ML13014A040

Response to Request for Additional Information, Relief Request 48 - Proposed Alternative to American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section III - Phased Array Ultrasonic Examination..

ML13014A040
Person / Time
Site:	Palo Verde
Issue date:	01/04/2013
From:	Mims D Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06641 -DCM/RKR/CJS
Download: ML13014A040 (58)

Text

2 10 CFR 50.55a AOA subsidiaryof Pinnacle West Capital Corporation Dwight C. Mims Mail Station 7605 Palo Verde Nuclear Sr. Vice President Tel. 623-393-5403 P. 0. Box 52034 Generating Station Nuclear Regulatory and Oversight Fax 623-393-6077 Phoenix, Arizona 85072-2034 102-06641 -DCM/RKR/CJS January 4, 2013 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, and 3 Docket Nos. STN 50-528, 529, and 530 Response to Request for Additional Information (RAI) - Relief Request 48 - Proposed Alternative to American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section III - Phased Array Ultrasonic Examination Techniques (PAUT) in lieu of Radiography Pursuant to 10 CFR 50.55a(a)(3) Arizona Public Service Company (APS) requested the Nuclear Regulatory Commission (NRC) approve Relief Request 48, by letter number 102-06558, dated August 1, 2012 [Agencywide Documents Access & Management System (ADAMS) Accession No. ML12229A046].

Specifically, APS requested an alternative to the ASME Code,Section III, which requires that ASME Class 2 carbon steel circumferential pipe weld joints be examined utilizing radiographic examination techniques to satisfy nondestructive examination requirements. The proposed alternative utilizes Phased Array Ultrasonic Examination Techniques (PAUT) and would provide an acceptable level of quality and safety.

In an e-mail dated November 21, 2012, the NRC staff indicated that the APS submittal had been reviewed and that additional information was needed to complete the review.

The NRC requested that the information be provided by December 31, 2012, in order to support the request by APS to have Relief Request 48 available for the spring 2013 outage in Unit 1. The specific work that was planned to be the first application of Relief Request 48 was economizer feedwater piping replacement in containment, however, A member of the STARS

........... . ....... rea...... QU (Strategic Teaming U ....... . .... ....

and Resource Sharing) Alliance

. o..

A WV ca away comanche ýeak

• v ablo canyon e valo verde a San Onofre

• south iexas o wolf Creek

'ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Response to RAI - Relief Request 48 Page 2 this work is not currently within the spring 2013 outage scope for Unit 1. The next p!anned application for Relief Request 48 is now in the fall 2013 outage in Unit 3 and also involves economizer feedwater piping replacement in containment. The specific details of the economizer feedwater piping replacement are provided in the response to question 1 in the Enclosure.

APS has revised the requested date for approval of Relief Request 48 to be March 15, 2013, which will allow for preparations to be completed for the fall outage. The Enclosure to this letter contains the requested information.

There are no commitments being made in this letter. Should you need further information regarding this relief request, please contact Robert K. Roehler, Licensing Section Leader, at (623) 393-5241.

Sincerely, DCM/RKR/CJS/hsc

Enclosure:

APS Response to NRC Request for Additional Information (RAI) - Relief Request 48, Proposed Alternative to American Society of Mechanical Engineers (ASME)Section III cc: E. E. Collins Jr. NRC Region IV Regional Administrator L. K. Gibson NRC NRR Project Manager for PVNGS M. A. Brown NRC Senior Resident Inspector for PVNGS

I ENCLOSURE APS Response to NRC Request for Additional Information (RAI) - Relief Request 48, Proposed Alternative to American Society of Mechanical Engineers (ASME)Section III

Enclosure Response to RAI - Relief Request 48 APS Response to NRC Request for Additional Information (RAI) - Relief Request 48, Proposed Alternative to American Society of Mechanical Engineers (ASME)Section III Pursuant to 10 CFR 50.55a(a)(3) Arizona Public Service Company (APS) requested the Nuclear Regulatory Commission (NRC) approve Relief Request 48 (RR 48), by letter number 102-06558, dated August 1, 2012 [Agencywide Documents Access & Management System (ADAMS) Accession No. ML12229A046]. APS also presented further information at a public meeting on August 30, 2012 (ADAMS Accession No. ML12243A435).

Specifically, APS requested an alternative to the ASME Code,Section III, which requires that ASME Class 2 carbon steel circumferential pipe weld joints be examined utilizing radiographic examination techniques to satisfy nondestructive examination requirements. The proposed alternative utilizes Phased Array Ultrasonic Examination Techniques (PAUT) and would provide an acceptable level of quality and safety.

In e-mail dated November 21, 2012, the NRC staff indicated that the APS submittal had been reviewed and that additional information was needed to complete their review. Each NRC request for additional information (RAI) is followed by the APS response.

NRC RAI Number 1 RR 48 describes that, in the near term, the licensee would like to use UT in Lieu of RT for economizer feedwater piping in containment. Please provide a description of the components to be examined in the upcoming outage, including the identification of the components, the inner diameters, thicknesses, and geometries.

APS Response The specific work that was planned to be the first application of RR 48 was economizer feedwater piping replacement in containment, however, this work is not currently within the spring 2013 outage scope for Unit 1. The next planned application for RR 48 is now in the fall 2013 outage in Unit 3 (3R1 7) and also involves economizer feedwater piping replacement in containment in accordance with the latest flow accelerated corrosion (FAC) replacement schedule. The need to change the date for the first implementation of RR 48 has been entered into the corrective action program as PVAR 4320041.

A copy from the work order of the weld map and materials listing for the 3R1 7 piping replacement is provided as Attachment A and includes nominal sizes of:

16" schedule 80 16" OD (14.31 ID) with 0.843" nominal wall thickness 14" schedule 100 14" OD (12.12 ID) with 0.938" nominal wall thickness Geometries will be as indicated on the weld map and include pipe to reducer and pipe to elbows as described in Attachment A. The welds identified as 3596293-1, 5, and 7 are those planned to be welded and examined in containment.

1

Enclosure Response to RAI - Relief Request 48 NRC RAI Number 2 Based on the submittal and the August 30, 2012, public meeting it appears that the specimens described in Attachment 1 have been examined extensively to develop the inspection procedures. Please provide flaw maps showing the true state for several examples of each type. of flaw including those found by PT, the ultrasonic results including detection and characterization of flaws, and the radiographic results for these specimens.

APS Response Attachment B includes a sample of flaw maps and provides examples of associated phased array graphics from several flaw types. The flaw maps were prepared from the examination.

results of both RT and PT and not from destructive. examinations. Coupons were labeled with the following convention:,

Example: 6-120-CS 6 is the nominal diameter 120 is the schedule CS represents carbon steel The results of the RT and PT examinations are included on the flaw map table. As illustrated on the maps none of the crack indications were identified on the radiographs.

NRC RAI Number 3 Radiographic testing provides an archival-quality record of the examination that can be stored and interpreted after several decades. Encoded electronic data requires backup and proprietary data formats may become obsolete in the future. How will the ultrasonic results be stored and protected from data loss and future changes in hardware and software that could render the data unreadable?

APS Response APS intends to utilize a printout of the examination report and associated graphics as the archive record.

2

Enclosure Response to RAI - Relief Request 48 NRC RAI Number 4 RR48 states that the proposed alternative will utilize ASME Section I11(2001 Edition 2003 Addenda) NC-5300 for acceptance criteria. However, the RT or UT acceptance criteria to be applied is not specified.

a. Which acceptance standards, NC-5320 "Radiographic Acceptance Standards",

or NC-5330 "Ultrasonic Acceptance Standards" will be used?

APS Response The ultrasonic acceptance'standards of NC-5330 will be utilized.

NRC RAI Number 4 (continued)

b. Both NC-5320 and NC-5330 require discrimination between defect types.

Please describe how discrimination between defect types will be accomplished, including examples of various defects and the ultrasonic features that allow for discrimination.

APS Response Attachment C provides characteristics that will be validated during the procedure demonstration to support flaw discrimination. The validated techniques and process will be included in the procedure.

NRC RAI Number 4 (continued)

c. If NC-5320 is to be used, discuss and provide data that UT inspection procedures can detect internal root weld conditions (undercut, concavity, etc.)

and characterize them using the acceptance standards in NC-5320.

APS Response NC-5320 will not be utilized.

NRC RAI Number 4 (continued)

d. If NC-5330 is to be used, the NC-5330 Ultrasonic Acceptance Standards require evaluation of responses greater than 20% of the reference level. Will procedures be held to the 20% of reference level standard, or will the procedures have freedom to evaluate indications with lower-amplitude responses?

3

Enclosure Response.to RAI - Relief Request 48 APS Response The procedure willrequire all the data to be evaluated.

NRC RAI Number 5 The qualification for the personnel who will acquire and analyze the ultrasonic data is described in RR 48, but some important details were not provided. Please answer the, following questions about the personnel qualifica'tios:

a. It was verbally stated at the August 30, 2012, public meeting that the procedure demonstration will be open and the personnel tests will be conducted as blind tests. Discuss how the open procedure demonstration and the blind personnel tests will be'conducted and why this provides an acceptable level of quality.

APS Response Response is provided in Attachment D.

NRC RAI Number 5 (continued)

b. In RR48 it is stated:

For,detection, the minimum number,of flawed and unflawed.gradingunits and associatedminimum detection criterianoted in ASME Section Xl table VIII-S2-1 will be met.

Will the false call test acceptance criteria from ASME Code Section XI Appendix VIII Supplement 2'also be required? Please discuss how false calls and or missed calls will affect the qualification of the inspector. (i.e., if the operator finds the 5 out of 5 flawed grading units in the mock-up but also has 2 false calls out of 10 unflawed grading units, does the operator receive his qualification?).

APS Response The false call criteria will be utilized per Table VIII-S2-1. If the specified qualification block has 10 unflawed grading units; then to be considered qualified the analyst could not have any false calls. Attachment D provide more details, but to be considered qualified the false call criteria of the table for the number of unflawed grading units would have to be met.

NRC RAI Number 5 (continued)

c. Will the blind personnel test require the inspector to correctly determine what types of flaws (porosity, slag, cracks, etc) have been detected? If not, why not?

4

Enclosure Response to RAI - Relief Request 48 APS Response The blind personnel test will require correct discrimination. Appendix D provides more details.

To.be considered qualified, personnel must discriminate flaw types as meeting paragraphs (a) or (b) of NC-5330.

NRC RAI Number 5 (continued)

d. During the blind personnel qualification, if an inspectordetected a crack but misidentified the crack as porosity or slag, would this be considered a successful detection or count as a missed flaw? If it considered a successful detection, how could the NC-5300 acceptance criteria is applied?

APS Response This individual would not be considered as successfully passing detection and it would be considered as a missed flaw.

NRC RAI Number 6 Page 2 of RR 48 states that the proposed alternative will utilize ASME Section V, Article 4 (2001 Edition 2003 Addenda), and that the demonstration will document the requirements of Table T-421. There is no Table T-421 in the 2001 Edition 2003 Addenda. Please clarify. Do you mean Table T-422?

APS Response For the 2001 Edition 2003 Addenda of ASME Section V; Table T-422 is the correct reference.

NRC RAI Number 7 Please provide Reference 14, "EPRI presentation, dated May 2010; Ultrasonic Capability study for reduction of weld repairduring the construction-UT Technical Presentation."

APS Responses:

The reference is provided as Attachment E.

5

Enclosure Response to RAI - Relief Request 48 Attachment A RAI Question 1 Weld Maps and Materials Listing

MA.UE.R:IALS/{

W*E. D MA I G 3596293-6/

F 3596293-5 A

B C

DESCRIPTIONI LINE 3PSGEL005 W.O.#3596293

Piping Material And Cleanliness Worker Verification Sheet This document is part of a work control document and is not to be sewarated from it.

Worker Verification (WV) & Second Party Verification (SPV) Material Verifications Cleanliness Verifications (Initials Indicate Acceptance of the Attribute.) (Class" C "I Item Item Description APN MR Heat WV SPV Verification WV SPV Number Number Number/ Initial ! Initial Method Initial Initial!

Serial Date Date Used Date Date Number A EXISTING REDUCER SA 234 GR. WPC N/A N/A N/A N/A N/A B PIPE, CARBON STEEL, 161N, SEAMLESS, ASME SA106 GRADE C, 00070176 WITH A 0.1% TO 0.25% RESIDUAL CHROMIUM CONTENT, SCHEDULE 80 C REDUCER, CONCENTRIC, 161N X 141N, CARBON STEEL, SEAMLESS, ASME SA234 GRWPC, WITH A 0.1% TO 00070172 0.25% RESIDUAL CHROMIUM CONTENT, SCHEDULE 100 _

D PIPE, 141N, CARBON STEEL, SEAMLESS, ASME SA106 GRADE B, WITH A CHROMIUM CONTENT RANGE 00070175 OF 0.1% TO 0.4%, SCHEDULE 100 E ELBOW, 90 DEGREE, 141N, CARBON STEEL, SEAMLESS, ASME SA420 GRADE WPL6, WITH A 0.1% TO 0.3% 00070173 CHROMIUM CONTENT, SCHEDULE 100 F PIPE, 141N, CARBON STEEL, SEAMLESS, ASME SA106 GRADE B, WITH A CHROMIUM CONTENT RANGE 00070175 OF 0.1% TO 0.4%, SCHEDULE 100 G ELBOW, 90 DEGREE, 141N, CARBON STEEL, SEAMLESS, ASME SA420 GRADE WPL6, WITH A 0.1% TO 0.3% 00070173 CHROMIUM CONTENT, SCHEDULE 100 H EXISTING 14" PIPE SA 106 GR. B N/A N/A N/A N/A N/A DESCRIPTION W.O. 3596293 LINE 3PSGEL005

Enclosure Response to RAI - Relief Request 48 Attachment B RAI Question 2 Flaw Maps, Results, and Examples

01 U..

0 1 2 3 4 5 6 7 8 9 10 11 12 13 INDICATION NUMBER RT-1 RT-2 RT-3 RT-4 RT-5 PT-1 INDICATION CLUSTER CLASSIFICATION IP IF POROSITY IF SLAG CRACK LOCATION FROM 0" 17/8 37/8 51/4 83/8 117/8 11 Y2 LOCATION FROM Weld CL CL 1/16 US CL CL 3/8 US 1 3/8 DS LENGTH 5/8 1/2 1 5/8 5/8 WIDTH NA NA NA NA 3/16 OTHER BASE METAL ID CIRC

oft U2M S- LWOUI:

&-" R- DdIA)

I A-01 wrtr FTF lu I Q-I, II

• a Gai~*n (B) F:69 HardGwn(d3) 1 40 I I zMC IChannel1 J~-n~

II 272 1-"91i sm2. =a in 6ca fti Figure 1-2 Flaw #1- Incomplete Penetration, DS Scan Direction

Sof Gminbqm~

(cjB MO V.

9lz~md) F -,

If II II1 I

(M)I 34-Chanm17 m

II 437 I*'n m Figure 1-3 Flaw #2- Lack of Fusion, DS Scan Direction

i.mt - Layout Anmt)sis RywDoW WO HardGwmC.) 3413 ýI I aI I

GObb.G- (.1)F-4 I I I I I ahowm I seý1 ROm-I I IL q.

Jr mII.

a(O n I me" Figure 1-5 Flaw #3- Cluster Porosity, DS Scan Direction

CI LA..

I. mm -- _

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2 INDICATION NUMBER RT-1 RT-2 RT-3 RT-4 RT-5 RT-6 PT-1 INDICATION CLUSTER CLASSIFICATION IP IF IF IF POROSITY SLAG CRACK LOCATION FROM 0" 6 10 3/8 10 1/2 13 15 7/8 19 5/8 2 1/2 LOCATION FROM Weld CL CL CL 1/4 DS CL CL 1/4 US 3/8 DS LENGTH 3/4 3/8 1/4 1/4 1/2 1 3/4 WIDTH NA NA NA NA 1/4 NA 3/8 OTHER WELD OD

1. Sample 6-XXS-CS Figure 1-1 Flaw #1- OD Crack, US Scan Direction

Figure 1-13 Flaw #7- Slag, DS Scan Direction 0

-j U-I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 INDICATION NUMBER RT-1 RT-2 RT-3 RT-4 RT-5 PT-1 INDICATION CLUSTER CLASSIFICATION POROSITY IF IP IF IF CRACK LOCATION FROM 0" 11/2 31/2 55/8 71/4 73/4 103/4 LOCATION FROM Weld CL CL 1/16 US 1/16 DS 1/8 US 3/16 US 1 1/4 DS LENGTH 1 1/2 7/8 1/4 1 1/8 5/8 WIDTH 1/4 NA NA NA 3/8 3/16 OTHER BASE METAL

Figure 1-11 Flaw #6- ID Crack, DS Scan Direction ID -120-CS' 1ý 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 INDICATION NUMBER RT-1 RT-2 RT-3 RT-4 RT-5 INDICATION CLUSTER CLASSIFICATION POROSITY CONCAVITY IF IP SLAG LOCATION FROM 0" FULL LENGTH 2 1/4 4 5/8 10 3/8 13 7/8 LOCATION FROM Weld CL CL CL CL CL 3/8 DS LENGTH FULL LENGTH 1 1/4 5/8 7/8 1/4 WIDTH Y4TO 3/8 3/16 NA NA NA OTHER

Figure 1-4 Flaw #3- Incomplete Penetration, US Scan Direction 1 5',

Figure 1-6 Flaw #4- Slag, US Scan Direction

0

-i LL 0 1 2 3 4 5 6 7 INDICATION NUMBER RT-1 RT-2 INDICATION CLASSIFICATION SLAG IP LOCATION FROM 0" 1 1/4 4 3/8 LOCATION FROM Weld CL 7/16 DS CL _______ ______________

LENGTH 7/8 7/8 _______ ____ ___

WIDTH NA NA OTHER

1. Sample 14-100-CS

• UMW~ftj.LA - U44W-Oi.G-SM~Wfto trdeNWysbM NOj~

DSij~

SM- -_ WDO __ _ -rMMA--A H~GI-I~(dq)

Lh-0 -_

Figure 1-1 Flaw #1- Slag, US Scan Direction

.I I I SI7FGC Gi,ý G-(0 i

LmoWA t0 "1s 1 a We W*

• IU U a so IN W 453.

M hb"X I in - " , Mod Figure 1-2 Flaw #2- Incomplete Penetration, US Scan Direction

-%COUPON NO: Z4- 100-CS I I 01

-J U-L 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 INDICATION NUMBER RT-1 RT-2 RT-3 RT-4 RT-5 RT-6 RT-7 RT-8 PT-1 PT-2 INDICATION CLUSTER CLASSIFICATION SLAG IF SLAG IP POROSITY CONCAVITY SLAG SLAG CRACK CRACK LOCATION FROM 0" 4 4 1/4 5 8 1/2 9 1/4 14 1/2 18 1/4 19 1/8 1 1/2 21 5/8 LOCATION FROM Weld CL 3/8 US CL 3/8 US CL CL CL 3/16 DS 5/16 DS CL 3/16 US LENGTH 3/4 3/8 3/4 3/4 3/4 1 1/2 3/4 7/8 1/2 WIDTH NA 1/4 NA NA 3/8 1/4 NA NA 1/4 1/32 OTHER WELD WELD ID CIRC OD CIRC

1, S.Um(1)F4 I I I I H~l~d G-( t B) T I = I I IIl jChmoI 1-N-Dw Ir I'

El- 421 m SsI a ___

Figure 1-5 Flaw #2- Slag, DS Scan Direction

I-I

-o~n~B H~- (5 Ga.3 G- (do! -17 L~Z4~

m *' -514.,~

smn oO I a -

Figure 1-12 Flaw #6- Slag, US Scan Direction

I t I I

III p

SceGin (M

-e m(Of3-I W N0 W so NO1 4.

Figure 1-14 Flaw #7- Slag, US Scan Direction

Sftjp PMo Vefde-Ana"-LIS AND JS Samim - Urmt M** RPw D04 9 G~&~w~km L

S.OG-(dB) 70-.

Q ..IG-(,1) 41*-

• f Cho".I Ics-I 1vflt Figure 1-15 Flaw #7- Slag, DS Scan Direction

k' IzP G.dw

( 415 I

al Ca-I Fdy-iR-.Ot-12184 m I Figure 1-16 Flaw #1- OD Crack, US Scan Direction

Enclosure Response to RAI - Relief Request 48 Attachment C RAI Question 4b Flaw Discrimination

Enclosure Response to RAI - Relief Request 48 APS Response to 4b (continued from page 3 of this Enclosure)

Based on the acceptance criteria documented in NC-5330; the examination must discriminate all indications greater than 20% of reference level. The discrimination techniques and instructions will be included in the procedure and will be validated during the procedure demonstration. For the procedure demonstration acceptance, the results will be required to utilize the correct acceptance standards of either (a) or (b):

NC-5330 ULTRASONIC ACCEPTANCE STANDARDS

-All imperfections which produce a response greater than 20% of the reference level shall be investigated to the extent that the operator can determine the shape.

identity, and location of all such imperfections and evaluate them in terms of the acceptance rejection standards as given in (a) and (b) below.

(a) hIperfections are unacceptable if the indications exceed the reference level amplitude and have lengths exceeding:

(1) / 4 in. (6 nmm) for t up to %4 in. (19 mm).

inclusive (2) 1/3 t for t from 3/4 in. to 2!/4 in. (19 mmn to 57 nun), inclusive (3) 3/4 in. (19 nmn) for r over 2'/> in. (57 nun) where t is the thickness of the weld being exanmined:

if a weld joins two members having different thicknesses at the weld, t is the thinner of these two thicknesses.

(b) Indications characterized as cracks, lack of fusion, or incomplete penetration are unacceptable regardless of length.

Prior to the actual examination performance, the examination procedure will require an examination plan to be developed. This plan will include an as-built sketch of the actual weld including joint geometry. Also included will be reference to the welding procedure utilized including the actual welding process(s). Typically at PVNGS welding smaller diameter/thickness piping components would utilize the gas tungsten arc welding process (GTAW). Thicker and larger diameters would utilize the GTAW process for the root and second layer (hot .pass) with the remainder of the weld being performed with the shielded metal arc welding process (SMAW). This plan is required to support the acquisition of the phased array data and the analysis including discrimination.

The key attributes to indication discrimination starts with the above plan and will include the following:

1. Map or plot of the indication for size, shape, and orientation:

a. C-scan 1

Enclosure Response to RAI - Relief Request 48

b. B-scan

c. Sectorial scan

d. Results from other scan directions

e. Results from 0 degree

2. Indication location:

a. Root pass

b. Bevel face

c. Fill passes

d. Base metal

3. Surface connected:

a. ID, review of 0 degree and other scan directions

b. OD, review of PT or MT results

4. Welding process utilized in that location:

a. GTAW

b. SMAW

c. Prior weld repair areas

5. Associated measured or validated geometries:

a. Review 0 degree data for thickness variations

b. Counterbores documented during weld fitup

c. Bevel angles

d. Root conditions (convexity, concavity, mismatch)

6. Indication response characteristics:

a. Sharp amplitude response

b. Defined start and stop or blending in

c. Tip responses

d. Signal travel or walk

e. Multiple points of reflection

f. Detection angles and associated amplitudes 2

Enclosure Response to RAI - Relief Request 48 Attachment D RAI Question 5a

Enclosure Response to RAI - Relief Request 48 APS Response to 5a (continued from page 4 of this Enclosure),

The entire procedure and personnel. qualification process.will be under the direction and control of the APS Designated Level Ill. This process will be proceduralized and steps included for maintaining security of the data and results. No one involved with the open procedure qualification process or proctoring examinations will be certified to perform analysis.

It should be noted that with the requirement to encode and store the data, all results can be reviewed, verified, and validated. The ANII will also be involved with the overall process and procedure review.

Procedure Qualification For each nominal pipe diameter and thickness a qualification- block meeting the requirements in RR 48 [Code Case N-659-2(d)] will be utilized for the procedure qualification. This will be an open (not blind) process. Acceptable performance will be when the specified flaws are detected, classified as.surface or subsurface, discriminated as to flaw type correctly, and sized to be equal to or larger than truth. The process will not be considered acceptable with missed flaws, false calls, incorrect classification or discrimination, or sized smaller than truth.

A procedure qualification record meeting ASME Section V will be developed, and documented.. The procedure will be finalized based on this qualification record.

Analyst Qualification For each nominal pipe diameter and thickness a qualification block meeting the requirements of RR 48 (ASME Section Xl Table VIII-$2-1) will be utilized for analyst's qualification. Data will be collected from this block in accordance with the above qualified procedure. The data collection does not need to be performed by the analyst. Similar to steam generator data analysis rules, the data need be collected once and then utilized (blind) to qualify the analysts.

The above qualification blocks can be combined into one, if there is sufficient length of weld to accommodate all the flaws and unflawed grading units required.

Acceptable performance will be when the specified flaws are detected, classified as surface or subsurface, discriminated as to flaw type correctly, and sized to be equal to or larger than truth. Table VIII-S2-1 will be utilized for detection and false calls in the following manner:

1. Flawed grading units will be 11/4" longer than the actual flaw

2. Unflawed grading units will be a minimum of 1" 1

Enclosure Response to RAI - Relief Request 48

3. Detection includes correct classification for surface and subsurface

4. Detection includes correct discrimination for flaw type as meeting paragraphs (a) or (b) of NC-5330

5. The false call test criteria is applicable TABLE VIII-S2-1 PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Detection Test False Call Test Acceptance CrItera Acceptance Criteria No. of No. of Maximum Flawed Minimum Unflawed Number Grading Detection Grading of False Units Criteria Units Calls 5 5 10 0 6 6 12 1 7 6 14 1 8 7 16 2 9 7 18 2 10 8 20 3 2

Enclosure Response to RAI - Relief Request 48 Attachment E RAI Question 7 Reference 14 of the August 1, 2012 APS Submittal

ELECTRIC POWER RESEARCH INSTITUTE Ultrasonic Capability study for reduction of weld repair during the construction

- UT Technical presentation -

Yoshi Sekinuma EPRI Project Manager, Level III ASME Code Meeting May 2010 San Antonio, TX

Today's topics

• Back Ground

• Project Goals

• Roadmap

• Test Samples for the project

• Weld defects in the Test Samples

• UT Examination equipment

• UT data evaluation flow

• Characteristics and classification of flaw types

• UT Results 9 UT Images vs. RT film

• UT results - Summary

• Conclusion ELECTRIC POWER

© 2010 Electric Power Research Institute, Inc. All rights reserved. 2 RESEARCH INSTITUTE

Back Ground dRoot cause of service induced defects such as IGSCC, PWSCC are:

- Weld repair during the construction

- Cold working

• List of plants which SCCs were generated due to the weld repair during the construction:

- VC Summer 2000 (RPV to hot leg) (MRP-139 and 1019134)

- Tsuruga-2 (Pressurizer Safety/Relief nozzle) (MRP-139)

- Tsuruga-2 (SG nozzle) (News Release)

- TMI-1 (MRP-139)

- Tomari-1 (News release)

- Takahama-3 (News Release)

- Ringhals-3 (MRP-139)

- Ringhals 2000 (RPV nozzle to hot leg) (MRP-139 & 1019134)

- Davis-Besse - 2006 (Cold leg drain nozzle) (1019134)

- Pilgrim - 2007 (Safe end to nozzle) 1019134) 2 cc I sESLECTRIC POWER

@ 2010 Electric Power Research Institute, Inc. All rights reserved. 3 RESEARC H INSTITUTE

Back Ground - cont.

• Disagreement in acceptance criteria between ASME Sec. III and XI

- Many of fabrication flaws could have been accepted by Sec. XI, IWB-3500

• Radiography is required during the construction, not UT

- RT can detect volumetric flaw but not planar flaw, which is more critical for fracture mechanical than volumetric or laminar flaws

- UT can detect and characterize (size and determine flaw location with respect to OD and ID surfaces) flaws as required for fitness-for-service evaluation

© 2010 Electric Power Research Institute, Inc. All rights reserved. 4

'2'I ELECTRIC POWER RESEARCH INSTITUTE

Project Goals

" Eliminate unnecessary repairs during construction

- Influence ASME Code Section III

" Promote inspectable component and weld configurations

- Influence plant design and construction, Apply lessons learned, Utilize risk informed approach where applicable i Establish and operate UT qualification programs

- Provide assurance of accurate and reliable weld inspections during the construction

• Regulatory acceptance of fitness-for-service philosophy

- Cost savings and elimination of delays during construction

- Improved resistance to stress corrosion cracking during plant ops ELECTRIC POWER

© 2010 Electric Power Research Institute, Inc. All rights reserved. 5 RESEARCH INSTITUTE

Project Roadmap Design and Technical Researching of Develop UT Fabrication of Justification of Technique weld defects Test Samples UT techniques 4

'I Yes No

- -Moretest -

,' samples (?)

- - ---- I- -- ----------------- I I I I Acceptance Criteria I PD Mockups ,* Qualification I I I

- - - - - - .=- m

- rm:*

- - q-

© 2010 Electric Power Research Institute, Inc. All rights reserved. 6 i ELECRIC POWER RESEARCH INSTITUTE

Test Samples for UT technique verification study U

Design and fabricate test samples

" Collaborate with other Dissimilar Metal Weld program in EPRI to save material and fabrication cost

• A total of fifteen (15) sectioned samples were designed and fabricated

• Representing the existing DMW configurations Test Number of Sample Weld Prep OD Thickness Number Series samples DM-05 Single-V 14.26" 1.13" 1 Single-V 23.02" 1.54" 2 DM-09 Double Buttering 27.68" 1.61" 1 27.91" 2.12" 5 DM-10 Double-V 30.12" 2.15" 3 DM-11 Single-V 32.68" 2.46" 3 EN] VFWB L.01KIKt'G T 0/AR-1 THE VES~SEL

© 2010 Electric Power Research Institute, Inc. All rights reserved. 7 ~ RESEARCH INSTITUTE

Weld defects in the Test Samples

" A total of 65 weld defects are designed to install in 15 test samples

" Distribution of weld defects

- Flaw classifications

" Surface Flaw .... 8

• SubSurface Flaw ,,,, 57

- Flaw characteristic types

" Planar Flaw ,,,, 35

" Non-Planar Flaw* ,,,, 30 Automated UT scanning Note: *: Non-Planar flaws: Slag, Porosities, Lack of bond, Incomplete penetration 8*ar dF II ELECTRIC I RESEARCH POWER INSTITUTE

© 2010 Electric Power Research Institute, Inc. All rights reserved.

UT Examination equipment/Scan parameters Data Acquisition: Automated Phased Array Technique

- Equipment: R&D Tech Tomo III

- Probe

" GEIT: 1.5 MHz, 2x16, EL 2x5mm, pitch-catch

" GEIT: 2.25 MHz, 2x16, EL 2x5mm, pitch-catch

- Wedge 0 GEIT contoured type wedges

- Scans

• Dual sides axial scans (perpendicular to the weld, no circ. scan)

" Scan speed: 25mm/sec.

• Resolution: 1mm

• Increment size: 1mm

-FocalLaws

• Multi focal depth

" Steer angles (00 - 850, 50 increment)

Data Analysis

- Software: Ultravision 1.1Q5 Open/Blind: Open

© 2010 Electric Power Research Institute, Inc. All rights reserved. 9

~VI2 IIRESEARCH ELECTRIC POWER INSTITUTE

Flow chart: Characterization & Classification of weld defect (1) Measure the flaw height (2d)

(2) Define "S"

© 2010 Electric Power Research Institute, Inc. All rights reserved. 10 5I~( II fLECTRIC POWER ESEARCH INSTITUTE

Characteristicsof flaw types - PlanarFlaw vs.

Non-PlanarFlaw (or Volumetric defects)

Planar Flaw Planar Flaw: Lack Of Fusion

- Lack of fusion (Crack)

- Both Upper and Lower tip signals are obtained by UT

- Located at the boundary (i.e., weld -7

-.7=--

bevel surface) ,, B-scan display

- Normally larger amplitude signals _

response from one direction than the other Non-Planar Flaw (or volumetric Non-Planar Flaw: Slag defects)

- Slag, Porosities, Lack of Inter-run Fusion

- No tip like signals

- Located any places

- Defining location: At the optimized UT signal response

© 2010 Electric Power Research Institute, Inc. All rights reserved. 11

UT Results (1) - Detection Detection

- Detected 64 of 65 flaws

• 98.5% of probability to detect

- At least one scan direction (either LKUP or LKDN) obtained flaw signals (which are able to resolve and distinguish from noise or geometrical signals = good SIN ratio)

• 1.5 MHz and 2.25 MHz probes

- No significant difference between two frequencies in detection results

• One miss-detection

- Small slag inclusion near OD surface

- S/N ratio was bad, and flaw signals was not able to distinguished.

©2010 Electric Power Research Institute, Inc. All rights reserved. 12 ~I I IRESEARCH ELECTRIC POWER INSTITUTE

Miss detection flaw - RT film i

RT results: No flaw is seen on the RT film No flaw image on the film Note: RT films are digitized and enhanced for presentation purpose 2010 Electric Power Research Institute, Inc. All rights reserved. 13 RESEARCH INSTITUTE

UT Images vs. RT film

[::77 77ý71ý Example

© 2010 Electric Power Research Institute, Inc. All rights reserved. 14 ~~I2 II ELECTRIC POWER ESEARCH INSTITUTE

UT results - Summary Summary

" Detection:

- Well Done

- No problem for detection

" Flaw type classification (Surface vs. Sub-Surface):

- Miss-Classification (2 of 8 Surface flaws were called Sub-Surface Flaw)

- Need to improve resolving flaw tip proximity to the ID surface i Flaw type characterization (Planar vs. non-planar):

- Some over-calls (5 of 31 non-planar flaws were called as Planar flaws)

- Need to investigate the actual installed flaws to determine the improvement plan ELECTRIC POWER

© 2010 Electric Power Research Institute, Inc. All rights reserved. 15 1 r I RESEARCH INSTITUTE

Conclusion

" It may say that:

- UT is capable to detect and characterize many of the manufacturing weld defects in Dissimilar Metal Weld Pipe Joints

- UT is capable to distinguish the flaw location in vertical location

- UT is capable for flaw sizing (both length and thru-wall) within the acceptable tolerances

" Test results: Very satisfied

- A total of 65 weld defects in 15 test samples were examined.

- 98.5% detectability

- 95.4% accuracy of flaw type classification (surface vs sub-surface flaws)

- 90.7% accuracy in flaw characterization (planar vs non-planar flaws)

ELECTRIC POWER

© 2010 Electric Power Research Institute, Inc. All rights reserved. 16 I RESEARCH INSTITUTE

Important Note WA

• Information in this presentation is open to the public, and a technical justification report will be published and available later in this year.

1 c o s I t c rIdELECTRIC POWER

© 201 0 Electric Power Research Institute, Inc. All rights reserved. 17 RESEARCH INSTITUTE

T' Together...Shaping the Future of Electricity

© 2010 Electric Power Research Institute, Inc. All rights reserved. 18

,v aar=i i I i ELECTRIC POWER RESEARCH INSTITUTE