LIC-02-0139, Generator Eddy Current Test Report - 2002 Refueling Outage

Generator Eddy Current Test Report - 2002 Refueling Outage

ML023400505
Person / Time
Site:	Fort Calhoun
Issue date:	12/03/2002
From:	Ridenoure R Omaha Public Power District
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LIC-02-0139
Download: ML023400505 (16)

Text

ma WpmH wm Omaha PuntbhcPower Distnct 444 Sou th 16th Street Mall Omaha NE 68102-2247 December 3, 2002 LIC-02-0139 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Reference:

Docket No. 50-285

SUBJECT:

Fort Calhoun Station (FCS) Steam Generator Eddy Current Test Report- 2002 Refueling Outage Pursuant to FCS Unit No. 1 Technical Specification 3.17(5)(ii), Omaha Public Power District (OPPD) submits the attached FCS Steam Generator Eddy Current Test Report which summarizes testing performed during the Spring 2002 Refueling Outage.

If you have any questions or require additional information, please contact Dr. R. L. Jaworski at (402) 533-6833. No commitments are made to the NRC in this letter.

Sncer*

lT.denou "ivs'n Ma ae Nuc ar Operations R JKM/rrl

Attachment:

Fort Calhoun Station Steam Generator Eddy Current Test Report, 2002 Refueling Outage c: E. W. Merschoff, NRC Regional Administrator, Region IV A. B. Wang, NRC Project Manager J. G. Kramer, NRC Senior Resident Inspector Winston & Strawn (w/o Attachment)

Employment with Equal Opportunity 4171

LIC-02-0139 Attachment Page 1 ATTACHMENT FORT CALHOUN STATION STEAM GENERATOR EDDY CURRENT TEST REPORT 2002 REFUELING OUTAGE

LIC-02-0139 Attachment Page 2 FORT CALHOUN STATION STEAM GENERATOR EDDY CURRENT TEST REPORT 2002 REFUELING OUTAGE INTRODUCTION This report summarizes steam generator eddy current test results obtained during the Fort Calhoun Station (FCS) 2002 refueling outage (RFO). Omaha Public Power District (OPPD) submitted summaries of results of the two previous eddy current inspections to the NRC in the following documents:

• Fort Calhoun Station (FCS)Steam GeneratorEddy CurrentTest Report - 2001 Refueling Outage, dated September 28, 2001 (LIC-01-0086)

Fort Calhoun Station (FCS)Steam GeneratorEddy Current Test Report - 1999 Refueling Outage, dated April 25, 2000 (LIC-00-0039)

DESCRIPTION OF FCS STEAM GENERATORS FCS has two steam generators of the vertical recirculating type manufactured by Combustion Engineering Inc. (CE). The steam generators each contain 5005 tubes installed in low alloy steel tubesheets by a full depth explosive expansion process. The tubes are seal welded to the primary faces of the tubesheets. The steam generator tubes at Fort Calhoun are seamless Inconel Alloy 600 with an outside diameter of% 3/4inchand a nominal wall thickness of 0.048 inch.

All tube supports in the FCS steam generators are carbon steel. The vertical supports at the top of the tube bundle are of the vertical strap/scallop bar design typical of early CE steam generators.

Support is provided in the U-bend region by diagonal bars, or "batwings", also a common CE design.

The uppermost horizontal support is a partial drilled plate which supports all tubes in rows 74 and above. The remaining horizontal supports are of the egg crate lattice type which have drilled tube support plates integrated into the egg crates on both the hot and the cold leg sides at each elevation.

Approximately 975 tubes pass through at least one drilled plate, and several hundred tubes pass through all of the drilled plates. The solid drilled plates also have 1/4 inch diameter flow holes nominally in the center of each triangular array of three tubes.

FCS steam generator support notations referenced throughout this report can be found on Figure 1.

SCOPE OF EXAMINATION Westinghouse conducted an inservice eddy current nondestructive examination of the steam generator (SG) tubing at Omaha Public Power District's Fort Calhoun Nuclear Power Plant in May 2002. Fort Calhoun has two steam generators designated as RC-2A and RC-2B. The purpose of the examination was to assess the condition of the SGs, identify tubes requiring repair, and to provide the necessary information needed to fulfill Technical Specification

LIC-02-0139 Attachment Page 3 requirements.

The examination program included multifrequency bobbin testing for indications of degradation or dents and motorized rotating pancake/plus point coil testing for axial and circumferential cracking and further evaluation of detected bobbin indications.

The eddy current raw data was transmitted by the site by T-l data lines to the Vemner & James (primary analysis) data room in Snoqualmie, WA and the Zetec (secondary analysis) data room in Issaquah, WA where it was independently analyzed by these two groups of analysts. In addition to the primary and secondary analysis, Zetec preformed a tertiary analysis by using Computerized Data Screening (CDS) on the Bobbin Data. Analysis results were then transmitted to Fort Calhoun where discrepancies between the two sets of evaluation results were resolved by,two groups of Level III Resolution Analysts representing primary and secondary analysis groups. All data analysts were certified to a minimum of ECT Level hA and they successfully completed the EPRI Qualified Data Analyst (QDA) program, which is documented on their personal certifications. Data Analysts received familiarization training on the data during the Data Analyst Indoctrination Optical disks with data from Fort Calhoun, similar CE plants, and Indian Point Unit 2 were also available for review. Data analysts were qualified by proficiency examination on Fort Calhoun data and supplementary data from Maine Yankee and Indian Point Unit 2 for damage mechanisms not detected to date at Fort Calhoun.

There were also two (2) Level III Independent QDAs representing OPPD who were not part of the Primary, Secondary, or Resolution analysis teams. These analysts were responsible for review, comments and changes to the Analysis Procedure, and for review of all acquisition and analysis technique sheets. The Independent QDAs reviewed all "I" codes which had been dispositioned to no detectable degradation (NDD) by the Resolution team. They were also responsible for randomly sampling inspection results to ensure proper disposition of resolved indications, to ensure proper reporting, to review repairable indications, and to review and disposition calls which were contested by either the Primary or Secondary analyst. The functions of these Independent Level Ills position were in accordance with EPRI PWR Steam Generator Examination Guidelines, Revision 5.

The test program included:

1. Full length bobbin coil testing of 100% of the open tubes in steam generators RC-2A and RC-2B.

2. Various Rotating coil examinations were performed, including 100% of the open hot leg top-of-tubesheet transitions in steam generators RC-2A and RC-2B with Plus Point probes.

3. A 20% sample of the U-bend region of rows 1-4 were tested with a mid-frequency range plus point coil. In addition, a 20% sample of rows 1 and 2 was examined with a high frequency plus point coil which were the same tubes tested with the mid-range plus point coil.

4. 4 tubes in S/G A and 16 tubes in S/G B with previous less than zero indications were tested with an MRPC probe.

5. A 20% sample of freespan dings were tested in both steam generators.

LIC-02-0139 Attachment Page 4

6. Extensive motorized rotating probe coil (MRPC) examinations were conducted at all hot leg intersections and C8 which included all open tubes in the drilled tube supports on the hot leg and 20% of C8.

7. All tubes in the hot leg critical area (CA) where the partial drilled plate sections are superpositioned were tested from DBH to H5. In addition, 20% of these examinations were tested up to VI.

8. An additional 20% of the dents in supports outside of the CA on the hot leg were tested.

9. An additional 45 tubes outside of the CA were tested in each steam generator to inspect the 90-degree bend.

10. There was also an expansion to 100% of the dented intersections at HI and H2 in both steam generators due to axial cracks detected in the base program.

11. Diagnostic examinations of bobbin coil indications and positive identifications totaled 187 in RC2-A, and 333 in RC2-B INSPECTION EQUIPMENT AND TECHNIQUES The state-of-the-art equipment used included the Zetec MIZ-30 digital ECT tester system for data acquisition and the Eddynet98 digital analysis system for data interpretation. The two systems were linked on a local area network via fiber optic cable. Software revision 2.21 was used for the 2002 refueling outage examination.

The ECT probes used included a standard bobbin probe (A540MULC and A560MULC) and spring flex bobbin probes (A560SFRM and A540SFRM) for the full-length inspections. Three coil motorized rotating coils were used at the hot and cold leg top-of-tubesheet and to investigate bobbin indications. Various versions of the rotating coil probe were used to inspect the vertical runs, horizontal runs and square bend sections as required. Low row U-bends were also inspected with rotating coil technology.

The frequencies used for the bobbin examination are as follows:

400 kHz differential and absolute 200 kHz differential and absolute 100 kHz differential and absolute 35 kHz differential and absolute 400/100 kHz differential support ring mix 400/100 kHz absolute support ring mix The primary frequency of 400 kHz satisfies the requirements of the ASME Boiler and Pressure Vessel Code for the examination of nonferromagnetic steam generator tubing. A technique using the differential support mix and a voltage base of 2.75 volts on the 20% outer diameter (OD)

ASME signal was used to perform dent sizing consistent with current industry techniques. The 100 kHz is provided for the confirmation of flaw indications and as a frequency used in the mixes to eliminate support and OD deposit signals. The 100 kHz absolute detects gradual wall thickness variations. The 200 kHz frequency is for confirmation of flaw indications. The 35 kHz is provided to facilitate locating the probe position in the steam generator. The 400/100 kHz differential mix is used to eliminate the tube support signal and OD tube deposits. The 400/100

LIC-02-0139 Attachment Page 5 absolute mix is used to detect gradual wall loss.

The frequencies used for the 3 coil top-of-tubesheet examination are as follows:

400 kHz Pancake, Mid-Freq. Plus PT. coil, and High-Freq. Panc. coil 300 kHz Pancake, and Mid-Freq. Plus PT. coil 100 kHz Pancake, and Mid-Freq. Plus PT. coil 700 kHz High-Freq. Panc. coil 20 kHz Pancake, and Mid-Freq. Plus PT. Coil The frequencies used for the single coil mid-frequency U-bend examinations were as follows:

400 kHz Mid-Freq. Plus PT. coil 300 kHz Mid-Freq. Plus PT. coil 200 kHz Mid-Freq. Plus PT. coil 100 kHz Mid-Freq. Plus PT. coil 20 kHz Mid-Freq. Plus PT. coil The frequencies used for the single coil high frequency U-bend examinations were as follows:

800 kHz High-Freq. Plus PT. coil 600 kHz High-Freq. Plus PT. coil 400 kHz High-Freq. Plus PT. coil 300 kHz High-Freq. Plus PT. coil The frequencies for the 2 coil Flex probe MRPC examinations were as follows:

400 kHz Pancake, and Mid-Freq. Plus PT. coil 300 kHz Pancake, and Mid-Freq. Plus PT. Coil 200 kHz Pancake, and Mid-Freq. Plus PT. coil 100 kHz Pancake, and Mid-Freq. Plus PT. coil 20 kHz Pancake, and Mid-Freq. Plus PT. Coil The frequencies for the 2 coil modular probe were as follows:

400 kHz High-Freq. Plus PT. coil 300 kHz High-Freq. Plus PT. coil 100 kHz High-Freq. Plus PT. coil 20 kHz High-Freq. Plus PT. coil The recorded multi-frequency eddy current data are analyzed by two independent teams of data analysts for the presence of flaw indications and dents. Discrepancies between the two sets of evaluation results are reviewed and dispositioned by the resolution analysts. Primary and Secondary analyst feedback was accomplished through the use of the Analyst Performance Tracking Software. The primary and secondary analysts were required to review all missed calls and a sample of overcalls. If there were any calls which were dispositioned as requiring no

LIC-02-0139 Attachment Page 6 further action by the resolution team which the primary or secondary analyst felt should have remained, that analyst could appeal the call and the appeal was then assigned to the independent Level III QDA for final disposition.

The bobbin probe is used primarily as a screening tool to flag indications for further evaluation by means of historical reviews and/or additional testing with rotating coil technology. All of the data for all examined regions was analyzed. Indications left in service were not sized due to lack of a qualified sizing technique for the indications present, and have been determined to be either non-reportable or manufacturing related through the use of diagnostic testing and historical reviews. Indications were not left in service based on depth sizing estimates.

Bobbin testing was performed mainly from the outlet side of each SG. The probe is positioned at the tubes using a GENESIS robot manipulator. Probes are inserted and withdrawn using a 1OD probe pusher and controller. Bobbin tests speeds ranged from 12" to 36" per second and varied depending on presence of dents or low row diameter restrictions. Bobbin test speeds were within the requirements of the EPRI Appendix H approved techniques.

MRPC test speeds also varied depending on test location and probe type. Test speeds were from

.1" to .55"/second axially with the sampling rate adjusted in accordance with EPRI Appendix H Qualified Techniques as detailed in analysis procedure.

INSPECTION RESULTS The numbers and locations of each type of indication found are summarized in Tables 1 and 2.

Support notations are shown on Figure 1 and definitions of indication acronyms can be found in the Appendix.

All pluggable indications are reported in Tables 3 and 4. Support notation for each steam generator is shown in Figure 1. Depth estimates were made only on pluggable indications for the purpose of providing input to assessments of overall steam generator condition. No tubes were left in service on the basis of sizing.

As a result of the inspection, several conclusions can be derived as follows:

Single Axial Indications (SAI) There were 74 axial indications recorded at various elevations of both steam generators. The majority of the indications reside in the drill support plates tubing between HI and H4 in the critical area where the partial tube support plates are superpositioned.

Most of these indications were transparent to the bobbin coil and were detected with the more sensitive rotating plus point coil. The deepest indication which was not detected by the bobbin coil was 45% as sized by plus point amplitude. This indication was at a dent where bobbin performance is degraded from liftoff. The deepest indication missed by the bobbin coil where no denting is present was 47%. Historical data reviews from the 2001 refueling outage inspection were conducted by the senior analyst during the course of the 2002 refueling outage examination.

Of the 74 indications all were reviewed to determine whether the flaw was present and if so, did it appear to grow. Thirty three (33) indications showed no change and 3 showed change. Some

LIC-02-0139 Attachment Page 7 indications which were detected by the plus point coil only could not be reviewed because that area of the tube had not been tested by plus point in 2000 or 2001. The results from this data review are qualitative in nature with no detailed sizing performed. 17 indications were reviewed in RC-2A and 19 indications were reviewed in RC-2B. In RC-2A 1 (6%) indications showed growth. In RC-2B 2 (11%) indications showed growth. There was one indication in RC-2B that appears to be inner diameter (ID) in nature, this indication is in conjunction with a 31 volt dent.

Single Volumetric Indications(SVI) One (1) indication was found in RC-2B steam generator.

The indication was located above the sixth hot leg support. This is the region where axial ouiteer diameter stress corrosion cracking (ODSCC) occurs and the damage mechanism which produced the ECT indications is presumed to be a patch of inter-granular attack (IGA).

Single CircumferentialIndications (SCI's) Nine (9) indication were found, three (3) at the top of the hot leg tubesheet (HTS) in RC-2A and six (6) at hot leg drilled support plates in each steam generator. These are the first instance of circumferential indications at the hot leg expansion transition in these steam generators. The maximum circumferential extent of the HTS indications was 55 degrees and the maximum indicated depth by plus point phase analysis was 61% through-wall. The maximum circumferential extent of the drilled support plate indications was 95 degrees and the maximum indicated depth by plus point phase analysis was 47% through wall. Several of the indications show growth from the last cycle. Of the 6 SCI indications reported at drilled supports all are associated with a dent from the bobbin coil. The dent voltages range from 2.3 volts to 22.09 volts.

Two tubes in RC-2A that were uninspectable due to a severe geometric condition that made it impossible to inspect the support with the rotating +point coil, were preventively plugged. Of the two tubes, one was at VI and the other one was at V2.

One tube in RC-2B was preventively placed on the repair list due to excessive ECT noise on the bobbin coil.

All of the tubes with the above indications were repaired by plugging. Tubes with circumferential indications were stabilized as well. A total of 40 tubes were plugged in RC-2A and 40 tubes were plugged in RC-2B with indications, there were 4 tubes plugged in both steam generators to facilitate future use of the flat-rail system. A total of 44 tubes were plugged in each steam generator.

IN-SITU PRESSURE TESTS AND RESULTS In-situ pressure tests were performed on I defect in 1 tubes with the Westinghouse in-situ pressure test device to verify structural and leakage performance criteria were satisfied. Specifically, this tube was tested to demonstrate that leakage would be below 150 gallons per day at normal operating differential pressure (NODP), below 1 gallon per minute at peak accident (main steam line break (MSLB)) differential pressure, and that it would be able to sustain a pressure of 3 times NODP without burst.

LIC-02-0139 Attachment Page 8 The defect tested covered axial indication. The indication exceeded screening criteria for pressure testing. Table 5 shows the indications tested with the in-situ pressure test method and gives the results of the test. The indications did not leak at pressures up to 3 times NODP. Based on the eddy current and in-situ pressure test results, the performance criteria were met for the entire previous operating cycle, and the requirement for condition monitoring was satisfied.

CONCLUSIONS Based on the results of the extensive eddy current examination and the in-situ pressure tests performed, OPPD has reached the conclusion that the steam generator tube performance criteria were met for the entire previous operating cycle, and the requirements for condition monitoring were fulfilled.

All tubes with identified degradation were plugged. Tubes with circumferential indications were stabilized. No tubes were repaired by sleeving. Overall, 44 tubes were plugged in steam generator RC-2A, and 44 tubes were plugged in steam generator RC-2B. To date, RC-2A has a total of 262 tubes plugged (5.36%), and RC-2B has a total of 271 tubes plugged (5.54%).

LIC-02-0139 Attachment Page 9 TABLE 1 STEAM GENERATOR RC-2A INDICATION3 LISTING BY LOCATION"2 JLaUni~ SRAL: -,MAT -RCl, SVLLL ~LL Ql on1ML ThlaL HTS+ A H2+

H3+II H4+ 0 H6+

H6+0 H7+  ? I?

H9+

V2+

V3+

DIACG 0 C7 C60 C5 C4 C3 +

C2f702 C10 ICTS TO TAL `,I* ' , 5  :*' , ,,** 5 *,. .  ::: * ...:- : ' , ** * **: 0 1l: > 1 1 Numbers are totals and include multiple locations for each tube if separated by more than -l" 2 Locations are +/- 2", Locations with a 'Y' are >2" from support location.

3 Indication Definitions are given in Appendix after Tables.

LIC-02-0139 Attachment Page 10 TABLE 2 STEAM3 GENERATOR RC-2B INDICATION LISTING RY LOCATION" 2 HI+

T42+0 H3+

J46~ _ _4_

H4+ 0 T45+ I T46+ 114 H7+ 1 1

ýDTAG+ 0 V2+

V3+ 0 DITAG C8+-,

-T C7 TAl,3 ,;, 0 4 2 C6 C4 C3+,

C2I Cl2+/-

CTS 1 Numbers are totals and include multiple locations for each tube if separated by more than -1" 2 Locations are +/- 2", Locations with a "+" are >2" from support location.

3 Indication Definitions are given in Appendix after Tables.

LIC-02-0139 Attachment Page 11 TABLE 3 LIST OF RC-2A TUBES PLUGGED Row Line Location Flaw Type(l) Estimated Depth(%)

9 28 HTS + 0.38 SAI 27 9 96 HTS + 0.18 SCI 55 10 91 HTS + 0.07 SO 53 11 90 HTS+0.11 SO 61 11 94 HTS + 0.39 SAI 32 12 55 HTS + 0.26 SAI 27 12 63 HTS + 0.21 SAI 28 12 91 HTS + 0.22 SAI 26 12 95 HTS + 0.60 SAI 29 15 70 HTS + 0.21 SAI 28 24 107 HTS + 0.64 SAI 30 25 52 HTS + 0.99 SAI 25 26 55 HTS + 1.19 SAI 27 31 66 H1 + 0.41 SAI 45 67 54 H2 +0.99 SAI 33 69 56 H2 +1.16 SAI 26 70 79 H1 + 0.77 SAI 52 73 58 H2 + 0.12 SAI 30 73 58 H4 + 0.14 SAI 43 80 59 H1 + 1.29 SAI 50 80 59 H1 + 1.25 SAI 33 80 65 Not testable at VI NA NA 81 58 HI + 1.29 SAI 31 88 77 Not testable at V2 NA NA 90 49 HI + 0.98 SAI 27 90 69 H4 - 0.21 SAI 32 92 79 H3 - 1.05 SAI 36 94 47 H3 - 0.19 SAI 31 94 81 H1 + 0.41 SAI 33 95 84 HI + 0.20 SO 35 96 47 H1 + 0.24 SAI 44 96 57 H6 +19.10 SAI 27 98 45 H3 + 0.14 SAI 33 98 69 H7 + 13.56 SAI 33 99 46 H3 +0.06 SAI 26 99 48 H3 - 0.07 SAI 33 99 50 HI + 0.04 SAI 42 99 80 H1 - 0.22 SAI 31 101 56 H2 - 0.03 SAI 25 101 62 H7 + 0.21 SO 47 101 66 H2 + 0.16 SAI 35 103 62 H7 + 7.55 SAI 40 1 Flaw Type Definitions are given in Appendix after Tables.

LIC-02-0139 Attachment Page 12 TABLE 4 LIST OF RC-2B TUBES PLUGGED Row Line Location Flaw Type (1) Estimated Depth (%)

10 33 HTS + 0.92 SAI 37 19 46 HTS + 0.97 SAI 28 19 60 HTS + 1.28 SAI 33 20 59 HTS + 0.82 SAT 38 20 61 HTS + 0.54 SAI 38 22 61 HTS + 1.01 SAI 25 22 61 HTS + 1.19 SAl 23 28 83 H2 - 0.06 SAI 47 31 116 H2 + 0.40 SAI 36 38 79 H2 + 0 83 SAI 38 49 66 HI -064 SAT 35 59 22 NA Noise NA 68 41 H211+038 SAT 44 71 84 H2 - 0.15 SAl 44 74 39 H8 - 0 07 SAl 35 77 64 H4 - 0.15 SAT 38 77 64 H3 + 0.13 SAT 29 78 59 H4 + 0.09 SAT 66 78 63 H7 + 0.25 SCI 33 79 74 H6+3.19 SVI 48 80 35 H8 - 0.17 SO 9 81 72 H7 - 0.17 SAI 37 82 69 H7 + 0 28 SCI 31 83 74 H5 + 1.33 SO 32 84 55 H6 + 19.73 SAT 30 84 59 H6 + 21.26 SAI 35 85 66 H7+1+069 SAI 31 88 57 H6 + 0.73 SAT 29 88 67 H4 + 2.00 SAT 36 88 67 H6 + 1.73 SAI 29 89 66 H6 + 0.76 SAI 28 91 48 HI - 0.18 SAI 29 91 58 HI + 0.11 SAT 42 91 70 HI - 0 06 SAT 37 51 70 H8 + 2.34 SAl 35 95 74 H1 +006 SAl 25 95 74 H6 + 1.22 SAT 33 97 54 H5 + 36 02 SAI 26 99 56 HI + 0 22 SAl 41 100 59 H211+026 SAT 30 101 52 H3 + 0 06 SAI 31 101 60 HI + 0 03 SAI 34 101 70 H8 + 9 21 SAI 41 103 58 H4 + 0 01 SAT 35 103 70 H3 + 0 19 SAT 36 1 Flaw Type Definitions are given in Appendix after Tables.

LIC-02-0139 Attachment Page 13 Table 5 IN-SITU PRESSURE TESTS SG RC-2B Crack Profile Pressure Hot (psig)

Row Line Location Orientation Volts Depth Length Circ Target Actual Hold Leakage Est. (in.) Extent Time (gpm)

(%tw) (deg) (min) 78 59 H4+0.04 Single Axial 1.29 55.18 1.00 N/A 1500 1600 2 0

... ___ '2500 2600 2 0

_-_.. 3000 3100 2 0

.__. . _ _ * ... 3500 3600 2 0

_4000 4050 2 0

__ __ _ ___ _ __ __ __ __ 4500 4550 2 0

LIC-02-0139" Attachment Page 14 APPENDIX DEFINITIONS The acronyms defined below are used in Tables 1 through 5.

CVI: Circumferential Volumetric Indication - Volumetric indication with orientation in a circumferential plane (pluggable)

DFI: Differential Freespan Indication - An indication in the freespan that gives a flaw-like response on the bobbin coil (diagnostic/review required)

MAI: Multiple Axial Indication - Axial indications in the same plane (pluggable)

MVI: Multiple Volumetric Indication - Volumetric indications in the same plane (pluggable)

NSY: Noisy Tube - Any undesired signal or signals in a tube that may obscure for interpretation those signals that are of interest (diagnostic/review required)

OBS: Obstructed Tube - Tube which will not permit full length passage of the 0.540 inch diameter bobbin probe (pluggable)

SAI: Single Axial Indication - Axially oriented crack-like indication (pluggable)

SCI Single Circumferential Indication - Circumferentially oriented crack-like indication (pluggable)

SVI: Single Volumetric Indication - Indication which represents that volumetric (non-oriented) degradation is present (pluggable)

VOL: Volumetric - Indication which is volumetric in nature and generally associated with tube manufacturing (diagnostic/review required)

LIC-02-0139' Attachment Page 15 FIGURE 1 FCS STEAM GENERATOR ELEVATION DRAWING HTE Hot Leg Tube End HTS Hot Leg Tubesheet H1-H6 Hot Leg Full Supports H7 Hot Leg Partial Egg Crate H8 Hot Leg Partial Drilled Support DBH Diagonal Bar Hot Leg V1-V3 Vertical Supports DBC Diagonal Bar Cold Leg C8 Cold Leg Partial Drilled Support SI.-- DBC C7 Cold Leg Partial Egg Crate C1-C6 Cold Leg Full Supports CTS Cold Leg Tubesheet DBIt CTE Cold Leg Tube End H8 H7 H6 H5 H4 H3 H2 HI HTS HTE