ML022940415

Meeting with Entergy Operations, Inc., to Discuss Arkansas Nuclear One, Unit 1 Reactor Pressure Vessel Head Weld Repairs

ML022940415
Person / Time
Site:	Arkansas Nuclear
Issue date:	10/16/2002
From:	Alexion T NRC/NRR/DLPM/LPD4
To:
References
TAC MB5870
Download: ML022940415 (40)

Text

NRC FORM 658 U.S. NUCLEAR REGULATORY COMMISSION (9-19991 TRANSMITTAL OF MEETING HANDOUT MATERIALS FOR IMMEDIATE PLACEMENT IN THE PUBLIC DOMAIN This form is to be filled out (typed or hand-printed)by the person who announced the meeting (i.e., the person who issued the meeting notice). The completed form, and the attachedcopy of meeting handout materials, will be sent to the Document ControlDesk on the same day of the meeting; underno circumstances will this be done later than the working day after the meeting.

Do not include proprietarymaterials.

DATE OF MEETING F I The attached document(s), which was/were handed out in this meeting, is/are to be placed

( 0 (1( 02... inthe public domain as soon as possible. The minutes of the meeting will be issued in the near future. Following are administrative details regarding this meeting:

Docket Number(s) 5 - 13 Plant/Facility Name ,41\J0 TAC Number(s) (ifavailable) t& 5"-9"*7 3 Reference Meeting Notice ID I Is- 101- tL 0(? **?213.')

Purpose of Meeting (copy from meeting notice) "0 015)S 5 '---i6 /A-K--A, 5/AS NUtLeA?

O)N!& UN ml-) 1r?6S?

Ne1 S-L- WJA9A WSI-0 K<PA19-3 NAM- OF PERSON WHO ISSUED MEETING NOTICE TITLE OFFICE DIVISION BRANCH Distribution of this form and attachments:

Docket File/Central File PUBLIC

-prA NAC FORM 658 19-19991 rPlR INTED ON RE-CYCLE.D PAPER T1vs form w~as designed using InForms

ANO-1 Reactor Vessel Nozzle Repair Entergy Operations Inc.

October 16, 2002

Agenda

°* Introduction/Purpose Craig Anderson o 1 R1i6 (Spring 2001) Findings/Repair William Sims

o. 1R17 NDE Findings Steve Lewis o1 R1i7 Weld Repair Details William Sims

• . Evaluation of Weld Repair Steve Lewis o, Assurance for Not Having Leakage Path to Steve Lewis Annulus

• Safety Perspective Mike Krupa

• • Concluding Remarks Craig Anderson 2

Introductory Remarks Craig Anderson 3

I Status of ANO-1 CRDM Nozzle Examinations

• 100% Bare Metal Visual Exam Completed

Periphery Nozzle 56 was identified to be leaking

• • oVolumetric Examinations in Progress

.Liquid Penetrant and Eddy Current Exams Performed on Nozzle 56 4

1R16 (Spring 2001)

Findings/Repair William Sims Entergy A600 Technical Lead

Repairs Performed During IR16 on Nozzle 56

• • .Visual Inspection Performed Identified Nozzle 56 was the Only Leaking Nozzle UT and PT Performed LI

• Flaw was determined to be axial in the weld to nozzle interface at -30 degrees from low hill side

• Extended above J-weld in thenozzle

• Circumferential flaw in nozzle below J-weld 6

Repairs Performed During 1R16

• °*~-.

on Nozzle 56 (cont.)

- '- - _ - .* -- -.- - -*-+/-"

• • -Severed Nozzle above the OD Circ Crack

• • .Excavated the Flaw in nozzle/J-Weld to Butter Region At Triple Point o*Excavated Area Filled with 152 Weld Material to Surface of Existing 082/182 weld

• • .New Weld was PT Cleared with Progressive Exams 7

1R17 NDE Findings Steve Lewis Supervisor, Engineering

Status of Current Findings of Examinations of CRDM Nozzles

• Top Head Bare Metal Visual Inspections

> Nozzle 56 Determined to be the only leaking nozzle

> No evidence of wastage.

9

1R17 Nozzle 56 BoricAcid 10

1R17 Post Cleaning of Nozzle 56

-..- - *-- .- . . - * ' . w* . . .. ** w- . . - ... - * *

• o**_ _

' "-  ;(,

-_ -. , -~,

~ ~11

Status of Current Findings of Examinations of CRDM Nozzles (cont.)

Nozzle 56 Ultrasonic Data

• • .Four Indications Adjacent to 1 R1i6 Weld Repair o*o Two Indications on Hill Side of Nozzle Flaw # Depth Length Az. Above Below 1A 0.177 0.56 200 .16 --

2A 0.145 0.44 370 .12 --

4A 0.177 0.28 1750 .16 --

5A 0.125 0.6 1640 0 .12 1C 0.266 0.4 240 --_

2C 0.180 0.68 390 .32 -

• With uncertainty below weld only

• %No Indications Identified to Have Circumferential Extent 12

PT Layout of Nozzle 56 (General Representation)

Up Hill Side 1800 082/182 Weld Butter Area 90 0-0 RI-..062" RI~,100,-

R 1 ~.0 6 2 . _ /. ... ..

RI~ 062"__. - R1~.062" RI~-.03 General Area R~.185" J0° of IR16 Weld Down Hill Side Repair 10 I0 Col

Preliminary Results of Nozzle 56 Findings

• • .No Evidence of Alloy 052 cracking

o. No Wastage Identified at Nozzle Bore Annulus Area from Bare Metal Visual Inspection (Boric Acid Showed No Discoloration) 14

1R17 CRDM Nozzle Weld Repair William Sims Entergy A600 Technical Lead

Design Repair Objectives

• -Maintain Safe Operation of the Unit

) Provide ASME Code Compliance for Two Cycles of Operation

• Maintain Code margins

• Isolate the Flaw from the PWSCC Environment

"* Use of PWSCC resistant material

"* Control of repair processes SNo leaks

• • Incorporate Lessons Learned 16

Incorporate Lessons Learned AN0 North Anna Exposed -Crack 82/182 Weld I52 Weld Overlay Exposed Potential 1R3 82/182 Weld Crack Locations 17

Description of Weld Repair Option-s

• oEmbedded Flaw Repair Features (used in combination or individually)

S3600 J-Groove weld and butter overlay

> 3600 Nozzle inlay or overlay

> 90' Nozzle inlay

> Weld overlay on nozzle OD surface to mitigate crack initiation

• Or Just Remove The Flaw 18 Inlay

Weld Repair Process S-Identification of 082/182 Material Boundary

> Entergy will identify boundary between existing 082 material and SS clad using "ferrite" tool SMarks will be applied to location of 082/182 SS clad interface to identify boundary

> Personnel will be trained and qualified by blind mockup

> Independent verification will be performed

> Welds will overlap SS Clad by a minimum of 1/2"

> Written instructions will control this process 19

Weld Repair Process S**oWeld Process Applied at ANO-1

> J-weld overlay will be at least 3/8" thick (minimum of 3 layers)

• • .*Post Weld NDE

> Surface exam of J-weld overlay and nozzle inlay

> Volumetric exam of nozzle inlay

> Visual of weld surfaces 20

I Weld Repair Design Steve Lewis Supervisor, Engineering

Weld Repair Design

• • -Repairs were Designed by Detailed State of the Art Analysis

> Repairs are Designed by Detailed 3D FE Analysis

> Stress determination performed by Dominion Engineering

> All other analysis performed by Structural Integrity Associates 22

Weld Repair Design_(cont.)

• .*Testing and history to date has shown that 052 integrity is established for greater than two cycles SEPRI NP-3061, SSC of A600 and A690, May 1983

"*Tests @ 6800F for 6300 hrs

"*Could not get 052 to crack due to PWSCC

) McDermott Tech Report, Evaluation of 82, 152 and 052 SSC, Constant Extension Rate Tests performed

• 152(052) Materials tested at 6500F

> Westinghouse Bettis Pub. PWSCC Crack Growth (1999) 23

Weld Repair Design o:. Westinghouse Bettis Publication on PWSCC Crack Growth Results for Alloy 82H and Alloy 052 SFracture mechanics crack growth test a 3600C (680 0 F)

> Results compared to industry data

> Alloy 82H crack growth rates consistent with industry data for Alloy 600

> No crack extension in Alloy 52 at high stress intensity and extended times 24

Recent Industry Experience with Alloy 052/152

• DC Cook Inlay Repair

+VC Summer Butt Weld Repair

• .*Canopy Seal Weld Overlay Repairs S-BWR Nozzle to Safe End Weld Overlay Repairs o*North Anna Overlay Repairs

• • -ANO-1 Repair in 1R16 To Date, No Problems Have Been Reported 25

Weld Repair Design_(cont.)

. Summary

> Material Demonstrated to be Resistant to PWSCC Initiation and Growth

> Repair Qualified to Meet All Pertinent ASME Code Section III & XI Criteria 26

Repair Assurance for Not Having Leak Paths to Annulus

Repair Assurance for Not Having Leak Paths toAnnulus

• Evaluation of Leak Paths to Annulus

> Boron from above RV nozzle annulus

> Flowpath through ID of nozzle to annulus

> Flowpath through 052 weld material

> Flowpath around 052 weld repair 28

Boron from Above RV Nozzle Annulus 6-A -600

• Geometry and Temperature Result in Low Probability of Maintaining a Wetted Surface

• -Not Considered to be a Credible Condition 29

Flowpath Through ID of Nozzle to Annulus

• .*Volumetric Exam of Nozzles Performed

• "*No Indications will be Left in Service

• ".'Adequate Assurance is Being Provided to Prevent Leakage through ID of Nozzle 30

Flowpath Through 052 Weld Material

+ Previously Discussed the Integrity of the 052 Weld Material

o. Not considered to be a Credible Leak Path 31

Flowpath Around 052 Weld Repair v*Existing 082/182 Weld Boundary Will Be Clearly Identified

• -Lessons Learned on Ensuring Adequate Coverage of 082/182 Material with Repair Weld Included in Repair Procedures o*Repair Process Will Ensure Integrity of Weld Repair 32

Safety Perspective Mike Krupa Director, Nuclear Safety Assurance

SafetyPerspective o: Repair Plans will Remove All Mechanistic Failures that Can Create Leak Paths

• • • Repair meets ASME Section Xl Code Requirements

• .*Repair Process Has Incorporated Industry Lessons Learned

• • • Boundary of 082/182 and SS Clad will be Defined

• • . Appendix B Program will Ensure Proper Weld Application and Quality Control 34

Safety Perspective o*Annulus Will Be Isolated from PWSCC Environment

• I lndustry/MRP Analyses Have Demonstrated that Alloy 600 Will Not Become a Safety Concern when Properly Managed 35

Concluding Remarks 36

Backup CRDM Nozzle Slides Nozzle 56 UT pper Scans Lower Weld Toe *velOW* J Weld Lower Ao Edge 38

UT Graphic of I RI 7 Nozzle 56 L, ,. ..

f If *

• Ulpe" J.Ne Id 0e 000/1,1 ouoo Circumference (degrees) 39