for additional examination of adjacent piping so that pipe replacement can be planned to reduce impact on system availability, including Maintenance Rule applicability and availability of replacement materials.
to TXX-04009 Page 2 of 4 TXU GENERATION COMPANY LP COMANCHE PEAK STEAM ELECTRIC STATION UNIT 1 SECOND TEN-YEAR INTERVAL ISI RELIEF REQUEST NO. C-2 AND UNIT 2 FIRST TEN YEAR INTERVAL FOR ISI RELIEF NO. C-7 PROPOSED USE OF SUBSEQUENT ASME CODE EDITION AND ADDENDA PURSUANT TO 10 CFR 50.55a(g)(4)(iv) AND INVOKING CODE CASE N-661 Continued IV. Basis of Using Subsequent Code Editions and Addenda and Code Case:
A number of alternatives (e.g., Generic Letter GL 90-05 "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1,2, and 3 Piping", Code Cases N-513 "Evaluation Criteria for Temporary Acceptance of Flaws in Class 3 Piping,Section XI, Division 1" and N-523-1 "Mechanical Clamping Devices for Class 2 and 3 Piping,Section XI, Division 1") are currently available and approved by the NRC for evaluating and repairing of piping wall thinning and pitting (including through wall leaks). Nonetheless, these alternatives have limitations and do not always encompass the specific situations that arise from a piping leak.
While the guidance provided by GL 90-05 and Code Case N-513 could be used to evaluate and accept the leaking condition, if the structural integrity of the piping can be ascertained, the leak would most likely continue to increase in size over time and would pose more significant housekeeping difficulties. On the other hand, if the flaw exceeds the acceptance criteria provided by GL 90-05 or Code Case N-513, an emergency code repair (which may include up to full piping replacement of the affected sections) would be warranted.
Therefore this would pose a significant hardship on plant operations to isolate and drain the affected piping sections (some of which are not isolable and would require extended plant shutdown). For that reason, TXU Energy requests that relief be granted to use a weld overlay in lieu of a code weld repair on Class 2 and 3 carbon steel raw water piping systems. This would provide additional assurance that an unscheduled plant shutdown could be avoided.
Comanche Peak Steam Electric Station Unit 1 and Unit 2 will implement the requirements of ASME Code Case N-661 for Class 2 and 3 plant raw water piping system repairs resulting from degradation mechanisms such as erosion, corrosion, cavitation, or pitting as an alternative to the requirements of IW A-4000. These type defects are typically identified by small leaks in the piping system or by pre-emptive non-code required examinations performed by the Licensee to monitor the degradation mechanisms. The alternative repair technique described in Code Case N-661 involves the application of additional weld metal on the exterior of the piping system, which restores the wall thickness requirement. This repair technique will be utilized whenever engineering evaluation determines that such a repair is suitable for the particular defect or degradation being resolved. Provisions for use of this Code Case will be addressed in the Repair and Replacement Program.
to TXX-04009 Page 3 of 4 TXU GENERATION COMPANY LP COMANCHE PEAK STEAM ELECTRIC STATION UNIT 1 SECOND TEN-YEAR INTERVAL ISI RELIEF REQUEST NO. C-2 AND UNIT 2 FIRST TEN YEAR INTERVAL FOR ISI RELIEF NO. C-7 PROPOSED USE OF SUBSEQUENT ASME CODE EDITION AND ADDENDA PURSUANT TO 10 CFR 50.55a(g)(4)(iv) AND INVOKING CODE CASE N-661 Continued Those provisions will require that adjacent areas be examined to verify that the entire flawed area will be encompassed by the repair and that there are no other unacceptable degraded locations within a representative area dependent on the degradation mechanism present. An evaluation of the degradation mechanism will be performed to determine the re-examination schedule to be performed over the life of the repair. The repair will be considered to have a maximum service life of two fuel cycles unless examinations during each of the two fuel cycles are performed to establish a different life expectancy.
The basis for use of the repair technique described in Code Case N-661 isSection XI of the ASME Code has determined that this repair technique provides an acceptable alternative to the requirements of IW A-4000 and provides an acceptable level of quality and safety.
Therefore, the proposed alternative is justified per 10CFR50.55a(a)(3)(i).
Additionally, TXU Energy is proposing the following restrictions on the use of the Code Case N-661, to assure that the use of the Code Case will provide an acceptable alternative pursuant to 10 CFR 50.55a(a)(3)(i):
(a) If the root cause of the degradation has not been determined, the repair is only acceptable for one cycle.
(b) Weld overlay repair of an area can only be performed once in the same location.
(c) When through-wall repairs are made by welding on surfaces that are wet or exposed to water, the weld overlay repair is only acceptable until the next refueling outage.
Code Case N-661 was approved by the ASME Section XI Code on July 23, 2002; however, it has not been incorporated into NRC Regulatory Guide 1.147 and thus is not available for application at nuclear power plants without specific NRC approval. Therefore, TXU Energy is documenting the request to apply the alternative repair technique described in the Code Case via this relief request. A copy of ASME Section XI Code Case N-661 is attached for reference.
to TXX-04009 Page 4 of 4 TXU GENERATION COMPANY LP COMANCHE PEAK STEAM ELECTRIC STATION UNIT 1 SECOND TEN-YEAR INTERVAL ISI RELIEF REQUEST NO. C-2 AND UNIT 2 FIRST TEN YEAR INTERVAL FOR ISI RELIEF NO. C-7 PROPOSED USE OF SUBSEQUENT ASME CODE EDITION AND ADDENDA PURSUANT TO 10 CFR 50.55a(g)(4)(iv) AND INVOKING CODE CASE N-661 Continued V. Duration of Proposed Alternative:
This Technical Alternative will be used at Comanche Peak Steam Electric Station Unit 1 and Unit 2 during each plant's present ten- year ISI interval. The use of this Technical Alternative is requested until the NRC publishes Code Case N-661 in a future revision of the applicable Regulatory Guide.
Granting of this relief request will not have an impact on plant quality or safety and will not adversely impact the health and safety of the public.
VI. Precedents:
- 1)
Subject:
Edwin I. Hatch Nuclear Plant, Units 1 and 2, Joseph M. Farley Nuclear Power Plant, Units 1 and 2, and Vogtle Electric Generating Plant, Units 1 and 2 (TAC Nos. MB8959, MB8960, MB8961, MB8962, MB8963, and MB8964) dated 11/21/2003.
to TXX-04009 Page 1 of 5 I CASE N-661 CASVS OF ASNMEBtOILER AND PRSSURE WThSF.. C'ODE Approval Date: July 23, 2002 See Numeric Index for expiration and any reaffirmation dates.
Cae N-661 2.0 INITIAL EVALUATION Alternatlie Requirements for Wall Thickness Mic material beneath the surface lo vwhich the weld Restoration of Clsses 2 and 3 Carbon Steel overlay is to be applied shall be evaluated to establish riping for Raw WVater Seriice the exiting average wall thickness and the extent and Section Xl. D)iision I configuration o degradation to be reinforced by the weld overlay. The adjacent area shall be examined to Inquiryl: As an alternative to replacement or internal verify that the repair will encompa-s the entire defective weld repair. what rquirements may be applied for wall thickness restoration of Classes 2 and 3 carbon steel arra. Consideration shall be given to the cause of degradation. The extent of degradation in the piping.
raw Watcr piping systems that have experienced internal shall be evaluated to ensure that there arc no other wall thinning fmm localized crrosion, corrosion. cavita-tion. or pitting? unacceptable locations within the surrounding area that could affect the integrity of the repaired piping. Thc RepaI: It is the opinion of the Committee that areas dimensions of the surrounding area to be evaluated or ChscLn. 2 and 3 carbon steel raw water piping shall be determined by the Ov ner. considering the type experiencing internal wall thinning from localized cro- of degradation present. The effect of the repair on the sion. corrosion. cavitation. or pitting may have the wall piping, and any remaining degradation shall be evaluated thickness rstored externally by means of a weld- in accordance with IWA-4160 deposited arbon or low-alky steel reinforcement on the outside surfacc of the piping in accordance with the following rquirements. excluded from thcse provi-sions arc conditions involving corrosion-assisted crack-ing or any other form of cracking.
3.0 DSIGN 1.0 (;ENERAL, REQUIREMENTS 3.1 Ceneral Design Requirements (a) Thc wall thickness rcstoration shall e performed (a) Unless otherwise stablisied by theoretical or in accordance with a Repair/Replacement Plan satisfying experimental analysis. or by proof testing as provided the requirements of IA4150.2 for in 3.3 or 3.4, the full thickncss of the weld overlay (lb) The wall thickness restoration shall meet the re- shall extend a distance of at least s in each direction quiremcents of IWA-40X.3 except as stated in this Casc. beyond the area predicted, over the design life of the (r) If the minimum required thickness of deposited restoration to infringe upon the rcquired thickness? 5 weld metal necessary to stisfy the requirements of 3.0 is greatcr than the nominal thickncss for the size and w.here schedule of the piping. the provisions of this Ctsc shall not apply. In addition. the total thickness of filler metal applied over multiple rairs shall not exceed R= outer radius of the component the original nominal thickness of the piping. t. = nominal wall thickness of the component or brwnkiWsh3 usae
- d in plant e1gaipneta. area sonL rs. ano Edges of the weld overlay shall b tapered to the beat exchan5 en In many rLis it hs relmoed 1- as -Sen.r Winer.- existing piping surface at a maximum angle (" in
'IWA-tl4 in the 19 diatn uith the 1991 AJnt tugh 1995 dti-nu. IWA4t3O tRepair Piogani) in the 9X9 Ldition %ikh the 199) Andu ard :lkti-e dii and AddenL at
'IWA-4ititflttl nat a tWCtW-4ttN70)(10. as arpie-iW. h the I995 rdhim. IA.t13t) Repair fogram) in he 1989 lEdifion with 19s9 EUiti wit d IW1 Atnda and earlier Atitims and the t9WtO Adkna and eadlir Gtiias aM Addenda.
A&"La 'iflsign tickao a rtscwrihed by heConsnirmlai G C
INVA-41501hb the 19)9 rthin sith th, 199 Aesk twm M'A-44 In Ih 19S9 Witon sih the 1991 Addenda hutugh 1173 to TXX-04009 Page 2 of 5 CASE (continued)
N-661 CASES OF ASNIE BOILER AND PRSSURE VESSEL CODE branch reinforcement X -,21/2 RO, FIG. 1 BRANCH REINFORCEMENT Fig. ) of 45 deg. Final configuration of the reinforce- 3.2 Design ment shall permit the examinations and evaluations The design of weld overlays not prequalified by 3.3, required herein. including any required preservice or 3.4. or 3.5 shall be in accordance with the applicable insrvice examinations of encompassed or adjacent requirements of the Construction Code or NC/ND-3100 welds.
and NC/ND-36(X) (including Appendix II). and shall (b) The thickness shall be sufficient to maintain consider the weld overlay as an integral portion of the required thickness for the predicted life of the repair.
piping or component upon which it is applied (not as and. except for the tapered edges, the overlay shall a weld). Thc allowable stress values of the base metal have a unifoml thickness.
shall apply to the design of the deposited weld metal.
(r) he tensile strength of the weld filler metal for The following factors shall be considered, as applicable.
the reinforcement shall be at least that specified for in the design and application of the reinforcement:
the base metal to which it is applied.
(d} The predicted maximum degradation of the over- (a) The shrinkage effects, if any, on the piping:
laid piping and the overlay over the design life of (b) Stress concentrations caused by application of the restoration shall be considered in the design. The the overlay or resulting from existing and predicted predicted degradation of the piping shall be based on piping internal surface configuration:
in situ inspection and established data for similar base (rc)If flexibility analysis was required by the original metals. If the weld overlay is predicted to become Construction Code, the effect of the weld overlay shall exposed to the corroding medium. the predicted degrada- be reconciled with the original analysis. For rectangular-tion of the overlay shall be based upon established data shaped overlays on piping designed to NC/ND-3650 for base metals or weld metals with similar chemical and aligned parallel or perpendicular to the axis of the composition to that of the filler metal used for the piping. unless a lower stress intensification factor (Sit' weld overlay. or i) is established, an SIF (i) of 2.1 shall be applied (e) Thc effect of weld overlay application on interior for overlays on straight pipe and adjacent welds. Also.
coatings shall be addressed in the Rcpair/Replacemcnt a stress multiplier of 1.7 shall be applied to the SIF Plan (previously Repair Program). (i) for standard elbows; and an SIF (i) of 2.1 shall be 1174 SUPP. 5- NC I
to TXX-04009 Page 3 of 5 I CASE continued)
N-661 CASS (V'AStE BCILER AND 'RSSIURE VUSSEL. CODE applied for ees and branch connections when the toe tively, an equivalent volume of base metal may be of the overlay is not less than 2/.,i/i from any removed from the inside surface of the mockup by branch reinforcement in ig. 1. machining or grinding, without need for welding in a closure plug.
(c) The mockup weld overlay shall be applied in 3.3 Proof Test Qualification as a Piping Product accordance with the design or specified configuration As an alternative to design. the configuration of weld using the specified weld filler metal. Maximum section thickness at the overlaid opening (weld metal plus base overlays may be qualified by performance of proof testing of a mockup in accordance with the following metal plug, or as+ ) shall not exceed 71/.% of the requirements: nominal thickness of the piping.
(a) A satisfactory mockup burst test shall qualify (d) Straight pipe equivalent to a minimum of one the design or configuration for application in the same pipe diameter. or one-half diameter fr piping over orientation on the same type of item. and the same NPS 14, shall be provided (butt-welded to the mockup.
location on fittings, when the following conditions are if necessary) beyond both ends of the overlay. The satisfied (see Fig. I). piping shall be capped. and the completed mockup assembly shall be thoroughly vented and hydrostatically
(/) The base metal is of the same P-No. and pressure tested to bursting. To qualify the design for Group Number when impact properties are applicable.
general application within the limits of 3.3(a), burst as the base metal tested.
pressure shall not be less than:
(2) The specified minimum tensile strength of the item does not exceed that specified for the base metal tested.
(3) The average thickness of the overlay areas is 1),,
at least the thickness of the mockup plug. ii.
(4) The overlap on the full thickness or base metal. where
- s. is at least that of the mockup. P= minimum acceptable burst pressure. psi (S) The transition angle at the outer edges of the t= minimum specified thickness (excluding manu-overlay, a. is not greater than that of the mockup. facturing tolerances) of the base metal being (6) The overlay surface finish is similar to or tested. in.
smoother than that tested. S,,,i = reported actual tensile strength of the base metal (7) The maximum proportionate axial dimension, being tested, psi LID, is not more than that tested. D,,= outside diameter of the pipe. in.
(8) The maximum proportionate circumferential (e) If flexibility analysis was required by the original dimension. CID. is not more than that tested.
Construction Code, the effect of the weld overlay shall (9) The nominal diameter is not less than one- be reconciled in accordance with 3.2(c).
half nor more than two times the diameter tested.
(10) The nominal thicknessldiameter ratio. /D is not less than one-half nor more than three times the M/D). ratio tested. 3.4 Proof Test Qualification for Specific Applications (Ii) The mockup base shall consist of new base material of similar configuration. or type of item, as As an alternative to design by analysis or proof the item to be overlaid. A rounded-corner segment of test qualification as a piping product, the design or the base material shall be removed to represent the configuration of weld overlays may b qualified for maximum proportionate size (axial dimension of L and limited service conditions using the provisions of NCI circumferential dimension of C) and location of thinning ND-690X. "Proof Tests to Establish Design ressure.~
or pitting to be compensated for by the weld overlay. except that component hydrostatic testing is not required A plug of the same base metal and of uniform thickness. (other than as required by IWA-40OW). The mockups it, which shall not exceed the smallest average thickness shall be fabricated and tested in accordance with the on which the overlays will be permanently applied. provisions of 3.3(b), (c), and (d). and shall be applied shall be full-penetration welded around the opening in accordance with the provisions and conditions of and flush with the outside surface of the piping. Alterna- 3.3(a). The provisions of 3.3(e) shall be met.
1175 StJPP. 5 - NC to TXX-04009 Page 4 of 5 I CASE (continued)
N-661 CASS OF ASNIKIRO(ILIKRl AND) PR SURE:VIMSSEL COI)E 3.5 Prequalified Design 5.0 INSTALLATION Application of weld overlavs on straight pipc, portions (a) The entire surface area to which the weld overlay or tees not less than 2 Rm from any branch rein- is to be applied shall be examined using the liquid forcement in rig. 1, standard elbows, and associated penetrant or magnetic particle method. with acceptance wclds to correct limited degradation shall be exempt criteria in accordance with NC/ND-2500. NC/ND-530()
from the requirements of 3.2 through 3.4 provided all for the product form (base metal or weld) involved.
of the following conditions are satisfied. (b) If through-wall repairs are required to satisfy the (a) All the requirements of 3.1 apply. acceptance criteria. or result from application of the (b) The provisions of 3.3(e) shall be met. weld overlay, they shall be accomplished by sealing (c) The full thickness of weld overlay shall not with weld metal using a qualified weld procedure exceed a maximum axial length of the greater of 6 suitable for open-root welding. This weld shall be in. or the outside diameter of the piping. examined in accordance with 5.0(a). In addition, the (di) The finished overlay shall be circular, oval. full- first layer of overlay over the repaired area shall be circumferential or rectangular in shape. examined in accordance with 5.0(a).
(I) For each repair, the maximum dimension com- (c) Overlay weld metal shall be deposited using a pensated by a circular overlay shall not exceed 2/3 the grove-welding procedure qualified in accordance with nominal outside diameter of the piping. Section IX and the Construction Code. or Section IX and Section Xi. IWA-4610 and either IWA-4620 or (2) Rectangular overlays shall be aligned parallel IVA-4650 The qualified minimum thickness specified with or perpendicular to the axis of the piping. and in the weld procedure does not apply to the weld comers shall be rounded with radii not less than the overlay or associated base metal repairs.8 ovelay thickness.
(d) The surface of the weld overlay shall be prepared (3) For oval overlays, the end radii shall not be by machining or grinding. as necessary, to permit less than R,. and the axis of the overlay shall 5r4 performance of surface and volumetric examinations be aligned parallel with or perpendicular to the axis required by 6.0. or ultrasonic examination. a surface of the piping. finish of 250 RMS or better is required.
(e) The distance between toes of adjacent overlays shall not be less than Inmn 6.0 FXAMINATION (a) The completed weld overlay shall be examined 4.0 W%'ATER-BACKED APPLICATIONS using the liquid penetrant or magnetic particle method and shall satisfy the surface examination acceptance (a) Manual application of overlays on water-backed criteria for welds of the Construction Code or NC/
piping shall be restricted to P-No. I base materials. ND-5300.
Welding of such overlays shall use the SMAW process (b) The weld overlay, including the existing piping and low-hydrogen electrodes. In addition. the surface upon which it is applied. shall be examined to verify examination required in 6.0 shall be performed no acceptable wall thickness.
sooner than 48 hr after completion of welding. For (c) Weld overlays shall be volumetrically examined such overlays consideration should be given to using as base metal repairs when required by the Construction a temper bead technique similar to that described in Code, except as follows:
IWA-4650. 6
(/) Weld overlays not exceeding 10 in.2 surface (b) Piping with wall thickness less than the diameter area are exempt from volumetric examination.
of the electrode shall be depressurized before welding.
with the 1991 Addenda through 1995 Edition. tWA45I tO or IVF.420O the 1H9i Edition. IWF-.2(X0 In the 1986 Editina with the 1988 In the 1986 Edition with the 1988 Addenda through 1989 Edition Addenda thrugh the 1989 Flilion with ithe 1990 AdendL IWE4320 with the 1990 Addenda. IWH-4.20 or tNvE-4320 In the 1986 Edition In the 1986 Ediion With the 1987 Addenda and earlier Editions and with the 1987 Addenda or earlier tiditioas and Addenda.
Adienda. 'EXception to IWA-4000.
7R-A4-I5 and either IWA45 In or IWA440 in the 1989 dition 'IWA-3(XX) and IWB-3514 in the 989 dition with the 1990 1176 SUPP. 5 - NC to TXX-04009 Page 5 of 5 I CASE (continued)
N-661 CWSS OF ASMFE BOILlR AND PRSSURE VUlSEL CO)tE (2) Other weld overlays shall be exempt from criteria of NC/ND-2500. NCIND-5300 for the product volumetric examination when the finished applied thick- form. or IA-3000.9 ncs ( in Fig. 1) does not exceed:
(a) 1/3t for I, -/4 in.
(b) 1/4 in. for 3/4 in. < i 2k4 in. 7.0 INSERVICE EXAMINATION (o) The lesser of 3*s in. or 10% of for > (a) The Owner shall prepare a plan for additional 2'A/ in. examination to verify that minimum wall thickness is not violated over the life of the repair. The frequency where and method of examination shall be determined based t= finished full-section thickness of compensated on an evaluation of the degradation mechanism.
area (e.g.. it' + in Fig. 1) (b) The maximum expected life of the repair shall be two fuel cycles unless examinations during each of When volumetric examination is required, the full the two fuel cycles are performed to establish the volume of the finished overlay, excluding the tapered expected life of the repair.
edges. but including the volume of base mctal required for the design life of the overlay. shall be examined using either the ultrasonic or radiographic method. and 8.0 DOCUMENTATION shall. to the depth at the surface of the existing piping. Use of this Case shall be documented on an NIS-2 satisfy the acceptance criteria for wcldments of the Form.
Construction Code or NC/ND-5300. The volume of the existing piping. beneath the weld overlay. taken credit Addenda and cartier Editions and Addenda.
for in the design. shall satisfy the volumetric acceptance IRaw water drined as watr tuch a from a rer. lake. or vctl 1177 SUPP. 5 - NC