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Slides from Meeting Review Meeting for NRC RES NA2 CRDM Program, Industry NDE of North Anna 2 RPV Head Penetrations 31 & 59
	ML060230399
Person / Time
Site:	North Anna
Issue date:	01/18/2006
From:	Ahluwalia A, Robin Barnes; Electric Power Research Institute
To:	; Office of Nuclear Reactor Regulation
References
	Download: ML060230399 (26)
	v • d • e

Industry NDE of North Anna 2 RPV Head Penetrations 31 & 59 Robert M Barnes, EPRI Al Ahluwalia, EPRI Review Meeting for NRC RES NA2 CRDM Program 18 January 2006

Main Topics

Project Background

NDE Activities

Geometry and References

Demonstration

Nozzle 31

Nozzle 59 06 Electric Power Research Institute, Inc. All rights reserved. 2

Project Background - Fall 2001

Fall 2001 - North Anna Unit 2 Reactor Pressure Vessel (RPV) Head Penetrations were inspected via bare metal visuals (BMV) of the upper head surface

Results of BMV

- Nozzle 51, 62 and 63 potential leaks

Tested J-Groove welds with Dye Penetrant

- Several indications on each weld

Removed the thermal sleeves

Performed Ultrasonic (UT) and Eddy Current Test (ECT) from the ID of the nozzles

Dye Penetrant tested all the welds after repairs were completed

Returned Head to Service 06 Electric Power Research Institute, Inc. All rights reserved. 3

Project Background - Fall 2002

Fall 2002 - North Anna Unit 2 was inspected via bare metal visual, eddy current testing of all J-Groove welds, and UT/ETC of nozzle inside diameters

- Bare Metal Visual

6 potential leaks

- ECT of the J-Groove Welds

63 of 65 J-Groove welds had indications

42 J-Groove welds would require repair

- UT/ECT of nozzle ID

6 nozzles with UT OD circumferential indications

Utility decided to replace the Reactor Vessel Head

Harvesting and Selection of CRDMs

Harvested six (6) selected CRDM Penetrations for the RPV Head

- Based on selected damage mechanisms

Axial or Circ indications

Parent tube or J-Groove weld indications

Potential primary coolant leakage

- Penetrations selected

10, 31, 51, 54, 59 and 63

Shipped to Pacific Northwest National Laboratories

Decontaminated four (4) penetrations at PNNL

Fabricated stand to hold penetrations for vendor inspections 06 Electric Power Research Institute, Inc. All rights reserved. 5

NDE Project Goals

Perform examinations that were applied in the field

- Ultrasonic TOFD and PE Straight beam form the tube inside diameter

- Surface scan of the tube inside diameter with eddy current from 2 above the J-Groove weld to the tube end wet side

- Surface scan the J-Groove wetted surface weld with eddy current to include any buttering associated with the weldment from the attached tube interface out to and beyond the weld into the cladding

- Scan the ID surface of the tubing from the upper weld interface to the dry side of the vessel head with available technology to detect possible leakage path of primary coolant

This is a technology evaluation project; not vendor comparison 06 Electric Power Research Institute, Inc. All rights reserved. 6

Vendor Examinations by Technique

Vendors developed their own examination programs that included the following:

- Ultrasonic scanning of the tube ID from the tube end wet side to above the dry side of the vessel head using:

TOFD and Pulse echo straight beam

Pulse echo shear wave

- Electromagnetic Acoustic Transmission (EMAT) from the tube OD above the reactor head

- Eddy Current surface scan with plus point / driver pick-up technology from the tube end wet side to above the J-Groove ID of the tubing

Some low frequency data was collected tube ID above the J-Groove

- Specialized eddy current scans of the tube ID and OD accessible surfaces and the J-Groove weld

Array driver/pick up probes on the wetted surface of the J-Groove weldment

Hall effect probes for magnetic residual field detection 06 Electric Power Research Institute, Inc. All rights reserved. 7

NDE Examination Activities

RPV CRDM NDE Examination Activities

- December 2003 to March 2004

- At Pacific Northwest National Laboratories

- Vendor Invitations

7 Vendors were invited to participate

4 Vendors accepted

- R Brooks & Associates Inc.

- Areva (Framatome-ANP)

- Pacific Gas & Electric Inspection

- WesDyne International Inc.

Samples 90° The head as downhill 180° - vent pipe seen from above 270° References Angles: 0° =

downhill; the arrow points to the 270° location of the penetration Elevation: 0 =

Establishing Reference Points

Reference points for reporting indications

Angular ZERO is lowest point of OD of head and CW (+) is looking down from the Adaptor Zero

Tube end was notched for ZERO reference location

+

Penetration Nozzle 31

Three vendors inspected the nozzle to various degrees

- UT & ET tube ID and EMATS

EMATS data was inconclusive due to upper end adaptor signal interference

- J-Groove weld wet surface not inspected

- A new technology (ET) identified a possible leak path

Penetration Nozzle 31 Summary

2002 Field Results

Vendors Inspection Results

BMV Visual: Leak indicated

Visual: Not Applicable

UT 1: possible leak path,

UT 1: Two vendors reported 80/120° possible leak path

UT 2: nozzle mid wall

UT 2: Mid wall indication not indication, 0.28, above the reported weld, 300/304°

ET 3 to 7: weld surface axial

ET 3 to 7: No vendor examined indications, outer portion of the this region weld, 154°, 209°, 235°, 264°,

265°

Newly reported UT LOF intermittent around weld, ET Permeability Variation (PV) indications above weld and ET (Low Freq) possible leak path 06 Electric Power Research Institute, Inc. All rights reserved. 17

Field NDE Results

Penetration 31:

Visual: leaking

UT 1: possible leak path, 80/120° 1

?

UT 2: nozzle mid wall indication, 2 0.28, above the weld, 300/304°

?1 2

3 4 7 6 5 3

ET 3 to 7: weld 5 4

surface axial 7 6

indications, outer portion of the weld, 154°, 209°, 235°,

Nozzle 31 UT Indications Reported by Vendors 12.00 Top of Weld 11.00 10.00 Bottom of the Weld 9.00 Ind #1 8.00 Ind 1 UT Leak Path (UT1)

I Ind # 4 n 7.00 c Ind 2 UT (WII Not 6.00 Prevoiusly h Reported) e 5.00 Ind #3 Stop Ind 3 UT (WII Not s Ind #3 Start Prevoiusly 4.00 Ind #2 Reported) 3.00 Ind 3 continue UT (WII Not Prevoiusly Reported) 2.00 Ind 4 UT Leak Path 1.00 (UT1) 0.00 0 30 60 90 120 150 180 210 240 270 300 330 360 Degrees 06 Electric Power Research Institute, Inc. All rights reserved. 19

Nozzles 31 ET Indications Reported by Vendors 12.00 11.00 10.00 ET # 1 Leak Path 9.00 I 8.00 ET # 2 Leak Path n 7.00 c ET # 3 Leak Path 6.00 h

Penetration Nozzle 59

Three Vendors inspected the nozzle

- UT, ET, and EMATS

J-Groove weld wet surface not inspected at PNNL

- Indications 2 and 4 in the weld wetted surfaces were reported in the original field NDE. These were not re-inspected

UT reported one additional axial indication, not reported during field NDE

Penetration Nozzle 59 Summary

2002 Field Results

Vendors Inspection Results

Visual : masked

Visual: Not Applicable

UT 1: circumferential indication at the

UT 1: One vendor reported same nozzle OD, middle of the weld, 347/63° indication

ET 2: multiple weld surface circumferential

ET 2: No vendor inspected this region indications, outer portion of the weld, 49/136°

UT 3: One vendor reported same

UT 3: OD circumferential indication, top of indication the weld, 156/206°

ET 4: multiple weld surface circumferential indications, outer portion of the weld,

ET 4: No vendor inspected this region 256/306°

UT 5: axial indication on the nozzle ID,

UT 5: One vendor reported same above the weld, 159° indication

ET 7: axial nozzle ID indication, opposite

ET 7: One vendor reported indication with middle of the weld, extends above the ET and one vendor with UT weld, 146°

Results

Penetration 59:

Visual : masked

UT 1: circumferential indication at the nozzle OD, middle of the weld, 347/63°

ET 2: multiple weld surface circumferential indications, outer portion of the weld, 5 49/136° 3

UT 3: OD circumferential 7 indication, top of the weld, 156/206° 2

ET 4: multiple weld surface 1 circumferential indications, outer portion of the weld, 256/306° 4

UT 5: axial indication on the nozzle ID, above the weld, 159°

Nozzle #59 UT Indications Reported by Vendors Degrees Top of Weld 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 12.00 Bottom of the 11.00 Weld 10.00 Ind 1 UT (UT1) 9.00 Ind 1 con't (UT1)

Ind 3 8.00 Ind 2 UT (UT3) 7.00 6.00 Ind 2 Ind 3 UT (UT5 &

Nozzle #59 ET Indications Reported by Vendors Degrees 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 12.00 11.00 10.00 Top of Weld 9.00 Bottom of the Weld 8.00 I

n 7.00 ET # 1 (ET7) c 6.00 h

e 5.00 s

Summary

Awaiting final destructive analysis on penetrations 54, 31 and 59 before final report on NDE performance

Many flaws located in the weld material not re-examined due to configuration of penetration support jig not allowing for tools to properly access the J-Groove weld

Some vendors had equipment problems and did not complete their planned inspections

Some new equipment and probe designs show inspection improvements

ML060230399

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