ML18038A736
| ML18038A736 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 02/19/1993 |
| From: | MPM RESEARCH & CONSULTING |
| To: | |
| Shared Package | |
| ML17056C287 | List: |
| References | |
| MPM-USE-293515, NUDOCS 9303040241 | |
| Download: ML18038A736 (21) | |
Text
NMPC Project 03-9425 MPM-USE-293515 FINALREPORT entitled NINE MILEPOINT UNIT 1 BELTLINEPLATE ORIENTATIONDETERMINATION 3IPPX Resesrck cf Consulting
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8EPVIAO ot.IBVT APTS mrouue >oleo rznwocoov February 19, 1993 9303040241 930226 PDR ADOCK 05000220 P
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.1.0 Introduction During a telephone conference on January 29, 1993, between NMPC Licensing, the NRC, and MPM Research & Consulting, the NRC requested that NMPC provide a drawing which clearly indicates the vessel plate rolling direction relative to the axis of the vessel.
In addition, the NRC requested that the drawing contain the assumed flaw orientation for the ASME Appendix X analysis along with the surveillance specimen orientation.
There are no written materials at NMPC or at MPM Research &Consulting which specify how the plates were placed in the vessel during fabrication.
Therefore, MPM Research & Consulting proposed using the archive plate, currently stored at MPM Research & Consulting, to determine the direction of microstructural anisotropy, and thus determine the rolling direction relative to the vessel axis.
The detailed scope of work is as follows:
Machine microscopy specimens from the 1/4 thickness position of the archive plate.
Perform light microscopy to determine grain and MnS inclusion anisotropy orientation relative to the vessel axis.
Contact Lukens Steel to verify the ingot production procedures used in the mid-1960s are consistent with the orientation measurements.
Prepare a drawing which satisfies the NRC request.
2.0 Microstructural Orientation 2.1 Lukens Fabrication Practice MPM Research & Consulting contacted Lukens Steel and requested that Lukens describe the heavy section manufacturing procedures which were used when the NMP-1 vessel plates were fabricated.
Plate G-8-3 was produced by Lukens Steel Co. and given the heat number P2130.
The plate was cast into a rectangular ingot 72 inches high, by 101 inches wide, by 38 inches thick, with a total weight of approximately 39 tons.
The ingot was rolled by Lukens as follows: spread or'ross rolled to increase the transverse dimension (T) from 101 to 136 inches (a reduction of 26%); straightaway rolled to increase the length (L) by 3.5:1 from 72 to 252 inches (71% reduction).
The plate was shipped to Combustion Engineering, Inc. (CEI) in the "as-rolled" condition with areal dimensions of I 251-7/8 inches (rolling direction) x T=135-3/4 inches (transverse direction).
CEI roller-or otherwise bent the plate in the longitudinal or major rolling
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direction (L), as can be seen from Figure 4 of their surveillance test program desc'ription
[CE65]. This is consistent with the size of the plates in the as-built configuration and with the radius of curvature of the archive plate.
2.2 Metallographic Investigation I
The archive plate has identifying marks engraved on the OD surface of the plate:
"Test N G-8-3". This identification is also shown in Figure 5 of Reference [CE65] along with the rolling direction relative to the Charpy specimen axis.
MPM Research &
Consulting removed a section of.Test N which was 8-1/2 inches in the assumed L
direction x 11 inches in the assumed T direction.,From this section, a 1-1/4 inch slab was cut for further studies at the quarter thickness as shown in Figure 2-1. To ensure that the orientation of the plate was maintained throughout the study, a metallographic section, L=1 inch x T=1/2 inch x S=1-1/4 inches, was cut from the slab and polished for metallographic examination of the L-S and T-S faces (Figure 2-1).
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Micrographs from the as-polished L-S and T-S faces are shown in Figure 2-2 and 2-3.
As shown in the figures, MnS inclusions (gray) appear extremely elongated in the assumed rolling direction L, and flattened in the thickness direction S, giving them an oval shape on the T-S face.
Such shapes develop during rolling when the roughly spherical MnS inclusions, which are plastic at the rolling temperature, change shape in proportion to the change in shape of the plate; that is the MnS spheres are reduced in
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1 thickness S direction 79%, elongated 3.5:1 in the L direction, and spread 26% in the T direction.
In addition to the MnS inclusions, dark spherical oxide inclusions were observed which are hard and do not plastically deform during rolling.
The oxide inclusions tend to string out in planar arrays in the rolling L direction.
These observations confirm that the assumed rolling direction shown on CEI Figure 5 of Reference [CE65] is correct. Therefore, based on metallographic examination, it is clear that the principle rolling direction is in the vessel circumferential direction.'
Tes.t N G8-3 L-S S=l-1/0" L=,1" T=11" Ne ta110graphi c Specimen L=8-1/2" Figure 2-1 Orientation of Metallographic Section
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Figure 2-2 Mn-S Stringers Parallel to the Principle Rolling Direction Viewed on the L-S Face (200x Magnification)
Figure 2-3 Mn-S Stringers Viewed End-on On the T-S Face (200x Magnification)
3.0 Mechanical Behavior Trend Reference [MA91]contains all of the mechanical behavior'data currently available on the NMP-1 beltline materials.
The archive plate G-8-3 material was Charpy tested in both the L-T 1
and T-L orientations.
These data are shown in Figures 3-1 and 3-2.
The test specimens were prepared under the assumption that the principle rolling "direction corresponds to the circumferential direction. 'As expected, the T-L orientation yields a significantly lower upper shelf energy.
NINE MILE POINT UNIT
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UNIRRADIATED BASE METAL G83/G84 (1,2)
EXPERIMENTAL DATA 120 100 Q3 l
IL
~ 80 0-6'0 40 V
20
~ g 0
+ ra/4 WEIBULL FIT TRANSITION WEIBULL FIT UPPER SHELF HYPERBOLIC TANGENT FIT CONFlDENCE LIMIT (9 5%)
CONFIDENCE LIMIT (9 5%)
CONFlDENCE LIMIT (95m) 0 A
-'I 00 -50 0
50
'I 00 i 50 2'00 250 LIMIT (9 5%)
TEST TEMPERATURE (F)
Figure 3-1 Unirradiated Plate 6-8-3 Charpy Data for the L-T Orientation
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UNIRRADIATEP QASE METAI G
g 3(TL)(1 2) ~
EXPERIMENTAL DATA 120 WEIBULL FIT TRANSITION 100 I
l U
80 0-60 R
Lil 40 V
20 L
HYPERBOLIC TANl ENT FIT CONFIDENCE LIMIT (95%)
CONFIDENCE LIMIT (95%)
CONFIDENCE LIMIT (95%)
-100,50 0
50-100 150 200 250 TEST TEMPERATURE (F)
CONFIDENCE LIMIT (95%)
Figure 3-2 Unirradiated Plate 6-8-3 Charpy Data for the T-L Orientation
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'4.0 Conclusion Based on the microstructural examination, discussions with Lukens steel, the mechanical behavior trends, and review of the plant documentation, it has been conclusively determined that 3
the principle rolling direction is in the vessel circumferential direction.
The rolling direction, Charpy specimen orientation relative to the rolling direction, and the postulated flaw orientation used in the ASME Appendix X'nalysis are shown in the attached drawing number MPM-NMP1-001.
5.0 References
[CE65]
Combustion Engineering, "Surveillance Test Program for Niagara Mohawk
[MA91]
Reactor Vessel", Contract 164, Rev. 2, 4/20/64.
Manahan, M.P., "Nine Mile Point Unit 1 Surveillance Capsule Program",
NMEL-'0001, January 4, 1991.
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DETAILA Postulated Circumferential Raw ID Surface Postulated Axial Flaw Core Pertphery Stainless Steel Shroud Reactor Pressure Vessel 800 Degree Capsule 00 30 Degree Capsule Stainless Steel Liner
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( (L-TOrientation) 1/4 t Transverse (T-LOrientation) 270 See Detail A l
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OD Surface t
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t 1/4 t Pnnclpal Rolling Directton t = Plate Thickness SI APERTUIO" CARD Also Available On Aperture Card 120 Degree Capsule 180 Principal Rolling Direction NOT A SCALE DRAWING MPM Research & Consulting 915 Pike Street Box 84p Lemont, PA 16851-084P Signature Date Drawn By
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NINE MILEPOINT UNIT 1 FRACTURE SPECIMEN ORIENTATION Project Appd.
Scale Dwg. No.
Rev.
n/a MPM-NMP1-001 0