ML031110283
| ML031110283 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/31/2002 |
| From: | Cullen W Office of Nuclear Regulatory Research |
| To: | Robert Tregoning Office of Nuclear Regulatory Research |
| References | |
| FOIA/PA-2003-0018 | |
| Download: ML031110283 (9) | |
Text
Robert Tregoning - BA1 Data Page.
From:
William Cullen /1e To:
Robert Tregoning Date:
10/31/02 9:26AM
Subject:
BAC Data Rob - it looks like Mark took his data from Table 1 c of our MEB report, EPRI-designated experiments "G" and "H" using the data found on pages 12 and 14.
I believe this to be a reasonable approach, although there are certainly other ways of looking at the data, and envisioning the process.
Table 1. Sample Summary SEM/EDS Met Mount for Sample Location Met Optical Unmounted Mount*
metallography*
CRDM Nozzle 3 (1" Ring)
Lower Portion I (crack opened up)
Middle Portion 1
1 Upper Portion Reserve for PNL J-Groove Weld Area axial crack (.180°)
l l
axial crack (-10°)
1 (crack opened up) 1 2
axial crack (-10°)
Reserve for PNL circ crack (.20°)
1 (crack opened up) 1 2
circ crack (0-450)
Reserve for PNL Cladding Cracking Clad crack (near center bulge)
I (crack opened up) 1 2
Clad crack (toward 900) 1 1
Clad crack (toward 2700) 1 1
Clad crack (near center bulge)
Reserve for PNL Cavity Wall and Undercut Regions Cavity undercut regions 3
Cavity side wall (toward 900) 1 2
Cavity side wall (toward 2700) 1 2
Clad/head interface (DONE) 1 Totals 6
6 18
- Six (6) of the eighteen (18) mounted samples for optical metallography will also be examined by SEM/EDS.
Disclaimer The major cuts are outlined in the description and photos below; however, additional cuts for obtaining the appropriate sample size will be necessary, but are not detailed here. Provided that sectioning follows the outline given here, no additional FENOC/NRC approval for these cuts is required.
Page I of 8
PT photo of 1" ring section taken from lower portion of nozzle Lower surface of nozzle is oriented up in this photo. 1.8X Nozzle #3, 1" Ring First two cuts (RI and R2) will be made radially through the nozzle wall at approximately 1700 and 220° to isolate the cracked region. Detailed stereovisual inspections will be performed on the nozzle ID surface after sectioning; results will be documented photographically.
Two transverse cuts (R3 and R4) will be made through the cracked region using an EDM machine to minimize saw kerf. Cuts will also be made as necessary to trim away excess material (e.g., above the crack). In all, three samples containing crack lengths of approximately 3/16" (lower portion of crack), 3/16" (middle portion of crack), and 1/8" (upper portion of crack) will be produced. The lower portion will be opened up for SEM/EDS; a transverse met mount will be made from the middle portion, and the upper portion will be reserved for PNL analysis. Note that the lower and middle sections will contain more than one crack. The met mount (middle portion) will also be analyzed by SEM/EDS.
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Top view of Piece A-2-A.
Piece A-2-A 1800 Axial Crack in the bore:
Cut #6 was already made; this created pieces A-2-A and A-2-B (spare). A section will be made through the nozzle #3 bore in the 90°-270° direction just uphill of the cavity to isolate the axial crack near 1800 (cut #7). After detailed stereovisual inspections, two radial sections will be made through the nozzle #3 bore near 2200 and 1400 (cuts #8 and
- 9) to reduce the sample size. Transverse cuts will be made as necessary to produce one transverse metallographic mount through the axial crack. No SEMIEDS is planned for this met mount.
100 Axial Crack and Circ. Crack (-20°):
Cut #10 will then be made in the 90°-270° direction to isolate the J-weld axial crack at 100 and the circumferential cracks at 0O°45°. This cut will be made through the cladding, not the J-weld. Two additional radial cuts (cuts #11 and #12) will be made at -340° and
-60° to reduce sample size. After detailed stereovisual inspections, transverse sections will be made through the axial crack to determine if there is communication with the circumferential cracks. A portion of the axial and circ cracks will be opened up for Page 3 of 8
SEM/EDS; two transverse met mounts will be prepared through the axial crack and the circ cracks (4 mounts total). Two of the 4 met mounts will also be analyzed by SEMIEDS. (Note: This scope would change if communication exists between the axial and circ cracks; additional SEMIEDS samples would be required to characterize the cracking.) Portions of the axial and circumferential cracks will also be reserved for PNL.
Cladding Cracking:
Cut #13 will be made to facilitate inspection of the cladding cracks and undercut regions.
The cladding cracks will be examined at four locations. The center portion of the cracking (near the bulge) will be sectioned out and opened up for SEMIEDS analysis.
Two transverse met mounts will be prepared from the mirror faces of these cuts to evaluate crack depth, morphology, etc. The third area of the cracking will be located toward 90° and the fourth area toward 270°. Three of these met mounts (one near the center, one toward 900, and one toward 2700) will also be analyzed by SEMJEDS for crack contents, Cr profile, etc. A portion of the cracks near the center bulge will also be reserved for PNL. The following figure provides the section locations.
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Toward 2700 Dashed lines indicate 4 polished met mount surfaces I
Center portion Toward 900 Photo mosaic of cladding cracks.
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Cavity Wall and Undercut Regions:
Undercut regions between the exposed cladding and the low alloy steel head will be examined metallographically at three locations in the transverse direction. Two of these locations (30° and 3150) exhibited significant undercutting (see figures below); the third sample will be taken through the cavity nose at 100, which is the farthest point from the nozzle #3 bore. This sample will provide information for this region, even though no undercutting was visible (however, there may be incipient undercutting). No SEM/EDS is proposed for these samples.
Undercut region near 30°. 4X Undercut regions near 3150. 4X Page 6 of 8
Piece A-1 Portions of the cavity side wall will be selected for metallographic and SEM/EDS examinations. A section will be made in the 90°-270° direction as shown below. A macro etch inspection will be performed on one of the cut surfaces to evaluate banding in the low alloy steel microstructure.
Underside of cavity (piece A-i).
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Striated portions of the side wall will be evaluated by SEM/EDS (one sample/side) and transverse metallography (two samples/side). The sample locations detailed below were selected from the thickest portion of the remaining head and will provide information regarding both the cavity progression and the head microstructure. The met mount surface is the cut face as indicated by the long-dashed line; the surface examined by SEM/EDS is the cavity side wall as outlined by the short-dashed line.
Met mount
+~
SEM/EDS Met mount C
.,X-II. b 4 ? X
,' i r
Ci y
si w -
toward 9Q*
Cavity side wall toward 90°.
Met mount SEM/EDS Met mount Cavity side wall toward 270°.
Page 8 of 8