ML13102A034
| ML13102A034 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/04/2013 |
| From: | Grecheck E Virginia Electric & Power Co (VEPCO), Dominion |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 13-189 | |
| Download: ML13102A034 (17) | |
Text
10 CFR 50.55a ViRGINIA ELEcTRic AND POWER COMPANY RxcHMoND, VIRGINIA 23261 April 4, 2013 U.S. Nuclear Regulatory Commission Serial No.13-189 Attention: Document Control Desk NL&OS/ETS RO Washington, D.C. 20555 Docket No.
50-339 License No. NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNIT 2 ASME SECTION XI INSERVICE INSPECTION PROGRAM REQUEST FOR ALTERNATIVE TO ASME CODE STEAM GENERATOR NOZZLE-TO-VESSEL WELD EXAMINATION REQUIREMENTS ALTERNATIVE REQUEST N2-14-LMT-001 Pursuant to 10 CFR 50.55a(a)(3)(ii), Dominion requests an alternative from the requirements of American Society Mechanical Engineers (ASME) Code Case N-770-1, as amended by 10CFR50.55a(g)(6)(ii)(F), for North Anna Power Station Unit 2. The existing geometry of the Unit 2 Steam Generator nozzle welds will not permit the required volumetric examination coverage as required by Code Case N-770-1.
Therefore, Dominion requests an alternative to the requirements of Code Case N-770-1. provides the specific alternative request and a discussion of the basis for the request.
Dominion requests approval of this alternative to support the Unit 2 spring 2013 refueling outage. Dominion also requests approval to implement this alternative for the entire 4th year Inservice Inspection Interval for North Anna Unit 2, which began December 14, 2010 and will end December 13, 2020.
If you have any questions or require additional information, please contact Mr. Thomas Shaub at (804) 273-2763.
Respectfully, E. S. Grecheck Vice President - Nuclear Engineering and Development Commitments made in this letter:
- 1. Examination results will be forwarded when the examinations are completed during the spring 2013 refueling outage.
Attachment:
Alternative Request N2-14-NDE-LMT-001
Serial No.13-189 Docket No. 50-339 N2-14-LMT-001 Page 2 of 2 cc:
U.S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, Georgia 30303-1257 Mr. J. E. Reasor, Jr.
Old Dominion Electric Cooperative Innsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 NRC Senior Resident Inspector North Anna Power Station Ms. K. R. Cotton NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 0-8 G9A 11555 Rockville Pike Rockville, Maryland 20852 Dr. V. Sreenivas NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, MD 20852-2738
Serial No.13-189 ATTACHMENT Request for Alternative to ASME Code Steam Generator Nozzle-to-Vessel Weld Examination Requirements Alternative Request N2-14-LMT-001 North Anna Power Station Unit 2 Virginia Electric and Power Company (Dominion)
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4th Interval Alternative Request N2-14-LMT-001 Page 1 of 14 N2-14-LMT-001 UNIT 2 FOURTH INTERVAL CODE CASE N-770-1 LIMITED EXAMS Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
-- Hardship or Unusual Difficulty Without Compensating Increase in Level of Quality or Safety --
1.0 ASME CODE COMPONENT(S) AFFECTED North Anna Power Station (NAPS) Unit 2 Steam Generator Primary Loop hot leg and cold leg nozzle-to-safe-end welds, Code Class 1 PWR Pressure Retaining Dissimilar Metal Piping and Vessel Nozzle Butt Welds Containing Alloy 82/182, identified below. Figures 1 through 8 of this enclosure include sketches of the safe-end configuration and materials.
2.0 APPLICABLE CODE EDITION AND ADDENDA North Anna Power Station Unit 2 applicable Code for the fourth 10-year inservice inspection (ISI) interval and the ISI program is the 2004 Edition of Section Xl with no Addenda (Reference 8.1).
The NAPS Unit 2 fourthl0-year interval started December 14, 2010 and ends December 13, 2020.
3.0 APPLICABLE CODE REQUIREMENT Examination requirements for Class 1 piping and nozzle dissimilar-metal butt welds as required by 10 CFR 50.55a(g)(6)(ii)(F) implementing the requirements of ASME Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities, Section Xl, Division 1" (ASME Approval Date:
December 25, 2009), are as follows:
ASME Code Case N-770-1, Inspection Item "B", Unmitigated Butt Weld at Cold Leg Operating Temperature (-2410) > 5250 (2740C) and <580°F (3040C). Requires visual examination once per interval, and volumetric examination every second inspection period not to exceed 7 years.
ASME Code Case N-770-1, Inspection Item "A-2", Unmitigated Butt Weld at Hot Leg Operating Temperature (-2410) < 625°F (329°C). Requires visual examination each refueling outage, and volumetric examination every 5 years.
Baseline and subsequent volumetric examinations are to be conducted in accordance with ASME Section Xl, Appendix VIII, Supplement 10, "Qualification Requirements for Dissimilar Metal Piping Welds," which is applicable to dissimilar metal welds.
Additionally, 10 CFR 50.55a(g)(6)(ii)(F)(3) requires that the baseline examinations for welds in Code Case N-770-1, Table 1, "shall be completed by the end of the next refueling outage after January 20, 2012."
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 th Interval Alternative Request N2-14-LMT-001 Page 2 of 14 4.0 REASON FOR REQUEST The proposed alternative is necessary due to the limited scan distance of the safe-end and the adjacent weld, which restricts the movement of the ultrasonic probe to provide effective coverage of the welds in the axial beam direction for the detection of circumferentially oriented flaws. Approval of this alternative will allow the examination of the SG nozzle dissimilar metal welds (DMWs) performed in the spring 2013 Unit 2 refueling outage to be credited as a "baseline" examination per the regulation, and accept at least the same coverage obtained in successive examinations during the fourth inspection interval. Therefore, an Alternative is requested to the "Code required examination volume of essentially 100 percent" of Code Case N-770-1 as conditioned in 10 CFR 50.55a(g)(6)(ii)(F)(3) for volumetric examination of the NAPS 2 Steam Generator hot leg and cold leg nozzle-to-safe-end welds.
Dominion will perform ultrasonic examinations of Alloy 82/182 steam generator nozzle-to-safe-end welds during the spring 2013 refueling outage to meet the baseline examination requirements of 10 CFR 50.55a(g)(6)(ii)(F). Examination personnel, procedures, and equipment were qualified in accordance with ASME Section Xl, Appendix VIII, Supplement 10 requirements as modified by the Performance Demonstration Initiative (PDI). The examinations will be performed to the extent possible using phased array ultrasonic examination technology. No further examination coverage of the required examination volume is possible due to the weld geometry and surface configuration. Configuration of the subject welds is identified in the enclosed Figures 1 through 8.
Estimated Mark/Weld #
Line #
Scan Coverage %
Figures*
(axial & circumferential)
Loop A Welds:
N-SE29 IN.
29-RC-401 88%
A-1 N-SE31 IN.
31-RC-402 88%
A-2 Loop B Welds:
N-SE29 IN.
29-RC-404 88%
B-1 N-SE31 IN.
31-RC-405 88%
B-2 Loop C Welds:
N-SE29 IN.
29-RC-407 88%
C-1 N-SE31 IN.
31-RC-408 88%
C-2 Examination results will be forwarded once examinations are completed during the spring 2013 refueling outage.
The nozzle-to-safe-end dissimilar metal welds will be examined with encoded phased array ultrasonic examination technology from the outside surface in both the axial and circumferential beam directions. The examination procedure was optimized to account for the 11 degree outside diameter (OD) taper of the safe-end by adjusting the focal laws to produce inside
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 Interval Alternative Request N2-14-LMT-001 Page 3 of 14 surface impingement angles representing those of the Appendix VIII, Supplement 10 qualified procedure.
Examination of these welds are limited in the axial beam direction for the detection of circumferentially oriented flaws due to the length of the safe-end scan surface and the adjacent weld. The estimated coverage of the required examination volume is approximately 88%, with the restricted volume consisting primarily of the safe-end base material and a small portion of the weld material.
The weld examination in the circumferential beam direction for axially oriented flaws is not impacted by the component configuration and essentially 100% coverage of the examination volume is expected.
The Unit 2 steam generator primary loop nozzles are Alloy 82/182 butter welds with Alloy 52/152 weld inlays. Under the previous MRP-1 39, Revision 1, inspection program, these welds were considered resistant to primary water stress corrosion cracking (PWSCC). The welds were inspected per Code Case N-722 and 10 CFR 50.55a(g)(6)(ii)(E), with bare metal visual examinations of the cold legs each inservice inspection interval and the hot legs each refueling outage. Ultrasonic examinations of two of these welds were performed early in the Third Inservice Inspection interval as Risk-Informed ISI selections. Third interval examination of the Loop A SG nozzle-to-safe-end welds N-SE29 IN. (29-RC-401) and N-SE31 IN. (31-RC-402) achieved 80 percent coverage. This coverage was approved by the NRC on August 17, 2012 for Relief Request N2-13-PRT-002 (TAC No. ME7180).
In accordance with the requirements of MRP-1 39, these welds were considered mitigated because of the PWSCC resistant Alloy 52/152 barrier applied on the inside surface of the dissimilar metal welds (DMWs) during manufacture. Per design, the inlay material can be either ERNiCrFe-7 (Alloy
- 52) or ENiCrFe-7 (Alloy 152) depending whether the Gas Tungsten Arc Welding (GTAW) or Shielded Metal Arc Welding (SMAW) process was utilized (reference Figure 1). Both Alloy 52 and 152 have a specified minimum chromium content of 28% (per Reference 8.6). Therefore, an adequate thickness of the inlay material would effectively protect the Alloy 82/182 DM weld and butter from the initiation of PWSCC. Maintaining a nominal chromium content greater than 24%
has a proven effectiveness in mitigating PWSCC, and is not an expected degradation mechanism in the Unit 2 DMWs.
5.0 PROPOSED ALTERNATIVE AND BASIS FOR USE Dominion proposes that the combined axial and circumferential examination volume coverage of approximately 88 percent, to be obtained during the spring 2013 refueling outage, provides reasonable assurance of the structural integrity of the Unit 2, RCS Loops A, B, and C, six Steam Generator nozzle-to-safe-end welds, and that those examinations may be credited as baseline examinations per the requirements of ASME Code Case N-770-1, as conditioned in Final Rule 10 CFR 50.55a(g)(6)(ii)(F)(3) which became effective June 21, 2011. Acceptance of the reduced examination volume is based on the following:
North Anna Power Station will utilize volumetric examination techniques that are qualified to the requirements of ASME Section XI, Appendix VIII, as required in 10 CFR 50.55a(g)(6), that will achieve the maximum practical amount of coverage obtainable within the limitations imposed by the design of the Steam Generator nozzles. Additionally, bare-metal visual (BMV) examinations for leakage (VE examinations in accordance with ASME Code Case N-722-1) were performed on the Steam Generator nozzle DMWs during the fall 2011 refueling outage (during the current interval),
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 Interval Alternative Request N2-14-LMT-001 Page 4 of 14 and will continue as required by Code Case N-722-1 and the station's Boric Acid Corrosion Control Program. To date, those examinations identified no evidence of leakage at the Steam Generator nozzle-to-safe-end DMWs. The combination of the limited volumetric and BMV examinations provides confidence that an acceptable level of quality and safety has been maintained.
The examinations will be performed to the extent possible. The applicable procedure utilizes encoded phased array technology to provide data imaging, which allows off-line analysis by multiple qualified examiners. The examinations are to be performed with a series of beam angles in order to interrogate the examination volume. Low inside impingement angles, i.e., 30 degrees, were qualified to ASME Section Xl, Appendix VIII, Supplement 10 requirements as modified by the Performance Demonstration Initiative (PDI), and will be applied to maximize coverage of the examination volume where restricted scan areas exist.
Based on existing fabrication records, the DMWs final inside diameter (ID) welding would have been completed using the Automated GTAW process with weld filler materials having a minimum chromium content of 28% (i.e., Alloy 52). The fabrication records also show that the Alloy 52 material would have filled the last 0.27" of the Safe-End DM weld grove. Documentation from Westinghouse engineering has confirmed that it is conservative to assume a minimum of two weld layers were used in the application of the weld inlays, while maintaining the >24% chromium content of the weld surfaces that contact the primary water. After final machining, the Alloy 52 inlays have a nominal thickness of 0.13", and the Alloy 52 cladding tie-in to the nozzles have a nominal thickness of 0.22". Figure 7 illustrates the final configuration and filler materials used during the construction of the Nozzle-to-Safe-End DMWs. The completed DMWs received a final visual, liquid penetrant, radiographic, and ultrasonic nondestructive examinations for ASME Section III and Section Xl acceptance or initiation of any repairs.
6.0 DURATION OF PROPOSED ALTERNATIVE The proposed alternative in this request if approved will be applicable for the fourth 10 year ISI interval for NAPS 2 which ends December 13, 2020.
7.0 PRECEDENTS 7.1 NAPS Unit 2 Relief Request N2-13-PRT-002 (TAC No. ME7180) granted Third Interval relief for 80 percent coverage of Loop A SG nozzle-to-safe-end welds N-SE29 IN. (29-RC-401) and N-SE31 IN. (31-RC-402) approved August 17, 2012.
7.2 Calvert Cliffs Nuclear Power Plant Relief Requests RR-ISI-04-06 & ISI-04-07 (TAC No.
ME7791) for Limited ASME Code Case N-770-1 Inspection Coverage, approved December 19, 2012.
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4th Interval Alternative Request N2-14-LMT-001 Page 5 of 14
8.0 REFERENCES
8.1 ASME Code Section XI, 2004 Edition with No Addenda.
8.2 Summary of Public Meeting Between The Nuclear Regulatory Commission Staff and Industry Representatives On Implementation Of ASME Code Case N-770-1, August 12, 2011 8.3 ASME Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated With UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities,"Section XI, Division 1, Approval date: December 25, 2009.
8.4 Electric Power Research Institute, "Material Reliability Program: Primary System Piping Butt Weld Inspection and Evaluation Guideline, (MRP-139, Revision 1)," December 2008 (ADAMS Accession No. ML100970671).
8.5 Westinghouse Letter LTR-SGDA-06-79,
Subject:
"North Anna Unit 2 Replacement Steam Generator Safe End to Inlet and Outlet Nozzle Welds," June 28, 2006.
8.6 ASME Section II, Part C, SFA-5.11/SFA-5.11M and SFA-5.14/SFA-5.14M
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Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4th Interval Alternative Request N2-14-LMT-001 FIGURE 3 Page 8 of 14 031 53H 03 NOTE 13 049 25 REF O2,00 MIN R BLEND E NOTE 23 STEP 2 NOZZLE WELD OVERLAY BUILOUP AND NOZZLE BORE I D MACHINING
FIGURE Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 th Interval Alternative Request N2-14-LMT-001 4
Page 9 of 14 GTAW. SFA-S 14 CL ERNiCrF'-7 SMAW, SPA-5 1 CL ENt~rFo-?
PWHT SEE NOTES 5 7, 8 AND 10 2 25 25 VT-P UT-F -<SEE NOTE 15 030 63 MAX
[WELD OVERLAYi GTAW SFA-B 9 CL ER3*OL UIST LAYER)
OR SMAW SFA-5 4 CL E309L (IST LAYER)
AND IN ADDITION TO ONE OF 'THE ABOVE GTAW SFA-3 9 CL ER3O8L (REM LAYERS)
OD SMAW S*A-5 4 CL E306L (REM LAYERS)
PWH T SEE NOTES 5 7 AND 10
-UT F -<SEE NOTE 15 STEP 3 NOZZLE BORE WEL 0 OVERLAY BUILDUP AND NOZZLE CONE WELD CLAD TIE-IN
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 th Interval Alternative Request N2-14-LMT-001 FIGURE 5 Page 10 of 14
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STEP 4 NOZZLE END BORE AND CONE SECTION WELD OVERLAYS FINAL MACHINING
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 th Interval Alternative Request N2-14-LMT-001 FIGURE 6 (Pg l of 2)
Page 11 of 14 GENERAL NOTES FOR CHANNEL HEAD NOZZLES, MANWAYS, SUPPORTS AND BOWL I ALL FABRICATION SHALL MEET THE REQUIREMENTS OF THE ASME BOILER AND PRESSURE VESSEL
{ASME B6PVI CODE SECTION 1II, NB-4000 CAUTION AIR ARC GOUGING OR OXY-FUEL CUTTING IS PROHIBITED WITHIN 25 OF THE FINAL SURFACE OF STAINLESS STEEL AND NI -Cr ALLOY MATERIALS 2
WESTINOHOUSE PENSACOLA PLANT IWPPI PROCESS SPECIFICATION 'PSI 8331BLW CLEANLINESS CONTROLS AND CLEANING REQUIREMENTS APPLY INCLUDING TABLE I VERIFICATIONrINSPECTION POINTS AND ACCEPTANCE CRITERIA 3 AXE$
DATUM PLANE W-Y AND AXES DATUM PLANE X-Z SHALL BE THE SAME AS THOSE SHOWN ON THE PREVIOUS AND SUBSEQUENT DRAWINGS IN ORDER TO MAINTAIN MACHINING AND INSPECTION ORIENTATION DATUM AXES ANO SUPPLIER IDENTIFICATION MARKINGISt SUBSEQUENTLY REMOVED DURING MACHINING SHALL FIRST BE RECORDED THEN TRANSFERRED IN ACCORDANCE WITH ESTABLISHED MATERIAL CONTROL PROCEOURES.
4 CAUTION LIFT USING A MINIMUM OF TWO (21 LUGS AND SUITABLE LIFTING EQUIPMENT IN A SAFE LIFTING ARRANGEMENT 5 ALL WELDING OF PRESSURE BOUNDARY PARTS ATTACHMENTS THERETO AND SAFETY RELATED ITEMS SHALL MEET THE ASME B&PV CODE SECTION Ill, NB-4000 AND SECTION IX WELD REQUIREMENTS AND THE REQUIREMENTS OF WPP POST WELD HEAT TREATMENT IPWHTI PROCESS SPECIFICATION (PSI 83031WR NOZZLE SAFE END PRESSURE BOUNDARY WELDS REQUIRING IN-SERVICE INSPECTION SHALL BE PERMANENTLY MARKED IN A MANNER SATISFYING THE ASME B&PV CODE SECTION XIS IWA-Z2O0 WELD REFERENCE SYSTEM CRITERION MARK THE STARTING NUMBERLOCATION CLOSEST TO THE WORKLINE ELEVATION WITH ALL OTHER NUMBERS SEQUENCED CLOCKWISE IN THE NOZZLE END VIEW 6
WPP PS S4900RM WELD ACCEPTANCE STANDARD APPLIES,
- 7. ALL WELDING CONSUMABLES SHALL BE IN ACCORDANCE WITH WESI INGHOUSE WELD MATERIAL SPECIFICATIONS UNLESS SPECIFICALLY AUTHORIZED OTHERWISE BY WPP B ALL NON-FERROUS AND AUSTENITIC STAINLESS STEEL WELD CONSUMABLES USED FOR OVERLAY WELDS ONTO ASME B&PV CODE SECTION Ill PRESSURE BOUNDARY MATERIAL HAVINO PRESSURE BOUNDARY, PRESSURE RETAINING OR SAFETY RELATED ITEMS ATTACHED THERETO SHALL MEET WPP ENGINEERINO MATERIAL SPECIFICATION EMSI UIOOCO2.
S WELD OVERLAY MATERIAL THICKNESS VARIES WITH WELD PROCESS USED AND NUMBER OF LAYERS DEPOSITED.
THE 13 MINIMUM FINAL WELD OVERLAY THICKNESS SHALL BE MAINTAINED AFTER REPAIR WELDINO AND SURFACE RECONDITIONING LOCAL AREAS OF WEL0 REQUIRINO UPGRADE TO MEET ACCEPTANCE STANDARDS SHALL BE RADIUSED 25 MINIMUM ON THE BOTTOM AND TAPERED 4-TO-I MINIMUM ON THE SIDES, LEAVING NO DISCERNIBLE EDGES AT THE SURFACE, WITH E,/
SURFACE FINISH OR BETTER 10 WELD OVERLAY DEPOSITS SHALL BE PWHT AT 1125iF'2S'F FOR 0 75 HOUR MINIMUM
[BUT LESS THAN 1 25 HOURS MAXIMUM IF ONLY A SOLITARY WELD PWHTI IN ACCORDANCE WITH THE ASME BaPV CODE SECTION III NB-4OO REQUIREMENTS. EXCEPT THAT ALTERNATIVE HOLDING TEMPERATURES AT LONGER TIMES ARE PROHIBITEO It VERIFY iI? MINIMUM DISTANCE FROM CHANNEL HEAD OPEN END WELD JOINT PREP IS FREE OF WELD OVERLAY MATERIAL AC ID E TCH PER WPP PS B31145M IF BOND LINE IS NOT VISIBLE 12 A THE PARTITION PLATE (ITEM 02 OR 051 SHALL BE CENTERED WITHIN 12 TRUE POSITION OF THE CHANNEL HEAD DIVIDER LANE CENTER LINE THE PARTITION PLATE MAY NOT BE WELD ASSEMBLED UNTIL AFTER CHANNEL HCAD PWHT COMPLETION CAUTION ORIENT PARTITION PLATE CORNER END WELD JOINT PREP SINGLE BEVEL OPENING TOWARDS THE Y Z AXES QUADRANT B
THE FINAL LAYER OF THE PARTITION PLATE [ITEM 02 OR OS WELD ASSEMBLY SHALL BE DEPOSITED USING SNAW SFA-S II CL ENiCrF&-7 AND/OR GTAW, SFA-S i4 CL ERNiCrFG-7 WELD ELECTRODES ONLY THESE MATERIALS SHALL COVER ALL PREVIOUSLY DEPOSITED PARTITION PLATE ATTACHMENT WELD SURFACES WELD REPAIRS, IF ANY, TO THE EXPOSED FINAL WELD SURFACES SHALL BE MADE WITH SMAW SFA-S II CL ENiCrFE-? AND/OR GTAW SFA-5 O1 GTAW SFA-5 14 CL ERNtCrFe-7 MATERIALISt 13 ALL EXAMINATIONS SHALL MEET THE ASME BSPV CODE SECTION Ill NB-D00D REQUIREMENTS WITH THE ADDITIONAL RESTRICT ION OF 25 MAXIMUM LENGTH FOR THE NB-5I30 I LAMINAR TYPE IMPERFECTIONS 14 WHERE MORE THAN 12 MATERIAL IS REMOVED FROM THE CHANNEL HEAD MACHINED FORGING SURFACE, THE EXPOSED ACCESSIBLE SURFACE SHALL BE MT EXAMINED TO ASME BAPV CODE SECTION Ili, NB-2540 REQUIREMENTS CAUTION USE YOKE METHOD ONLY ON CHANNEL HEAD FINISHED SURFACES I
ULTRASONIC TEST lUTI ALL CHANNEL HEAD WELD OVERLAY MATERIAL FOR.ACK OF BOND AND FOR DEFECTS CER THE ASME BPV CODE SECTION V, ARTICLE 5, PARAGRAPH T-543, TECHNIQUES I AND 2 CALIBRAT.ION SHALL BE BASED ON A 12S DIAMETER FLAT BOTTOM HOLE FOR TECHNIQUES I AND Z ANY INDICATION PRODUCING AN AMPLITUDE IN EXCESS OF THAT OBTAINED FROM THE CALIBRATION STANDARD Is UNACCEPTABLE t6 PRIOR TO MANWAY WELD OVERLAY CLADOINO A MEASURE AND RECORD MANWAY BORE AS-BUILT INSIDE DIAMETER AND BORE CONCENTRICITY WITH RESPECT TO REFERENCE DATUM DIAMETER
-E-SURFACE ENCIRCLING THE PAD OUTER RIM B MEASURE AND RECORD MANWAY FACE AS BUILT COUNTERBORE DEPTH WITH RESPECT TO THE REFERENCE DATUM STEP SURFACE -J-ENCIRCI INO THE PAD OUTER RIM CAUTION VERIFY AMOUNT OF MACHINE STCCK ON MANWAY RAISED PAD BEFORE MACHINING TO MANWAY PAD IN TERF'ACE COORDINATES (43 66 AND 45 281 ADJUST INTERFACE COORDINATES WITHIN DRAWING SPECIFIED TOLERANCES TO MAINTAIN 28 MINIMUM DISTANCE FROM PAD FINAL MACHINED FACE TO REFERENCE DATUM SURFACE -J-11 A SURFACE FIN bH RANGE OF 12ý/
TO.2D, AS JUDDED BY VISUAL COMPARISON WITH AA STANDARDS IS REQUIRED WITHIN THE GASKET SEATING SURFACE ZONE THE SURFACE TEXTURE OF THE GASKET SEATING SURFACE SHAL.I BE FORMED IN A CIRCULAR LAY, WITH EITHER A CONCENTRIC SERRATED OR CONTINUOUS SPIRAL IPHONOORAPFIICI FINISH, HAVING 35 TO 40 GROOVES PER RADIAL INCH PRODUCED WIT,( A 06 MINIMUM RADIUS ROUND NOSE CUTTING 'TOOL CAUTION TOOL MARKS ARE NOT PERMIT TED IN THE RADIAL UIRECTION ANYWHERE ON THE GASKET SEATING SURFACE 1B CAUTION PROTECT FINAL MACHINED SURFACE WITH SUITABLE COVERING, AFTER CLEANING, IMMEDIATELY FOLLOWING MACHINING 19 ALL MANWAY I 875 SUN 26 THREADS SHALL BE VERIFIED PER ANSI/ASME 6I 3M SYSTEM 22 GAGING SYSTE MY FOR FULL LENGTH OF THREADS (REF JOHNSON GAGE OR EGUIVALENTI SURFACE F INISH ON I 85 BUN-ZB THREADS SHALL BE I2ZV OR BETTER AS JUDGED BY COMPARISON WITH AA STANDARDS 20 VISUALLY INSPECT THREADS FOR COMPLETE THREAD PROFILE AND 12,5' MAX SURFACE FINISH APPEARANCE.
CHECK THREAD FORM ACCEPTABILITY WITH CERTIFIED GO, NO-GO PLUG CADE
- 21. C.HANNFI HEAR RIM 3 nT AN" FNTN WVI nI P*FP 5hi I NI nw" MA"IJNurC lINTi FpAMO rTinm "r 'Tw
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 th Interval Alternative Request N2-14-LMT-001 FIGURE 6 (Pg 2 of 2)
Page 12 of 14 SPECIFIC NOTES FOR THE CHANNEL HEAD NOZZLE END BUILDUP AND SAFE END WELD 2Z RECORD NOZZLE END AXIAL DISTANCE FROM QATUM SURFACE AT EACH OF THE FOUR SET-UP BLOCKS AROUND THE NOZZLE OUTSIDE BODY REPORT ALL FOUR MEASUREMENTS TO ENGINEERING IF VARIANCE EXCEEOS 03 RANGE AVERAGE ALL FOUR MEASUREMENTS FOR DIMENSION
'L' AS-BUILT ARIAL L.ENGTH 23 PRIOR TO WELD OVERLAY, RECORD THE NOZZLE FORGING INTERNAL SLOPED SURFACE AS-BUILT ANGLE FROM NOZZLE BORE CENTERLINE AT FOUR (41 EQUALLY SPACED LOCATIONS AROUND THE NOZZLE INTERIOR MACHINE NOZZLE WELD OVERLAY TAPER PARALLEL TO NOZZLE FORGING AS-BUILT TAPER. MAINTAININO 13 MINIMUM CLAD THICKNESS THROUOHOUT 24 MAGNETIC PARTICLE TEST (MTI THE NOZZLE FORGING BASE METAL IITEFI OIl SURFACE AREAS SHOWN PRIOR 1O WELD OVERLAY BUILDUP PER ASME BAPR CODE SECTION 11, NB-5130 REQUIREMENTS WITH THE ADDITIONAL RESTRICTION OF.OS MAXIMUM LENGTH FOR NB-SIGIibl LAMINAR-TYPE IMPERFECTIONS.
25, NOT USED 26 PWHT NOZZLE END WELD OVERLAY BUILDUP PER ASME B&PV CODE SECTION II1, NS-4D00 REOUIREMENTS FOR I 75 HOUR MINIMUM, 2 25 HOUR MAXIMUM AT IIZSOFt2SOF.
27 IREMOVEOt 26 WELD PREHEAT POST WELD BARE AND POST WELD HEAT TREATMENT ARE NOT REQUIRED PROVIDING WELD DEPOSIT MATERIAL MAIJTAINS IS MINIMUM DISTANCE FROM THE BOND LINE BETWEEN THE NOZZLE FORDING FERRITIC MATERIAL AND THE NJCrFI WELD OVERLAY BUILOUP.
29 RADIOORAPHIC TEST IRTI EXAMINE THE ENTIRE NOZZLE END WELD OVERLAY BUILDUP AND THE I 0, TIE-IN THE SAFE END WELD AND SO MINIMUM TO EACH SIDE TO THE ASME B&AV CODE SECTION ItI, NB-SOO REQUIREMENTS PRIOR TO FINAL OU SIDE CONTOUR MACHINING 30 ULTRASONIC TEST !UTI EXAMINE THE FrINAL WELD TO ASME BAPV COOE SECTION XI, IWB-ESO0 REQUIREMENTS PRIOR TO FINAL OUTSIDE CONTOUR MACHINING THE NOZZLE FINAL OUTSIDE SURFACE CONTOUR SHALL BE SUITABLE FOR ASME BAPV CODE SECTION XI ULTRASONIC EXAMINATION 31 THE SAFE END 11o SLOPE MUST INTERSECT THE SAFE ENO WELD CENTER LINE ON THE NOZZLE DO WITHIN '.03 INCH BLEND SLOPE TO PROVIDE A SMOOTH TRANSITION INO STEPS OR UNDERCUTSI TO EXISTING OUTSIDE Sý.OPE (HI NOMINAL)
OF NOZZLE END WELD OVERLAY BUILDUP.
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PENETRANT TEST IPTJ THE FINAL MACHINED SURFACES OF THE PRIMARY NOZZLE SAFE END FORGING THE SAFE END WELD THE NOZZLE ENO BUILDUP, AN0 THE NOZZLE INSIDE CLADOING ANO OUTSIDE FORGING WIT 4HIN THE EXAMINATION ZONE SHOWN PER THE ASME O&PV CODE SECTION Ill. NB-SOOO REQUIREMENTS INDICATIONS WITH MAJOR DIMENSIONS GREATER THAN.03 SHALL BE REPORTED TO ENOINEERING FOR INFORMATION ONLY 33 FILL THE F;NAL 77 MINIMUM THICKNESS ON THE NOZZLE BORE SIDE OF THE SAFE END WELD-TO-CHANNEL HEAD NOZZLE WITH THE DESIGNATED WELD FILLER MATERIAL PRIOR TO FINAL MACHINING OF THE SAFE END AND NOZZLE BORE INSIDE DIAMETER (4 UNIT I HOT LEG NOZZLES MODIFIED FER STRUCTURAL INTEGRITY DRAWINGk 110A226.510 IN ACCORDANCE WITH DESIGN CHANGE DC NA-11-01047.
Serial No.13-189 Docket No. 50-339 NAPS Unit 2 4 th Interval Alternative Request N2-14-LMT-001 FIGURE 7 Page 13 of 14 Possible material removed during final machining Safe End to Nozzle Weld (Alloy 82)
- Nozzle Buttering (Alloy 82)
- Stainless WO Steel Cladding (0.22" Nominal Clad Thickness)
Notes:
- 1) 0.27" minimum deposited thickness of Alloy 52 prior to final machining of the Safe End and Nozzle Bore inside diameter.
Approx. 0.13" nominal Alloy 52 deposit thickness following final machining.
Note: The above sketch details the weld classifications used during fabrication based on available records. The actual weld materials/classifications used may vary depending on the fabrication repair history for the individual Nozzle-to-Safe End Dissimilar Metal Weld.
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