ML030360349
| ML030360349 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 11/22/2002 |
| From: | NRC/RGN-III |
| To: | |
| References | |
| Download: ML030360349 (41) | |
Text
Prairie Island 1R22 SG Inspection*
Category C-3 NRC phone Call November 22, 2002
- The attached information has not been validated. In many cases, it is preliminary information from ongoing inspection activities. To our knowledge, it is the best information available as of 112202 at 0000, but may be changed following further inspection, review, and analysis.
ENCLOSURE 2
Present at Prairie Island Scott Redner - SG NDE Level 111 Jeff LeClair - SG Program Lead Jim Begley - CMOA Analyst Richard Pearson - Replacement SG Engineer
- Jeff Kivi - PI Licensing
- Randy Womack - PI Program Manager
- Scott Northard - PI Director of Engineering 11/22/2002 Page 2
Docket No. 50-282 Questions
- 1. Discuss whether any primary to secondary leakage existed in Unit I prior to shutdown.
- 2. Discuss the results of secondary side pressure tests.
- 3. For each SG, provide a general description of areas examined, including the expansion criteria utilized and the type of probe used in each area. Also, be prepared to discuss your inspection of the tube within the tubesheet, particularly the portion of the tube below the expansion/transition region.
- 4. Provide a summary of the number of indications identified to-date of each degradation mode and steam generator tube location (i.e., tube support plate, top-of-tubesheet, etc.). Also provide information, such as voltages, and estimated depths and lengths of the most significant indications.
- 5. Describe repair/plugging plans for the SG tubes that meet the repair/plugging criteria.
- 6. Discuss the previous history of SG tube inspection results, including any "look backs" performed. Specifically for significant indications or indications where look backs are used in support of dispositioning (i.e., Manufacturing burnish marks).
- 7. Discuss, in general, new inspection findings (i.e., Degradation mode or location of dearadation 11722/2002 new to this unit). Page 3
Docket No. 50-282 Questions
- 8. IfSGs contain alloy 600 thermally treated tubing, discuss actions taken (if any) based on recent findings at Seabrook.
- 9. Discuss your use or reliance on inspection probes (eddy current or ultrasonic) other than bobbin and typical rotating probes, if applicable.
- 10. Describe in-situ pressure test plans and results, if applicable and available, including tube selection criteria.
- 11. Describe tube pull plans and preliminary results, if applicable and available; include tube selection criteria.
- 12. Discuss the assessment of tube integrity for the previous operating cycle (i.e.,
condition monitoring).
- 13. Discuss the assessment of tube integrity for next operating cycle (i.e.,
operational assessment).
- 14. Provide the schedule for steam generator-related activities during the remainder of the current outage.
11/22/2002 Page 4
Question 1 Discuss whether any primary to secondary leakage existed in Unit 1 prior to shutdown.
11 and 12 Steam Generator leak rates prior to shutdown were less than one gallon per day based on Tritium activity.
Unit 1 Steam Generator leak rates prior to shutdown were less than 2 gallons per day based on Argon and Xenon activity.
Leak rates are typically less than minimum detectable test sensitivity for Xe and Ar analysis.
11/22/2002 Page 5
Question 1 Response
I "Steamn Gen era'tor Le'aakRa'te (bas4ed on.Triti um)
- 5 I---'Leak Rate gaI/day "a "'a a"'a
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a"' ' a "a a. 'a 'a a a 'a, 'a' 'a ' a
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'O 04/04/02 04/24102.....4102 06/03102 06/23/02 07/13/02 08/02/02 08122102 0.9.11/02.10/01/02 10/21/02.
"Date a '
11/22/2002 Page 6
Question 1 Response 77.777, 77,7777 7 77777, 12 Steam Generator Leak Rate (based on 'Tritium) 4<' 4' I:"":u
- )
- 7fý ii!*ii!*!i Leak Rate dIIUd --. 114-I 44 44 4 4' .4 444
- 44. 4 44 444< 44' '4 "44, 44<
44 4> 444 4.4 4'4<44' 444444 4<444 44 4 44444 A '
4- ,I' 4<' 4 . 4444<444 4 4
'0 4 '4 .444 4<
444 4<4> tS>
44 444 44u 44 44>4' 44'4
- 44," 44'44 444<44' 4 4<44 Lu 24 44444< 4< 4444 44<
'-a
-4 44< 44444'44444 .4 44
k'" 4< 4"">' 4> 44' .4.< 4<
444 444444 444 4<' 4' , . 4 4<
1- 4<4 44 4 4
'44% .4'> .444 4, <4* 4 444<4<
",4 444 444444
.> 4 4 44'44, '4444 < 444 4'
.444' 4 4,
4 4.4 4 'X%4 44444<4 4 4' 44 44> * 44 444.44' 4< 4< 444
, r , :**,, ** ******d
- 44/02 4129102 5/24/02 6/16/02 17/13102 '81/02 8<'4 911/02,.
44 - ~Date 44 4 11/22/2002 Page 7
Question 1 Response Unit I Leak Rate Based on Argon and Xenon Decay 5 '3 ',' '2 3-3 --4--Argon
- 3
.3' 3,
'-s.--Xenon 3333,3 3 33 -3 33 33 *, '3,3 , 3, 3333 3 331
'33" *333
-3""
31511 4 33 3"'
m~ 3 32' 3',
Z! 34 A, 3 33 4' '3
'.33 '3'", 3 339 3 333'33 Xca 333 33333 ;3 '33'3 3 33t3 4, 3 3"
33,4-33 3< 3' 433.3
'333' ,3'3 3> "K I
- Ii;!!-...i*X;!, '3 3,' '3 i
i1IOII 11I19/02, 3/10/02 42/0 /112 817/02 9/610
- 3. . .'D ate .... . . -Date 11/22/2002 Page 8
Question 2 Discuss the results of secondary side pressure tests.
There are currently no plans for secondary side pressure tests.
We have, as a contingency, pressure tests scheduled in the event of welded tube plug replacement or welded sleeve installation.
11/22/2002 Page 9
Question 3 For each SG, provide a general description of areas examined, including the expansion criteria utilized and the type of probe used in each area. Also, be prepared to discuss your inspection of the tube within the tubesheet, particularly the portion of the tube below the expansion/transition region.
UNIT #1 STEAM GENERATOR INSPECTION PLAN Rev. 2 - 11/19/2002 VISUAL Hot Leg -100% all Plugs for visual signs of leakage - After probed to remove H20 100% all Sleeves for visual signs of leakage Cold Leg - 100% all plugs for visual signs of leakage - After probed to remove H20 BOBBIN Hot Leg -100% rows I through 4 07H TEH A-720-M/ULCIRF (Non Sleeved Tubes)
Cold Leg - 100% rows 1 and 2 007C TEC A-700-SF/RM 100% rows 3 through 4 007H TEC A-700-SF/RM 100% rows 5 through 46 OTEH TEC A-720-M/ULC/RF 100% PID's 0 Various Various 11/22/2002 Page 10
Question 3 Response MRPC Hot Leg 100% Tube sheets +3" TSH TEH +Point-720-115/36/S80 25% ABB Sleeves STH TEH .610 GPP LF/HF Slv +Pt 25% ABB 1-690 plugs UPH LPH .600 +Point MB 100% Supplemental 0 Various +Point-720-115/36/S80 100% PID's @ Various Various Cold Leg - 100% rows 1 and 2 (or HL) 07H 07C .650 PP11A(MR) +pt Noisy rows 1 and 2 (or HL) 07H 07C .650 PP9A(HF) +pt 100% Supplemental 0 Various +Point-720-115/36/S80 100% PID's 0 Various Various 11/22/2002 Page I11
Question 3 Response REPAIRS - PLANNED Hot Leg 100% Post In-Situ Various Various Cold Leg 100% Post In-Situ Various Various REPAIRS - CONTINGENCY Hot Leg 100% Re-Rolls Various Combo Probe Hot Leg 100% Sleeves STH TEH .610 GPP LF/HF Slv +Pt 11/22/2002 Page 12
Question 3 Response o STH TEC for Sleeved tubes O PID = ->40%,MAI, MCI, MVI, SAI, SCI, SVI, WCI and WVI.
O Supplemental MRPC = ADR, CUD, DEP, DNI, DNT >_5.0 volts @ TSP, DNT > 5.0 volts @ TS, 25% of all free span DNT> 5.0 volts, DRI, DSI, DTI, INR > 1.5 volts @ TSP, MBM, MRI, NQI, PLP (Bound MRPC PLP's), PSI, Cold Leg Thinning _>40% or < 40% and >_1.5 volts.
11/22/2002 Page 13
Question 3 Response 0 Expansions - for MRPC of hot leg sleeves and plugs
- Evaluate extent of indications
- Expand to 100 % sampling of selected population per EPRI guidelines 11/22/2002 Page 14
Question 4 Provide a summary of the number of indications identified to-date of each degradation mode and steam generator tube location (i.e., tube support plate, top-of-tubesheet, etc.). Also provide information, such as voltages, and estimated depths and lengths of the most significant indications.
Analysis Status (as of 11/22/00 0000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />)
SG 11 SG12 Hot Cold Hot Cold Tubesheet Crevice MRPC 54% NA 71% NA Bobbin 71% 46% 82% 54%
Sleeve RPC NA NA 0% NA U-Bend RPC 0% 0%
Plug RPC 0% NA 0% NA
. 11/22/2002 Page 15
Question 4 Response 12 SG Analysis Results to date CL Thinning Indications - 6 AVB Wear Indications- 7 TSP DSI Indications - 130 HL Crevice Indications - 152 11/22/2002 Page 16
Question 4 Response 12 SG CL Thinning Indications (6)
Row Col Loc Volts Depth 37 71 O1C 2.04 2%
42 60 O1C 1.34 7%
37 73 O1C 1.59 12%
40 68 O1C 1.53 18%
46 53 O1C 0.51 29%
45 49 01C 0.63 55%
11/22/2002 Page 17
Question 4 Response 12 SG AVB Wear Indications (7)
Depths Range from 20% to 27% TW No change from history 11/22/2002 Page 18
Question 4 Response 12 SG Distribution of DSI Indications 50 40 PC 30 94 20 ~44 -
10 11 0F1
ýIr I ~E=;E L
OIH 02H 11 2:F 03H 04H 05H SP.WPML 06H 07H 07C 06C 05C 04C 03C A-1 02C 01C
-i TSP Location 11/22/2002 Page 19
Question 4 Response 12 SG DSI Voltage Distribution i
PC c
1.5 Voltage 11/22/2002 Page 20
Question 4 Response 12 SG HL Crevice Indications (152)
Location Within Crevice Number Largest RPC Voltage Below F*0 Distance 3 NA Within 0.25" of Roll Transition 82 0.8 V
>0.25" above Roll Transition 67 0.21 V 11/22/2002 Page 21
Question 4 Response 11 SG Analysis Results to date CL Thinning Indications- 9 AVB Wear Indications - 16 Old TLBD Wear- 2 TSP DSI Indications - 150 HL Crevice Indications -37 11/22/2002 Page 22
Question 4 Response 11 SG CL Thinning Indications (9)
Row Col Loc Volts Depth 30 15 O1C 0.75 3 42 31 O1C 0.97 6 28 11 OIC 1.02 21 33 16 OIC 1.11 25 43 36 OIC 0.91 38 44 33 03C 1.12 4 42 28 03C 1.11 6 42 31 03C 1.15 30 42 30 03C 0.98 32 11/22/2002 Page 23
Question 4 Response 11 SG AVB Wear Indications (16)
Depths Range from 8% to 44% TW No change from history 11 SG Old TLBD Wear (2) 40% and 44% indications No change from history 11/22/2002 Page 24
Question 4 Response 11 SG Distribution of DSI Indications 60 S40
-30 50 41H IMii
- g 20- -J 10 w 0 -r .-
F4-fl 01H 02H 03H 04H 05H i
06H 07H 07C TSP Location 06C OSC 04C 03C 02C 01C 11/22/2002 Page 25
Question 4 Response 11 SG DSI Voltage Distribution 1001 80
-* 60
.40 Max 1.43 volts 20 04 0.5 1 1.5 2 >2.0 Voltage 11/22/2002 Page 26
Question 4 Response
- 11 SG HL Crevice Indications (37)
Location Within Crevice Number Largest RPC Voltage Below F*0 Distance 23 NA Within 0.25" of Roll Transition 5 0.46 V
>0.25" above Roll Transition 5 0.4,5 V Above Top of Tubesheet (VOL) 3 0.44 V Above Top of Tubesheet (SAI) 1 0.15 V 11/22/2002 Page 27
Question 5 Describe repair/plugging plans for the SG tubes that meet the repair/plugging criteria.
Current Repair Plans
- Plug indications in 11 and 12 SG
- Use F*O ARC for indications greater than 1.3 inches below the hard roll transition
- Use F* and EF* for previous indications left in service under F*
and EF* repair criteria.
- Contingent Plans
- Re-roll
- Sleeve 11/22/2002 Page 28
Q uestion 6 Discuss the previous history of SG tube inspection results, including any "look backs" performed. Specifically for significant indications or indications where look backs are used in support of dispositioning (i.e., Manufacturing burnish marks).
LOOK BACKS All historical "look backs" except 7.4.4 of ISI-ET-3.0 are performed by resolution analysts and/or the Independent QDA.
ISI-ET-1.0 Rev.14, Bobbin Coil Specific"look backs":
- Review history on all INF calls to verify correct tube.
- Review history on all calls located > 0.5" from the historical call to verify it's the same indication.
- Previous raw data shall be reviewed as necessary in support of the resolution process and as requested by M&MR.
-DENT WITH INDICATION (DNI) signal must show change in signal formation, voltage
(>0.5 volts) or phase angle (>100) between the current indication and history (8/88 Unit #1 or 3/89 Unit #2). The Analyst may ignore the change rule and report the signal ifin their experience they believe the signal is indicative of a flaw.
-MANUFACTURING BURNISH MARK (MBM) - signal must show no change in signal formation, voltage (<10%) or phase angle (<100) between the current indication and history (8/88 Unit #1 or 3/89 Unit #2).
11/22/2002 Page 29
Question 6 Response NON QUANTIFIABLE INDICATION (NQI) - signal must show change in signal formation, voltage (>0.5 volts) or phase angle (>100) between the current indication and history (8/88 Unit #1 or 3/89 Unit #2). The Analyst may ignore the change rule and report the signal if in their experience they believe the signal is indicative of a flaw.
ISI-ET-3.0 Rev.1 1 MRPC Specific Requirements:
- Previous F* and EF* indications reported as MAI, MAN, MCN, MVN, SAI, SAN, SCN and SVN shall be reported as MAN, MCN, MVN, SAN, SCN or SVN (N = No change) provided no significant change in length, voltage or phase angle has occurred (significant is defined as change that warrants the attention of engineering for indications outside the tube pressure boundary). A decrease in voltage and or detectability can be expected due to the reroll of the OEM roll which is performed in an attempt to prevent leakage. MAI and SAI indications may also disappear due to the reroll of the OEM roll. These prior indications no longer detectable will be called MAD or SAD at a single location within the prior location range. Historical INF, INR, MAD and SAD indications will be entered as MAD or SAD in the current inspection with a location as close as possible to historical location.
Resolution analysts are responsible to review history on current WZI indications with a historical VOL indication. It is permissible to change a WZI to VOL if the voltages and phase angles between current and history are within 10% and the indication is located above the weld centerline.
11/22/2002 Page 30
Question 6 Response
- Review history on all INF calls to verify correct tube.
- Review history on all calls located > 0.5" from the historical or special interest call to verify it's the same indication.
- Previous raw data shall be reviewed as necessary in support of the resolution process and as requested by M&MR.
- MANUFACTURING BURNISH MARK (MBM) - shows no change in the bobbin coil signal formation, voltage (<10%) or phase angle (<100) between the current indication and history (8/88 Unit
- 1 or 3/89 Unit #2).
ISI-ET-4.0 Rev.5 IQDA Specific Requirements:
- Review history (prior outage) on the following indications to determine if any significant indications which reasonably should have been detected and reported were missed in the prior examination:
"* bobbin coil DSI indications at TSP's greater than 2.0 volts,
"* MRPC roll transition I code indications greater than 1.5 volts,
"* MRPC tubesheet crevice I code indications greater than 0.5 volts,
"* MRPC freespan I code indications greater than 0.3" long,
"* all MRPC u-bend I code indications and
"* all MRPC TSP I code indications.
- Review history (8/88 Unit #1 and 3/89 Unit #2) on all MBM indications to determine if any change in the signal formation, voltage (>10%) or phase angle (>10%) has occurred.
11/22/2002 Page 31
Question 6 Response Mixed Residual Signal Issue
"* During 1997 the MRI CDS sort was in effect and NO MRI indications were reported.
"* During 1999 the MRI CDS sort was inadvertently left out of the master sorts.
"* During 2001 the MRI CDS sort was again inadvertently left out of the master sorts.
"* During the current inspection with the MRI CDS sort in effect, the followingpreliminary results are available:
SG MRI % Bobbin Complete 11 1 at 2.08 volts 56 12 0 61
- MRI codes require supplemental MRPC testing, which is scheduled.
- Captured in Site Action Request process - CE001489 11/22/2002 Page 32
Question 7 Discuss, ingeneral, new inspection findings (i.e., Degradation mode or location of degradation new to this unit).
New Dents Possibly Due to U-Bend Heat Treatment - Preliminary Findings
- Only identified in low row (rows 1 and 2) u-bends
- Was identified during look back on post heat treat bobbin tests
- Was not present before heat treatment
- Approximately 66% complete on 11 SG and 33% complete on 12 SG I SG 106C 06H I07C 107H 1120 11 0 18 0 0 0 Additional Actions Pending
- Requested Root Cause from Westinghouse
- Completing Analysis
- Action Request CE001498 11/22/2002 Page 33
Question 8 IfSGs contain alloy 600 thermally treated tubing, discuss actions taken (if any) based on recent findings at Seabrook.
"* Prairie Island Original Steam Generators (OSGs) do NOT contain Thermally Treated 1-600 tubes.
"* Prairie Island has evaluated the Seabrook experience for generic implications under OE 020655.
- Applicability to Replacement Steam Generators is currently being evaluated per OE023071.
11/22/2002 Page 34
Question 9 Discuss your use or reliance on inspection probes (eddy current or ultrasonic) other than bobbin and typical rotating probes, if applicable.
Probes used for Prairie Island ISI inspection of steam generators are listed in Question 3 and are considered typical rotating probes.
11/22/2002 Page 35
Question 10 Describe in-situ pressure test plans and results, if applicable and available, including tube selection criteria.
o PI In Situ Screening Criteria (from H25.2)
Type of Indication Screening Criteria Uniform Wall Thinning (bobbin coil) > 50% TW Axial crack length > 0.30 inches Circumferential Indications > 200 degrees RPC Volumetric Indications > 0.75 inch long or >50% TW Axial Indications For Leakage > 2.5 Volts ID or >1.5 Volts OD and >0.1 inch long Bobbin Coil Indications For Leakage > 80% TW 11/22/2002 Page 36
Question 10 Response
"* Currently no candidate indications identified
"* ISPT will be performed, as necessary, based on the screening criteria
"* Initial Contingency assumed 5 In Situ Pressure Tests per SG 11/22/2002 Page 37
Question 11 Describe tube pull plans and preliminary results, if applicable and available; include tube selection criteria.
- Contingency plans are in place for tube pulls.
- Tube pulls will be considered, in the event indications are identified that are substantially higher than the structural limit from the ARC burst correlation.
11/22/2002 Page 38
Question 12 Discuss the assessment of tube integrity for the previous operating cycle (i.e., condition monitoring).
- Condition Monitoring Assessment is in progress - awaiting completion of ET exams
- Condition monitoring will be conducted in accordance with PI procedure H25.2 11/22/2002 Page 39
Question 13 Discuss the assessment of tube integrity for next operating cycle (i.e., operational assessment).
"* Contract in place with Foreline to perform Operational Assessment
"* Operational Assessment will be performed in accordance with PI procedure /
H25.4
"* Plan to use Addendum 5 to the SGDSM ODSCC Database for the 90 Day VARC report.
11/22/2002 Page 40
Question 14 Provide the schedule for steam generator related activities during the remainder of the current outage.
- ET exams scheduled for completion on November 25
- In-situ testing will be performed following ET exams, if necessary
- Plugging scheduled to be completed on November 27
- Sleeving and/or re-rolling contingencies would add additional time to the schedule 11/22/2002 Page 41