ML031120666

E-mail from R. Tregoning to J. Torres, Regarding Permanent Set Measured in DB Clad

ML031120666
Person / Time
Site:	Davis Besse  (NPF-003)
Issue date:	11/27/2002
From:	Robert Tregoning Office of Nuclear Regulatory Research
To:	Torres J Office of Nuclear Regulatory Research
References
FOIA/PA-2003-0018
Download: ML031120666 (19)

Text

Jeannette Torres - Fwd: Permanent set "Measured" in DB Clad Page From:

Robert Tregoning et!i To:

Jeannette Torres Date:

11/27/02 8:18AM

Subject:

Fwd: Permanent set 'Measured" in DB Clad First of many

[ O
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e'Torres

- Permanent set "Measured" in DB Clad !..JeanneAe Torres

- Permanent set XMEasured" in OB Clad Page From:

Mark Kirk Ho To:

Bass, Richard - ORNL Date:

10/29/02 9:28AM

Subject:

Permanent set "Measured" in DB Clad Richard -

Attached is a file with the measurements that you requested last week (& i forgot to send). The info you are looking for is on p. 19-20... by my very coarse interpretation of these data i'd say a permanent set of 0.18-in. was measured. I'd be interested to hear how well this number compares with the results of Paul's FE analysis. Since we have argued that the analysis is "intentionally conservative" (i.e. larger wastage area than actual modelled, reinforcing effect of J-groove weld not modelled) i'm hoping that the FE analysis predicts more set than 0.1 8-in..... but let's see.

Thanks Mark CC:

Nilesh Chokshi; Robert Tregoning; Williams, Paul - ORNL

IJeannette Torres - Sample Phase 3 Results Sept 1 9.doc Page Phase 3 Status Report, 9/19/02 1 of 22

Reference:

Phase 3, Rev 9/11/02 Davis-Besse Reactor Head Sample Characterization Phase 3 Status Report, 9/19/02 V Every Phase 3 status report supersedes the previous one. Please read the entire document.

From this status update (9/12/02), the descriptions of the test items or steps are deleted. Please refer to the latest Phase 3 revision on the top left corner, which will always be attached in the same email message with the update.

/

Test plan(s) proposed will continue to be included in the status report. However, once the proposed test plan is finalized and approved by FENOC/NRC, it will be included in the revised Phase 3 test plan.

Step 1.Nozzle 2 (Work has been completed)

(a)

Completed on 8/23/02; no obvious evidence of cracking observed. Photos were taken to document nozzle condition. Based on measurement, it was estimated that 5/8" was sectioned off the bottom of the nozzle during the removal at Davis-Besse site.

(b)

Decontamination was not necessary (c)

Performed - see (a) above.

Step 2. Nozzle 3 (a)

Completed on 8/21/02; photographs were taken to document condition of the nozzle. It was determined that 4-1/2" was sectioned off the bottom of the nozzle during removal.

(b)

Completed on 8/22/02.

(c)

Completed on 8/23102; NOTE: Prior to sectioning, a PT exam was performed on the nozzle OD in the reduced area. No indications were found.

(d)

Completed on 8/28/02, see photo below.

I, Jeannette Torres - SaMDle Phase 3 Results SeDt 19.doc

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. I-Pa-qe I Jeannette Torres - Samole Phase 3 Results Seot 19.doc Pane Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 2 of 22 Figure 2(d). 2.5" long ring cut from Nozzle 3. Top face (from the 3.5" cut) and Bottom Face (from the 1 " cut). The 0, 90, 180, and 2700 markings are approximate.

Jeannette Torres-Sample Phase 3 Results Sept 1 9.doc Page Phase 3 Status Report, 9119/02

Reference:

Phase 3, Rev 9/11102 3 of 22

Jeannette Torres - Samnle Phase 3 Results Ser)t 19.doc Page d1 a nnett e Torres-7-

Saol Pae Rsut SeI 1

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Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 4 of 22 (e)

NRC and FENOC shipment authorization and ANL contact information received on 09/03/02. Shipment was received by ANL on 09/17/02. contact:

John R. McDade, (630)252-5168, Fax (630)252-7367, jmcdade@anl.gov (f)

Completed on 8/26/02; a patch of axial crack-like indications was observed on the lower end of the nozzle OD. The largest indication extended -0.5" axially and -1/8" into the nozzle wall. These indications were located on the uphill side of the nozzle (i.e., 1800 or the side facing toward nozzle #1).

ing at the Nozzle 3 lower end face.

Figure L-ki). viewing onentauon: bc Proposed sectioning plan for 1" ring from end of nozzle #3 (Dated 09/03/02).

The majority of cracks will be sectioned out of the ring (cuts #RI-3). Also, after Cuts #RI-2, the I.D. surface of the nozzle segment will be examined under SEM. Cut #R4, which is parallel to Cut #3, will be made transverse through the cracks (red line) and the two mirror surfaces will be mounted. This will permit observation of the cracks in two directions with further progressive grinding.

Further testing of Nozzle 3 is currently on-hold, until the details of further sectioning and testing plan are finalized.

1.1PqnnPttP Torrps - Sample Phase 3 Results Ser)t 19.doc Page

.I~n~l om anePae3RslsSn 9dcP Phase 3 Status Report, 9/19/02 5 of 22

Reference:

Phase 3, Rev 9/11/02 Step 3. Nozzle 3 Corrosion Area (a)

The first mold of the cavity was successfully performed with FENOC and NRC personnel concurrence on June 14, 2002. Complete on 06/14/02.

(b)

The second mold of cavity (intended as a backup) was successfully performed with FENOC and NRC concurrence on June 27, 2002. Complete on 06/27/02.

(c)

A mold of the stainless cladding from the underside (RCS side) of the cavity was successfully performed with FENOC and NRC personnel concurrence on June 27, 2002. Complete on 06/27/02.

(d)

Completed on 8/23/02. NOTE: Cut #2 impinged approximately 1/16" into the side of the cavity, resulted in a small hole (1/2 to 3/4/" dia.) on the cavity side wall. This is a deviation from the planned cutting of 0.5" min. outside cavity walls. This was caused by deflection of the band saw blade. However, this is not expected to have any significant adverse impact on the investigation.

(e)

Completed on 8/23/02; no evidence of disbond noted between the stainless steel clad and low alloy steel. One small void measuring -1/8" in length was present near the nozzle #11 J-groove weld root. See photos below, before and after removing the PT dye and developer.

e 3(e). PT of stainless steel cladding and low alloy steel interface.

L JPennette Torres - Sample Phase 3 Results Sent 1 9.doc Page V -,- -11,1-=

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I Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 6 of 22 (f)

Microhardness (Knoop 500gram) traverse on Block B completed on 9/6/02.

See plot below.

350 300 E 250

'n 200 In In 0

M 150 0.

0 100 50 0

0.00 0.10 0.20 0.30 0.40 Inch 0.50 0.60 0.70 0.80 Figure 3(f). Microhardness traverse across stainless steel cladding and into low alloy steel

• The micrographs of low alloy steels and stainless steel cladding microstructures are documented in a separate Microsoft Word file, "Supplement 1, Microstructure of Low Alloy Steel and Stainless Steel Cladding, Rev 9/11/02." This is to limit the status report file size (make it easy on email systems and computer ram).

[ Jeannette Torres - Sample Phase 3 Results Sept 1 9.doc Page Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 7 of 22 (g)

Cut #4 completed on 8/26/02 (see photo below); NRC and FENOC shipment authorization and ANL contact information received on 09103/02. Shipment was received by ANL on 09/17/02, contact: John R. McDade, (630)252-5168, Fax (630)252-7367, jmcdade@anl.gov.

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4!!s,§ep!,j 9.doc Page E Jeanett Tores SaplePhae 3 esuts ept 9.oc aae Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 8 of 22 (i)

Completed on 8/28/02; linear crack-like indication present on ID surface; circumferential cracking present on the J-groove weld's underside surface (RSC side, the same as stainless steel cladding surface); linear voids present in J-groove weld. See the following three photos.

Figure 3(i)-I. PT results for nozzle #3 J-groove weld. Orientation: looking at stainless steel clad surface (or underside, i.e., RCS side). O° is downhill side facing the cavity, and 180° is uphill side. A crack-like indication measuring -1.4" long was present at

-10 degrees on the J-groove weld bore (arrow). This crack was visible on the top of the J-groove weld and was aligned with the deepest portion of the cavity.

Circumferential cracking was observed on the J-groove weld's underside surface (same as stainless steel cladding surface). These circumferential cracks are located

-3/4" radially from the penetration bore and between 00 and 450 (higher magnification photos follow). Linearly aligned voids were also present on the J-groove weld bore

-0.3" below the top surface of the J-groove weld. These voids extended from 240 degrees to 30 degrees (through 0 degrees) and measured a maximum -0.1" wide and

-1.4" in length. These voids likely formed during original welding.

[ Jeannette Torres - Sample Phase 3 Results Sept 19.doc Page 9 Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 1WWZ"g 9 of 22 Figure 3(i)-2. Circumferential cracking on the J -groove weld underside or RCS side (6X). The yellow spot at the top of the photo is a grid marking for the UT thickness measurement performed at the Davis-Besse site.

Figure 3(i)-i. Detail of circumterential cracking (I

[Jeannette Torres - Sarnple Phase 3 Results Sept 1 9.doc Page10 Phase 3 Status Report, 9/19/02 10 of 22

Reference:

Phase 3, Rev 9/11/02 Additional Stereomicroscope Inspections of Nozzle 3 J-groove Weld Area (Performed between 09/06/02 - 09/09/02).

The PT performed did reveal one axial crack indication on the J-groove weld bore surface (1800) and some circumferential crack indications on the J-groove weld un-machined undersurface (0-45°) see above. However, the surface condition of the J-groove weld, especially the upper surface and the machined bore of the J-groove weld are not conducive to PT. Hence, it was decided to use the stereo microscope (up to X50) to completely scan the J-groove weld area. This led to the following new information to the PT indication, cracking indications not revealed by the PT, and cracking in the exposed stainless steel cladding top surface.

Figure 3(i)4. Looking at J-groove weld underface (bored surface). Crack indication corresponds to axial crack (near 00) indication in Figure 3(i)-i.

L Jeannette Torres - SarnDle Phase 3 Results Seot 19.doc Page I.Janet Tors-aDe hs 3Rslt et

.ocPg Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 17 of 22 Figure 3(i)-11. Close-up of underside (RCS side) of the corrosion cavity, inside the maximum deflection 6X. No indication of cracking is found on the underside with stereo microscope scanning.

(i)

Cut #5 completed on 8/27/02; Stainless clad thickness measurement completed on 9/5/02.

The Figure below shows the cladding thickness measurements superimposed on the exposed stainless steel cladding contour taken from the cavity molding*. It should be noted that some portion of the exposed cladding along its edge is inaccessible for measurement due to the undercutting close to the bottom. The #5 cut did not remove all the overhang above the exposed cladding surface.

Average thickness of all 78 readings: 0.256" Minimum measured clad thickness: 0.202" Maximum measured clad thickness: 0.314"

• Note, the area of the exposed stainless steel cladding captured by the molding of the cavity was twice measured at BWXT. On the first occasion (81/02), the image analysis was performed on a photograph of the cavity molding and yielded 17.3 sq. inch. On the second occasion (8/9/02), the image analysis was performed on a grid paper which had

Jeannette Torres - Sample Phase 3 Results Sept 19.doc Page 18 Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 18 of 22 traced the outline (the outline shown in Figure 3(j)-i) of the exposed cladding area captured by the molding. By preventing inaccuracy arising form a slight cladding curvature and/or perspective distortion in the photograph, the second method is considered to be slightly more accurate. The second measurement resulted in 16.5 sq.

inch of exposed cladding area.

0 208 4025 2700

+0 236 40244 4029 0266 40293 40290 278 0293 4252 0252 0.267 0268 0264 A0,251 0244 0256

+0252

+0259 +0242 0278

+0267

+0253

+0228 +0244 O00

+0253

+0 243

+0259

+0236 0251 0262

+0 27

+0 258

+0.239 0277

+0 261

+0 0

+0 263

+0.236 0 254 0238

+0.297 024o0274 40286 40259 40242 40239 1026 02 0 0.24 0.252 900 023.0239 40299 40283 40255 40247 40235 0238 02420261 0202 4-4 4

.4 4

4 JO3 i0239 0246 0297 0.314 0274 0233 40234 0239 40239 4

0278 400275 402 0245

Jeannette I orres - Sample Phase 3 Results Sept 19.doc Page 19 Phase 3 Status Report, 9/19/02 19 of 22

Reference:

Phase 3, Rev 9/11/02 Figure 3(j)-I. Exposed stainless steel cladding thickness measurement.

Clad Thickness 0.3 42 0.2i 0.24 Hj-0.23 fi.Ad Ad 0.25 0.22 muQ p...Jrx 022

,~0.21

-202 M3 X

~

-3 x

2 Figure 3(j)-2. Color representation of the exposed stainless steel cladding thickness based on Figure 3(j)-1 numbers.

I Jeannette Torres - Sample Phase 3 Results Sept 1 9.doc Page 20 I Jeanriette Torres - Sample Phase 3 Results Sept 1 9.doc Page 20 Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 20 of 22 Clad Profile - Top Surface 4.21 y

13 0.09

-0.0 Ei 0.03

-0.0 9Sf-0.03

-0.09

-0.12

-2 2

X Figure 3(j)-3, Color representation of the elevation profile of the upper exposed cladding surface.

Jeannette Torres - Sample Phase 3 Results Sept 1 9.doc Page 2 Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 21 of 22 Clad Profile - Bottom Surface 4.2 y

-0.14

-0.16

-0.18

-0.2

-0.22

-0.24

-026

-028

-03

-0.32

-0.34 Figure 3()-4, Color representation of the elevation profile of area on the lower cladding surface corresponding to the exposed cladding on the upper side.

I Jeannette Torres - Sample Phase 3 Results Sept 19.doc e T Page 2.

Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 22 of 22 kness measurement. The two opposing dials are mechanicallly connected to ensure their identical X-Y positioning.

I Jeannette Torres - Samp~le Phase 3 Results Serpt 1 9.doc Page I

Phase 3 Status Report, 9/19/02

Reference:

Phase 3, Rev 9/11/02 23 of 22 (k) Approved, but not performed yet.

(1) Approved, but not performed yet.

(m)Approved, but not performed yet.

Beside the above items already approved, all other testing of samples originated from Nozzle 3 Corrosion Area is currently on-hold, until the details of further sectioning and testing plan are finalized.