AP1000 Response to Request for Additional Information (SRP ... · All of the Grafoil Rings used for...

B Westinghouse

U.S. Nuclear Regulatory CommissionATTENTION: Document Control DeskWashington, D.C. 20555

Westinghouse Electric CompanyNuclear Power PlantsP.O. Box 355Pittsburgh, Pennsylvania 15230-0355USA

Direct tel: 412-374-6206

Direct fax: 724-940-8505

e-mail: [email protected]

Your ref: Docket No. 52-006Our ref: DCPNRC_002996

August 3, 2010

Subject: AP1000 Response to Request for Additional Information (SRP 5)

Westinghouse is submitting a response to the NRC request for additional information (RAI) on SRP

Section 5. This RAI response is submitted in support of the AP1000 Design Certification AmendmentApplication (Docket No. 52-006). The information included in this response is generic and is expected toapply to all COL applications referencing the AP1000 Design Certification and the AP1000 Design

Certification Amendment Application.

Enclosure 1 provides the response for the following RAI(s):

RAI-SRP5.2.3-CI 1-03 R2

Questions or requests for additional information related to the content and preparation of this responseshould be directed to Westinghouse. Please send copies of such questions or requests to the prospectiveapplicants for combined licenses referencing the AP1000 Design Certification. A representative for each

applicant is included on the cc: list of this letter.

Very truly yours,

Robert Sisk, ManagerLicensing and Customer InterfaceRegulatory Affairs and Strategy

/Enclosure

1. Response to Request for Additional Information on SRP Section 5

8/3/2010 8:41 AM0618]jb.doc

DCPNRC 002996August 3, 2010

of 2

cc: D. JaffeE. McKennaP. BuckbergT. SpinkP. HastingsR. KitchenA. MonroeP. JacobsC. PierceE. SchmiechG. ZinkeR. GrumbirJ. DeBlasio

U.S. NRCU.S. NRCU.S. NRCTVADuke PowerProgress EnergySCANAFlorida Power & LightSouthern CompanyWestinghouseNuStart/EntergyNuStartWestinghouse

1E1E1E1E1E1E1E1E1E1E1E1E1E

06181jb.doc 8/3/2010 8:41 AM

DCPNRC 002996August 3, 2010

ENCLOSURE 1

Response to Request for Additional Information on SRP Section 5

0618 jb.doc 8/3/2010 8:41 AM

AP1000 TECHNICAL REPORT REVIEW

Response to Request For Additional Information (RAI)

RAI Response Number: RAI-SRP5.2.3-CIB1-03Revision: 2

Questions (Revision 0):

Discuss the Quickloc component specified in AP1 000 DCD, FSAR Figure 5.3-1 toinclude at least the following information. A summary of this information should beincluded in the DCD.

1) What materials are used?2) How is it welded to the top head?3) Discuss how the pressure boundary is maintained with the Quickloc?4) Is the Quickloc a flared, flareless or compression type mechanical

fitting? Are flanges or gaskets used?5) Provide a drawing/sketch detailing the Quickloc, including the

dimensions?6) Discuss operating experience of the Quickloc.7) Are Quickloc addressed in the ASME Code?8) What type of inspections and maintenance is performed for this

component (Quickloc fittings and the weld for the Quickloc to the reactorvessel head) to ensure the integrity of the pressure boundary.

Additional Questions (Revision 1): /

Based on your January 15, 2010 response to RAI SRP 5.2.3-CIB1-03 Revision 0, thestaff has the following supplemental requests for additional information:

a) The following is in regards to Westinghouse's response to question 2:i. What are the dimensions of the weld buildup, and is this

considered a weld buildup reinforcement to accommodate a weldprep, or is it considered to be a piping nozzle based on the weldbuildup dimensions?

ii. Provide the filler materials used for the weld buildup and the Ni-Cr-Fe weld buttering and include them in the AP1 000 DCD.

b) In response to question 3, Westinghouse specified a Quickloc compressioncollar. Discuss how this compression type fitting meets ASME Code, Section III,Subsection NB-3671.4.

c) In response to question 8, Westinghouse stated that every time a pressureboundary part of the Quickloc is disassembled; the Grafoil seals are replaced,which includes the Quickloc Seal Carrier Assembly. In addition, it was specifiedthat the sealing areas are inspected for scratches or any other imperfections thatmay prevent a proper seal and the threads of the Quickloc Nut and Quicklocinstrumentation nozzle are visually inspected.

RAI-SRP5.2.3-CB1-03 R2Page 1 of 25



i. Since this is an application that is not specifically addressed in theASME Code, and is used to ensure the integrity of the reactorcoolant pressure boundary, these requirements should beincluded in the DCD.

ii. In addition, since this is a specific application, the DCD shouldinclude the installation inspection and inservice inspectionrequirements and acceptance criteria.

iii. It should be clarified that buttering, dissimilar metal weld and theweld buildup used to fabricate the nozzle for which the Quicklocinstrumentation nozzle is welded to, should be inspected to therequirements of ASME Code, Section III, Section NB-5000,including radiographic and surface examinations.

d) In response to question 8, Westinghouse provided nineteen inspection notes forthe Quickloc instrumentation nozzle, the dissimilar metal weld and the weldbuildup as listed on the design drawing. The following is in regards to thesenotes:

i. Note 9 specifies that a radiographic test be performed on theentire weld. This note should be clarified so that the entire weldincludes the weld buildup, the buttering and the dissimilar metalweld. These welds form the pressure boundary and are requiredto receive an inspection to verify the pressure boundary integrity.

ii. Note 16 specifies that the dissimilar metal weld requires inserviceinspections per the ASME Code, Section Xl, Table IWB-2500-1,Item Number B5.10. Since the specifics of the Quickloc assemblyare not covered in the ASME Code, the weld buildup and the weldbuttering should also receive inservice inspections since it is partof the reactor coolant pressure boundary, and its integrity shouldbe verified.

iii. Note 8 specifies that the dissimilar metal weld should beultrasonically inspected to the requirements of ASME Code,Section III, Subsection NB-5000 and Section Xl, Subsection IWB-2500. This should be clarified so that Section XI applies toinservice inspection only.

Additional Questions (Revision 2):

1) In response to RAI Rev. 1 question 1 d (ii), Westinghouse stated that theQuickloc nozzle weld buildup is a base metal weld buildup and is considered anextension of the reactor vessel closure head forging and would not require futureISI. Discuss why the pressure boundary weld buildup does not require ISI perASME Code, Section XI, since even an attachment weld to the reactor vessel,Examination Category B-K, requires a surface examination. This discussionshould also include how the structural integrity of this pressure boundary will bemaintained.

RAI-SRP5.2.3-cIBl-03 R2Page 2 of 25


Response to Request For Additional Gnformation (RAI)

2) In response to question RAI Rev. 1 c (iii) and 1 d (i), Westinghouse stated thatNote 9 would be revised to clarify that the dissimilar metal weld and the weldbuttering shall receive radiographic examination. Therefore, Note 9 shoulddelete "Where noted."

Westinghouse Response (Revision 0):

1) Below is a list of the Quickloc parts and their associated materials.

Quickloc Part Name Material TypeQuickloc Can SA-213, Type 304 SSTQuickloc Can Base SA-479, Type 304 SSTQuickloc Grafoil Ring Grafoil (See additional

information below)Quickloc Spring AMS 5699G, UNS

N07750*Quickloc Plug SA-479, UNS S21800Quickloc Tube Flange SA-479, Type 304 SSTQuickloc Seal Carrier SA-479, Type 304 SSTQuickloc Inner Ring SA-479, Type 304 SSTQuickloc Outer Ring SA-479, Type 304 SSTQuickloc Inner Grafoil Ring Grafoil (See additional

information below)Quickloc Outer Grafoil Ring Grafoil (See additional

information below)*Quickloc Compression Collar SA-479, Type 304 SST*Quickloc Nut SA-479, UNS S21800*Quickloc Modified Swagelok Body SA-479, Type 316 SST

Quickloc Hold Down Screw SA-1 93, GRD B8MQuickloc Large Locking Cup SA-479, Type 304L SSTQuickloc Alignment Screw SA-193, GRD B8MQuickloc Stalk Bottom Flange SA-479, Type 304 SSTQuickloc Stalk Stabilizer Flange SA-479, Type 304 SSTQuickloc Stop SA-479, Type 304 SSTQuickloc Pin SA-479, Type 304 SST*Swagelok Plug SA-479, Type 316 SST*Quickloc Instrument Nozzle SA-1 82, Type F304 SST

* Pressure Boundary Parts

All of the Grafoil Rings used for the Quickloc are made from the same material.The raw material used in forming the Grafoil Rings is Graftech Advanced EnergyTechnology Inc. Grafoil Brand Flexible Graphite, Grade GTJ (99% Graphite) orWestinghouse approved equivalent, refer to the attached Technical Bulletin 102on the following two pages. It has a nominal density of 70 Ibs/ft3. The final die

OWestinghouseRAI-SRP5.2.3-CIBl-03 R2

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formed Grafoil Rings have a density of 90 Ibs/ft3. Grafoil Grade GTJ is premiumflexible graphite that was developed for use in nuclear applications. Grafoil hasbeen used in numerous pressure boundary applications in the nuclear industry.In addition to Quickloc, Westinghouse uses Grafoil in the CETNA, theMechanical Nozzle Seal Assembly (MNSA), the Canopy Seal Clamp Assembly(CSCA) and Incore Instrument Plugs.

O WestinghouseRAI-SRP5.2.3-CIB1-03 R2

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The following information is from Graftech Advanced Energy Technology Inc.

standard fluid sealing(• GradGT

TECHNICAL BULLETIN 102

Grade GTJ Specification'

GRAFOIL GTJ premium flexible graphite Is an oxidation corrosion inhibited grade developed for use in nuclearapplications. It is certified to meet the most rigorous purity specifications of the nuclear industry, including theGeneral Electric Nuclear Nonmetallic Material Specification DSOYPI2 (Rev 2).

IN EN LI _ _ _ _ _ _ _ _ _ _ _

CHARACTERISTIC 1--_bn

Thickness0.0IS" (0.38 mm) Standard0.030" (0.76 mm) StandardNon-standard thicknesses may be available upon requestTolerance +/- 0.002" (+/- 0.05 mm)

ASTM F-104 Hand HeldMicrometer

24" (610 mm) StandardWidth Non-standard widths may be available upon request Tape Measure

Tolerance +/- 0.25" (+1- 6.35 mm)100' (30.5 m) Standard

Length Non-standard lengths may be available upon requestTolerance +31-0' (+11-0 m)70 Ib/fe (1. 12 g/cc) Standard

Bulk Density Non-standard densities may be available upon request ASTM F-1315Tolerance +/-10%

Ash Content 1.0% Maximum ASTM C-561Carbon Content 99.0% Minimum ASTM C-561Leachable Chloride 50 ppm Maximum ASTM F -1277Phosphorus 250 ppm Minimum Colormetric DeterminationSulfur Content 630 ppm Maximum LECO Combustion Method

Tos4S ppn Maximum Parr Bomb followed byTotal Halogens 4Ion Chromatography

Aqueous ExtractionTotal Nitrates 820 ppm Maximum followed by Ion

I ChromatographyAqueous Extraction

Total Nitrites 5 ppm Maximum followed by IonChromatography

Certification Certify to Grade

C1Tol2 ens5. m rn( ÷ C35.453 4.+ Total Nitrates ipom7

< 13.2 ppm1,- 62.004

ITypkcal properte re alisted under Technical Buletin 437.P o I d2

For additional infarintuee. caontact the Graffed1 Sales Office + I (800) 253-8003 (Toll-Free in USA). + 1 (216) 529.3777 (nterneaationa ÷1 (216) 529-3922 (Fax)

T5102-GF-GTI-SPEC doc Updated: 11101 2006 Advanced Energy Technoloep, Inc. All Rights Reserved.

Co be taken as waranty efrepresentaien for which we ml aucrme legal respovn'sbl .

* WestinghouseRAI-SRP5.2.3-CIB1-03 R2

Page 5 of 25



777 -777 N"'W, -71ý7-- 71 7 7 "Yý % A

SEALING SOLUTIONS standard Puid sealing

( Grade GTJ )

Total Embrittling Metals

Tbttlin e 500 ppm Maximum X-Ray FluorescenceSieron (Ag ) 200 ppm Madmum X-Ray FluorescenceSadmive (Ad) 200 ppm Maximum X-Ray FluorescenceZA•snc (As) 200 ppm Maximum X-Ray FluorescenceA ctZimn (Sb) 200 ppm Maximum X-Ray FluorescenceCadmium (Ga) 200 ppm Maximum X-Ray FluorescenceBismuth (I) 200 ppm Maximum X-Ray FluorescenceMeadr (P ) 200 ppm Maximum X-Ray FluorescenceTium (G) 200 ppm Maximum X-Ray FluorescenceIndum In)200 ppm Maximum X(-Ra A Fluo esec

Lead (Pb) 200 ppm Maximum X-R1ayFursecTin (Sn) 200 ppm Maximum X-Ray Fl:uorescence12

Rev.: kApproved: Gary MllsDate: I

P.o. 2 d2For additional infzajhwi. c*imo dte GrofTech Sales Offce, + I (800) 253-8003 (Toll-free in USA), +1 (216) 529.3777 (Intemnaion4 + I (216) 529.3922 (Fx)

T9102-GF-GTf-SPlE-dý Updated: I4I/0=0 0 2006 Advanced Energy Technology. Inc. An Right Rer-ved.

ro be taken asn wwr ofrepresertacan fo rwich we will e mum4 repon.qb~.nt20Apr-DACWA DIOtfltnLSArV -., c11=2 týf... - A

O WestinghouseRAI-SRP5.2.3-C1B1-03 R2

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2) The Quickloc Instrument Nozzle (QIN) is the part that is welded to the top of theReactor Vessel Closure Head (RVCH) (refer to Figure 2-1)., Initially, there is a weldbuildup made of P3 material on the RVCH. This weld buildup is machined andcladding is applied to the inner diameter. On the top of the weld buildup a minimumof 0.50" NI-CR-FE weld buttering is applied. Then the QIN is welded to the weldbutter.

0;" =.URE •A

Figure 2-1: Quickloc Instrument Nozzle (QIN)

3) There are two (2) main pressure boundaries associated with Quickloc (see Figure 3-1 for pressure boundary components). There is a pressure boundary between theQuickloc Plug and the Instrument Thimble Assembly (IITA); this pressure boundary'is only disassembled when the IITA is replaced. The other pressure boundary isbetween the Quickloc Plug and the Quickloc Instrument Nozzle (QIN); this pressure


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boundary is disassembled when the RVCH is removed.

The pressure boundary between the Quickloc Plug and the IITA is as follows:

The pressure boundary is maintained with the Quickloc Plug through the ModifiedSwagelok Body. The Modified Swagelok Body is sealed to the Quickloc Plug by two(2) Grafoil Rings. The IITA is sealed to the Modified Swagelok Body by theSwagelok compression feature.

The pressure boundary between the QIN and the Quickloc Plug is as follows:

The other pressure boundary connection is between the QIN and the Quickloc Plug.Only after the Reactor Vessel Closure Head (RVCH) has been installed and hasbeen tensioned may the pressure boundary be put together. First, the Quickloc SealCarrier Assembly is installed (refer to Figure 3-2). The Quickloc Seal CarrierAssembly consists of one (1) Quickloc Seal Carrier, two (2) Quickloc Inner GrafoilRings, two (2) Quickloc Outer Grafoil Rings, one (1) Quickloc Inner Ring and one (1)Quickloc Outer Ring. Next a Quickloc Compression Collar is installed and then theQuickloc Nut is threaded on hand tight. A Quickloc Hydraulic Load Tool is then usedto apply an axial downward force on the Quickloc Compression Collar which in turncompresses the Quickloc Inner and Outer Grafoil Rings created a radial sealing forcebetween the QIN and the Quickloc Plug. While the hydraulic load is being appliedthe Quickloc Nut is hand tightened and this process is repeated two (2) more times.


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I ITAPOST

*QUICKLOCMODIFIED SWAGELOK

BODY

QUICKLOC GRAFOIL-...

*SWAGELOK PLUG

1'

RINGS %

QUICKLOC SEALCARRIER

QUICKLOC INNER ANDOUTER RINGS

*QUICKLOC COMPRESSION

COLLAR

QUICKLOC NUT

QUICKLOC INNER ANDOUTER GRAFOIL RINGS

*QUICKLOC INSTRUMENT

NOZZLE

*QUICKLOC PLUG -•

Figure 3-1: Quickloc Pressure Boundary(* Pressure Boundary Parts)

OWestinghouseRAI-SRP5.2.3-CIBI-03 R2

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API1000 TECHNICAL REPORT REVIEW


QUICKLOC INNER-\RING

QUICKLOC SEALCARRIER

QUICKLOC INNERGRAFOIL RINGS

QUICKLOC OUTERRING

QUICKLOC OUTERGRAFOIL RINGS

Figure 3-2: Quickloc Seal Carrier Assembly

4) Please refer to the response to Question 3 for an explanation of the Quicklocmechanical design.

5) Figure 3-1 shows the Quickloc pressure boundary configuration and Figure 2-1shows the Quickloc Instrument Nozzle (QIN) overall dimensions. The thread size onthe QIN and the Quickloc Nut is 6.25-5 ACME thread. All of the other parts of theQuickloc fit within the QIN. The envelope dimensions of the Quickloc Plug areapproximately 4.3" outside diameter by 7.5" long.

6) The Quickloc Stalk Assembly design has been installed in five (5) CombustionEngineering (CE) designed plants to date. These plants are Waterford Unit 3,Calvert Cliffs Units 1 and 2 and St. Lucie Units 1 and 2. Quickloc was a modificationfor these plants. The dates of the Quickloc installations are given in Table 6-1 below.

The Quicklocs that have been properly installed have not leaked. There have been afew situations where there have been leaks due to improper installation. For thesesituations the assemblies were disassembled and reassembled properly and theleakage stopped. Installation manuals are provided for the Quicklocs.


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Table 6-1: Quickloc Plants and Installation Date

Quickloc Plants Installation DateWaterford Unit 3 Fall 1995St. Lucie Unit 2 Spring 1997St. Lucie Unit 1 Fall 1997Calvert Cliffs Unit 2 Spring 2001Calvert Cliffs Unit 1 Spring 2006


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7) The Quickloc contains both pressure boundary and non pressure boundary (internalstructure) parts (refer to Figure 7-1). Requirements for evaluating are provided in theASME Boiler and Pressure Vessel Code, Section III Division I, Subsection NB for thepressure boundary parts. Subsection NG requirements have been specified for thenon pressure boundary parts.

RNAL STRUCTURE

-QUICKLOC STALKASSEMBLY

JICKLOC INSTRUMENT

Figure 7-1: Quickloc Jurisdictional Boundary(Dark Line)

O WestinghouseRAI-SRP5.2.3-CIBl-03 R2

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8) Quickloc Pressure Boundary Parts:

Shown below is an example of the inspection requirements for the machined non-integral Quickloc pressure boundary parts.

* The Quickloc Instrument Nozzle Pressure Boundary parts shall be designedand fabricated in accordance with ASME B&PV Code, Section III Division 1,Subsection NB, 1998 Edition up to and including the 2000 Addenda.Classified as a primary pressure boundary part.

* Intergranular corrosion test per ASTM A262-02a (Reapproved 2008) PracticeE required.

* Examination per Section III, Subsection NB-2540 is required.• Final machined part shall be liquid penetrant examined per Section III,

Subsection NB-2546.

Every time a pressure boundary is disassembled the Grafoil seals are replaced. Inthe case of the pressure boundary between the QIN and the Quickloc Plug, theentire Quickloc Seal Carrier Assembly (refer to Figure 3-2) is replaced. Also, thesealing areas are inspected for scratches or any other imperfections that mayprevent a proper seal and the threads on the Quickloc Nut and the QIN are visuallyinspected. The same inspection requirements are required for the ModifiedSwagelok Bodies and the Quickloc Plug when the Quickloc Modified Swagelokbodies are replaced.

Quickloc Instrument Nozzle (QIN) / Weld / Weld Buildup:

The inspection requirements for the QIN, dissimilar metal weld and the weld buildup,which are provided below, are listed on the design drawing.

1. ALL WELDING, FABRICATION AND INSPECTION SHALL BE IN ACCORDANCEWITH THE FOLLOWING:

" APP-MVO1-ZO-101, DESIGN SPECIFICATION FOR AP1000 REACTOR

VESSEL* APP-GW-VLR-0 10, AP1000 SUPPLEMENTAL FABRICATION AND

INSPECTION REQUIREMENTSASME BOILER AND PRESSURE VESSEL CODE:

* SECTION II, MATERIALS* SECTION III, RULES FOR CONSTRUCTION OF NUCLEAR POWER

PLANT COMPONENTS

* SECTION V, NONDESTRUCTIVE EXAMINATION

* SECTION IX, WELDING AND BRAZING QUALIFICATIONS

* SECTION XI, RULES FOR IN-SERVICE INSPECTION OF NUCLEAR

POWER PLANT COMPONENTS

2. NONDESTRUCTIVE TESTING OF WELD PREPARATION SURFACES SHALL BE INACCORDANCE WITH ASME B&PV CODE SECTION III, NB-5000.

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3.1 WELD MATERIAL SHALL MEET THE REQUIREMENTS OF APP-VW30-ZO-043 (P43BUTTER AND GROOVE WELD MATERIAL)

4. ALL BUTTERING AND REPAIRS TO BUTTERING SHALL BE ULTRASONICALLYEXAMINED (100%) TO VERIFY THAT IT IS BONDED TO THE BASE METAL ANDFOR LAMINAR DEFECTS IN ACCORDANCE WITH ASME B&PV CODE SECTION V,ARTICLE 5, T-543, TECHNIQUE 1. THE EXAMINATION SHALL BE PERFORMEDFROM THE PREPARED BUTTERED SURFACE USING A SUPPLIER FURNISHEDCALIBRATION BLOCK. THE ACCEPTANCE STANDARD FOR THESE ULTRASONICEXAMINATIONS IS: INDICATIONS WHICH EQUAL OR EXCEED 20% OF THEREFERENCE LEVEL SHALL BE RECORDED AND SHALL BE INVESTIGATED TODETERMINE THE SHAPE, IDENTITY AND LOCATION OF ALL SUCH REFLECTORS.INDICATIONS WHICH EQUAL OR EXCEED 100% OF THE REFERENCE LEVEL ORARE INTERPRETED TO BE CRACKS OR LACK OF FUSION SHALL BE REPAIREDAND RE-EXAMINED.

5. ALL WELD DEPOSITED CLADDING SHALL BE ULTRASONICALLY EXAMINED(100%) TO VERIFY THAT IT IS BONDED TO THE BASE METAL AND FOR LAMINARDEFECTS IN ACCORDANCE WITH ASME B&PV CODE SECTION V, ARTICLE 5, T-543, TECHNIQUE 2. THE EXAMINATION SHALL BE PERFORMED FROM THEPREPARED BUTTERED SURFACE USING A SUPPLIER FURNISHED CALIBRATIONBLOCK. THE ACCEPTANCE STANDARD FOR THESE ULTRASONICEXAMINATIONS IS: THE SIZE OF CLADDING BOND DEFECT ALLOWED IS .25INCH X .75 INCH [6.35 mm X 19.05 mm] WITH THE GREATER DIRECTIONPARALLEL TO THE WELD IN THE REGION BOUNDED BY 2T (T=WALLTHICKNESS) ON BOTH SIDES OF EACH FULL PENETRATION PRESSUREBOUNDARY WELD. UNBONDED AREAS EXCEEDING .442 SQUARE INCHES (.75INCH DIAMETER) [285 SQUARE mm (19.05 mm DIAMETER)] IN OTHER AREAS AREREJECTED.

6. FINAL THICKNESS OF NOZZLE END BUTTERING TO BE .5 INCH [12.5 mm]MINIMUM AFTER MACHINING THE QUICKLOC INSTRUMENT NOZZLE WELDPREP.

7. QUICKLOC INSTRUMENT NOZZLE TO BE WELDED TO NI-CR-FE BUTTERINGAFTER FINAL POST WELD HEAT TREATMENT OF THE CLOSURE HEADASSEMBLY.

8. ULTRASONICALLY EXAMINE THE FINAL DISSIMILAR METAL WELD TO THEASME B&PV CODE SECTION III, NB-5000 AND SECTION XI, IWB-2500REQUIREMENTS. THE OUTSIDE AND INSIDE GENERAL EXAMINATIONSURFACE CONDITION FOR AT LEAST TWO TIMES THE THICKNESS PLUS 2INCHES [50.8 mm] ON EITHER SIDE OF THE WELD IS TO BE 225 min [5.7 mm] Ra ORBETTER UNLESS OTHERWISE NOTED, AND SHALL BE FREE OFIRREGULARITIES, LOOSE MATERIAL, OR COATINGS WHICH MAY INTERFEREWITH THE ULTRASONIC WAVE TRANSMISSION. THE WELD CROWN SHALL BEFLUSH WITH THE SURROUNDING BASE MATERIAL, WHERE FLUSH IS DEFINEDAS NO MORE THAN A 1/32 INCH [0.79 mm] GAP PER LINEAR INCH [25.4 mm] OFMATERIAL.

RAI-SRP5.2.3-Cae1-03 R2

e ftsinghusePage 14 of 25



9. RADIOGRAPHIC TEST EXAMINE THE ENTIRE WELD TO ASME CODE SECTION 111,NB-5000 REQUIREMENTS.

10. DYE PENETRANT EXAMINE WELD BACKCHIP AND FINAL SURFACES OFDISSIMILAR METAL WELD PER ASME B&PV CODE SECTION III, NB-5200.ACCEPTANCE CRITERIA SHALL BE TO ASME B&PV CODE SECTION III, NB-5350.

11. FINAL SURFACE OF WELD BUILDUP SHALL BE MAGNETIC PARTICLE TESTED INACCORDANCE WITH ASME B&PV SECTION III, NB-5000

12. INTERGRANULAR CORROSION TEST PER ASTM-A262-02a (REAPPROVED) 2008 ORLATER PRACTICE E IS REQUIRED ON QUICKLOC INSTRUMENT NOZZLESTAINLESS STEEL MATERIAL.

13. EXAMINATION OF QUICKLOC INSTRUMENT NOZZLE SHALL BE PERFORMED INACCORDANCE WITH ASME B&PV CODE, SECTION III, NB-255 I(C) AFTER ROUGHMACHINING AND BORING.

14. ALL THREADS SHALL BE VISUALLY EXAMINED FOR COMPLETE THREADFORMATION AND SURFACE APPEARANCE. INSPECT THREAD PROFILEACCEPTABILITY FOR FULL THREAD LENGTH WITH CERTIFIED GO, NO-GO RINGGAGE PER ASME B1.3M SYSTEM 22 GAGING.

15. ALL FINAL MACHINED SURFACES OF THE QUICKLOC INSTRUMENT NOZZLESHALL BE DYE PENETRANT EXAMINED PER ASME B&PV CODE, SECTION III,NB-4121.3 PRIOR TO CHROME PLATING THREADS. CHROME PLATE THREADSTO APP-GW-ZO-625 (CHROMIUM PLATING), CLASS 2, .0002 - .0006 INCH [.005 - .015mm] THICK. DIMENSIONS SPECIFIED ARE AFTER PLATING.

16. THE DISSIMILAR METAL WELD ON THE QIN REQUIRES IN-SERVICEINSPECTIONS PER THE ASME BOILER AND PRESSURE VESSEL CODE, SECTIONXI, DIVISION 1, ART IWB-2000, TABLE IWB-2500-1, ITEM NUMBER B5.10.

17. WELD BUILDUP SHALL BE ULTRASONICALLY EXAMINED FOR LACK OF FUSIONAND LAMINAR DEFECTS IN ACCORDANCE WITH ASME B&PV CODE SECTIONIII, NB-5244(a). ACCEPTANCE CRITERIA SHALL BE TO ASME B&PV CODESECTION III, NB-533 1.

18. SURFACES TO BE CLAD OR BUTTERED SHALL BE MAGNETIC PARTICLE TESTEDPRIOR TO THE CLADDING OR BUTTERING OPERATION IN ACCORDANCE WITHASME B&PV CODE SECTION III, NB-5000.

19. ALL CLADDING SHALL BE .125 INCH MINIMUM THICK AND SHALL BE DYEPENATRANT EXAMINED AND MEET THE ASME B&PV CODE SECTION III, NB-5350 ACCEPTANCE CRITERIA.

A summary of the Quickloc design will be added to DCD section 5.3.4.1 as shown in themarkup included under the "Design Control Document (DCD) Revision Associated withRAI Revision 0 Responses" heading below.

WRAI-SRP5.2.3-cIB1-03 R2ng Page 15 of 25




a i)The dimensions of the Quickloc nozzle weld buildup are shown in Figure a-1 below. Thereference dimensions for the height of the uphill and downhill side weld buildups wereextracted from the Autodesk Inventor model; however these dimensions are not used todefine the height of the Quickloc nozzle weld buildup to the RV supplier. On theWestinghouse design drawings, the height of the Quickloc nozzle weld buildup is definedby a distance to the mating surface as shown above in Figure 2-1 of Westinghouse'sRevision 0 response to this RAI.

07.38.60 1187.5]

[Ro. 7 0 1- 0.014 [0.361 A IC

[167.41

( 14.85

[377.2]

+ 7e25 _

-.00[ 1 9 .1 .4 ]

BASEMETAL

,22[5..61

NOMINALSTRUCTURAL - 05.19

CLAD "- [131.8]

SEE NOTE 23 BASE METAL

0.14 [0.3611 C-L 10.003 [0.081 iC

DETAIL B - STEP 1TYPICAL 8 PLACES

SCALE 4/12(SHEET 1)

Figure a-1 - APi 000 RV Quickloc Nozzle Weld Build Up Dimensions


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The Quickloc nozzle weld buildup is considered a base metal weld buildup toaccommodate a weld prep for attachment of the Quickloc instrument nozzle to theclosure head.

a ii)The filler metal for the low alloy pressure boundary portion of the Quickloc nozzle weldbuildup shall be SFA 5.5, SFA 5.23 or SFA 5.28. The filler metal for the Ni-Cr-Febuttering shall be SFA 5.11 or SFA 5.14. These filler metals are defined under the"Welding Consumables" section of Table 5.2-1 of Revision 17 of the DCD.

b)The ASME Code, Section III, Subsection NB-3671.4 is for flared, flareless, andcompression type tubing fittings which does not apply to the Quickloc compressioncollar. Although the Quickloc compression collar has the word compression in its name,the Quickloc compression collar is not a compression tubing fitting. The Quickloccompression collar is the means in which the applied vertical load from the Quicklochydraulic loading tool is transferred to the Quickloc Grafoil seals. Once the requiredvertical load is reached, the Quickloc nut is tightened and the joint is complete. Thethreaded joint between the Quickloc Instrument Nozzle and the Quickloc nut maintainsthe load in the Grafoil seals.

c i) & ii)The Quickloc installation, removal, and maintenance requirements are captured in theAP1 000 Quickloc Instruction Manual. Westinghouse believes that this is the properlocation for this material and not in the DCD. The preliminary Quickloc InstructionManual (APP-MV01-GEM-900) is a Westinghouse Proprietary document. It will bemade available for NRC review at the Westinghouse Rockville office.

c iii)ASME Code, Section III, Subsection NB-5244 (a) requires that the weld buildup beexamined by UT only. ASME Code, Section III, Subsection NB-5244 also states that if apipe connection is attached by a full penetration weld then the full penetration weld (nomention of the weld build up) shall be examined by UT or RT and MT or PT. Note 9 willbe revised as follows to clarify that the dissimilar metal weld and weld buttering shallreceive RT:

WHERE NOTED, RADIOGRAPHIC TEST EXAMINE THE DISSIMILAR METAL WELD(BUTTERING AND FULL PENETRATION WELD) TO ASME CODE SECTION III, NB-5000 REQUIREMENTS.-

d i)ASME Code, Section III, Subsection NB-5244 (a) requires that the weld buildup beexamined by UT only. Note 9 will be revised as follows to clarify that the "entire weld"consists of the dissimilar metal weld and weld buttering:

RAI-sRP5.2.3-c0B1-03 R2Page 17 of 25



WHERE NOTED, RADIOGRAPHIC TEST EXAMINE THE DISSIMILAR METAL WELD(BUTTERING AND FULL PENETRATION WELD) TO ASME CODE SECTION III, NB-5000 REQUIREMENTS.

d ii)The Quickloc nozzle weld buildup is a base metal weld buildup and is considered anextension of the reactor vessel closure head forging and would not require future ISI.The weld buttering and dissimilar metal weld would require ISI per Section XI, TableIWB-2500-1, Examination Category B-O. The examination volume is defined in ASMESection XI, Figure IWB-2500-18 (e). This examination volume includes the weldbuttering, the dissimilar metal weld and 1/2 inch of base metal adjacent to the weldbuttering and dissimilar metal weld.

d iii)Note 8 references Section XI for the supplemental Section III post-hydro UT and the PSIexaminations. Note 8 will be clarified to read as follows:

ULTRASONICALLY EXAMINE THE FINAL DISSIMILAR METAL WELD TO THE ASMEB&PV CODE SECTION III, NB-5000 AND SECTION XI, IWB-2500REQUIREMENTS. SECTION XI, IWB-2500 REQUIREMENTS ARE APPLICABLE TOTHE SUPPLEMENTAL SECTION III POST-HYDRO UT EXAMINATIONS ANDSECTION XI PRESERVICE UT EXAMINATIONS ONLY. THE OUTSIDE AND INSIDEGENERAL EXAMINATION SURFACE CONDITION FOR AT LEAST TWO TIMES THETHICKNESS PLUS 2 INCHES [50.8 mm] ON EITHER SIDE OF THE WELD IS TO BE225 MIN [5.7 mm] Ra OR BETTER UNLESS OTHERWISE NOTED, AND SHALL BEFREE OF IRREGULARITIES, LOOSE MATERIAL, OR COATINGS WHICH MAYINTERFERE WITH THE ULTRASONIC WAVE TRANSMISSION. THE WELD CROWNSHALL BE FLUSH WITH THE SURROUNDING BASE MATERIAL, WHERE FLUSH ISDEFINED AS NO MORE THAN 1/32 INCH [0.79 mm] GAP PER LINEAR INCH [25.4mm] OF MATERIAL.


1) Based on further discussions with the NRC staff, it was agreed that the in-serviceinspection of the reactor vessel head weld buildup for the Quickloc was not a designissue, but rather should be addressed in the in-service inspection program which willbe developed by the COL holder. Therefore, the following COL item will be added assection 5.3.6.6 under DCD section 5.3.6 "Combined License Information":

The Combined License holder will establish an in-service inspection program prior tofuel load. The in-service inspection program will include the performance of a 100percent volumetric examination of the weld build-up on the reactor vessel head for theinstrumentation penetrations (Quickloc) conducted once during each 120-monthinspection interval in accordance with the ASME Code, Section XI. The weld build-upshall meet the acceptance standards of ASME Code, Section XI, IWB-3514. Personnel

RAI-SRP5.2.3-c)n-03 P2Page 18 of 25



performing examinations and the ultrasonic examination systems shall be qualified inaccordance with ASME Code, Section XI, Appendix VIII. Alternatively, the CombinedLicense holder may develop an alternative inspection in conjunction with the voluntaryconsensus standards bodies (i.e., ASME) and submit to the NRC for approval.

The markup of the DCD to include this COL item is shown below under the heading"Design Control Document (DCD) Revision Associated with RAI Revision 2Responses."

2) As shown below in Figure 2-1, Detail B of Westinghouse design drawing APP-MVO1-V6-152 Rev. 3, there are specific note call outs applicable to the Ni-Cr-Fe butter toQuickloc nozzle weld. The applicable notes specified on the WEC design drawingare notes 9, 12,15, 16 & 17. These note numbers correspond to the notes listed onthe Westinghouse design drawings. These note numbers do not correspond to thenote numbers provided in Westinghouse's initial response in RAI-SRP5.2.3-CIB1-03.In the initial response only the drawing notes applicable to the RAI response wereincluded and the notes were sequentially numbered accordingly. Below is acomparison of how the note numbers in Figure 2-1 below correspond to the notesprovided in the initial (Revision 0) RAI response.

WEC Drawing Note # RAI Response Note #9 312 615 816 917 10

The use of the wording "Where noted," along with note call outs in specific details ofa drawing is common practice across all of the AP1 000 Reactor Vessel designdrawings.

*WestinghouseRAI-SRP5.2.3-CiBl-03 R2

Page 19 of 25



9200

[2349.5 +64

TO MATINGSURFACE

[117-4]1

14* TAPER -

07.381187,1

WELD BUILDUPSEE NOTES 14, 18&24

OUTSIDE SURFACEOF CLOSURE HEAD

DETAIL B -STEP 2TYPICAL 8 PLACES

SCALE 4/12(SHEET 1)

Figure 2-1 - Detail B of APP-MV01-V6-152 Rev. 3

ý WestinghouseRAI-SRP5.2.3-CIB1-03 R2

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Design Control Document (DCD) Revision Associated with RAI Revision 0

Responses:

DCD section 5.3.4.1 markup is shown starting on the next page.


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Response to Request For Additional lnformation (RAI)

5.3.4 Reactor Vessel Integrity

5.3.4.1 Design

The reactor vessel is the high pressure containment boundary used to support and enclose thereactor core. It provides flow direction with the reactor internals through the core and maintains avolume of coolant around the core. The vessel is cylindrical, with a transition ring, hemisphericalbottom head, and removable flanged hemispherical upper head. The vessel is fabricated bywelding together the lower head, the transition ring, the lower shell, and the upper shell. Theupper shell contains the penetrations from the inlet and outlet nozzles and direct vessel injectionnozzles. The closure head is fabricated with a head dome and bolting flange. The upper head haspenetrations for the control rod drive mechanisms, the incore instrumentation, head vent, andsupport lugs for the integrated head package.

The reactor vessel (including closure head) is approximately 40 feet long and has an innerdiameter at the core region of 159 inches. The total weight of the vessel (including closure headand CRDMs) is approximately 417 tons. Surfaces which can become wetted during operation andrefueling are clad to a nominal 0.22 inches of thickness with stainless steel welded overlay whichincludes the upper shell top surface but not the stud holes. The AP 1000 reactor vessel's designobjective is to withstand the design environment of 2500 psi and 650'F for 60 years. The majorfactor affecting vessel life is radiation degradation of the lower shell.

As a safety precaution, there aie no penetrations below the top of the core. This eliminates thepossibility of a loss of coolant accident by leakage from the reactor vessel which could allow thecore to be uncovered. The core is positioned as low as possible in the vessel to limit reflood timein an accident. The main radial support system of the lower end of the reactor internals isaccomplished by key and keyway joints to the vessel wall. At equally spaced points around thecircumference, a clevis block is located on the reactor vessel inner diameter. A permanent cavityliner seal ring is attached to the top of the vessel shell for welding to the refueling cavity liner. Todecrease outage time during refueling, access to the stud holes is provided to allow stud holeplugging with the head in place. By the use of a ring forging with an integral flange, the numberof welds is minimized to decrease inservice inspection time.

The lower head has an approximate 6.5 feet inner spherical radius. The lower radial supports arelocated on the head at the elevation of the lower internals lower core support plate. The transitionring is welded to the lower shell course with the weld located outside the high fluence active coreregion. The lower shell is a ring forging about 8 inches thick with an inner diameter of 159 inches.The length of the shell is greater than 168 'inches to place the upper shell weld outside of theactive fuel region. The upper shell is a large ring forging. Included in this forging are four 22-inchinner diameter inlet nozzles, two 3 1 -inch inner diameter outlet nozzles and two 6.81 -inch innerdiameter direct vessel injection nozzles (8-inch schedule 160 pipe connections). These nozzles areforged into the ring or are fabricated by "set in" construction. The inlet and outlet nozzles areoffset axially in different planes by 17.5 inches. The injection nozzles are 100 inches down fromthe main flange and the outlet nozzles are 80 inches down and the inlet nozzles are 62.5 inchesbelow the mating surface.

RAI-SRP5.2.3-C61-03 P2Page 22 of 25

9C.1 Westinghouse



The closure head has a 77.5-inch inner spherical radius and a 188.0-inch O.D. outerflange. Cladding is extended across the bottom of the flange for refueling purposes.Forty-five, seven-inch diameter studs attach the head to the lower vessel and twometal o-rings are used for sealing. The upper head has sixty-nine 4-inch outerdiameter penetrations for the control rod drive mechanism housings and eightpenetrations for the incore instrumentation tubes.

The eight penetrations for the incore instrumentation tubes are Quickloc instrumentnozzles which are welded to the reactor vessel head. Up to six instrument thimbleassemblies pass through each Quickloc instrument nozzle. The reactor vessel headpenetration diameter is approximately 4.75 inches to the cladding. The material ofthe pressure boundary parts of the Quickloc are SA-479 - Type 304, Type 316, andUNS S21800. The Quickloc instrument nozzle is welded to the Ni-Cr-Fe butteringon the weld buildup on the reactor vessel closure head. The Quickloc provides twopressure boundaries: 1) between the Quickloc plug and the incore instrument thimbleassemblies (this pressure boundary is only disassembled when the instrument thimbleis replaced) and 2) between the Quickloc plug and the instrument nozzle (thispressure boundary is disassembled when the reactor vessel closure head is removed).The Quickloc instrument nozzle pressure boundary parts are designed and fabricatedto the requirements of the ASME Code, Section III Division 1, Subsection NB. TheQuickloc internal, non pressure boundary, parts are designed to Subsection NG. TheQuickloc assembly is a proven design that was first installed in an operating plant in1995. Since then they have been installed on four additional operating plants.

The vessel is manufactured from low alloy steel plates and forgings to minimize size.The chemical content of the core region base material is specifically controlled. Asurveillance program is used to monitor the radiation damage to the vessel material.The four vessel supports are located beneath the inlet nozzles and the internalssupport ledge is machined into the top of the upper shell. The top of the upper shellcontains the stud holes and has the sealing surface for the closure head. Inner andouter monitor tubes are provided through the shell to collect any leakage past theclosure region o-rings.

The reactor vessel is designed and fabricated in accordance with the quality standardsset forth in 10 CFR 50, General Design Criteria 1, 14, 30, and 31, and 50.55a; and therequirements of the American Society of Mechanical Engineers (ASME) Code,Section mI. Principal design parameters of the reactor vessel are given in Table 5.3-5.The vessel design and construction enables inspection in accordance with the ASMECode, Section XI.

Cyclic loads are introduced by normal power changes, reactor trips, and startup andshutdown operations. These design base cycles are selected for fatigue evaluation andconstitute a conservative design envelope for the design life. Thermal stratificationduring passive core cooling system operation and natural circulation cooldown isconsidered by performing a thermal/flow analysis using computational fluiddynamics techniques. This analysis includes thermally-induced fluid buoyancy, heattransfer between the coolant and the metal of the vessel and internals and uses

RAI-SRP5.2.3-CIB1-03 R2ng Page 23 of 25



thermal/flow boundary conditions based on an existing thermal/hydraulic transientanalysis of the primary reactor coolant system. This analysis provides temperaturemaps that are used to evaluate thermal stresses.

Analysis proves that the vessel is in compliance with the fatigue and stress limits ofthe ASME Code, Section H. The loadings and transients specified for the analysisare based on the most severe conditions expected during service. The heatup andcooldown rates imposed by plant operating limits are 100'F per hour for normaloperations.

PRA Revision: None.

Technical Report (TR) Revision: None.

Design Control Document (DCD) Revision Associated with RAI Revision 1Responses: None.

PRA Revision: None.


Design Control Document (DCD) Revision Associated with RAI Revision 2

Responses:

Modify Tier 2 Table 1.8-2, "Summary of AP1 000 Standard Plant Combined LicenseInformation Items," as follows:


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Table 1.8-2

SUMMARY OF AP1000 STANDARD PLANTCOMBINED LICENSE INFORMATION ITEMS

Action Action

Addressed by Required by RequiredSubsecti Westinghouse COL by COL

Item No. Subject on Document Applicant Holder

5.3-4 Reactor Vessel Materials 5.3.6.4.1 N/A No YesProperties Verification

5.3-5 Reactor Vessel Insulation 5.3.6.5 APP-GW-GLR- No No060

5.3-6 Analysis of Reactor Vessel 5.3.6.4.2 APP-GW-GLR- No NoInsulation and Support 060Structure

5.3-7 Quickloc Weld Build-up ISI 5.3.6.6 N/A Yes --

5.4-1 Steam Generator Tube 5.4.15 N/A Yes -

Integrity

The additional section to be added to DCD section 5.3.6 is shown below.

5.3.6 Combined License Information

5.3.6.6 In-Service Inspection of Reactor Vessel Head Weld Buildup

The Combined License holder will establish an in-service inspection program prior tofuel load. The in-service inspection program will include the performance of a 100percent volumetric examination of the weld build-up on the reactor vessel head forthe instrumentation penetrations (Quickloc) conducted once during each 120-monthinspection interval in accordance with the ASME Code, Section XI. The weld build-up shall meet the acceptance standards of ASME Code, Section XI, IWB-3514. Personnel performing examinations and the ultrasonic examination systemsshall be qualified in accordance with ASME Code, Section XI, AppendixVIn. Alternatively, the Combined License holder may develop an alternativeinspection in conjunction with the voluntary consensus standards bodies (i.e., ASME)and submit to the NRC for approval.

PRA Revision: None.



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