ML20129B705
| ML20129B705 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 09/22/1995 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20129B697 | List: |
| References | |
| BVP-200-34T1, NUDOCS 9609230200 | |
| Download: ML20129B705 (83) | |
Text
.,
i BVP 200-34T1 Revision 0 c.
\\
Byron /Braidwood Units 1 & 2 Steam Generator l
l Bddy Current Analysis Guidelines l
l Revision:
Date:
l
/
Reviewed By:
d Date:
, ~
9!2.D!97
~
Approved By:
Ar Date:
Contractor Level III
/
Concurrence:
e d
Date:
9 ')~1/9 f J'
/
't
/
File Location:
3.11.0565 1
(Guideline Document Attached)
I l
1 i
9609230200 960917 (Final)
PDR ADOCK 05000456 i
G PDR AUG 101932 (9796SS/WPF/080694)
Table of Contents Section Iltle Eage 1.0 Purpose 1
2.0 General Characteristics of Steam Generators 1
3.0 Responsibilities 2
4.0 Personnel Qualifications 3
5.0 General Analysis Requirements 3
6.0 Bobbin Coil Eddy Current Requirements 5
7.0
' Rotating Pancake Coil (RPC) Requirements 13 8.0 Resolution Criteria 17 APPENDICES Appendix A Data Acquisition and Analysis Requirements for TSP ODSCC IPC Appendix B Analysis Guideline Change Form Appendix C Analysis and Retest Codes i
Appendix D Support Structures Nomenclature and Measurements ATTACHMENT 1 Figure 1 Flow Diagram for Tube Support Plate Inideations Figure 2 Flow Diagram for Tubesheet Indications (F*)
Figure 3 Flow Diagram for U-Bend Region (11H Through 11C)
Figure 4 Flow Diagram for indications at AVB's Figure 5 Flow Diagram for Free-span Straight Sections Figure 6 Flow Diagram for Resolution of Free-span Indications Figure 7 Flow Diagram for Rotaing Probe Analysis
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 and Unit 2 Revtsson 9. September 11995 1.0 PURPOSE l
1.1 The purpose of this guideline is to provide general instructions and to define specific requirements for the analysis of eddy current data acquired for the Comed Byron and Braidwood Units 1 & 2 steam generators.
1.2 Analysis guidelines provide a structure to ensure that data is (a) analyzed in accordance with the appropriate techniques and practices that reflect current industry experience, (b) in a consistent and repeatable manner and (c) in compliance with Comed requirements.
1.3 Conditions encountered during the course of a steam generator examination not foreseen by this guideline are to be reported by data analysts to the Resolution or Lead Analyst of the job.
2.0 GENERAL CHARACTERISTICS OF STEAM GENERATORS 2.1 D.4 Steam Generators (Byron 1 & Braidwood 1) 2.1.1 Each plant operates at 1175 Megawatts.
2.1.2 Steam Generators are Westinghouse D-4 vertical U-Bend type tubes containing 4,578 mill-annealed inconel 600 tubes per steam generator.
2.1.3 The tubes are mechanically rolled in the tubesheet.
2.1.4 The tube support plates are 0.750" drilled carbon steel.
2.2 D-5 Steam Generators (Byron 2 & Braidwood 2) l-2.2.1 Each plant operates at 1175 Megawatts.
2.2.2 Steam Generators are Westinghouse D-5 vertical U-Bend type tubes containing 4,570 thermally treated inconel 600 tubes per steam generator.
2.2.3 The tubes are hydraulically expanded in the tubesheet.
2.2.4 The tube support plates are 1,125' stainless steel with Quatrefoil holes.
2.3 Operating History of Steam Generators (D-4's) 2.3.1 Outer Diameter Stress Corrosion Cracking (ODSCC) at the support plates. This is the primary mode of degradation at Byron 1 and Braidwood 1. The majority of the indications are found on 3H, SH, and 7H support plates. Most of the tubes plugged in the steam generators have been plugged as a result of this problem. These cracks are axially orientated.
1 2.3.2 Primary Water Stress Corrosion Cracking (PWSCC). This mode of degradation has been found at Byron only and it is considered the second highest mode of degradation. This type of degradation occurs within the confines of the hot leg tubesheet These cracks are axial orientated and ID initiated.
2.3.3 Circurmerential Cracking at the top of the tubesheet This mode of degradation was found at Byron first during a limited inspection at the top of the tubesheet during refueling outage 6.
These indications occur in the expansion transition of the tube above the tubesheet These cracks are circumferentially orientated and OD initiated.
Braidwood has also found i
circumferential cracking at the top of their tubesheet. -
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bra &vood Unit 1 and Unit 2 Revsson 9, September 11995 2.3.4 Pitting has also been a concem for Byron. Pitting usually occurs at the edge of support plates (above or below) and primanly on the hot leg side, however some tubes have been plugged due to cold leg pitting.
2.3.5 Low row U-Bend PWSCC has been a concem for Byron Station during earlier refueling outages. In fact Byron has had two leaker outages (April and June of 1988) as a result of cracks found in the U-Bend region. Since that time, U-Bend stress relief was performed to mitigate this problem.
2.3.6 Very limited amounts of Anti-Vibration Bar (AVB) Wear and preheater wear have been found in the Unit 1 steam generators. However, Unit 2 has seen a considerable amount of AVB wear.
2.4 Operating History of Steam Generators (D-5's) 2.4.1 AVB Wear has been the primary mode of degradation at Byron 2 and Braidwood 2. AVB wear occurs in the U-Bend region and it is caused as a result of tne AVB's rubbing the tubing beyond the technical specification limit of 40% Through-Wall. Particular attention should be made in obtaining accurate % through wall for purposes of growth studies and projections.
2.4.2 Loose paits have been found in several areas in these steam generators. These parts have been found utilizing the 10 kHz channel. Tubes subject to loose part damage are either in the extreme peripheral areas or in the tube lane.
3.0 RESPONSIBILITIES 3.1 Comed Representative 3.1.1 Responsible for interpreting, maintaining and implementing these guidelines, and determining plant specific Interim Plugging Criteria (IPC) eddy current data analysis applicability as well as dispositioning any unusualindications with the Lead Analyst of the job.
3.2.1 Responsible for selecting the Lead Analyst. Resoldion Analyst and Data Analysts. The vendor may select the analysts as long as there is Comed concurrence.
3.2 Lead Analyst 3.2.1 Analyzes eddy current data in accordance with this guideline.
3.2.2 Maintains supervision over all Shift Lead Analysts and Data Analysts during the job.
3.2.3 Responsible for communicating any problems that may arise during the inspection, i.e. "new modes of degradation" unfamiliar to the site or problems which could impact the schedule.
3.2.4 Identifies and processes required changes to the guideline during the course of the l
examination as circumstances may warrant. Changes are documented using the Analysis l
Guideline Change Form in Appendix B of this guideline and are subject to Comed approval prior to usage.
3.2.5 Promptly informs all data Analysts of changes to this guideline as such changes occur. The Analysis Guideline Change Acknowledgment Form in Appendix B is used to document receipt and review of changes by all Analysts. l
~,
~
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bradwood Unit 1 ard Unit 2 l
Reveston 9, September 11995 3.2.6 Perform duties of Lead Analyst or Resolution Analyst as required.
3.3 Resolution Analyst 3.3.1 Analyzes eddy current data in accordance with this guideline.
3.3.2 Resolves any discrepancies between primary and secondary analysts and resolves LAR (Lead Analyst Resolution) calls in accordance with the resolution criteria in Section 8 of this guideline.
3.3.3 Promptly informs the Lead Analyst of circumstances that arise during the course of data l
analysis that are not consistent with or not addressed by this guideline which may require changes to this guideline.
3.4 Data Analyst 3.4.1 Analyzes eddy current data in accordance with this guideline.
l 3.4.2 Prepares and submits a final report consistent with this guideline that is complete and free of errors for each calibration group.
4.0 PERSONNEL QUALIFICATIONS 4.1 Personnel analyzing data shall be qualified in accordance with SNT-TC-1A and certified to Level llA or Level 111.
l 4.2 in addition, the analyst shall have received training in the evaluation of eddy current data for l
nonferromagnetic tubing.
4.3 Data analysts will have successfully passed a Comed eddy current data Analyst performance demonstration program consisting of site specific training and testing prior to analyzing production data.
4.4 Per Comed's response to Generic letter 95-03 *Circumferential Cracking of Steam Generator Tubes" all analsysts who review RPC results from the top of tubesheet RPC inspection will be Qualified Data Analsyts (ODA's) per EPRI Guidelines Appendix G.
5.0 GENERAL ANALYSIS REQUIREMENTS l
5.1 All recorded indications shall be evaluated in accordance with this guideline. Guideline changes j
must be implemented using the change form given in Appendix B.
j 5.2 There is no minimum voltage threshold for reporting indications believed to be attributed to tube wall degradation.
1 5.3 Data analysis consists of reviewing Lissajous and strip chart displays to the extent that all indications of tube wall degradation and other signals as defined by this document are reported and dispositioned in accordance with the requirements of this document.
i 5.3.1 All recorded data shall be evaluated regarc4ess of the extent tested.
5.3.2 Phase angle measurements shall be made utilizing VOLTS MAXRATE for signals which have a welLdefined transition. For cases where no clear transition exists, a VOLTS PEAK-TO-PEAK approach shall be used. The use of guess angle shall be kept to a minimum l l
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 and Unit 2 F;avssson 9, september 11995 and only used when the latter two analysis functions do not give a good representation of the rignal phase angle.
5.3.3 Indications for which there are no applicable reporting criteria or which the Analyst considers to be ambiguous or indeterminate should be reported as LAR. The Resolution Analyst must resolve such indications with the concurrence of the Lead Analyst.
5.4 All acquired data shall be subjected to two independent analyses. These are referred to as "pnmary" and " secondary" analyses.
5.4.1 The two individual analysis results shall be reviewed for discrepancies in accordance with Section 8.0 of this guideline.
5.4.2 If no discrepancies exist between the primary and secondary analyses, then the primary analysis results shall be considered as final.
5.5 All previous history must be addressed. If no indication is identified from the previous history at the location in question an INF or INR analysis code shall be reported (See Appendix C).
5.6 Axial locations in the hot leg shall be reported in a positive direction from supports. AVB's, tube sheet, and tube end up to but not including 11C.
5.7 Axial locations in the cold leg shall be reported in a positive direction from supports, tube sheet, and tube end up to 11C.
5.8 Probe speed (axial traverse speed and RPM as applicable) should be verified on the following occasions:
5.8.1 At each calibration run.
5.8.2 At any time probe speed is questionable.
5.9 Storing Analysis Setups are as follows:
5.9.1 The analysis setup established for each calibration group shall be stored to the data recording medium.
5.9.2 Each primary, secondary or resolution Analyst shall store results to primary, secondary, or resolution files respectively.
i 5.10 Reporting Criteria should be as follows:
5.10.1 The record of each tube analyzed shall include the Tube (Row, Column); VOLTS, DEG, % or three letter code, CH# and axial location corresponding to any reported indication (s); and the extent tested.
l 5.10.2 Acceptable three letter analysis codes for reported indications that are not assigned a percent l
through-wall are identified in Appendix C of this guideline.
5.10.3 Support structure (landmark) nomenclature and measurements are identified in Appendix D of this guideline.
5.11 Calibration Venfication for the ASME Standard should be as follows:
4
i
-]
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 and Unit 2 Revtson 9, september 11995 I _.
5.11.1 Calibration venfication shall be performed at the beginning and end of each calibration group. If the requirements are not met for bobbin probe data then the data Analyst will identify the affected data and determine which tubes, if any, require retest.
5.11.2 The ASME calibrations shall be compared within the following parameters using Channel 1:
(1) The phase angle of the 100% through-wall hole response should be at 40' +/- 1 '.
(2) The phase angle of the 20% dnll hole response should be between 50" and 130' clockwise from the 100% drill hole response, i
(3) Responses from the calibration discontinuities should be clearly indicated and discemible from each other as well as probe motion.
5.12 IPC, F* and Circumferential cracking commitments with the NRC 5.12.1 Interim Plugging Criteria for TSP cracking will be implemented at both Byron and Braidwood Station's Unit 1. Plugging will be based on the upper voltage Repair Limit set forth by the site.
i l
5.12.2 F* will be applied to both Byron and Braidwood Station. Particular detail should be placed on l
the location of the indications found within the tubesheet so that F* may be applied. The F*
l cnterib includes indications which are found to be 1.7 inches or more below the top of the l
tubesheet.
(
5.12.3 Circumferential cracking has been found at both Bryon and Braidwood Station at the top of the l
tubesheet. NRC committments have been made to perform a representative sample (20%) of RPC inspections in low row U-bends and a 100% RPC inspection of the top of the tubesheet for all steam generators.
5.13 Probe pull speeds for implementation of IPC should not exceed 24 inches per second.
l 6.0 BOBBIN COIL EDDY CURRENT REQUIREMENTS 6.1 Analysis Set-un l
l t
6.1.1 Examination Frequencies (see Table 6-1) l Table 6-1 Tube Examination Frequencies Frequency Differential-Absolute -
(kHz)
Channel.
Channel -
l l
550 1
2 300 3
4 i
130 5
6 l
l 10 7
8 6.1.2 Setting Mixes (see Table 6-2)
~
, l
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bra &ood Unit 1 and Unit 2 Revisson 9. september 11995 Table 6-2 Mix Set-up Mix
. Channel Suppress on:
Save on:
Sequence-Mix 1 1,5 Support Ring N/A Mix 2 4,6 Support Ring N/A Mix 3 1,3,5 Support Ring &
ASME Cal Std Drill (optional)
Clean TTS Holes & OD Groove Mix 5 4,6 Support Ring N/A Note: Additional mixes may be; established for screening and diagnostic applications'at-the discretion of the analyst. However, as a minimum, data sctmening and reporting shall be conducted using the applicable channels specifiedin Section 6.2..
6.1.2.1 Mix 1: 550/130 kHz differential support mix; mix on ASME standard support ring. Set 3-point phase angle-depth calibration curve using ASME 100%,60%, and 20% drill ilole signals. Mix #1 is the primary channel for reporting indications at support structures (other than AVB's).
6.1.2.2 Mix 2: 300/130 kHz absolute; mix on ASME support ring signal. Set amplitude (voltage) 3-point calibration curve (VERTMAX) using the 0%,20%, and 40% AVB wear scar signals. (Note: 50% wear scar may be substituted if 40% wear scar does not exist in standard). Mix 2 is used for reporting indications at AVB's.
6.1.2.3 Mix 3 (optional): 550/300/130 kHz differential; suppress ASME support plate and normal in-generator roll expansion signal; save signals from ASME standard drill holes. Mix 3 is used to screen TTS expansion regions for indications and to aid in the confirmation of otherindications.
6.1.2.4 Mix 4: Reserved for computer data screening (CDS)
)
6.1.2.5 Mix 5: 300/130 kHz absolute; mix on ASME support ring signal. Set amplitude (voltage) 3-point calibration curve (VERTMAX) using the 0%, 30%, and 50% AVB wear scar signals. (No transformation curve required). Mix 5 is used for reporting j
indications at cokMeg TSP's within the preheater section of the generator.
i 6.1.3 Setting Rotations 6.1.3.1 Channels 1,3, and 5: Adjust the rotation so that the phase angle of the signal from the 100% through-wall hole is 40 * (+/- 1 *) with initial signal excursion down and to the right as the probe is pulled through the calibration standard.
l 6.1.3.2 Channels 2, 4, 6, Mix 2, and Mix 5: Adjust the rotation so that probe motion is horizontal with the through-wall hole signal starting upwards.
6.1.3.3 Channel 6: As an option, the signal response from the ASME 100% drill hole may be rotated to 32*(+/- 1*).
l l
F COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braovood unit 1 and unit 2 nevnsnon 9. septemoer 1 1995 l
6.1.3.4 Channels 7 and & Adjust the rotation so that the initial excursion of the signal from I
the support ring is oriented vertically starting downwards.
6.1.3.5 Mix 1 and Mix 3 Set probe motion horizontal with the signal from the 100% drill hole starting downwards and to the right.
l 6.1.4 Setting Spans 6.1.4.1 Channel 1 and Mix 1: As a minimum, set span so that the magnitude of the ASME 20% drill hole response is approximately 25% of the full screen height (FSH) of the Lissajous display. Venfy that the magnitude of the ASME 100% drill hole response is at least 50% of FSH.
l l
6.1.4.2 Mix 2 Set span so that the magnitude of the AVB 20%. wear scar response is approximately 25% of FSH.
6.1.4.3 Locator Channels 7 and & Set span so that the magnitude of the support plate response on Channels 7 and 8 are at least 50% and 25% of FSH, respectively.
6.1.5 Setting Volts 6.1.5.1 Channel 1: Set the ASME 20% Flat Bottom Hole (FBH) signal to 4 volts +/- 0.1 volts l
peak-to-peak in Channel 1 and save/ store to all other channels and mixes.
l 6.1.5.2 Mix 1: If an IPC calibration standard is used to establish a voltage scale, then the j
voltage shall be set to the normalized value on the applicable transfer standard drawing. Save/ store to Mix 1. If an ASME calibration standard is used, then set the 20% FBH signal to 2.75 volts +/- 0.1 volts peak-to-peak in Mix 1. Save/ store to Mix 1.
6.1.5.3 Mix 2 Set the 40% wear scar signal (or 50% wear scar signal if applicable) to 5 volts (VERTMAX). Save/ store to Mix 2.
6.1.5.4 Mix 5: Set the 50% wear scar signal to 5 volts (VERTMAX). Save/ store to Mix 5.
6.1.6 Setting Curves j
6.1.6.1 Calibration Standard Hole Depths *
(1)
The actual depths corresponding to the nominal depths provided below shall be used in establishing calibration curves. "As built" hole dimensions shall be obtained from the applicable calibration standard drawings.
(2)
Normalized calibration curves generated using phase angles based on a nominal wall thickness and a standard depth of penetration of 37% are permitted if the requirements of Section 6.1.6.1(1) cannot be satisfied.
6.1.6.2 Use ofArtificialCurves' The use of artificial curves i.e. set 4.1,is prohibited.
Note: Use snax rate for Channels 1,3,5, and Mix 1, andpeak-to-peak for channels 4 and 6.
l 6.1.6.3 Mix 1 and Channels 1,3,4, 5, and 6: Establish phase angle versus depth curves using the following nominal set points:
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and BraK%ood Unit 1 and Unit 2 Revtsson 9, septemOer 11995 (1)
Set Point 1: 100 %
l (2)
Set Point 2: 60%
(3)
Set Point 3: 20%
l 6.1.6.4 Mix 2 Establish a VERT MAX voltage versus depth curve using either of the following two cases of typical nominal set points, depending on the AVB calibration stancard l
used:
Case 1 Case 2 (1)
Set Point 1:
0%
0%
(2)
Set Point 2:
20 %
30%
(3)
Set Point 3: 40%
50 %
6.1.6.5 Mix 3 (Optional Turbo Mix); No calibration curve is required.
6.1.6.6 Mix 5: Establish a VERTMAX versus depth curve using the following nominal set l
points:
l (1)
Set Point 1: 0%
(2)
Set Point 2: 30%
(3)
Set Point 3: 50%
6.1.7 Data Display 6.1.7.1 As a minimum, set up the display configuration for initial data screening according to Table 6-3 using the span settings established in Section 6.1.4.
Table 6-3 Minimum Display Configuration Requirements
~
Display Channel -
Lissajous CH3 Left Strip Chart CH 6 Vertical Right Strip Mix 1 Vertical Chart 6.1.8 Setting Scale and Axial Locations 6.1.8.1 Set the axial scale to the nearest one-hundredth (0.00) of an inch using Appendix D for dimensions and venfy proper setting each time an indication is reported.
6.1.8.2 Scale should be set using the two support structures which bound the region of interest. For U-Bend indications, set scale using the two uppermost TSP's on either leg of the steam generator.
l (1)
Use the TSP centerline as the zero reference point when setting scale between TSP's.
(2)
Use the top of the tubesheet and next TSP or baffle plate centerline when setting scale between the top of the tubesheet and the lowest TSP or baffle plate. !
r
l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Brasdmxx1 Und 1 and Und 2 Reason 9, September 11995 (3)
Use the tube end and top of tubesheet when the region of interest is within the tubesheet.
l i
6.1.8.3 Axial locations of indications are measured with a positive offset and physically upward in relation to the adjacent landmark.
2 (1)
Locations of indications within the boundaries of support and baffle plates are
{
l referenced (+) or (-) as they occur above or below the support structure j
centerline.
(2)
Indications within the expansion transition region near the secondary tubesheet l
face are referenced relative to the top of the tubesheet.
t l
(3)
U-bend indications are referenced (+) in relation to the adjacent AVB toward the I
hot-leg or upper hot-leg support plate as appropriate.
4 (4)
AVB indications are referenced to (0.00) at the corresponding AVB.
6.1.8.4 Location landmarks are identified using the appropriate three-letter codes as specified l
in Appendix D.
l 6.2 Data Evaluation Note: This section defines special augmented data screening.and. analysis requirements for
\\
various classes ofindications. Particular attention should focus on analysis procedures for
- 1) free-span indications, and dings. Both of these types ofIndications have.*>een associated l
with recent industry forced outages in preheater steam generators. In addition, evaluation requirements for screening support structures, e.g., support and baffle plates, A VB's, and the tubesheet secondary face, are described.
6.2.1 Support Plates and Baffle Plates:
l 6.2.1.1 Scroll support plates using Channel 3 and Mix 1. There is no minimum threshold voltage for reporting.
6.2.1.2 Channel 3 is usually a very useful channel for data screening and locating the initial position for phase angle measurement.
6.2.1.3 Mix 1 shall be used to determine the final phase angle measurement point.
l Note: Interim Plugging Criteria (Applicable to Byron /Braidwood Unit 1 only) '
6.2.1.4 Scroll support plates using Channel 3 and Mix 1. There is no minimum threshold voltage for reporting purposes.
6.2.1.5 initial placement of the dots for identification of the flaw location' may be perfonned using Channel 1 or 3, but the final peak-to-peak measurements must be performed using the Mix 1 Lissajous signal to include the full flaw segment of the signal. It may be necessary to iterate the positions of the measumment points between the identifying frequency and the Mix 1 channel to obtain properplacement..
l
.g.
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bra &ood Unit 1 and Unit 2 Revnsion 9. september 11995 6.2.1.6 The largest amplitude portion of the Lissajous signal (not necessarily the MAXRATE position) representing the indication should then be reported using Mix 1 to establish the voltage.
6.2.1.7 See Appendix A for additional information conceming ODSCC at the supports plates for Unit 1 only. Also, Figure 1 of Attachment 1 contains a flow diagram indicating the process for the Analyst to follow while reporting indications at the supports.
l 6.2.2 Tube-end through Top of Tubesheet+1.00"(Hot and Cold Legs)
Note: This section explains the requirements for identifying and calling any type of degradation that may occurin the tubesheet +1.00". The primary modes of degradation for Byron and
\\
Braidwood at these locations are Primary Water Stress Corrosion Cracking (PWSCC) within
. the tubesheet and Outer Diameter Stress Corrosion Cracking (ODSCC) at.the top of the l
tubesheet f'willbe appliedto tubes which contain tubeheetindications.-
l l
6.2.2.1 Scroll all tubesheet secondary face expansion transitions using Channe!s 1, 3, 5, and l
Mix 1 at span settings such that the expansion signal (except for Mix 1) occupies the maximum extent of the Lissajous display without saturating.
i l
S.2.2.2 As an option, Mix 3 (Turbo mix) may be used to carefully screen for degradation-like indications at the top of the tubesheet.
l 6.2.2.3 Distorted tube sheet entry signals or possible indications should be reported using the appropriate analysis code.
6.2.2.4 Figure 2 of Attachment 1 shows a flowchart illustrating data screening and reporting requirements.
6.2.3 U-Bend Region (11H through 11C) 6.2.3.1 Data Screening (Data Analysis)- Freespan regions (1)
The U-bend region between the uppermost support plates shall be scrolled in i
the Lissajous window using Channel 5 at a numerical span se+ ting of 10 or less.
Straight-leg sections shall be scrolled at normal span settings established during 1
calibration.
(2)
Possible indications observed in Channel 5 should be confirmed using Channel
- 3. It is emphasized that definitive indications may not always be observed in i
either of the two channels. Rather, the indications may assume a noise-like j
structure, with multiple discrete indications occurring in close proximity over a longer axial distance.
(3)
Report all confirmed indications using a Free-Span Differential (FSD) analysis code. Subsequent disposition of all reported indications will be accomplished by a resolution analyst.
(4)
Single indications may be reported using a discrete location while multiple in6 cations in close proximity may be reported using a to from location.
(5)
Figure 3 of Attachment 1 shows a flowchart illustrating U-bend data screening l
and reporting requirements.
l t
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 and Unit 2 Revison 9, september 11995 l
6.2.3.2 Disposition (Resolution Analysts)
(1)
Previous history or rotating probe diagnostics shall be used to disposition l
FSD's.
l (2)
FSD's may be further reclassified as Free-Span Indications (FSI's) or i
Manufacturing Bumish Mark (MBM) etc., depending on the relative response of the absolute / differential bobbin coil modes.
(3)
All FSI's will be RPC'd for confirmation.
6.2.3 3 Anti-vibration Bars:
(1)
Scroll Anti-vibration bar locations using Mix 1 or Mix 2.
(2)
Report indications using the Mix 2 VERTMAX analysis function. Signal amplitude, as measured on the conservadve leg of the indication, shall be utilized for sizing indications at AVB's.
(3)
Figure 4 of Attachment 1 shows a flowchart illustrating data screening and reporting requirements.
6.2.4 Freespan Region (Straight Sections of Tubing between support plates) 6.2.4.1 Ding signals or Freespan signals discovered during data screening shall be scroled in the Lissajous window using Channels 1,3 and 5.
6.2.4.2 Possible Indications should be detected using Channel 3.
6.2.4.3 It should be noted that generally distorted indications are more apparent in Channels 3 and 5, and often are not evident in Channel i because of the overwhelming horizontal response caused by local tube indentation or deformation.
6.2.4.4 Channel 1 should be used to confirm % TW. If there is a +/- 10% TW difference between channels 4 and 6, the FSD code should be used, otherwise report as MBM.
6.2.4.5 The Resoultion Analyst should be involved to evaluate all FSD's with the use of previous history. Any FSD's that grow in voltage and phase angle should be reported by the Resoultion Analyst as a FSI so that the indication will be included on the RPC list.
6.2.4.6 Figure 5 of Attachment 1 shows a flowchart illustrating data screening and reporting requirements.
6.3 Renortino Reauirements 6.3.1 All quantifiable indications of tube wall degradation shall be reported. For AVB indications, the reporting threshold is 15%.
i l
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 and Unit 2 Revtsson 9, September 11995 6.3.2 All non-quantifiable indications (See Appendix C, Category 11) shall be reported. As a general rule, Category 11 indications shall be considered a repairable condition unless proven otherwise using supplemental diagnostic techniques, e.g. RPC or equivalent, or historical review.
6.3.3 Dents or dings > 5.0 volts peak-to-peak (Mix 1). With the implementation of IPC a 20%
sample of dents between 2.5 and 5,0 volts will be performed.
6.3.4 Distorted dents or dings having flaw-like characteristics shall be reported as FSI in the Free-Span only. Any dents or dings found at the support plates that contain an indication should by reported as DN!'s (Dent with Indication) 6.3.5 Actual test extent shall be reported as the furthest landmark from the entry leg observed.
6,4 Recordina Reauirements 6.4.1 As a minimum, the following graphic printouts shall be generated for each reported quantifiable indic' tion, "1" code indication, Free-Span Differential (FSD) and LAR indication:
6.4.1.1 Multiple-channel Listajous graphics as specified in Tables 6-4 or Table 6-5.
6.4.2 The folfowing information will be recorded in the FINAL REPORT section of tne RECORDING MEDIUM:
6.4.2.1 For each tube evaluated, an entry must be made that, as a minimum, contains the S/G, ROW, COL, and EXTENT tested.
6.4.2.2 The evaluation of all indications to include the S/G, ROW, COL, VOLTS, DEG,
%, CH#, LOCATION, and EXTENT tested.
6.4.2.3 Any RESTRICTED tubes and the location where probe passage is obstructed.
Restricted locations must include elevation where restriction occurs.
6.4.3 The
SUMMARY
portion of the RECORDING MEDIUM shallinclude:
6.4.3.1 All information recorded on the RECORDING MEDIUM.
Table 6 4 Eight-Channel Graphics Location Lissajous Charts -
Supports 1,3,5 Mix 1,2,4,6, Mix 2 Mix 1 AVB's 1,3,5, Mix 1, 2,4,6, Mix 2 Mix 2 Free Span 1,3,5 Mix 1,2,4.6, Mix 2 5
Top of Tubesheet 1,3,5 Mix 1,2.4,6, Mix 2 or Mix 3 Mix 1 Table 6-5 Four-Channel Graphics Location -
Lissajous :
Charts Supports 1,3,5, Mix 1
- 6. Mix 1 AVB's 1,3,6, Mix 2
- 6. Mix 2 Free Span 1,3,5,6 1, 5 Top of Tubesheet 1,3,5 Mix 1
- 5. Mix 1 4
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Brasdwood Unit 1 and Unit 2 Revoon 9 September 11995 7.0 ROTATING PANCAKE COIL (RPC) REQUIREMENTS 7.1 Analysis Setun 7.1.1 Examination Frequencies (see Table 7-1)
Table 7-1 Three-Coll Rotating Probe
- Channel Frequency Coil CoilType Function -
(kHz)"
1 300 1
Pancake General Detection 2
300 5
Cire Axial Detection Wound 3
300 7
Axial Circumferential Wound Detection 4
200 1
Pancake General Confirmation 5
200 5
Circ Axial Wound Confirmation 6
200 7
Axial Circumferential Wound Confirmation 7
100 1
Pancake General Confirmation 8
100 4
Pancake Trigger 9
100 5
Circ Axial Wound Confirmation 10 100 7
Axial Circumferential Wound Confirmation 11 10 1
Pancake Locator 7.1.2 Setting Mixes (Optional) 7.1.2.1 At the option of the data analysts or at the direction of the Lead Analyst, mixes may l
be established for information only.
7.1.3 Setting Rotations l
7.1.3.1 Detection / Confirmation Channels: Set probe motion to within +/- 5
- of horizontal with flaw excursions directed upwards.
7.1.3.2 Channel 8: Set the trigger pulse vertically upwards at 90 *-120
- 7.1.3.3 Channel 11: Set the response of the support plate vertically downward at l
approximately 270* 1 l
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bra &ood Unit 1 and Unit 2 Revtsson 9, SeptemDer 11995 7.1.4 Setting Spans 7.1.4.1 Channels 1,2,4,5,8 9: Set spans such that the peak-to-peak response of the axially oriented 40% EDM notch is at least 25% FSH.
7.1.4.2 Channels 3,6 & 10 Set spans to same nominal numerical values as Channels 2,5, and 9 respectively.
7.1.4.3 Channel 8: Set span so that the trigger pulse occupies approximately 50% FSH.
7.1.4.4 Channel 11: Set span so that the support plate occupies 25%-50% FSH.
7.1.5 Setting Volts 7.1.5.1 Pancake Coil (1)
Set the voltage for Channel 1 to 20.00 +/- 0.3 volts on the largest peak-to-peak response of the 100% EDM notch.
(2)
Normalize the voltage for other pancake coil channels (CH 4 and CH 7) in reference to Channel 1. Store to all other channels for that coil.
7.1.5.2 Circumferential Wound Coil (1)
Set the voltage for Channel 2 to 20.00 +/- 0.3 volts on the largest peak-to-peak response of the 100% EDM notch.
(2)
Normalize the voltage for all other pancake coil channels (CH 5 and CH 9) in reference to Channel 2. Store to all other channels for that coil.
7.1.5.3 Axial Wound Coil (1)
Set the voltage for Channel 3 to 20.00 +/- 0.3 volts on the largest peak-to-peak response of the 100% EDM notch.
(2)
Normalize the voltage for all other pancake coil channels (CH 6 and CH 10) in reference to Channel 3. Store to all other channels for that coil.
7.1.6 Setting Curves 7.1.6.1 Depth calibration curves are not required. Phase angle or amplitude curves may be established at the Analysts' option for information only.
7.1.7 Data Display l
7.1.7.1 Setup the display configuration for initial data screening according to Table 7-2 using span settings established above.
Table 7-2 Display Configuration Display -
Channel Lissajous CH 1 (300 kHz) 4 Left Chart CH 1 or CH P1 Vertical
(
Right Chart CH 2 or CH 3 Vertical l
l l
i COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bradwood und 1 and und 2 Revsson 9, september 11995 7.1.8 Setting Scale and Axial Locations 7.1.8.1 Using Channel 1, set scale using the as built length of the calibration standard.
l 7.1.8.2 Verify proper scale setting when reporting each indication.
7.1.8.3 For support plate indications, axial locations should be referenced positively (+)
upward or negatively (-) downward from the centerline (0.00) of the nearest support plate.
7.1.8.4 For top of tubesheet indications, axial locations should be referenced positively (+)
l upward or negatively (-) downward from the top of the tubesheet zero (0.00) l reference.
l 7.1.9 C-Scan l
7.1.9.1 C-scan features shall be adjusted consistent with the software suppliers j
recommended practice.
7.1.10 Indication Length Measurements 7.1.10.1 Software features for measuring indication lengths will be invoked consistent with the software supplier's recommended practice.
l 7.1.10.2 Setup of measurement features should be done using the nominal tube inside l
Diameter (ID) and the as-built dimensions of the EDM notch standard discontinuities.
7.1.11 Filters (Optional) 7.1.11.1 At the option of the data analysts or at the direction of the Lead Analyst, bandpass filters on process channels P1, P2 and P3 using Channels 1,2 and 3 (300 KHz),
respectively, may be established using the nominal settings of Table 7-3. Settings
(
may be adjusted slightly to improve signal-to-noise.
Table 7-3 Bandpass Filter Setup Parameter Value -
Sharpness 23 coefficients i
Low cutoff frequency 10 Hz
~
l High cutoff frequency 100 Hz 7.2 Qata Evaluation 7.2.1 Screening t.2.1.1 Review strip chart data while scrolling all acquired data using Channel 1 to establish the presence of an indication. Other analysis channels may be used for additional confirmation.
i COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and BrarcMood Unit 1 and Unit 2 Rensson 9, Septemoer 11995 l
7.2.1.2 Decrease initial span settings (higher gain) as required such that proper detailed l
analysis is conducted on all data.
l 7.2.1.3 Indications which are flaw-like on any of the degradation channels shall be reported regardless of the extent to which the channels correlate.
7.2.2 Analysis 7.2.2.1 Graphic displays and relative three-coil amplitude response shall be used to i
determine flaw orientation and dimensionally using the basic logic summarizt.d in Figure 7 of Attachment 1.
7.2.2.2 Three-coil relative signal response as shown in Table 7-4 may be used to assist in determining flaw dimensionally and orientation.
Table 7-4 Three-coil Relative Amplitude Response Coil Flaw Dimensionality / Orientation Vol Axial.
Circ Pancake
+
+
+
Axial
+
+
j Circ
+
+
i i
7.2.2.3 Three-dimensional discontinuities in general will have a comparable response from the pancake and axial / circ coils. Linear or two-dimensional discontinuities will typically show a preferred response to either the axial or circ coils (or both) dependent on flaw orientation. The pancake coil is equally sensitive to linear discontinuities independent of their orientation.
7.2.2.4 Indications with a preferred amplitude response from either the axial or cire coil shall be analyzed using a three-letter analysis code indicative of the orientation (axial or circumferential) and frequency of occurrence in a given plane. Indications with comparable amplitude responses from all three coils shall be analyzed as three-dimensional (volumetric) using an appropnate analysis code.
i 7.2.2.5 Locations with both axial and circumferential indications present concurrently shall be analyzed as mixed-mode.
7.3 Renortino Reauirements 7.3.1 The voltage of an indication will be measured at the peak signal for each indication. This will generally be at the center most " hit" of the indication using the detection channel (CH 1 typically). Peak-to-peak voltage should be used for the voltage reading, adjusting the window width to minimize noise in the signal.
7.3.2 indication location will be derived from the center most " hit" point of the calling channel.
7.3.3 Indications will not be reported as a percent depth, but assigned an analysis code indicative of the Dimensionality, orientation and frequency of occurrence of the flaw in a given plane.
Permissible analysis codes are listed in Appendix C.
l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bradwood Unit 1 and Unit 2 Revision 9. September 11995 7.4 Recordino Reauirements 7.4.1 The following graphic printouts should be generated for each reported indication:
7.4.1.1 Main display screen typically with the Lissajous of the calling channel (CH 1), left strip chart of a low frequency channel adequate to display the bounding or nearest support and right strip chart with the vertical component of a confirmatory channel (e.g., CH P1 or CH 2).
7.4.1.2 C-scan of indication with the low frequency channel displayed on the strip chart and either the calling channel or corresponding filtered channel for the C-scan plot.
8.0 RESOLUTION CRITERIA 8.1 Primary and secondary analyses results will be compared and referred to the Lead and/or Resolution analysts for resolution and disposition.
8.2 Conditions requiring resolution include:
8.2.1 All quantifiable indications > 40% through-wall, and Category 2 Indications listed in Appendix C where primary and secondary analysis results do not match.
8.2.2 Quanfifiable indications between 20% and 39% reported by one Analyst but not the other.
s 8.2.3 Indications in which the depth estimate differs by more than 10% through-wall 8.2.4 Indications for which location measurements differ by more than; 8.2.4.1 +/- 1" for free-span.
8.2.4.2 +/- 0.5" at support structures.
8.2.5 Indications at tube support plates for plants implementing IPC for which; 8.2.5.1 Bobbin coil indications are greater than the repair limit voltage where primary and secondary analysis results do not match.
8.2.5.2 The reported location extends beyond either support plate edge.
8.2.5.3 Indications are diagnosed as circumferential cracking by RPC.
8.2.5.4 The bobbin coil voltage values called by primary and secondary analysts deviate by more than 20% and one or both calls exceeds 1 volt.
8.2.5.5 Alllarge mix residuals that could mask a 1.0 volt indication found at TSP's.
8.2.6 Reporting errors or discrepancies in such items as steam generator, tube or reel ID, probe type, extent tested, analysis code assignment, etc.
j 8.2.7 One analyst reports a tube not reported by another.
t j
8.3 Any tube with an initially reported repairable condition - by either the primary or secondary analyst, or both - that is subsequently resolved to a non-repairable condition during resolution - shall be reported to a Comed representative for information.
i - -
-a,e__l_A J.
.hA.a.-
-.r&rb_.AAea4L.S.+aeda.ds-M.uJ.sa.AJ.m M.
- m-J4
.a.- en h e W Jeh.dama-AMm-- a deamme..e-es----e.-oe-4 sa-was..,
maamp..,e..
m_.
m g,_2, i
l APPENDIX A j
DATA ACQUISITION AND ANALYSIS REQUIREMENTS FOR TSP ODSCC 4
J
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995 A.
1.0 INTRODUCTION
A.1.1 This appendix documents techniques for the inspection of Byron and Braidwood Unit 1 steam generator tubes related to the identification of ODSCC or IGA / SCC at tube support plate (TSP) regions.
A.1.2 This appendix contains guidelines which provide direction in applying the ODSCC Interim Plugging Criteria (IPC) described in this report. The procedures for eddy current testing using bobbin coil (BC) and rotating pancake coil (RPC) techniques are summarized. The procedures given apply to the bobbin coil inspection, except as explicitly noted for RPC inspection. The methods and techniques detailed in this appendix are requisite for implementation of TSP IPC.
Note: The following sections define specific acquisition and analysis parameters and snethods to be used for the inspection of steam generator tubing.-
A.2.0 DATA ACQUISITION Note:. Byron and Braldwood Unit 1 steam generators utilize 3/4" 0D.x 0.043"' wall, Alloy 600 mill-annealed tubing. The carbon steel support plates and baffle plates are designed with drilled holes.
A.2.1 Instrumentation utilized shall be the Zetec MlZ-18 (For the acquisition of Eddy current data) equipment, the Echoram ERDAU or other equipment with similar specifications.
A.2.2 Probes which will be used are the following:
A2.2.1 Bobbin Coil Probes - To maximize consistency with laboratory IPC data, differential probes with the following parameters shall be used for examination of IPC tube support plate intersections:
(a) 0.610 outer diameter i
(b)
Two bobbin coils, each 60 mils long, with 60 mils between coils (coil centers separated by 120 mils) i (c) in addition, the probe design must incorporate centering features that provide for minimum probe wobble and offset; the centering features must maintain constant probe center to tube ID offset for nominal diameter tubing. For locations which must be inspected with smaller than nominal diameter probes, it is essential that the reduced diameter probe be calibrated to the reference normaltzation (Section A.2.6.1 and Section A.2.6.2) and that the centering features permit constant probe center to tube ID offset. Probes must have l
centering adjustment that collapse to the reference probe diameter.
(d)
Once probe has been calibrated on the 20% WI holes, the voltages response for new bobbin coil probes for the 40% TW to 100% "IW holes should not differ j
from the nominal voltage by more than 10%.
A2.2.2 Rotating Pancake Coil Probes - Pancake coil designs (vertical dipole moment) with a coil diameter d, where d is 0.060" < d < 0.125", shall be used. While other multkoil (i.e.,1,2 or 3-coil) probes can be utilized, it is recommended that if a 3-coil probe is used, any voltage measurements should be made with the probe's pancake coil rather l
than its circumferential or axial coil.
l l
-A1-l 1
I
__~
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Draidwood Unit 1 Appendix A Revision 9. September 1 1995 (a)
The maximum probe pulling speed shall be 0.2 inisec for the 1-coil or 3-coil probe, or 0.4 in/sec. for the 2-coil probe. The maximum rotation shall be 300 rpm. This would result in a pitch of 40 mils for the 3 coil probe.
A.2.3 Cahbration Standards to be utilized for IPC A.2.3.1 Bobbin Coil Standards - These standards will meet the following criteria:
A.2.3.1.1 Voltage Normalization Standard Note: All hoics shall be machined using a mechanical drilling technique. This calibration standard will need to be calibrated against the reference standard used for the IPC laboratory work by direct testing or thmugh the use of a transferstandard.
1 (a) One 0.052" diameter 100% thrcugh wall hole
)
i (b) Four 0.028" diameter through wall holes, 90 degrees apart in a single plane around the tube circumference; the hole diameter tolerance shall be +/- 0.001" (optional).
(c) One 0.109" diameter flat bottom hole,60% through from OD (d) One 0.187" diameter flat bottom hole,40% through from the OD i
(e) Four 0.187" diameter flat bottom holes, 20% through from the OD,
{
spaced 90 apart in a single plane around the tube circumference. The tolerance on hole diameter and depth shall be +/-0.001" (f) A simulated support ring, 0.75" long, comprised of SA-285 Grade C carbon steel or equivalent.
A2.3.1.2 Probe Wear Standard Note: A probe wear standard is used for monitoring the degradation of probe centering devices leading to off-center coilpositioning and potential variations in flaw amplitude responses.
(a) Contains four 0.052" +/- 0.001 inch diameter through-wall holes.
spaced 90 degrees apart around the tube circumference (b) Has axial spacing such that signals can be clearly distinguished from one another. See Figure A-1.
l l
i l
.A2-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and BraKfwood Unit 1 Appendix A Revision 9, September 1 1995 4
E\\w..>=
f I.
IN i
i
.(.
j h
I t
h
., y.. T;.y....j
~.
Figure A-1: Probe Wear Standard Schematic i
A.2.3.2 Rotating Probe Standard - This standard may contain the following:
(a)
Two axial EDM notches, located at the same axial position but 180 degrees apart circumferential, each 0.006" wide and 0.5"long, one 80% and one 100%
through wall from the OD.
(b)
Two axial EDM notches, located at the same axial position but 180 degrees apart circumferentially, each 0.006" wide and 0.5" long, one 60% and one 40%
through-wall from the OD.
(c)
Two circumfemtial EDM notches, one 50% through wall from the OD with a 75 degree (0.49" arc length), and one 100% through wall with a 26 degree (0.20")
arc length, with both notches 0.006" wide.
(d)
A simulated support segment 270 degrees in circumferential extent 0.75" thick, comprised of SA-285 Grade C carbon steel or equivalent.
(e)
The center to center distance between the support plate simulation and the nearest slot shall be at least 1.25". The center to center distance between the EDM notches sha)I be at least 1.0". The tolerance for the widths and depths of the notches shat! be 0.001". The tolerance for slot lengths shall be 0.010".
A.2.4 Apolication of Bobbin CoilWear Standard l
A.2.4.1 A calibration standard has been designed to monitor bobbin coil probe wear. During j
steam generator examination, the bobbin probe is inserted into the wear monitoring l
standard; the initial (new probe) amplitude response from each of the four holes is I
determined and compared on an individual basis with subsequent measurements.
Signal amplitudes or voltages from the individual holes - compared with their initial amplitudes - must remain within 15% of their initial amplrtude (i.e., ((wom-new)/new}
l for an acceptable probe wear condition. If this condition is not satisfied, then the probe
-A3-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braicwood Unit 1 Appencix A Revision 9. September 1 1995 must be replaced. All tubes since the last acceptable probe wear measurement must be re-inspectected with the new probe.
A.2.4.2 Bobbin Coil Wear Standard Placement Under ideal circumstances, the incorporation of a wear standard in line with the conduit and guide tube configuration would provide 1
continuous monitoring of the behavior of bobbin probe wear. However, the curvature of the channel head places restrictions on the length on in line tubing inserts which can be accommodated. The spacing of the ASME Section XI holes and the wear standard results in a length of tubing which cannot be freely positioned within the restricted space available. The flexible conduit sections inside the channel head, together with the guide tube, limit the space available for additional in line components. Voltage responses for the wear standard are sensitive to bending of the leads, and mock up tests have shown sensitivity to the robot end effector position in the tubesheet, even when the wear standard is placed on th.e bottom of the channel head. Wear standard measurements must permit some optimization of positions for the measurement and this should be a periodic measurement for inspection efficiency.
The preexisting requirement to check calibration using the ASME tubing standard is 1
satisfied by periodic probing at the beginning and end of each probe's use as well as at four hour intervals. This frequency is adequate for wear standard purposes as well.
Evaluating the probe wear under uncontrollable circumstances would present variability in response due to channel head orientations rather than changes in the probe itself.
A.2.5 Acouisition Parameters Note: The following pa.ameters apply to bobbin coil data acquisition and should be incorporated in j
the appilcable inspection procedures to supplement (not necessarily replace) the parameters normally used.
A.2.5.1 TestFrequencies A.2.5.1.1 This technique requires the use of bobbin coi! 550 kHz and 130 kHz test frequencies in the differential mode. It is recommended that the absolute mode also be used, at test frequencies of 130 kHz and 10 - 35 kHz. The low frequency (10-35 kHz) channel should be recorded to provide a means of venfying tube support plate edge detection for flaw location purposes.
The 550/130 kHz mix or the 550 kHz differential channel is used to access changes in signal amplitude for the probe wear standard as well as for flaw detection.
A.2.5.1.2 RPC frequencies should include channels adequate for detection of OD degradation in the range of 100 kHz to 550 kHz, as well as a low frequency channel to support location of the TSP edges.
A2.5.2 Digitizing Rate i
A.2.5.2.1 A minimum digitizing rate of 30 samples per inch should be used.
Combinations of probe speeds and instrument sample rates should be chosen such that' Samole Rate (samoles/sec ) 2 30 (samples /in.)
Probe Speed (in/sec)
-A4-i
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995 A.2.6 Analysis Parameters i
Note: This section discusses 1) the methodology for establishing bobbin coil data analysis variables such as spans, rotations, mixes, voltage scales, and calibration curves. Although indicated dsoth measurement may not be required to support an alternative repair limit, the methodology for establishing the calibration curves is presented. The use of these curves is recommended for consistency in reporting and to provide compatibility of results with subsequent inspections of the same steam generator and for comparison with other steam generators and/orplants.
A.2.6.1 Bobbin Coli 550 kHz Differential Channel Note: (1) For all new probes the analyst must minimize mix residuals on the calibration standard as i
applicable (2) Probes exceeding the 15% sensitivity voltage for wear shall be disposed and all tubes since the last sucessful measurement for probe wear shall be re-inspected with the new i
probe.
A.2.6.1.1 Spans and Rotations Spans and rotations can be set at the discretion of l
the user and/or in accordance with applicable procedures, but all TSP intersections must be viewed at a span setting one-half or less than that which provides 3/4 full screen amplitude for 4x20% holes with bobbin probes and 1/10 or less the corresponding span for 0.5" long through-wall slot (EDM notch)with RPC probes.
A.2.6.1.2 Voltage Scale: The peak-to-peak signal amplitude of the signal from the four 20% through-wall holes should be set to produce a voltage equivalent to that obtained from the IPC lab standard. The laboratory standard normalization voltages are 4.0 volts at 550 kHz and 2.75 volts for the 550/130 kHz mix.
Note: The transfer / field standard will be calibrated against the laboratory standard using a reference laboratory probe to establish voltages for the field standard that are equivalent to the above laboratory standard. These equivalent voltages are then set on the field standard to establish calibration voltages for any other standard.
(a) Voltage normalization to the standard calibration voltages at 550 kHz is the preferred normalization to minimize analyst sensitivity in establishing the mix. However, if the bobbin probes used result in a 550/130 kHz mix to 550 kHz voltage ratios differing from the laboratory standard ratio of 0.69 by more than 5% (0.66 to 0.72), the 550/130 kHz mix calibration voltage should be used for voltage normalization.
A.2.6.1.3 Calibration Curve: Establish a phase versus depth calibration curve using measured signal phase angles in combination with the "as-built" flaw depths for the 100%,60%, and 20% holes.
A.2.6.2 Bobbin Coi!550/130 kHz DifferentialMix Channel A.2.6.2.1 Spans and Rotations Spans and rotations can be set at the discretion of the user and/or in accordance with applicable procedures.
-AS-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Brascwuod Unit 1 Appendix A Revision 9, September 1 1995 A.2.6.2.2 Voltage scale: See Section A.2.6.1 A.2.6.2.3 Calibration Curve: Mix 1 is a 550/130 kHz differential support mix; mix on ASME standard support ring. Set 3-point phase angle-depth calibration curve using ASME 100%,60%, and 20% drill hole signals. Mix 1 is the primary channel for reporting indications at support structures.
A.2.6.3 Rotating Pancake Coll Channel A.2.6.3.1 Voltage Scale: The RPC amplitude will be referenced to 20 volts for a 0.5 inch long 100% through wall notch at 300 kHz. Each channel shall be set individually to the desired amplitude for the EDM notches on the plant standards; cross calibration will be achieved by comparison of the RPC responses from the 100% drilled hole.
l A.2.7 Anatrsis Methodoloav A.T.7.1 Bobbin coil indications at support plates attnbutable to ODSCC are quandfied using the Mix 1 (550 kHz/130 kHz) data channel. This is illustrated with the examp;e shown ir) Figure A-2. The 500/130 kHz mix channel or other channels appropriate for ilaw detection (550 kHz,300 kHz, or 130 kHz) may be used to locate the indications of interest within the support plate signal. The largest amplitude portion of the Lissajous signal representing the flaw should then be measured using the 550/130 kHz Mix 1 channel to establish the peak-to-peak voltage as shown in Figure A-2. Initial placement of the dots for identfication of the flaw location may be performed as shown in Figures A-3 and A-4, but the final peak-to-peak measurements must be performed on the Mix 1 Lissajous signal to include the full flaw segment of the signal.
It may be necessary to iterate the positions of the dots between the identfying frequency and the 550/130 kHz mix to obtain proper placement. As can be seen in Figure A 4, failure to do so can reduce the voltage measurement of Mix 1 by as much as 65% to 70% due to the interference of the support plate signal in the raw frequencies. The voltage as measured from Mix 1 is then entered as the analysis of i
record for comparison with the repair limit voltage.
A.2.7.2 To support the uncertainty allowances maintained in the IPC, the difference in amplitude measurements for each indication will be limited to 20%. If the voltage i
values called by the independent analysts deviate by more than 20% and one or both of the calls exceeds 1.0 volts, analysis by the resolution analyst will be performed.
These triplicate analyses result in assurance that the voltage reported departs from the correct call by no more than 20%.
A.2.8 Reportino Guidelines Note: The reporting requirements. identified below,. are in addition to any other reporting requirements specifiedby the user A.2.8.1 Minimum Requirements A.2.8.1.1 All bobbin coil flaw indications in the 550/130 kHz mix channel at the tube support plate intersections regardless of the peak-to-peak signal ampirtude must be reported. All TSP locations with indicatons exceeding the repair limit must be examined with RPC probes.
-AS-
~
s
~
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braicwood Unit 1 Appendix A Remion 9, Septernber 1 1995 A.2.8.2 AdditionalRequirements A.2.8.2.1 For each reported indication, the following information should also be recorded:
(a) Tube identification (row, column)
(b) Signalamplitude (volts) l (c) Signal phase angle (degrees) l (d) Indication (3 letter code) i (e) Test Channel (ch#)
(f) Axial position of tube (location)
(g) Extentof test (extent)
(h) Pobe size (1) Tape #
f l
2.8.2.2 RPC reporting requirements should include as a minimum: type of degradation (axial, circumferential or other), maximum voltage, phase angle, crack lengths, and location of the center of the crack within the TSP.
The crack axial center to edge need not coincide with the position of maximum amplitude. Locations which do not exhibit flaw-like indications in l
the RPC isometric plots may continue in service, except that all l
' intersections exhibiting flaw-like bobbin behavior and bobbin amplitudes in l
excess of the repair limit voltage must be repaired, notwithstanding the RPC analyses. RPC isometrics should be interpreted by the analyst to l
characterize the signals observed; only featureless isometrics are to be reported as NDD. Signals not interpreted as flaws include dents, liftoff, deposits, copper, magnetite, etc.
i A.3.0 DATA EVALUATION i
A.3.1 Use of 550/130 Differential Mix for Extractino the Bobbin Flaw Sianal A.3.1.1 in order to identify a discontinuity in the composite signal as an indication of a flaw in the tube wall, a simple signal processing procedure of mixing the data from the two l-test frequencies is used which reduces the interference from the support plate signal by approximately one order of magnitude. The test frequencies most often used for this signal processing are 550 kHz and 130 kHz for 43 mil wall Alloy 600 tubing. Any of the differential data channels including the mix channel may be used for flaw detection (though the 130 kHz is often subject to the influence from many different effects), but the final evaluation of signal detection, amplitude and phase angle will be made from the 550/130 kHz differential mix channel. Upon detection of a flaw signal in l
the differential mix channel, confirmation from other raw channels is not required; all I
such signals must be reported as indications of possible ODSCC. The voltage scale for the 550/130 kHz differential channel should be normalized as described in Section A.2.1.6.1 and A.2.1.6.2.
A.3.1.2 The present evaluation procedure requires that there is no minimum voltage for flaw detection purposes and that all flaw signals, however small, be identified. The i
intersections with flaw signals > the repair limit will be inspected with RPC. Although the signal voltage is not a measure of flaw depth, it is an indicator of the tube burst pressure when the flaw is identified as axial ODSCC with or without minor IGA.
l
-A7-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revtsson 9, September 1 1995 A.3.2 Amolitude Variability A.3.2.1 !! has been observed that voltage measurements taken from the same data by different analysts may vary, even when using identical analysis guidelines. This is largely due to differences in analyst interpretation of where to place the dots on the lissajous figure for the peak-to-peak amplitude measurement. Figures A-5 and A4 show the correct placement of the dots on the Mix 1 Lissajous figures for the peak-to-peak voltage amplitude measurements for two tubes from Plant S. In Figure A-5, the placement is quite obvious. Ir. Figure A-6, the placement requires slightly more of a judgment call. Figures A-7 and A-8 show these same two tubes with peak-to-peak measurtments being made, but in both cases the dots have been placed at locations where the normal max-rate dots would be located. The reduction in the voltage amplitude measurement is 19.3% in Figure A-7 and 16.3% in Figure A-8.
While this is an accepted method of analysis for phase-angle measurements, it is not appropriate for the voltage amplitude measurements required.
A.3.2.2 in Figures A-5 and A-6, the locations of the dots for the peak-to-peak measurements 4
being performed from Mix 1 show the corresponding dots on the 550 kHz raw frequencies as also being located at the peak or maximum points of the flaw portion of the Lissajous figure. In no case should the dots to measure the voltage amplrtude be at locations less than the maximum points of the flaw portion of the 550 kHz raw frequency.
A.3.2.3 Figure A-9 is an example of where the dots have been placed on the transition region of the 550 kHz raw frequency data Lissajous figure. It is clear from the~ Mix 1 Lissajous figure that this does not correspond to the maximum voltage measurement. The correct placement on the Mix 1 Lissajous figure is shown in Figure A10. This placement also corresponds to the maximum voltage measurement on the 550 kHz raw frequency data channel.
A.3.2.4 in some cases, it will be found that little if any definitive help is available from the use of the raw frequencies. Such as the example shown in Figure A-11, where there are no significantly sharp transitions in any of the raw frequencies. Consequently, the placement of the measurement dots must be made completely on the basis of the Mix 1 channel Lissajous figure as shown in the upper left of the graphic. An even more difficult example is shown in Figure A-12. The logic behind the placement of the dots in Mix 1 is that sharp transitions in the residual support plate signals can be observed at the locations of both dots. In the following graphic, Figure A-13, somewhat the same logic could be applied in determining the flaw-like portion of the signal from the Mix 1 Lissajous pattem. However, inasmuch as there is no sharp, clearly defined transition, coupled with the fact that the entry lobe into the support plate is distorted on all of the raw frequencies, the dots should be placed as shown in Figure A-14. This is a conservative approach and should be taken whenever a degree of doubt as to the l
dot placement exists.
A.3.2.5 it is noted that by employing these techniques, identification of flaws is improved and that conservative amplitude measurements are promoted. The Mix 1 traces which result from this approach confirm to the model of TSP ODSCC which represents the degradation as a series of microcrack segments axially integrated by the bobbin coil; i.e., short segments of changing phase angle direction represent changes in average depth with changing axial position. This procedure may not yield the maximum bobbin depth call. If maximum depth is desired for inforrnation purposes, shorter segments of the overall crack may have to be evaluated to obtain the maximum depth estimate.
-A8-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES byron and Draadwood Unit 1 Appendix A Revision 9, September 1 1995 However, the peak to peak voltages as described herein must be reported, even if a different segment is used for the depth call.
A.3.3 Allov Pronerty Chanaes l
Note: Only thoseAll mix residuals located at tube supports that could mask a 1.0 voit indication shall be reported as MRI (Mix ResidualIndication) and these indications will be included on i
the RPC list.: Large mix residuals are those that could cause a 4.0 voit indication to be missed ormisteed. Anyindications foundatsuch intersections with RPCshallbe repaired.:
A.3.3.1 This signal manifests itself as part of the support plate " mix residuar' in both the differential and absolute mix channels. It has often been confused with copper deposits as the cause. Such signals are often found at support plate intersections of operating plants, as well as in some model boiler test samples, and are not necessarily indicative of tube wall degradation. Six support plate intersections from Plant A, judged as free of tube wall degradation on the basis of the mixed differential channel using the guidelines given in Section A.2.7 of this document, were pulled in 1989. Examples of the bobbin coil field data are shown in Figure A-15. (inspection data from a plant with 7/8 inch diameter tubing.) The mix residual for this example is approximately 3 volts in the differential mix channel and no discontinuity suggestive of
, a flaw can be found in this channel. An offset in the absolute mix channel which could be confused as a possible indication is also present. These signals persisted without l
any significant change even after chemically cleaning the OD and the ID of the tubes.
The destructive examination of these intersections showed very minor or no tube wall degradation. Thus, the overall
- residuals" of both the differential and absolute mix channels were not indications of tube wall degradation. One needs to examine the detailed structure of the " mix residuar'(as outlined in Section A.2.7) in order to assess the possibility that a flaw signal is present in the residual composite. Verification of the integrity of TSP intersections exhibiting alloy property or artifact signals is accomplished by RPC testing of a representative sample of such signals.
i A.3.4 Conner and Dentina interference's l
A.3.4.1 CopperInterference Note: All intersections with interferring. copper deposits shall be inspected with RPC. All indications foundat such intersections with RPC shall be repaired.
(a) in situations where significant copper interference in the eddy current data is noted, the eddy current technique basically becomes unreliable. This results from the unpredictability of the amount and morphology of copper deposit on the tubes which may be found in operating steam generators. The above observation is true both for bobbin and RPC or any other eddy current probe. Fortunately, significant copper interference has not occurred in the support plate crevice l
regions at Byron or Braidwood. Copper is not expected to become a problem j
since both Byron and Braidwood contain copper free secondary plants.
1 (b) Inspections with RPC and bobbin probes have shown good correlation for flaw amplitudes exceeding 1.0 volt; i.e., more than 50% of the bobbin signals identified have been confirmed to exhibit flaws to the RPC probe. This suggests that spurious signals from conductive deposits do not result in excessively high false call rates. Furthermore, signals judged as NDD with the bobbin guidelines have
-A9-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braiowood Unit 1 Appendix A Revision 9, Septernber 1 1995 been confirmed to be free of RPC detectable flaws. Copper is a concem for NDE only when plated directly on the tube surface in elemental form. Copper particles with the sludge in the crevice do not significantly influence the eddy current response. To Westinghouse's kr'owledge, no pulled tubes have been identrfied with copper deposits on the tube at the TSP intersections - in contrast with free span tubing. Copper deposits have not been identified at TSP intersections in the Byron or Braidwood steam generators and no copper alloys are used in the secondary system. Thus, it is not expected that copper influence will significantly influence the TSP signals in the Byron or Braidwood steam generators.
A.3.4.2 Dentinterforence Note:. Allinteresections with dent signals greater than orequal to 2.5 volts shallbe reported by the analyst.jAll dents.> 5.0 volts will be inspected using RPC and 20% of dents at supports between'2.5 and 5.0 volts will be inspected using RPC. All dents > 5.0 volts that contain an indication per RPC shall be repaired. ;
(a) The 550/130 kHz (differential) support plate suppression mix reduces or eliminates the support plate and the magnetite which may be present with the support plate, but the resulting processed signal will still be a composite flaw, other artifacts and a dent, if present. These composite signals represent vectorial i
combinations of the constituent effects, and as such they may not conform to the l.
behavi.or expected from simple flaw simulations as a function of test frequencies.
(b) The effect of the dent on the detection and evaluation of a flaw signal depends on both the relative amplitudes of the flaw and dent signals and the relative spatial relationship between them, if the flaw is located near the center of the dent signal, interference with flaw detection may become insignificant, even for relatively large dent to flaw ratios. The flaws signal in a typical support plate dent in this event l
occurs at mid-plane, away from the support plate edges where the dent signal exhibits maximum voltage; thus the flaw in the middle section of the support plate l
appears as a discontinuity in the middle of the composite signal. It can be l
observed in Figures A-20 through A-25, from Plant A, that one can often extract a flaw signal even when the flaw signal-to-noise ratio (S/N) is less than unity. The l
l question of S/N ratio requirements necessary for flaw detection is not a number that can be readily determined; but as can be seen from these figures, even with ratios as low as 0.184/1.0, the flaw signal can be detected and evaluated.
(c) The greatest challenge to flaw detection due to dent interference occurs when the flaw occurs at the peak of the dent signal. Detection of flaw signals of amplitudes equal to or greater than 1.0 volts (flaws greater that 1.0 volts require RPC testing) in the presence of peak dent voltages can be understood by vectorial combination
[
of a 1.0 voit flaw signal across the range of phase angles associated with 40%
l-(110 degrees) to 100% (40 degrees) through wall penetrations with dent signals of various amplitudes, it is easily shown that 1.0 voit flaw signals combined with dent signals up to approximately 5.0 volts peak to peak will yield resultant signals with phase angles that fall within the flaw reporting range, and in all cases will exceed 1.0 volts. All such dent signals with a flaw indication signal will be j
subjected to RPC testing. To demonstrate this, one-half the dent peak-to-peak i
voltage (entrance of exit lobe) can be combined with the 1.0 volt flaw signal at the desired phase angle.
(d) The Plant A inspection data is shown in Figures A-20 through A-25 to permit flaw detection and evaluation for flaws situated away from the peak dent voltages.
-A10-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES j
Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995 The vector combination analysis shows that for moderate dent voltages where flaws occur coincident with dent entrance or exit locations, flaw detection at the 1.5 volts amplitude level is successful via phase discrimination of combined flaw / dent signals from dent only signals.
(e) The vector addition model for axial cracks coincident with denting at the TSP edge is illustrated as follows:
~g A
p 4
g' '
0 A * --
where R = Resultant Signal Amplitude A = Flaw Signal Amplitude D = TSP Dent Amplitude - one edge (Peak-to-Peak = 2D) 0 = Flaw Signal Phase Angle (100% = 40*; 40% -110 )
4g = Phase Angle of Resultant Signal and 2
R = (D+ Acos0)' + (Asin0)2 Ba = arctan" (Asin/D + Acos0)
Note: For dents without flaws, a nominalphase angle of 180 is expected. The presence of a flaw results in rotation of the phase angle to < 180* andinto the flaw plane.: A phase angle of 170 (10*) away from nominal dent signal) provides a sufficient change to identify a flaw. For dents with peak-to-peak amplitude of 5.0 volts, D = 2.5 y and the minimum phase angle rotation (OR) for a 1.0 volt ODSCC flaw signal greater than 40% through-wallis predicted to be at least 11*, sufficiently distinguishable from the 180* (0 *) phase angle associated with a simple dent.
(f) Supplement information to reinforce this phase discrimination oasis for flaw identification can be obtained by examination of a 300/130 kHz mix channel; dent response would be lessened while the OD originating flaw response is increased relative to the 550/130 kHz mix. RPC testing of indications identified in this fashion will confirm the dependability of flaw signal detection. Intersections with dent voltages exceeding 5.0 volts for which 1.0 volt flaws may not be detectable, are candidates for RPC inspection of dented TSP intersections.
A.3.5 TSP Noise Criteria Note: Data which contain quantitalve noise criteria (resulting from electrical noise, tube noise, calibration standard noise shall be re-inspected A.3.5.1 Eddy current data acquired from active tubes and calibration standards shall be l
reviewed for the presence of electrical and tube noise with the following criteria:
(a)
/D Chatter or Pilgering Noise-Tubes identified with noise associated with ID chatter or pilgering at TSP locations in excess of 5 volts peak-to-peak shall be inspected with RPC. If a flaw is confirmed with RPC, the tube shall be repaired.
-A11-i
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood unit 1 Appendix A Revision 9, Septernber 1 1995 (b)
Probe Noise-Electrical noise due to a failing or intermittent probe is readily recognizable as the noise signal often assumes the shape of a random square wave modulating the eddy current signal. General eddy current data quality must be monitored to ensure that a minimum 3:1 signal to noise (S/N) is maintained.
l (c)
Noise Spiking-Electrical or noise spikes at TSP's in excess of 0.3 volts peak-to-peak on the vertical channel will be rejected by the analyst and the tube will be reexamined.
Note: Data falling to meet the above requirements should be rejected and the tube should be re.
Inspected..
A.3.5.2 The data analysts must continuously verify probe acceptability for each tube examined by reviewing the overall quality of the data and determining if the probe is causing undesirable and interfering signal responses.
A.3.5.3 EPRI is currently developing a quantified noise criteria for industry use. The above criteria will be employed at Byron and Braidwood until the EPRI noise criteria is employed.
A.3.6 RPC Flaw Characterization 3.6.1 The RPC inspection of some support plate intersections with bobbin coil indications >
1.0 volts is recommended in order to verify the applicability of the attemate repair limit.
This is based on establishing the presence of ODSCC with minor IGA as the cause of the bobbin indications.
Note: The signal voltage for RPC data evaluation will be based on 20 volts for the 100% through-wall 0.5"long EDM notch at all frequencies. '
3.6.2 The nature of the degradation and its orientation (axial or circumferential) will be determined from careful examination of the isometnc plots of the RPC data. The presence of axial ODSCC at the support p!ates has been well documented, but the presence of circumferential indications related to ODSCC at support plate intersections has also been established by tube pulls at two plants. Figures A 16 to A-18 show examples of single and multiple axial ODSCC from Plant S.
3.6.3 Figure A-19 is an example of a circumferentialindication related to ODSCC at a tube support plate location from another plant. If circumferential invol'/ement results from circumferential cracks as opposed to multiple axial cracks, discrimination between axial and circumferentially oriented cracking can be generally established for affected arc lengths of about 45 degrees to 60 degrees or larger. Axial cracking has been found by pulled tube exams for RPC arcs of 150 degrees when the axial extent is significant, such as > 0.2 inch.
Note: Pancake coil resolution is considered adequate for separation between circumferential a."d l
axial cracks. This can be supplemented by careful interpretation of 3-coll results.'Since denting has not occurred at the Byron or Braidwood units, circumferential cracking is not
(_
expected to happen at the support plates.
-A12-
l i
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood unit 1 Appendtx A Revrmon 9, Septernber 1 1995 I
l 3.6.4 The presence of IGA as a local effect directly adjacent to crack faces is expected to be
}
indistinguishable from the crack responses and as such of no structural consequence.
When IGA exists as a general phenomenon, the eddy current response is proportional to the volume of affected tube material, with phase angle corresponding to depth of penetration and amplitude relatively larger than that expected for small cracks. The presence of distnbuted cracking, e.g., cellular SCC, may produce responses from microcracks of sufficient individual dimensions to be detected but not resolved by the RPC, resulting in volumetric responses similar to three-dimensional degradation.
l Note:. For hot leg TSP locations, there is little industry experience on the basis of tube pulls for i
volumetric degradation, i.e... actual wall loss or genera! IGA. For cold leg TSP locations, considerable experience is available for volumetric aegradation in the form of thinning of peripheral tubes, favoring the lower TSP elevations. Therefore, in the absence of conffrmed pulled tube experience to the contrary, volumetric OD irsdications at hot-leg tube suppon
\\
plates should be considad to represent ODSCC.
A.3.7 Confinement of ODSCCIIGA Within the Suonort Plate Reaion A.3.7.1 The measurement of axial crack lengths from RPC isometrics can be determined using the following analysis practices. For the location of interest, the low frequency channel (e.g.10 kHz) is used to set a local scale for measurement. By establishing the midpoint of the support plate response, a reference point for indication location is established. Calibration of the distance scale is accomplished by setting the displacement between the 10 kHz absolute, upper and lower support plate transitions equal to 0.75 inch.
l A.3.7.2 in order to establish that a bobbin indication is within the support plate, the displacement of each end of the signal is measured relative to the support plate center. The field measurement is then corrected for field spread (look-ahead) to determine the true distance fmm the TSP center to the crack tip. If this distance exceeds one-half the support plate axial length (0.375"), the crack will be considered to have progressed outside the support plate. This condition requires LAR and will be reported to the site representative. Dispositioning of the conditions may include further inspection with RPC. Per the repair enteria, indications, extending outside the support plate require tube repair.
A.3.8 Length Determination with RPC Probes A.3.8.1 At the analysis frecuency, either 300 kHz or 400 kHz, the ends of the crack are located using the slope-intercept method; i.e., the leading and trailing edges of the 1
l signal pattem are extrapolated to cross the null baseline (see Figure A-26). The difference between these two positions is the crack length estimate. A!temately, the number of scan lines indicating the presence of flaw behavior times the pitch of the i
RPC provides an estimate of the crack length which must be corrected for EC field spread.
A.3.9 RPC Insoection Plan A.3.9.1 The RPC inspection plan will include the following upon implementation of the IPC repairlimits:
(
(a)
Bobbin voltage indications > than 1 volt 4
l
-A13-
l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995
~
(b) Allintersections with interferring signals from copper deposits.
(c)
All intersections with dent signals greater than 5.0 volts and a 20% sample of dent signals between 2.5 and 5.0 volts.
(d)
All intersections with large mix residuals that could mask a 1.0 volt indication.
(e)
All intersections which may exhibit PWSCC or circumferentially initiated cracks at the supports.
Note: It is Comed's standard practice to use 3-coil RPC probes, incorporating a pancake coil, an axial preference coil, and a circumferential preference coll.' Comparisons for ODSCC with bobbin amplitudes exceeding 1.0 volts have shown that the pancake coil fulfills the need for discrimination between axial and circumferentialindicadons, when compared against the outputs of the preferred direction coils. Pancake colls have been the basis for reporting RPC voltages for model boiler and pulled tube indications in the IPC database; these data permit semi-quantitative Judgments on the potential significance of"RPC indications. The requirements for a pancake coil is satisfied by the single coil, 2-coil, and 3-coil probes m common use forRPCinspections.
\\
i l
e I
s
-A14-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appencix A Revision 9. September 1 1995 Figure A-2: Bobbin Coil Amplitude Analysis of ODSCC at TSP.
l sa 6 cm a e I mes a e i e is t.s ein n 62
. at tse sms cm a ta Ttt&
P a
~~
O
- 1' C
as v.e. as t.l es ta 7.
g'
==.uan etu 4 fts i
.....E Its IE 6
.., i is g
.1
..a e veo s.2 3 71 aan i
i 8
I
(
,I Q !
4
% l M I
<~'
l 1
s s
22..a 1st sne cm 3 ed '
22.21 k'
13e une os 1 47 i
- ,7 in a.
--O
-j
]r
)
7 63.
m t
.mme e emes mis 3 m na '
a..,
um 23 i-~*-....a A r.i 4
i-s i 4 i
s l..... 7"...
l f
h h
45 4.i a
l I
-A15-
I COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unst 1 Appencix A Revision 9. SeptemDer 1 1995 i
Figure A-3:
Bobbin Coil Amplitude Analysis of ODSCC Indication at TSP - Improper Identification of Full Flaw Segment Resulting in Reduced Voltage Measurement When Compared with Figure A-2.
ae aie i. i.,. is i.s is i ia
.n ss.
c i a
h J-n
= =.
r/
~
1, i,,.
fgg
-.-.. roi i = a n ste-N lit Sainsene stamini t
ue
,o e in i.e i
i
)
i 1
J
_b i
4 W l %
i i
i i
\\
l i
N u.ee ne ua en s u
u.n in a. em s l.
Le im 13e
-p j.
u.
~~
~
-t-
+
-... - o
=
ig t
i i
i i
i i
i M
b I
._r=e s., a s i.o 64, 9 2 i
N.
L._,
l __ -
5 i
di
,",'*l, I'
i l7_
s i
s l
i i
="' - ' "
i es t
l
-A16-
l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron anO Braidwood Unit 1 Appendix A Revision 9. Septemoer 1 1995 I
Figure A-4:
Bobbin Coil Amplrtude Analysis of ODSCC Indication at TSP - Improper identification of Full i
Flaw Segment Resulting in Reduced Voltage Measurement When Compared to Figure A-2.
l i
1 l
34 $ CJs t v i sia 4 e a e it
&:S NIX 4 13 e 34 TIC ~
%W the ta n 13 i
,5
~
7(s>
a
.=
N w
a.....,
g g
~...,..,...
x
~
2 v
eo e ee BE 13 tea n
..e a 51 EM 125
(
l
)
i l
i 1
- ss I
w i
c i
d
, 4 t
=::"
i i
I i
\\
I i
\\
22.es 3 0 Ene CM 3 ee s 33.31
- 13. Ems ou 5 61 1 916
\\M
\\
}
a.
i
+
- e. amine e-.nre e
aus i
g
,wiininsei.isses,sai L.
[
1 5i N-4 j g
_ EM e s i 3i I a
-5
- l y
a
+
l l
l i
-A17-l l
l
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appenoix A Revtsion 9. September 1 1995 Figure A-5:
Correct Placement of Voltage Set Points on Mix 1 Lissajous Traces for R18C103.
i
)
in, ate 4 9 i 01 8 e ien Ma sam G t t3 1s.ae je gas on 3 ei M
b, y
p-_..
.. w,_,
e i
5
\\.
WEIB 119.43 aswunn armate in 1.
l 1st I
gg w a..s eu ans vu, e es e sa nm.
6 N
6 6
i tx i<
h T
l F
(
i i
i r
n.
- i. e. G.
n im i.. ais i i.
i.
J -
IN I
t..
h tam
[
r summe uma en j
w s.2s e es gy.
- -. -e._,,,.
m
}
j
\\
sua j
f
/
l
^
?l 7'3 I%
( l_
S 3ll
'"l' l 'l'
h
--:ll;,
,7 l
ur i
i
.e.
l 4
I i
ei
-A18-i
I l
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES eyron ano Bramwooo unn 1 Appendix A Revtston 9. September 1 1995 Figure A-6:
Correct Placernent of Vector Dots on Mix 1 Lissajous Traces for R22C40.
=
u.
s..
iu
- mmo, y
e
=A, 9
=.
"5 W'm
=
_ sm # + =
- iid 154
-i=
/ f-
,o.
e.s LW 2~
,r. a
~
M WEED GJ 8&l tawees resse
(
v im LE
-=
vem 6D M lit 14
- .o J sJ M 1 53 tra E
~
d m
_s s
7 i
A M
i T
i-u I
a.is me sa. a. :
us u...
. m a=. a. s im lh Lia 3.
a a
/
7 7
'r f
..- -.a
.e5 y
7 i
Pt
~m y
3,.",
i n
-A19-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A flevision 9, September 1 1995 Figure A-7:
Incorrect Placement of Vector Dots on Mix 1 Lissajous Traces for R18C103.
xi ai, i.in i.
. i.
m aa. a i is n.i.
is.. a >
(
=
i-
[F emzt I
O j
-M i '8.96 ( sl 4:13 k,
l..
M
-.i m i etc i fec
=
== ii.. i m..
. r
\\.
.]
1x
{
... mu s.
.=
ix s
)
t a
%W A
14 w
-b h
l ~ M 7
l
'M l
i i-r
.,i...
i...i. i
- =
l 1m lial
==
B I
s x
t a
1 y
1 e mas 15 p'
' " ' e y"===
2.si e n
. ve a.a.
m.
um
~~
l l
(
)
__ sis i e i W
rus i e. a s i s.. s i s a r i s W3 1
7--
~i!!
i!
.ii.
s.
l l
-A20-l
l I
l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appenotx A Revision 9, September 1 1995 i
Figure A-8:
Incorrect Placement of Vector Dots on Mix 1 Lissajous Traces for R22C40.
l ss.
en a v ans a v
. es tis mia s in i tsi ssa an a i isa i L
L I*ct k
~=.
=,[-
tale 6.e.es t d ij oug
=
- =
m
--o=emi a
imC 20 spEER 122.saltavam irmasas 11C
-==
12C 13C
.s.
i.u a ta.
..e s.u a in us SE 7
d i
6 i
t i
e f
I k
.b M
l N
9 i
T I
T z.
e i
as.ss me o n cm a in. a s..,,
um an cm s nas
{
13 i
113
-==
=
m m
<=
m m
esemas GM S M M veo 6.23 m 113 m e veo s.31 M si es wa 4m m esse I
/
i6ais..Iis,isi rare 4
IM M
I i-
"l'
!lllll:
7 i
w l
r
= > > >
's t
Pe
-A21-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995 Figure A-9.:
Incorrect Maximum Voltage Derived from Placement of Vector Dots on Transition Region of 550 kHz Raw Frequency Data Lissajous Trace for R42C44.
m6 un i, 4 asa i e i t,e 6.s mis a is '
s.7) sie a e ce as '
's-sur sea
!T L-
= =.
==
.a....,
4,.
3 oTurri rtu 4 ret 6
=
fa
-lll:::.
- L
/
tRun 22.esa ine estatue ttC i
f, t
vue s.65 Hm tes 21 s see 6 89 M L22 een j-4,,7 ~ l 5
Y I
T 1
c is.
LlJa 4-1 1
k Y
k.
=
t b
i semne e asse sus fun v.,.... su sa sie i,,,..m am se
==
- * = = ' = ' = '
r ou T-I
~
~
G r
i l
i l
s l
i t
d i
.A22-1 i
1
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braicwood Unit 1 Appendix A Revtsson 9 September 1 1995 Figure A-10: Correct Placement of Vector Dots on Mix 1 Lissajous Figure for R42C44.
34 4 Os 1 y Q nas & v i 3.38 t:5 als i 18 1 6.77
$$$ Chs CM &
M 8C" 3
.::=.
l N
l,
/
18 l =4.99 l el
.ited g
-1 s.aiussie TDI i Ytc e M
AE k
N 122.861intems eftelsel
=
[
k{l att LE 4
1X
= 13.53 388 Ehe 0t 3 es l' 83.53 433 ou Os 5 eg t. nu l ( / l ti. = -H ( m a y at -L I lia e.see 8.5 = ..e m=
- u.,..e t.
E I 4 I .. a i i i. $ i. 4,,. d re. 1 i K N ',:::U : : ::! :. l r i e r c siise i.
- .6
) l I l h i -A23- COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revision 9. Septemoer 1 1995 Figure A-11: Placement of Vector Dots Based Solely on Mix 1 Lissajous Figure (no significantly shap transitions in any of the raw frequencies)- R10C44. p' -. ~ gy !
- EE 7
= 5" / 3 4., ItC z. g 321.ets wees#rtasm IE F i x L. [ = -)= - ta. aa, m-- ,,e r-i c e l h I y a f i la' N l m g \\ f \\ l f sas , L 12 * ===oia i... in,, o,, j nu E \\ r-y ( j $-4 k = w.. m.. ,2. , N 3m m a.as a -- ===> e ==, ,, mm,,,,,,, ) ) ( ) I / = 'l'l' '*l '~' y ~ i \\ / \\ i / _ im e s, l ="! o -A24- COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bra,owood Unit 1 Appendix A Revision 9, SeptemDer 1 1995 Figure A-12: Placement of Dots Marking Mix 1 Lissajous Figure for R16C26. 3s i cm a v 6 on s v 2.12 1:5 nas a to 1 6.35 sse ou on is N I am*T 1 kj 8"_ i* t s. seq,1 jeu 6 i - -. m # fa e a 1 8MIB 828.54s swome staas.4 t 1 i i ve, e.s2 - se saa 1 v.s. e.s3 m see su / f al l I f J i e i g j, I i I W L I I / I i / ~ gem as. _13.19 3m ces Os 3 et 21.te 13e esis os 5 23 1, n, ii., s .. 2.m .a v., . 3. .2. J-i I f ( l I ...........".i..,.., $ E-F ) i'e '". l ' ' ', ; l ' ' : s t P i r- -, 1-I l l ) l g j j ="i i.... 1 s i i -A25- COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appenda A Revision 9, September 1 1995 Figure A-13: Incorrect Placement of Vector Dots Marking Mix 1 Lissajous Figure for R30C74. is i :n i, i ai s, e 2.n i:s air i is 4 ..a sse can cx i u l .~, tt T" CITENil tem 6 se i 4 r i! ma sn... i,.. g isc j l v.s e.52 M 71 69 ..e 6.24 M 6s .e. 12C f s ( f a g 1 ax N l M MIY 9 i i P / i ( l I ( 12.24 see ans oi .s i an.ta in sn. os s si 1 918 J i 3D [ s / its ses ss se g j -m ( 6 I \\ l 8 \\ runs a e 6 a i a i "6 s i a iiT 2 31 d Q g g l nas s s i .ns 6 tn D aun a a.. toi T l M Pi > =.. l I / -A26- a COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995 Figure A-14: Correct Placement of Dots to Effect Maximum Voltage-R30C74. m,, im,, i,.... i. ..n --ei W .i i.i tc g u.-.. ten I tc t 5 2....... %. a- .e = ite l i.i. 3 72 tia i v.e i.se 3 es saa ix i d '? I 4 ,x 'i' I 9 I f x m. .., u.. i, - o,, >i im snn l ( I s.m a, sa vs. s.., m as, as i 5" *" * * * * * ' " ' " i i T -h H=T 4 I--T- = f l P Pi P -A27- ~_ COMED STEAM GENERATOR EDDY CURRENT GUIDELINES I 1 L Byron and Braidwood Unit 1 Appendix A Revision 9. Septemoer 1 1995 Figure A-15: Example of Bobbin Coil Field Data - Mix Residual Due to Alloy Change. i ni en i w e ass 2 y, 6.te .e. sms on a a.e : s.22 2:s at: 2 .a e se J cat 400/100 Absolute = i= = i-( 9 ses n is i E y ..y I i-w...... u i., g p Exituti_eas 6 am.. s ,af i m o :......, ~ s].i i l i 3.n us an 2.a as m ) I l (- I / l c =e x n n j i .it-- w i --e -e i h I i T l [" If m,..... 400/100 Differental 1 5 N- [ ~ f 5- ~~ ,f Q 1 r_ l T nae .-e.. .CamBt 6 809 t ens i = 1
- x....
.G. =s s, i i g i / l ( l t 1,....
- ssa m,
a n s-- ~ i 3=c-W Y E.- i i g.... i i 3 i T i s, t a s l l l i 1 .A28-i . =. I COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995 4 Figure A-16: Example of RPC Data for Single AxialIndication (sal) Attnbuted to ODSCC - Plant S. w i on e v ' on s v ..as 2es ou oi e se i 3 4 E Mgg g "s 3'E C a A v eserie. ==n s4-it ainst i
- m. er ese tissa.
rs esemos e,wumm. naven.seiwisee m { .a q.I sisel crmrrt ta t tai i 4 h Irsic,EEmi ictactassau s e s is.ssIt - transme ^- j up L.21 M 32 8E \\ l y M l [ l .. v..: Ctg 23rEMNflA GTs ea MS i as e.as 4.57 MS i r x . side. Tram es4A GTs 0.53 le + e l i J 4 b 4 -A29- l I COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braldwood Unit 1 Appendix A Revision 9. September 1 1995 Figure A-17: RPC Data for Single Axial ODSCC Indication (sal) - Plant S. l 3e l. Os e v on 1 e i e.es aan me at
- 85 EM E
M gg saan as e assetten a e eseessere F g an. er sem tests: J 23 eseAme rTWtumes asW186 444 West 8 gas g.g,39 g,g q qgg ,,,7 umn fDI f TERI ( yu I ITe tEER38 (C18ClantaLi SPEEB e.34 e ifVeas iftale 4 costs i 4 i voy 6,71 FEE 37 W8 / I f L i b i N i 3 ) i l J \\ g \\ i C180sFEMittaak GTs A M 8EE e.43 180se.42 -4.67 384 M8aL flaCE uleL GTa 8.24 tu l l N f ~, ~ ~ 1 I i a -A30- COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and bracwood Unit 1 Appenctx A Revision 9, September 1 1995 I Figure A-18: RPC Data for Multiple Axial ODSCC Indications (mal)- Plant S. 386 Os 4 e l 08 9 y 4 2.m 3a5 mus 08 e 183 i M E N @ g Has se s sesenens at v essereene age gggy sn. e tems tsmess is 8888E5 h al&l84 8 Bl&t 068 3 g.g,qg g,g pgg ( D meesman II ID' 0 IM 0 N con 7 Itassetal IClac4assaLj span o.as I swens trasassi ( g 1 vast e.55 0E5 57 es 2 s 4 ~ 6 A f h 388 assai. 7801 l ClaQsIFIEDrTIdL EITa 3& KE i l .o 36 4. 5 8.59 8 4 aaldL TEaCI MlaL G1s 6.40 15 0 W # i I l 1 -A31- 4 COMED STEAM GENERATOR EDDY CURRENT GUIDELINES j Byron and Bradwood Und 1 AppendLx A Revesson 9. September 1 1995 4 } Figure A-19: RPC Data for Circumferential ODSCC Indications at Dented Upper and Lower TSP Edges. 1 i = :S - ~ g 1 i l s
- s.
hi% r J.s.m, A i I I 1 t, d s i W j ,6 4 " =.,n. e 1".J:: '.::
- ."". lll:_.1
] MM -, -> - i M ,2.-,, n-u- \\ j . = = =.. l 4 . _: u _ =,=.:. j +' _a 3 j
- ll "4es I
E W ede " ".*,',' 'il 1." J;l:' 1" "~ 7 **, .E. -A32- l l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bradwood U1rt 1 Appendix A Revision 9, September 1 1995 Figure A-20: Example of Bobbin Coil Field Data - Flaw Signals for ODSCC at Dented TSP Intersection from Plant A. b a! a's i
- i=**i$a L
M ** 6waas.ransg = == L. i 1 = -i - - -i.= <e = i =, ...i ....a. .6 h ? f f =-- a I M. m e mmu.aus EBus m i y a= -m ,,..?" i' j l i Ai %i L I i T i 4
- M iy i
I o -A33- _ _ _ -.. ~. _ _ - . _ _. - ~ _ - - - 1 i i i l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES { Byron and Braidwood Una 1 Appendix A Revision 9, September 1 1995 j Figure A-21: Example of Bobbin Coil Field Data - Flaw Signals for ODSCC at Dented TSP Intersection frcm Plant A. 3 1 i i i } 1 i T 4-1 E .,s, y.., its 41B 4 9 P 9 b WW e sare.e.vessag b M ') 1 I O I 4 I 1 j l P e b -1 i see 6.73 M 473 WT vgip e.89 E E les hff ? 8..e se Ems 08 & M1 4.M til att & MS i b. e I j l l g-S i i e s mm.s e..e sua.s e.m a g 1 i ...e ...i.i... i ( l 5-5 I > i ;;4 3 y p y.- dt: z=r l i I i a 1 1 i i 4 a 4 4 i k I i, i -A34-i I 1 i COMED STEAM GENERATOR EDDY CURRENT GUIDELINES enn ano eracwooo uni 1 Appendix A Revision 9, September 1 1995 Figure A-22: Example of Bobbin Coil Field Data - Flaw Signals for ODSCC at Dented TSP Intersection from i Plant A. I i i m a A, M 9 i j i = * *.m e u. g I 3 i T k j j =m g ( = 4 ) .... - m j 3.as =es es e a e' W.M he ans a .e j 1 ~~ j i E J-I CNb-i = = .= I = 4 assemos 4 emum a sans as j aus er 5 sheer GWI j usub tl q 4.3 m in W w 1.5 M M M = <18 i<u!'1 j 4 j amr i ,u l 4 M i um y e i { I .e u C c i I 4 ? 1 o -A35-2 s 1' COMED STEAM GENERATOR EDDY CURRENT GUIDELINES 4 Byron and Braidwood Unit 1 Appendix A Revision 9, September 1 1995 1 Figure A-23: Example of Bobbin Coil Field Data - Flaw Signals for ODSCC at Dented TSP Intersection from ) Plant A. 1 ] ' ae ' ais i e i r.a t v n.as .se om a s an e ie i.e ars a m' i I i ~ l t F ^ "Is 6.e.en s. .a l J [ 8T1 fux I ru e a y7% unumummmuuuummus' Y-i wg i 1 l i b ~~ ~_ i 4 . ?se es.st._ p;E sta auf wie ..a e se arr i 1_ia.ss e om o a nu s.m os ass in i 4 I l 8 0 m l ( seen e == se ~~ eseam e emessesses j l I ME
- __ ue 8.95 m !=
4W i sep 4.10 mM 3, runs a rsaieearss,ivi l ,l 4 j s-3 J P !M M im i I i 1 1 es 4 Ui 1 1 4 3 -A36-f COMED STEAM GENERATOR EDDY CURRENT GUIDELINES syron ano eraiowooo unn 1 Appencix A Revision 9. September 1 1995 Figure A-24: Example of Bobbin Coil Field Data - Flaw Signals for ODSCC at Dented TSP Intersection from Plant A. I ee d esa a,, be I e i e at .as our on i es i t,te a es mis .o i I = * *.w i.. ,a =
- x. uan WI wI g
M.M M M M 8.Miestremei g i x3 i i D 4 M h y 9.15 ses 0,r Os 4 0-(,1a 4:6 835 4 e T T l I s i u i 9 j l. == e., e. g au, w = e.no e is na i e.m um a em i-o i' .>- i um i i [ g I W l i i-f i i y -A37- 4 COMED STEAM GENERATOR EDDY CURRENT GUIDELINES 1 Byron and Braidwood Unit 1 Appendtx A Revision 9, September 1 1995 Figure A-25: Example of Bobbin Coil Field Data - Flaw Signals for ODSCC at Dented TSP Intersection from 4 Plant A. 4 i i I f l 1 =......... ...... i 1 e i = i...... J W 'mmmmmmmmum 5 J P 1 1 I i a t I =... - in on 3.7, - in s .i n l i F i 3 i i i } l l 1 i i 1 a l i. ~ i. 1 I Eum ..n - n I s a 1 .= 7 w i p 55 J ^ J . i. i. g I 4 4 } 1 l A l i t } i ( I 4 4 -A38-i i i COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 Appendtx A Revtsion 9. September 1 1995 i l Figure A-26: Location of One End of an Indication Using an RPC Probe. b i i .. cu a vett.:. m a seur ;j cosmeat m - a la e sem a an. s: i E. man cemen a 3 a l < i ~ PWW e tsas l I? 95D8 - 15 l I 1. asserten - see aus l 1 N
- mer b... <
< = I I PWR - e het ! l l 9 838 - 15 1-t emna - su aus tieff m !P ta m f M e test l Ont SK "~ "" " m. tan.< r l 8e35 - MPela.T l i e a em 4 i mamm M 1 136 i ....lampaltfszz I l l mu-suas sees i se 4 l O .A39- t 4 i 1 APPENDIX B j ANALYSIS GUIDELINE CHANGE FORM 4 i e d 4 a i 4 f 4 I 1 5 4 k; I 1 .I d. 1 t 4 I a i J 4 4 'Y I t 4 i t t t f k i t> i 1 4* 2 h 1 'l i i 3 1 4 4 =! i f i i COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bram Unit 1 and Unit 2 Appendix B Revoon 9, September 11995 ANALYSIS GUIDELINES CHANGE FORM CHANGE FORM #:
SUBJECT:
i DESCRIPTION OF CHANGE:
1 REASON FOR CHANGE:
1 TECHNICAL BASIS:
l EXAMINATION IMPACT:
AUTHORIZATIONS:
Lead Analyst Date:
/
/
Comed Acknowledgment Date
/
/
l l
t I
l I
-B1-l l
l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bradwood Unit 1 and Unst 2 Appendix B Revnsson 9, September 11995 l
l ANALYSIS GUIDELINES CHANGE ACKNOWLEDGMENT FORM (Continued)
CHANGE FORM #:
l EFFECTIVE DATE OF CHANGE
/
/
TIME
/
am/pm l
Analyst Signature Dale Time
/
/
/
/
l
/
/
/
/
/
/
i
/
/
/
/
/
/
i
/
/
L
/
/
t
/
/
/
/
/
/
/
/
/
/
/
/
/
/
l
/
/
l, l
/
/
/
/
{
I I
l
' l
.u se.--_
__.Au ne m--mm-s
-se, A
naam14.,e-u.
62m--..,M-4
-e4x
,-4, 4
A
--n->
am-a.4mme-a-aus-aa-a n.
m a
APPENDIX C ANALYSIS AND RETEST CODES 1
4 r
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Brantwood Unit 1 and Unit 2 Appendix C Rettson 9 September 11995 Analysis & Retest Codes Cateaorv 1 - No Further Action:
Analysis Retest No Detectable Degradation NDD RND Plugged PLG Sleeved SLV RSV Positive indentification PID Cateoorv 2 - Possible Flaw. Further Action Reauired:
Analysis Retest Non-Quantifiable indication NOI RNO l
Absolute Drift Indication ADI RAD Distorted Support Indication DS!
RDI Distorted Tubesheet Indication DTI RTl Dent with Possible Indication DNI RN!
Distorted RoilIndication DRI RTI Single Axialindication sal RSA Multiple Axialindications mal RMA Single CircumferentialIndication SCI RSC Multiple Circumferential Indications MCI RMC Mixed ResidualIndications MRI RMI Free-Span indication FSI RSI Lead Analyst Resolution LAR RAR Cateaorv 3 - Possible Loose Part. Further Action Reauired; Analysis Retest Possible Loose Part PLP RLP Qateoorv 4 - Further Action Reauired. Retest Condition:
Analysis Retest Bad Dam RBD RBD incomplete Test INC RIC Obstructed OBS ROB Template Plug TMP RTP Tube No Test TNT RNT To Be Retested TBR Fixture FIX RFX Tube Number Check TNC RNC Cateaorv 5 - No Further Action Reau! red; Analysis Retest Bulge' BLG RBL l
Copper Deposit CUD RCD i
Dent DNT RDN Deposit DEP RDP l
Ding DNG RDG Distorted RollTransition Signal DRT RRT Distorted Support Plate Signal DSS RDS i
Distorted Tubesheet Signal DTS RDT Expansion EXP REX Free-span Signal FSS RFS Indication Not Reportable INR RNR j
-C1-
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES l
Byron and Branswood Unit 1 and Unit 2 Appendix C Revisson 9, September 11995 Cateuorv 5 - No Further Action Reauired (Con't) Analysis Ettrit Indication Not Found INF RNF Manufacturing Burnish Mark MBM RBM Manufacturing Anomaly Mark MAM RAM Noisy Tube NSY RSY Over Roll OVR RVR Overexpansion OXP RXP PartialTubesheet Expansion PTE RTE l
Permeability Variation PVN RPV Skipped Roll SKR RSR Sludge SLG RSG Top Main Roll TMR RTM Volumetic Indication (s)
VOL RVL i
Free-Span Differential FSD RSD Shot Peening Anamoly SPA RPA~
j l
l I
l i
i j
1 4
4
-C2-
,6 4
4 i
4 1
k.
t l
APPENDIX D SUPPORT STRUCTURES 3
NOMENCLATURE & MEASUREMENTS
)
i 1
i
(
i s
b 4
l i
I 4
i i
h l
I t
]
4 i
i 1
k l
J l
a i
4 s
i 1
i 1
COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Bradwood Unit 1 and Unit 2 Appendix D Revasson 9, September 11995 Support Structures Nomenclature and Measurements Westinghouse Model D4 S/G Support Structures Measurements
. Level.
Elevation Spacing (Inches) -
Hot Leg Cold Leg Tube End 0
0 Top of Tubesheet 21.2 21.2 Center of 1st support 6.4 6.4 Center of 2nd support n/a 12 Center of 3rd support 30 18 Center of 4th support n/a 18 Center of 5th support 36 18 Center of 6th support n/a 18 Center of 7th support 36 18 Center of 8th support 43 43 Center of 9th support 43 43 Center of 10th support 43 43 Center of 11th support 43 43 l
P
-D1-
l COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Brarduxx1 Unit 1 and Unit 2 Appenda D Revnsion 9. September 11995 l
Support Structures Nomenclature and Measurements i
Westinghouse Model D5 S/G Support Structures Measurements i
Level -
- Elevation Spacing
- .
-(Inches):
Hot Leg Cold Leg Tube End 0
0 Top of Tubesheet 21.2 21.2 Center of 1st support 8.4 8.4 Center of 2nd support n/a 12 Center of 3rd support 28 18 Center of 4th support n/a 18 Center of 5th support 36 18 Center of 6th support n/a 18 Center of 7th support 36 18 Center of 8th support 43 43 Center of 9th support 43 43 Center of 10th support 43 43 Center of 11th support 43 43 l
l l
-D2-
i COMED STEAM GENERATOR EDDY CURRENT GUIDELINES Byron and Braidwood Unit 1 and Unit 2 Appendtx D Reveraon 9, September 11995 l
Support Structures Nomenclature and Measurements Structures Nomenclature Notation >
Description '
TEH Tube end hot TSH Top of tubesheet-hot leg 01H 1st support plate - hot leg
)
03H 3rd support plate - hot leg 05H 5th support plate - hot leg 07H 7th support plate - hot leg OBH 8th support plate - hot leg 09H 9th support plate - hot leg 10H 10th support plate - hot leg I
11H 11th support plate - hot leg AV1 1st anti-vibration bar AV2 2nd anti-vibration bar AV3 3rd anti-vibration bar AV4 4th anti-vibration bar 11C 11th support plate - cold leg 10C 10th support plate - cold leg 09C 09th support plate - cold leg 08C 08th support plate - cold leg 07C 07th support plate - cold leg 06C 06th support plate - cold leg OSC 05th support plate - cold leg 04C 04th support plate - cold leg 03C 03th support plate - cold leg 02C 02th support plate - cold leg 01C 01st support plate - cold leg TSC Top of tubesheet - cold leg TEC Tube end cold 1
I
-D3-
ATTACHMENT 1
(' FIGURE 1, 2, 3, 4, 5 & 6)
)
)
4 i
4 1
e I
l i
4 ii 1
i i
e i
4 A
4 1
i e
i
i FLOW DIAGRAM FOR TUBE SUPPORT PLATE M
GMU identify indica, >n
@ TSP l
Y j Use lower frequencies to verify presence of I
TSP Y
' Utilize 550/130, Mix !
- for measurement of indication Y
s indication ID initiatedN Notify lead Analyst (PWSCC)?
immediately r
N !
- 4 Y
Does crack extend Notify Lead Analyst m
beyond TSP?
immediately Ni Y
Report and measure all A 20 % sample of i
dent > /= 2.5 volts @
r 2.5-5 volts will be TSP's RPC'd, all > 5.0 volts l
will be RPC'd g
Y is dent caused due to Notify lead Analyst corrosion?
ri a
immediately Nl 4
Y
' Continued on Page 2
(
Page 1 of 2
IContinued from Page i
1
)
\\
I i
Resoultion analyst will s large mix residua Y
i Report as MRI(Mix confirm all MRI's Prese TSP t may W ResidualIndication) w called by Primary or indication?
I,
'I Y
RPC for indication N l, Y
j Are copper deposits Report as CUD JNotify lead Analyst present @ TSP's?
h (Copper Deposit) r!
immediately I
L N
Y RPC Indications > /=
Repair limit i
Y
' Notify Lead Analyst Do Circumferential cracks exits @ TSP's?
Ei immediately i
l i
N t4 Y
IPC to be applied in accordance with Byron /Braidwood requirements s
i i
Page 2 0f 2
l FLOW DIAGRAM FOR TUBESHEET INDICATIONS (F*)
l (FIGURE 2) l l
1 l Indication found withm Tubesheet Note: Notify Lead Analyst if
+
l circumferential or measurement is questionable.
' ax(ial orientated) based on bobbin or RPC l
results l
l
'Y iIf found by bobbin and
' axial orienated report as DTI), if found by RPC and axial 1
l orienated report as SAI/MAI I
l V
If circumerentially orientated report as
. SCI / MCI as determined by RPC only 1
N Report as NDF (No Is indication Further action 6
SAI/MAI or SCI / MCI required) w th RPC?
l Y
Y Utilize approved eddy current method to determirr, length from crack t p to last roll withis tubesheet Does this measuremen exceed 1.7 inches
& Tube must be repaired Yi i
V I
lF' criteria may be used Appropriate documentation should to leave indication inservice "I be provided verifying Imcasurement mecu the i
1.7 inch criteria
?
]
FLOW DIAGRAM FOR U-BEND REGION 11H THROUGH 11C (FIGURE 3) l Scroll U-bnd utilizing Ch 5, Ch.3, P1, P2 l
l
[
N l
s a possible indication m
l present?
NDD r
L l
Y) l l
Y s the signal at an AVB?'
See Figure 4 (AVB Flow Diagram) l l
1 i
Nl
/
l N
/Does the signal appear on N
Ch.3?
l NDD Yl Y
See Figure 5 (Free-Span Flow l
Diagram) i I
FLOW DIAGRAM FOR INDICATIONS AT AVB'S (FIGURE 4) l l
l l
Signal at AVB l
structure i
I I
/
\\
s' indications > /= t N
NDD 15% TW as called on P2?
i Y!
I l
Y Report % TW utilizing l
P2 I
d r
l
- l FLOW DIAGRAM FOR FREESPAN STRAIGHT SECTIONS (FIGURE 5) 1 i
Possible indication j
detected in Free-Span i
Straight Section (Ch 3) i l
1 4
- f. N confirmation N
% TW confirmation i
j (CH 1)?
m g
Ch 4?
"[
i Y
Yl l
J i
/
j l
+/- 10% TW (CH 3 ots N 5)?
+/- 10% TW CH's 4 N
s signal characteristic and 6?
^
r' of MBM?
N y
Y y
V y
Repon as skg C
Repon as D using Report as M Using i
h l
=
FLOW DIAGRAM FOR RESOLUTION OF FREESPAN i
INDICATIONS (FIGURE 6)
FSD or >/= 20%
i TW (other than AVB indications) 1 Y
Evaluate FSD utilizing Previous History N
is indication growing in voltage or degrees?
y Report as FSS (Free-Span Signal) 1 l
i Y
Y Y
Report as FSI IKeep in database as (Free-Span f
FSS Indication) l t
Y 1
Will be included on RPC list l
l l
l l
i 1
1 i
FLOW DIAGRAM FOR ROTATING PROBE ANALYSIS (FIGURE 7)
Review 3-Coil Isometrics & Relative Coil Amplitude
Response
Are there Linear N
Indications?
A Y
Are there Volumetric N
Indications?
Y y
Y Report using appropriate analysis code.
Y Repon using appropriate analysis code.
OCT 05 '95 08:00Pr1 P.2 COMED STEAM GENERATOR EDDY CURRE'NT GUIDELINES Bron anc Seamo urut 1 and urut 2 Appendac a Revson e. 5eptemcor 11sss ANALYSIS GUIDELINES CHANGE FORM CHANGE FORM #:-1
$11BJFCT:
Editonal changes to guidelines in section 6.3.3, A.3.9.1(a), Figure 1 and Figure 5 of Attacnment 1 and note under A.3.3
- Alloy Property Changes
- DESCRIPTION OF CHANGE:
- 1) 6.3.3: Dents or dings > 5.0 volts peak to peak.." This should read "> 2.5 volts"
- 2) A.3.9.1:" Bobbin voltage indications > 1.0 volf. This should read ">/ower repairlimIt"
- 3) Figure 1: See attachment to this page for changes. All changes are generic and do not require any additionalinput from the analysts.
- 4) Figure 5: See attachment to this change form. M changes are generic and involve the anlayst making an FSI call rather than a % TW call.
- 5) Note under A.3.3: Remove the werd 'All" in the first sentence.
REASON FOR CHANGE:
To provide the analysts with additional information for reporting damage mechanisms.
TECHNICAL BASIS:
These changes are editorialin nature and they do not challenge the technical basis since the analsyts will already be addressing these types of damage mechanisms.
EXAMINATION IMPACT
- None AUTHORIZATIONS:
Lead Analyst Date;dl 3 /
Date [8 /1/ IS" Comed Acknowledgment,A, I
I
-B1-cg 7
.ge og:g 112 722 !!95 ZGE.002 c-
l OCT 05 #95 08:00PM P.3 FLOW DIAGRAM FOR TUBE SUPPORT PLATE INDICATIONS (FIGURE 1)
I Scroll TSP usr4 i Ch.1 & Mis I l
l I
I
{
(
a mers a possible N j
suscauen?
e No degradanos presern g TSP j
Y l
7
' Report as DS! using Mut I L
l JOB FIX)W DIAGRAM IUse lower frequencies t to ver fy presence of i
TSP i
Utilize $50/130. Mut 1 fbr measuremem of sad 4 cation s Wacarion ID initiaA I Not:fy Lead Analyst (PW5CC)7 c:im:daely i
t i
Does crack estand \\
m ' Notify Lead Aralysi beyond TSP 1 untnecawJy b
i
- Report and measure all l 2.5 5 volts will t:
A 20 E sarcple of I dem > /= 2.5 volts @
bi TSP's
,'RPC'd. a!! > S.0 volu e
will be RPC'd Y
i dscanson in W
- Report as DN1 l-Page ! cf 2
\\
t i
IPC to be appnea m a:gordanca wim Byron /Brandsond requiremensa Page 2 of 2 gi
!'M 03:01
_,; ;; !!66 AME.OO!
~.
OCT 05 '95 08:OOPM P.4 i
1 l
FLOW DIAGRAM FOR FREESPAN STRAIGHT SECTIONS (FIGURE 5) d j
?
Possible indication detec:ed in Free Span
]
Straight Section (Ch 3) j l
1 1
i I
i
}
% TW confirmation -
N
%' TW confirmation I
E (CH 1)7 Ch 47 l
i
.i 1
t l
Yl y
i l
1 N
I
+/ 10% TW (CH 3 oN
-/ 10% 'I'W CH's 4 N
'#8 ***
j 5)7 and 6'*
of M'BM7 p
4 l
N
-__Y Y
y Y
r y
Y F:55 Repon as % TW using j Rmna' using Repon as MBM Using CH 1 C
l l
Gr6 I
i j
k i
j 4
4 i
e
.e
,i OCT E '95 03:01 412 722 EE66 NGE.004
OCT 05 '95 08:01PM P.5 4
1 i
Y Is dent caused du: to
., g g J
corrosion?
immediately i
- h s large mix residua Y
Resoultion anabl st will Report as MRI (Mix confirm all
's
,- esent @ TSP that may Residual Indication)
+a m!!cd W Phry or mast a 1.0 volt gag indication?
N Y
RPC for indication S
l.
l 1
Are copper deoosits Report as CUD dNotify Lead Analyst present @ TSP's?
(Copper Deposit)
"j immediately a
0 i
I RPC Indications > /= l Repair limit l
t i
b 4
N tify Lead Analyst Do Circumferential
"*"d*'*II m
cracks exits @ TSP's?
IPC to be applied in accordance with Byron /Braidwood requirements Pag:2 of 2 OCT 5 '95 03:02
-312 722 5566 PAGE.005
OCT 05 'S5 07:57PM P.2 COMED STEAM GENERATOR EDDY CURRENT GUIDELINE Revsen 9, septemoer 11995 Bpon ana Brennoco und 1 and Unit 2%m B ANALYSIS GUIDELINES CHANGE ACKNOWLEDGMENT FO (Continued) 1 CHANGE FORM #:
1 I
i l
EFFECTIVE DATE OF CHANGE /.g.J.3._/j_.' T1ME/ _ am/pm i
Analvet Sicnature QAfA h
i
_kia aoa C,ed
.a./.r2.st ta.a 60#LY%* M
.@).2V./.?!
/2.LO i
i oH, i$46 dh 10 I oJ/ 9L Lt 29 U, GeDe k
.t.c./3)!)f
/.9 :.cL kM, tnt M) ein,49t 0r i
a
~
bmbfh
&/diB~~
LW
$,b w 8 L/_[_]jf J.2f_D v.%2W, MIi i 7f ij_,6 I
J:ihf a_j.ti.r_c c.ac.
0 YA 2 !.Df ~
A~.M v
/
/
1 I
/
/
l l
i
/
/
i l
/
/
f
/
/
/
/
/
/
l
-B2-
,c=
g7,2 112 722 556,6 FAGE.002
~
-