ML041620422

American Society of Mechanical EngineersSection XI Inservice Inspection Program - Weld Examination Limitation - Relief Request 1/2-ISI-26

ML041620422
Person / Time
Site:	Sequoyah
Issue date:	05/27/2004
From:	Salas P Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML041620422 (29)

Text

Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 May 27, 2004 10 CFR 50.50a(g)(5)(iii)

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentleman:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) SECTION XI INSERVICE INSPECTION (ISI) PROGRAM - WELD EXAMINATION LIMITATION - RELIEF REQUEST 1/2-ISI-26 Pursuant to 10 CFR 50.55a(g)(5)(iii), TVA is submitting two requests for relief from ASME Code requirements. The relief requests are based on limitations that preclude full-code examination of two ASME Class 2 welds. The welds are part of the seal water injection filters (i.e., head-to-shell welds). A full-code examination of the welds is limited due to design configurations and is considered impractical.

The need for relief was identified during ISI activities performed during SQN's third period of the second 10-year inspection interval. The relief requests apply to Unit 1 and Unit 2. The Unit 1 weld was examined during the Unit 1 Cycle 12 refueling outage, and the Unit 2 weld is scheduled for examination during the Unit 2 cycle 13 refueling outage in spring 2005.

The relief requests are submitted in accordance with 10 CFR 50.55a(g)(5)(iii). TVA requests that NRC provide approval in accordance with 10 CFR 50.55a(g)(6)(i).

The SQN ISI Program is currently in the second 10-year ISI interval. TVA is in the process of planning inspection activities for the end of the interval. NRC response is requested by May 2005 to support closeout of SQN's ISI program for the second 10-year interval.

Pted on recycled paper

U.S. Nuclear Regulatory Commission Page 2 May 27, 2004 provides the request for relief for both units (1/2-ISI-26). Enclosure 2 provides the examination data report for Unit 1. Enclosure 3 provides ISI drawings. provides TVA's procedure for calculation of the ASME code coverage for Section XI nondestructive examinations.

There are no commitments contained in this letter. If you have any questions about this change, please telephone me at (423) 843-7170 or J. D. Smith at (423) 843-6672.

alas/

nsing a Industry Affairs Manager Enclosur s cc (Enclosures):

Mr. Michael L. Marshall, Jr., Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop O-8G9A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739

e U.S. Nuclear Regulatory Commission Page 3 May 27, 2004 PS:JDS:DVG:KTS cc (Enclosures):

Mr. Michael L. Marshall, Jr., Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop O-8G9A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739 M. J. Burzynski, BR 4X-C M. F. DeRoche, OPS 4A-SQN D. A. Kulisek, POB 2B-SQN J. E. Maddox, LP 6A-C T. J. Niessen, LP 6A-C NSRB Support, LP 5M-C R. T. Purcell, OPS 4A-SQN J. A. Scalice, LP 6A-C K. W. Singer, LP 6A-C E. J. Vigluicci, ET 10A-K WBN Site Licensing Files, ADM lL-WBN EDMS, WTC A-K I:License/ASME/U1C12&U2C13 ISI-26 Weld Limitation.doc

ENCLOSURE 1 SEQUOYAH NUCLEAR PLANT (SQN)

AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)

REQUEST FOR RELIEF FOR UNITS 1 AND 2 1/2-ISI-26 El-l

Request for Relief 1/2-ISI-26 Executive Summary:

Pursuant to 10 CFR 50.55a(g)(5)(iii), TVA is requesting relief from the ASME code to address limited examination of two welds on the Sequoyah (SQN) Unit 1 and Unit 2 seal water injection filters (head-to-shell welds). The relief requests are based on limitations that preclude full code examination of the two ASME Class 2 welds. A full code examination of these welds is considered impractical due to design configuration of the welds.

The design configuration of welds precludes a 100%

ultrasonic examination of the required examination volume.

These physical examination limitations occur when the 1989 Code examination requirements are applied in areas of components constructed and fabricated to early plant physical designs. Based on the date of SQN's construction permit (May 27, 1970), SQN is exempt from the code requirements for examination access as allowed in 10 CFR 50.55a(g)(4).

An inservice ultrasonic examination of the Unit 1 seal water injection filter head-to-shell weld was performed on accessible areas to the maximum extent practical, given the physical limitations. The design configuration limits the best effort ultrasonic examination to approximately 65% of the head-to-shell weld. The Unit 2 weld is currently scheduled for examination during the cycle 13 refueling outage in the spring of 2005. The design configuration for Unit 2 weld is the same as the Unit 1 weld; and therefore, the projected examination coverage will essentially be the same as that obtained for the Unit 1 weld. Performance of an ultrasonic examination of essentially 100% of the full penetration welds is impractical due to the location of the welded support attachments to the seal water injection filter shell. The best effort ultrasonic examination and the required VT-2 examination will provide reasonable assurance of an acceptable level of quality and safety because the information and data obtained from the volume examined provides sufficient information to judge the overall integrity of the weld.

Therefore, pursuant to 10 CFR 50.55a(g)(5)(iii), it is requested that relief be granted for the second inspection interval.

EI-2

Request For Relief 1/2-ISI-26 (continued)

Unit: 1 and 2 System: Chemical Volume and Control System-System 62 Components: Seal Water Injection Filter, Head-to-Shell Weld, Full Penetration Weld ASME Code Class: ASME Code Class 2 (Equivalent)

Section XI Edition: 1989 Edition (1995 Edition with 1996 Addenda for NDE)

Code Table: IWC-2500-1 Examination Category: C-A, Pressure Retaining Welds in Pressure Vessels Examination Item Number: C1.20, Head-to-Shell Weld Code Requirement: ASME Section XI, Table IWC-2500-1, Examination Category C-A, Item Number C1.20 Code Requirement From Which Relief Is Requested: Volumetric Examination Coverage of Essentially 100% of the Head-to-Shell Weld List Of Items Associated With The Relief Request: SWIFW-2-A, Head-to-Shell Welds on both units E1-3

Request For Relief 1/2-ISI-26 (continued)

Basis for Relief:

The design configuration of the seal water injection filter precludes a complete volumetric examination of the required volume for the head-to-shell weld SWIFW-2-A on both units.

The limitation is due to the location of the steel attachments. This design configuration limits the volumetric (ultrasonic) examination to approximately 65% of the Unit 1 weld, as calculated in accordance with TVA procedure N-GP-28 (Enclosure 4).

The Unit 2 weld is currently scheduled for examination during the cycle 13 refueling outage in the spring of 2005.

The Unit 2 weld should achieve approximately the same ultrasonic examination coverage.

Alternative Examination:

In lieu of the code required 100% volumetric examination, an ultrasonic examination will be performed on accessible areas to the maximum extent practical given the physical limitations of the head-to-shell welds. Refer to for the Unit 1 examination data report.

Justification for the Granting of Relief:

A full code examination of the weld is considered impractical due to design configuration. The design configuration used in the fabrication of the seal water injection filter head-to-shell weld and support steel attachments precludes volumetric examination of essentially 100% of the required examination volume. In order to examine the weld in accordance with the code requirement, the seal water injection filter would require extensive design modifications. The physical arrangement of head-to-shell weld (SWIFW-2-A) and the welded support steel attachments which carry the weight of the component to the floor limit the access for a complete volumetric examination. A total of three support steel attachments are welded along the axial direction of the component at equally spaced locations. Each support steel attachment is approximately 4.0 inches in width and covers the adjoining circumferential head-to-shell weld. The complete circumference of the component is 34.25 inches (actual measurement). The unexamined area is 12 inches. The design configuration limits the best effort ultrasonic examination E1-4

Request For Relief 1/2-ISI-26 (continued)

Justification for the Granting of Relief (continued) to approximately 65% of the required volume and applies to both welds. The Unit 1 weld was examined using application of the best available ultrasonic technology. The Unit 2 weld will also be examined using application of the best available ultrasonic technology and would achieve approximately the same coverage.

The support steel attachments, which cover the subject weld induce negligible stresses in the head-to-shell weld. The function of the support attachment is to carry the weight of the component.

Radiographic examination as an alternate volumetric examination method was determined to be impractical due to the support steel attachment adversely affecting radiographic quality.

The performance of an ultrasonic volumetric or a surface examination from the inside was also determined to be impractical because of the following radiological factors.

Based on similar Unit 1 and 2 components, the estimated radiological conditions for the inside surface of the Seal Water Injection Filter are:

3-4 rad/hour beta 1-2 rem/hour gamma 1 rad/hour per 100 square-cm Maximum stay time to maintain exposure to < 1 rem is approximately 30 minutes. One rem is TVA's administrative annual dose limit for an individual. Protection from the extremely high contamination levels and from the high beta dose rate would be required. Respiratory protection would be required. The above estimates are based on actual experience inside primary components.

Performance of an ultrasonic volumetric examination of essentially 100% of the required volume of the head-to-shell weld SWIFW-2-A on seal water injection filters is impractical. As previously discussed, TVA determined that it would be impractical to attempt other volumetric or surface examinations in order to increase examination El-5

Request For Relief 1/2-ISI-26 (continued)

Justification for the Granting of Relief (continued) coverage. The high percentage (65%) for volumetric (ultrasonic) examination of the subject weld areas and adjacent metal and the code required VT-2 examinations for leakage provide reasonable assurance of weld integrity and is considered to provide an acceptable level of quality and safety. In addition, any significant degradation, if present, would be detected during the ultrasonic and VT-2 examinations that are performed on the subject welds. As a result, reasonable assurance of structural integrity of these welds is provided by the performance of these examinations.

Therefore, pursuant to 10 CFR 50.55a(g)(5)(iii), it is requested that relief be granted for the second 10-year inspection interval. If the examination of Unit 2 head-to-shell weld, SWIFW-2-A, does not result in 65% or greater volumetric coverage, TVA plans to submit a new relief request for this weld.

Implementation Schedule:

This request for relief is applicable to the second 10-year inspection interval for SQN Unit 1 and Unit 2. The examination of weld SWIFW-2-A for Unit 1 and Unit 2 occurs in the third period. - Examination Data Report: R-7976 for Unit 1.

The Unit 2 weld is scheduled to be examined during the spring 2005 outage. - ISI Program Drawing: ISI-0456-C-01 for Unit 1 and ISI-0457-C-01 for Unit 2 - Nondestructive Examination Procedure N-GP-28 "Calculation of ASME Code Coverage for Section XI NDE Examinations."

E1-6

ENCLOSURE 2 EXAMINATION DATA REPORTS Request for Examination Data Relief Number Reports 1-ISI-26 R7976 2-ISI-26 To be examined I _ _ _I_ in spring 2005 E2-1

TENNESSEE VALLEY E M AND ARY REPORT NUMBER:

AUTHORITY RESOLUTION SHEET 7 '? 76 PROJECT: SQN UNIT: I CYCLE: 12 COMPONENT ID: SWIFW-2-A DESCRIPTION/ head to shell LOCATION:

EXAMINATION METHOD SYSTEM: CVCS IISI DWG NO: ISJ-056-C-01 MT C I PT C UT 2 VT E CONFIGURATION: CATEGORY I PROCEDURE: N-UT-1i REV 25 TC: - VHEAD TO VSHELL . C-A EXAMINER: EXAMINER: "A c EXAMINER: EXAMINER:

LEVE:I di -- LEVEL: IILVE:j IEVL LEVEL: 11 LEVEL: 11 LEVEL: LEVEL:

Total coverage calculated to be apDroximateiv 65 This report containsthe data associatedwith the ultrasonicexamination of weid SWIFW-2-A. The weld was eramined with a 0.375 lnch. 2.25 MHZ 45 derree lmrdntueer ititizbw a ID-OD ealibraron.No reeordaileIndications were observed The exam was limiteddue to welded supports on the exam area.

3 - 21c 2!5e§*° RESOLU ON BY: REVIEWED BY: ANII:

LEVEL- DATE: 4 I- ON LEVELJ 1 -DATE: r _ . AT:

.page: __. ._ OF ACCESS: FORMS DATABASE R3t1W3 7Fff 6.

TENNESSEE VALLEY IGITAL ULTRASONIC REPORT NUMBER AUTHORITY CALIBRATION 2-79 76 DATA SHEET_________

PROJECT SQN UNIT/CYCLE 1/12 CALIBRATION DATE: 3-31-03 PROCEDURE: N-UT-I8 REV: -. *TCA T BO NTF TRACEDR:NSDUCER SIMULATOR BLOCIK:ROmPas MANUFACTURER KBA THERMOMETER SIN: 573207 DUE DATE: 9-25-03 MODEL: COMP-G S/N 00W27J COUPLANT: UltraEeIH BATCONL-ANGLE VERIFICATION SIZE: .375" FREQ: 2.25 MHz BLOCK TYPE Romcas S/N: 94-7995 SHAPE:Round # ELEMENTS: I #CONS: 0 NOMINAL ANGLE: 45' ACTUAL ANGLE 5' CABLE TYPE RG-174 LENGTHT: INSTRUMENT MODE: 0 SHEAR 0 LONG O RL MANUFACTURER Krautkramer DUE DATE 6-4-03 MODEL NO.: USN-52L S/N: E30218 DAC INSTRUMENT SETTINGS 100 _ _ REFLECTOR - REFERENCE MEMORY

- . l A SCAN DIRECT. NTC SDH SENSITIVITY NUMBER so8 M AXIAL 21 O 21.0 dB

__ P CIRC. 0 ° 29.0 dB 2 60 _ \- - _ _ L FREQ: 2fo-s lMHz REJECT: 0 %

• _ I AANGLE- 45 deg DAMPING:1000 ohms

• 40 _ _ T DELAY: 0msec PULSER: SINGLE

• U ZERO: 5.480rnsec 20 - _ - D VELOCITY .L1226 msec PRRIPRF: FIXED

• E RANGE: .4d0=2. Inches TOF: PE'K 0 _DISP. MODE: FULL WAVE* POWER: BATTERY DISPLAY WIDTH 4.012.0 Inches REF. REFLECTOR: . SDH GAIN: 21.0 dB CALIBRATION TIMES AMPLITUDE: 40 G/, METAL PATLU1.031n INITIAL TIME: 1 C'3 0 FINAL TIME:

1 2 3 6 7 nwal 8 )

VERIFICATIONTIMES 1 );toosl ) nwal ) na ) 1/aln) nia ) nzal ) nal19 ) n/a

• PDI QUALIFIED INSTRUMENT SETTINGS:

VERIFY INSTRUMENT SETTINGS AND CALIBRATION SEQUENCE ARE IN ACCORDANCE WITH TABLE 2 OF THE APPLICABLE PDI QUALIFICATION IMPLEMENTATION PROCEDURE!

LINEARITY CHECK VERTICAL SGA GAIN SET -6 dB -12dB SET +12 lSET +6 ATTNUATOR AMp 80% 32 TO 48 16 TO 24 20% 64 TO 96 l40% 64 TO 96 _

480 20 INN 80 Kl= s SWITFW-2-A

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I{XAMINER: ZY/K(4-& LVL: VI ANJ44_.,<h- ;k4, I.AXAMINER: Oa oSO /, - LVL4 DT: 4 03 IREVIEWER: 7 fQ LVL.IV.-. DATE: 1f3/b3 If PAGE 2- OF 7

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TENNESSEE VALLEY MANUAL ULTRASONIC I REPORT NUMBER AUTHORITY PIPING EXAMINATION I

,A 'S DATA SHEET 2

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.1OJECT: SQN UNIT/CYCLE 1112 EXAMINATION DATE 3-31-03 SYSTEM: CVCS START T'IME: aO %c END TIME: ;2 %c L WELD l.D.: SWIFW-2-A EXAM SURFACE OID ROD CONFIG.: VHEAD TO VSHELL COFI. MATERIAL TYPE: OCS OSS OCSCL ECCSS FLOW 3 SURFACE TEMP. 7) PYRO NO. 573207 PROCEDURE: N-UT-18 REV:  :.S TC: EXAMINATION ANGLE 45 DEG. n1a DEG.

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REFERENCE:

WELD CENTER LINE AXIAL SCAN SENSITIVITY 33.0 dB nra dB Lo

REFERENCE:

2 inch inlet vive CIRC. SCAN SENSITIVITY 35.0 dB n/a dB IND IN (in) FROM REF. I AT MAX AMP MAX AIP IEXAM NO NOM.

NRI INDICATION INFORMATIPN:

NO. Li L Max L2 W MAX MP MAX D MAX  % DAC 3-14 ANG. TYPE, DAMPING, ETC.

_ _ _ = =-_ ,4,5,f 451

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REMARKSALIMITATIONS eram limited to nnrvorimatelv 65% due to three 4inch rnnnorte on the weld exam area.

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EXAMINER: , { , , I . . , , . _

LEVEL:  : ANII:

VMINERW LEVEL: W DAfE.-j' 4-7-7-osb r

(REYIWED I ACnESS*- CFAtfOtAAAQ= 4MItt

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WALL THICKNESS REPORT NO:

TVAPROFILE SHEET,.

PROJE CT__________ WELD NO: S A UNIT:_______________ SYSTEM: C V C. S Record Thickness Measurements As Weld

• Weld Edge Indicated, Including Weld Width, Centerline Edge-To-Edge At V j.E-2.S' 1025' Position 0O ir 0i90 270' 1rlM Ela .1 1b~ AR, '*;id Sd oil' .~& ~

CROWN HEIGHT: *0!; DIAMETER: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

CROWN WIDTH: 11-WELD LENGTH: 3..Ž CLC EXAMINER: REVIEWEDBY LEVEL: LEVEL, IL DATE: :S3-0 I. PACE 77 OF4~

TVA 1%68 (NP-5-99) I-rq7 1y -

REPORT NO:

TVA WALL THICKNESS PROFILE SHEET, PROJECT:_______________ WELD NO: ML______________

UNIT:_______________ SYSTEM: V.

Record Thickness Measurements As Weld *Weld Edge Indicated, Including Weld Width, Centerline Edge-Te.Edge At 0 1 232sl Position 0" 90' 150' 270' ~ n 0 7ZS aSd CROWN HEIGHT: t, IMEE:I0 CROWN WIDTH:_______________ WELD LENGTH:

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EXAMINER: A4k REVIEWED 3:____

LEVEL: E1T DATE:___________GE A~ .

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-A, lq--7 7, REFMNCEF ORAWrUfS Cor>wRIcr No. S114J0 -26 M4 rERIAL SPECIFICA TIONS

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_ESsE 144#ERIAL 304 SMN . S..)

ASMECC-2 (GIAEftE~r)

I SLOWTME AN A OR FM X TO S!GN1Fr IWICK ?IL tFM IS EXAP4ACD. A OESIGM FES THE FZLTER OErMEEM VALVES62-547?

A 62-54w WNILE B D£sIGNiATEs BETrEEN VALVES 62-54 6 62-55a

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SW$, l 11 W.! Pt Rn *r raiTD SIwrpr I APPRO" ICH rA IINESMC VAtLLr AvPrI" SEOUOYAH MJCLEAR PLANRT UIrT I SEAL WA TER INJECTION FILTER WELO AND SLJPPORr LOCArlovs VRAf NV . ll. I0-6-"P rl. wr to r.

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ENCLOSURE 3 ISI PROGRAM DRAWINGS I

Request for ISI Program Relief Number Drawings 1-ISI-26 ISI-0456-C-01 2-ISI-26 ISI-0457-C-01 E4-1

REFERENCE DRAWINGS CONTRACT NO {N2-2

!2923i DRAWING NO: 9444-2023 -

MATERIAL SPECIFICATIONS A VESSEL MATERIAL 304 STNL. STL.

ASMW CC-2 (EQUIVALENT)

NOTES:

1. SUBSTITUE AN A OR FOM X TO SIGNIFY NWICfH FILTER IS EXAMINED. A DESIATES THE FILTER BETWEEN VALVES62-547 &

62-549 WHILE 8 DESIGNATES THE FILTER UA BETWEEN VALVES62-548 & 62-550

2. FOR PIPING SEE 151-0448-C-JO.

. DIMENSIONS ARE FOR INfMATIC LY.

F 3AlpZ 2 1a, X 2 t/2' 1I/L NWOOEE (4 PLACES)

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'A AOD HdArL SPECS. REAVVE OZZLt WELD 105. PER FCDT 96-1i V Il CHECKtE SLOMITTEO IAPED VATE rEMS3I! VALL(V A MMITr SEOiUOYAH NUCLEAR PLANT UNIT I SEAL WATER INJECTION FILTER WELD AND SUPPORT LOCATIONS DRAmIM RPG DATEt I2-16-951 SCALE: NOT TO SCALE CECtED: EDOC APPROVED: ai lCAO MAWINIAJfIE jIR RCE DRA SWlTTRED: FRS I ISI-0456-c- 1 101

I REFERENCE DRAWINGS CONTRACT NO. D9t9W N2U-2-26)

DRAWING NO. 9444-2023 MATERIAL SPECIFICATIONS VESSEL MATERIAL 304 STNL S ASME CC-2 (EQUIVALENT)

NOTES:

/. SWSTITUE AN A OR B FOR X TO SIGNIFY WHICH FILTER IS EXAMINED. A DESIGNATES THE FILTER BETWEEN VALVES62-547 & 62-549 A RUL ft DSIGN 7EF TEFL TER BETIWEEN VALVES62-540 & 62-550

2. FOR PIPING SEE ISI-0449-C-30.

3. DIMENSIONS ARE FOR INFORMA TION oNL. J r3AE X 2t X X2 /2 AE (4 PLACES)

(7 2/ OUTLET SC1 I60 SWIFHAlX r SWIFH-X-IA(3/8')

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'trrs PR REYV BY rW 4 MAD SM'CSAmO bg-o,. MM rPPOYT TO si.

AA&gno la I CHECKED SUMMED I APPROVEI REMW OtD 10. & mim Is SvI"w-J-r i X DATE TSESWE VALLEY AUWMI7Y SEQUOYAH NUCLEAR PLANt-UNIT 2 SEAL WATER INJECrION FILTER WELD AND SUPPORT LOCATIONS DRAWE lR I DATE, 12-16-95T SCALE: Nor rO SCALE CNECKED:JCC lAPPROVEOt DLCFICAD;AINTAINE (WANN REV St*AlTrED: fRS 1 ISI-0457-C -01 01

ENCLOSURE 4 TVA'S PROCEDURE FOR CALCULATION OF THE ASME CODE COVERAGE FOR THE SECTION XI NONDESTRUCTIVE EXAMINATIONS E4-1

NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 1 of 8 W47 031219 000 QA RECORD CALCULATION OF ASME CODE COVERAGE FOR SECTION Xi NDE EXAMINATIONS "QUALITY RELATED" i

Prepared By: Robert E. Hardawav Date: 12/18/03 Technical Review: Joel W. Whitaker NDE Level lii,Date: 12/18/03 ISO Approval: W. Ed Freeman Date: 12/18/03

NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 2 of 8 Rev. No. Date Description 0 4/3/96 Initial issue.

1 8/15/97 Incorporate TC 97-09.

2 10/18/00 General revision to Incorporate IOCFR50.55a ruling change which Implements Appendix VilI 3 524101 Revised to upgrade procedure to ASME Section XI 1995 Edition with Addenda through 1996 4 12/18/03 Revised to Incorporate corrective actions from PER 03-014859-000.

i

NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 3 of 8 1.0 Scope The scope of this procedure isto provide generic guidelines for calculating the ASME Section Xl code coverage and augmented examination coverage obtained during volumetric and surface examinations. This procedure Incorporates the requirements of Code Case N-460 and NRC Information Notice 9842. This procedure is not applicable for calculating the examination coverage for RPV examinations performed Inaccordance with Appendix Vill.

2.0 Pumose This procedure applies to the calculation of ASME Section Xl Code coverage for vessel welds (excluding the RPV welds performed Inaccordance with Appendix Vill) piping welds, and integral attachments. This procedure applies when performing surface, volumetric or visual examinations and may be used as a guide when calculating the examination coverage for preservice and inservice examinations. Coverage limitations may be due to an obstruction, Interference, geometric configuration or other applicable reason.

3.0 References 3.1 ASME Code Case N-460 3.2 10CFR 50.55a, as amended by the Federal Register Notice, Vol. 64, No. 183, dated September 22, 1999 (Final Rule)- Implementation of Appendix VIII as executed by the Performance Demonstration Initiative (PDI) Program Description Document, Rev. 1, Change 1.

3.3 Guideline for the Implementation of Appendix Vil and IOCFR 50.55a, Rev. D, April 18, 2000 3.4 NRC Information Notice 9842 3.5 SQN PER 03-014859-000 l 4.0 Definitions 4.1 Examination Coverage- The percentage of the examination surface or volume obtained during the performance of the examination.

4.2 Examination Surface- The surface of the weld and base material required to be examined by ASME Section Xi or other requirement using a surface and/or visual examination method as applicable.

4.3 Examination Volume- The volume of weld and base material required to be examined by ASME Section Xl or other requirement using a volumetric examination method.

4.4 Scan ULmitation- the inability to scan the surface(s) as required by procedure due to interferences.

4.5 Surface Limitation- the inability to perform a surface examination of the required surface(s) because of an Interference.

NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 4 of 8 4.6 Volumetric Limitation- the Inability to examine the required volume because of the geometric configuration, a physical Interference, or a metallurgical condition of the material being examined.

5.0 General 5.1 During the performance of Inservice Inspections, ASME Section Xl requires examination coverage to be essentially 100% of the weld area or volume. For examination coverage less than 100%, TVA has Implemented ASME Code Case N-460 which states that when the entire examination volume or area cannot be examined due to interference by another component or part geometry, a reduction in examination coverage for Class 1 or Class 2 welds may be accepted provided the reduction In coverage for that weld Is less than 10%. (NRC Information Notice 98-42 further defines the >90% rule to include all welds and other areas required by ASME Section Xl.

5.2 Surface and/or visual examinations are typically conducted on the weld area plus a defined amount of base material on each side of the weld. Volumetric examinations specify a particular volume to be examined. The Section Xl required examination volume or surface examination area for each type of weld is depicted in figures of IWB-2500, IVC-2500 and IWD-2500 as applicable. As depicted for piping welds, volume width generally constitutes the weld plus 1I4t on each side while volume thickness generally constitutes the lower 1/3 of the piping thickness for the length of the weld. The exception normally includes code category B-O which includes the weld plus 1/2 inch and full volume for the length of the weld. As depicted, for vessel welds, the volume width generally constitutes the weld plus 112t on each side of the weld while volume thickness generally constitutes the entire component thickness (i.e. full volume). The volume changes with variations in weld configuration (e.g. transition between different pipe thickness or vessel weld configurations).

Note: Risk-Informed (RD programs require larger volumes in certain areas.

5.3 The required examination volume or area shall be verified prior to calculation of the limitation.

6.0 Documenting and Calculating Examination Coverage 6.1 While performing a visual, surface or ultrasonic examination, the NDE Examiner shall make every attempt to examine 100 percent of the examination area or volume.

6.2 When practical, the two beam path directions for ultrasonic examinations should be performed from two sides of the weld or additional angles employed in order to maximize coverage.

6.3 If 100% percent of the examination surface or volume cannot be examined, the NDE Examiner should perform the following under the direction of the inspection coordinator or the NDE Level IlIl:

6.3.1 Perform additional examinations with higher angles in order to maximize cover for ultrasonic exams.

NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 5 of 8 6.3.2 Perform another surface method .e., PT in lieu of MT) In orderto maximize coverage.

6.3.3 Perform alternative NDE methods If applicable.

6.4 The examiner shall accurately document all limitations, obstructions, interferences, geometric configurations or other applicable reasons for not obtaining the required code coverage. This Information shall be validated and verified by the assisting examiner or Independent verifier and documented In the NDE data report.

6.5 The examiner shall document the limitation on a sketch. Examination coverage estimates may be performed by the examiner or the reviewer.

7.0 Calculation Basis 7.1 Volumetric Examinations- Piping Welds and Vessels 2 Inches and less in thickness a) Examination volume coverage may be Increased as previously discussed or by use of refracted longitudinal wave techniques on stainless steel or dissimilar metal welds. Use of refracted longitudinal waves to penetrate stainless steel weld material will Increase the examination volume coverage by the amount depicted on the examination coverage drawing.

b) Estimates shall be derived by estimating coverage based on two-beam path direction coverage of the complete examination. Each scan direction equals 25% (downstream, up-steam, clockwise, counterclockwise.)

(Reference Figure 1) c) The effects of adjacent component Interferences (e.g. welded lug attachments) along the weld length are also taken Into account with the reduction In coverage Identified as a percentage of reduced volume.

8.0 Visual and Surface Examinations - Pirina Welds And Intearal Attachments 8.1 Examination area coverage calculations are based upon one of the following suppositions:

a) The total examination area Is calculated, typically length x width, then the total area of limitation or Interference is subtracted from the total examination area.

b) The area of achieved coverage Is divided by the total examination area for percentage of examination achieved.

NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 6 of 8 9.0 Ultrasonic Examinations - Vessel Welds NOTE: THIS IS NOT APPLICABLE FOR APPENDIX %ill EXAMINATIONS OF THE RPV WELDS.

9.1 Examination volume coverage calculations are based upon the following suppositions:

a) To achieve full examination coverage nine different scans are required for a typical vessel weld or nozzle examination. The following may be used for other vessel configurations:

1) 0 degree (weld metal scan)

2) 45 degree Transverse-scan from vessel side of the weld

3) 45 degree Transverse-scan from nozzle side of the weld

4) 60 degree Transverse-scan from vessel side of the weld

5) 60 degree Transverse-scan from nozzle side of the weld

6) 45 degree Parallel-scan CWdirection

7) 45 degree Parallel-scan CCW direction

8) 60 degree Parallel-scan CW0i1rection

9) 60 degree Parallel-scan CCW direction 9.2 The examination volume achieved for each above examination scan shall be obtained and documented on a percentage basis. This calculation considers the required examination volume required perthe ASME Section Xi Code.

a) The total examination coverage may be calculated by averaging the exam volume coverage for all nine scans.

10.0 PDI Implementation for Piping Welds 10.1 Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds provided the examiner is qualified for single sided examination. Current technology Is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to US nuclear applications. Therefore, examination of austenitic material welds shall be performed from both sides or a scan limitation shall be documented.

10.2 The NDE Level IlIl shall make an evaluation in the Weld Resolution document regarding total examination coverage (best effort) as calculated above In Section 7.0. In addition, a coverage evaluation which considers the PDI Implementation Guideline shall also be indicated In the Weld Resolution sheet. These two coverage evaluations shall be reported to the ISI Programs Engineer for incorporation into the Relief Request.

10.3 Typically a one-sided austenitic weld examination with no circumferential restrictions would be indicated as 75% examination coverage or 50% if circumferential scans were limited to one side.

4 NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 7 of 8 NOTE: These requirements do not apply to augmented examinations of piping welds.

11.0 Resoonsibilities 11.1 The examiner, assisting examiner or designee shall document the amount of code coverage obtained after all necessary steps to perform additional examinations has been completed In orderto maximize coverage. The documentation Including verification of limitations shall become part of the examination weld data package.

11.2 The documentation may be reviewed by another Individual with the same or higher NDE certification.

11.3 The NDE Level IlIl or data reviewer may review the calculations In order to verify that the information Is accurate and correct.

11.4 The NDE Level Ill may recalculate the examination coverage to obtain a more accurate value of the examination surface or volume examined. The calculation shall be documented on the exam report.

11.5 The NDE Level Ill may require an altemale examination technique or method, or request that the interference be removed. For nozzle examinations, supplemental scans from the nozzle bore or flange face may provide complete coverage of the weld.

11.6 If the examination coverage indicates less than 90 percent of the required examination volume or surface, the site ISI Program Engineer shall be notified.

11.7 The site ISI supervisor shall ensure that examination results are accurately documented and Incorporate results Into a Request for Relief if necessary.

NONDESTRUCTIVE EXAMINATION PROCEDURE Procedure No. N-GP-28 TVA Nuclear Power Revision 4 Page 8 of 8 ma320 APPENDIX "- MANDATOkY m.3310 I

IF l_ Exam vol i C-D-E-F-GENERAL NOTE:

For this example of Interference with e YV examination applied from both sides, only the E-f-G4H portion of the examination volume receives two direction coverage, whia volumes C-G-F end H40E receive one direction coverage. In Ihhicase. ihe examination beam path shill be increased to

%V IO.. Ito LID.end back towards 0.0. for Ytl to provide the required two direction roverage over the examination volume. Use e a %V examinaton besm path 1O0D. to LD. to 'Atr provides additional beam path lpast '%tIto help In obtaining required coverage when examination part thicknes r Incresses.

IG.111-3230-1 EXAMPLE OF PHYSICAL RESTRICTIONS TO THE WELD EXAMINATION Figure 1