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{{#Wiki_filter:~Larry D. | {{#Wiki_filter:~Larry D. Smith Exeton Ge e ato ReuaoyAsuac aae 1650 Calvert Cliffs Parkway Lusby, MD 20657 410 495 5219 Office www.exeloncorp.com larry~smith2@exeloncorp.com TS 5.6.9 November 6, 2015 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Calvert Cliffs Nuclear Power Plant, Unit No. 2 Renewed Facility Operating License No. DPR-69 NRC Docket No. 50-318 | ||
==Subject:== | ==Subject:== | ||
Sprinpq 2015 -180 Day Steam Generator Report | |||
Sprinpq 2015 -180 Day Steam Generator Report | |||
==Reference:== | ==Reference:== | ||
: 1. Calvert Cliffs Nuclear Power Plant Units 1 and 2 Technical Specification 5.6. | : 1. Calvert Cliffs Nuclear Power Plant Units 1 and 2 Technical Specification 5.6.9 In accordance with Reference 1, Attachment (1) provides the results of the steam generator tube inspection conducted on Calvert Cliffs Unit 2 in 2015. This report includes the number and extent of tubes examined and indications identified. | ||
This revision was necessary to correct | This revision was necessary to correct the number of tubes with foreign object wear and to add clarifying information concerning the TW indication. | ||
This issue has been entered into our corrective action program.There are no regulatory commitments contained in this correspondence. | This issue has been entered into our corrective action program.There are no regulatory commitments contained in this correspondence. | ||
Should you have questions regarding this matter, please contact Mr. Larry D. Smith at(410) 495-5219. | Should you have questions regarding this matter, please contact Mr. Larry D. Smith at (410) 495-5219.Respectfully, Larry D. Smith Regulatory Assurance Manager LDS/PSF/bjm | ||
Respectfully, Larry D. | |||
==Attachment:== | ==Attachment:== | ||
(1) Steam Generator Tube Inspection Report, Calvert Cliffs Unit 2, Refueling Outage 21, Revision | (1) Steam Generator Tube Inspection Report, Calvert Cliffs Unit 2, Refueling Outage 21, Revision 1 cc: NRC Project Manager, Calvert Cliffs NRC Resident Inspector, Calvert Cliffs NRC Regional Administrator, Region I S. Gray, MD-DNR ATTACHMENT (1)STEAM GENERATOR TUBE INSPECTION REPORT, CALVERT CLIFFS UNIT 2, REFUELING OUTAGE 21, REVISION 1 Calvert Cliffs Nuclear Power Plant November 6, 2015 Exelon Generation Company, LLC Calvert Cliffs Nuclear Power Plant Unit 2 1650 Calvert Cliffs Parkway Lusby, MD 20657 Calvert Cliffs Unit 2 STEAM GENERATOR TUBE INSPECTION REPORT REFUELING OUTAGE 21 November 2015 Rev. 1 Page Ilof 31 Revisions Minor editorial corrections throughout document 5.3: 21 foreign object wear indications were Rev 1 detected in 14 tubes. This was corrected to 17 tubes.5.3 Clarified that the 36% ITW indication was the deepest new indication. | ||
Added deepest legacy Indication. | |||
Added deepest | Page 2 of 31 TABLE OF CONTENTS | ||
Page 2 of 31 TABLE OF CONTENTS | |||
==1.0 INTRODUCTION== | ==1.0 INTRODUCTION== | ||
................................................................................ | ................................................................................ | ||
4 2.0 THE SCOPE OF THE INSPECTIONS PERFORMED ON EACH SG (5.6.9.A).... | |||
5 3.0 DEGRADATION MECHANISMS FOUND (5.6.9.B)...................................... | |||
6 4.0 NONDESTRUCTIVE EXAMINATION TECIHNIQUES UTILIZED FOR EACH DEGRADATION MECHANISM (5.6.9.C) | |||
.......................................................... | .......................................................... | ||
6 4.1 TABLE 1 -NDE TECHNIQUES UTILIZED FOR IDENT7IFIED DEGRADATION........................................... | |||
6 5.0 LOCATION, ORIENTATION (IF LINEAR), AND MEASURED SIZES (IF AVAILABLE) | |||
AND MEASURED SIZES ( | |||
OF SERVICE INDUCED INDICATIONS (5.6.9.D) | OF SERVICE INDUCED INDICATIONS (5.6.9.D) | ||
..................... | ..................... | ||
7 5.1 FAN BAR WEAR ................................................................................................................. | |||
7 5.1.1 Table 2 -Fan Bar Wear Indication Summary ..................................................................... | |||
8 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth................................................................... | |||
8 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map ..................... | |||
:.......................................................... | :.......................................................... | ||
9 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map ............................................................................... | |||
9 5.2 LATTICE GRID SUPPORT WEAR............................................................................................. | |||
10 5.2.1 Table 3 -Summary of Lattice Grid Support Wear lndications | |||
................................................ | ................................................ | ||
10 5.3 FOREIGN OBJECT WEAR...................................................................................................... | |||
10 5.3.1 Table 4 -Summary of Foreign Object Wear ...................................................................... | |||
11 6.0 NUMBER OF TUBES PLUGGED DURING THE INSPECTION OUTAGE FOR EACH ACTIVE DEGRADATION MECHANISM (5.6.9.E).................................... | |||
11 7.0 TOTAL NUMBER AND PERCENTAGE OF TUBES PLUGGED TO DATE AND THlE EFEECTIVE PLUGGING PERCENTAGE IN EACH STEAM GENERATOR (5.6.9.F) | |||
................................................................................................... | ................................................................................................... | ||
12 7.1 TABLE 5- TUBE PLUGGING | |||
==SUMMARY== | |||
................................................................................... | |||
12 8.0 THE RESULTS OF CONDITION MONITORING, INCLUDING RESULTS OF TUBE PULLS AND IN-SITU TESTING (5.6.9.G) | |||
............................................... | ............................................... | ||
12 8.1 FAN BAR WEAR................................... | |||
............................................................................ | ............................................................................ | ||
12 8.2 FOREIGN OBJECT WEAR...................................................................................................... | |||
12 8.3 LATTICE GRID WEAR......................................................................................................... | |||
13 8.3.1 Figure 4 -Condition Monitoring Results for Fan Bar Wear................................................... | |||
14 8.3.2 Figure 5- Condition Monitoring for Foreign Object Wear ..................................................... | |||
1 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear........................................................ | |||
16 8.4 OPERATIONAL LEAKAGE CRITERION AND VALIDATION OF PREVIOUS OA ........................................ | |||
16 APPENDIX A- TYPICAL U-BEND SUPPORT SYSTEM ..................................... | |||
17 APPENDIX B CAL VERT CLIFFS U-2 TUBE SUPPORT LAYOUT......................... | |||
18 APPENDIX C -CC2R21 FAN BAR WEAR | |||
==SUMMARY== | |||
....................................... | |||
19 TABLE C-i 1:G21 FAN BAR WEAR | |||
==SUMMARY== | |||
.................................................................................... | |||
19 TABLE C- 2: SG22 FAN BAR WEAR | |||
==SUMMARY== | |||
.................................................................................... | |||
24 Page 3 of 31 Calvert Cliffs Nuclear Power Plant Unit 2 CC2R21 Spring 2015 Steam Generator Inspection | |||
==1.0 Introduction== | ==1.0 Introduction== | ||
Calvert Cliffs Nuclear Power Plant Unit 2 (CCNPP2) has two recirculating | Calvert Cliffs Nuclear Power Plant Unit 2 (CCNPP2) has two recirculating steam generators designed and fabricated by Babcock and Wilcox (B&W) of Cambridge, Ontario, Canada. These replacement steam generators (RSG's), SG21 and SG22 were installed in 2003.Each RSG contains 8471 tubes. Three tubes were plugged in SG 21 during manufacturing. | ||
The tubing material is thermally treated Inconel 690 having a nominal outer diameter (OD) of 0.75 inches and a nominal wall thickness of 0.042 inches. The RSG's were designed and fabricated to the ASME Boiler and Pressure Vessel Code, Section III, subsection NB (Class 1), 1989 Edition with no Addenda. All tubes with a bend radius of 12 inches or less (the first 18 rows) were thermally stress-relieved following bending to reduce the residual stress imparted during bending.The straight section of the tube bundle are supported by seven 410 stainless steel (SA-240 Type 410S) lattice grid supports. | |||
SG21 and SG22 | The fan Bar U-Bend support system incorporates sets of SA-240 Type 410S stainless steel Fan Bars on each side of the bundle as shown in Appendix A. Appendix B shows the tube support layout for U-2 Generators. | ||
The tubing material is thermally treated Inconel 690 having a | |||
All tubes with | |||
The fan Bar U-Bend support system incorporates sets of SA-240 Type 410S stainless steel Fan Bars on each side of the bundle | |||
Technical Specification (TS) 5.5.9.d provides the requirements for SG inspection frequencies and requires periodictube inspections be performed. | Technical Specification (TS) 5.5.9.d provides the requirements for SG inspection frequencies and requires periodictube inspections be performed. | ||
TS 5.5.9.d | TS 5.5.9.d requires that 100% of the Unit-2 tubes be inspected at sequential periods of 144, 120, 96, and thereafter 72 effective full power months (EFPM)During the CCNPP2 spring 2015 refueling outage (CC2R21) both Unit 2 steam generators (SG21 and SG22) were inspected in accordance with CCNPP TS 5.5.9. This was the fourth in-service inspection of the replacement steam generators. | ||
The SG's | The SG's had been in operation for 11.205 effective full power years (EFPY) at the time of the inspection. | ||
Below summarizes the results of the inspection in accordance with the 180- | Below summarizes the results of the inspection in accordance with the 180-Day reporting requirements of TS 5.6.9. Bold wording restates the TS requirement, followed by the required CC2R21 information. | ||
A report shall be submitted within 180 days after the initial entry into Mode | A report shall be submitted within 180 days after the initial entry into Mode 4 following completion of an inspection performed in accordance with the Specification 5.5.9, Steam Generator (SG) Program.Page 4 of 31 The report shall include: 2.0 The Scope of the inspections performed on each SG (5.6.9.a)o Eddy Current Bobbin probe examinations (both SG's)* 100% Full Length (FL) of all in-service tubes with a bobbin coil probe for tube-to-support wear at the fan bars and lattice grids and for potential foreign objects and associated wear.o Eddy Current Array Probe (both SG's)* 50% X-Probe examination of all in-service tubes (periphery tubes)from the bottom end of the tube to the 1 st lattice grid on both the HL and CL for potential foreign objects and associated wear.* In addition to the 50% of the in-service tubes that were examined by X-Probe as mentioned above, the following X-probe examinations were performed. | ||
* Inspect all previous PLPs (part not removed) plus a one | * Inspect all previous PLPs (part not removed) plus a one tube bounding examination of such tubes at the elevation of interest not covered by the baseline 50% peripheral X-probe scope* All new PLPs and foreign object wear indications between the tubesheet and first support plus a one-tube bounding examination | ||
* All foreign objects identified by secondary side | * All foreign objects identified by secondary side visual inspection plus a one-tube bounding examination o Special Interest inspection of bobbin and X-Probe indications with+PointTM.* Sizing of all foreign object wear detected by bobbin or X-probe* 10 deepest FBW bobbin indications in each RSG* All 3 wear indications detected at lattice supports in each RSG ( 2 in SG21 and i in SG22)* A sample of MBMs, DNTs, and DNGs as directed by B&W or CCNPP Engineering | ||
* Sizing of all foreign object wear detected by bobbin or X-probe* 10 deepest FBW bobbin indications in each RSG* All 3 wear indications detected at lattice supports in each RSG ( | |||
* All bobbin probe or X-P robe I-codes* Additional bobbin indications as directed by CCNPP Engineering | * All bobbin probe or X-P robe I-codes* Additional bobbin indications as directed by CCNPP Engineering | ||
* Additional indications as needed to meet operational assessment requirements for tube integrity, as identified by B&W Engineering o Visual Examination | * Additional indications as needed to meet operational assessment requirements for tube integrity, as identified by B&W Engineering o Visual Examination | ||
* Visual inspection of all installed tube plugs in both SGs | * Visual inspection of all installed tube plugs in both SGs in accordance with section 6.9 of the EPRI PWR Steam Generator Examination Guidelines, Rev 7. This included both welded and mechanical plugs.Page 5 of 31. | ||
* Visual inspections of the hot and cold leg channel heads including the divider plate/tubesheet interface, the entire bowl | * Visual inspections of the hot and cold leg channel heads including the divider plate/tubesheet interface, the entire bowl per Westinghouse NSAL 12-1 methods for evidence of cladding degradation and/or cracking oThe following secondary side inspections were performed (both SG's)* Secondary side visual inspection of tubesheet ,including the inner bundle passes, the annulus, and the no-tube lane regions* Secondary side visual inspection of the 1 st lattice grid support* Targeted inspection locations identified as PLP (Possible loose Part) by ECT* Visual Upper Bundle inspection | ||
,including the | * Visual inspection of moisture separators 3.0 Degradation mechanisms found (5.6.9.b)Three degradations mechanisms were confirmed to be present in the CCNPP U2 SG's. These are: 1) fan bar wear, 2) lattice grid support wear, and 3) foreign object wear. No other degradation mechanisms, including tube-to-tube wear, were detected.Lattice grid support wear (LGSW) had not been previously detected on U2, however as it has been found on the U1 SG's the presence of LGSW was not unexpected based on the CC2R21 degradation assessment. | ||
* Visual inspection of moisture separators 3.0 Degradation mechanisms found (5.6.9.b) | The visual inspection of the cladding, previously installed plugs, and divider plate found no degradation. | ||
Three degradations mechanisms were confirmed to be present in the CCNPP | |||
Lattice grid support wear (LGSW) had not been previously detected on U2,however as it has been found on the U1 SG's the presence of LGSW was | |||
The visual inspection of the cladding, previously installed plugs, and divider | |||
The secondary side visual inspections of the steam drum, upper bundle,1st lattice grid support, and moisture separators found no degradation. | The secondary side visual inspections of the steam drum, upper bundle,1st lattice grid support, and moisture separators found no degradation. | ||
4.0 Nondestructive examination techniques utilized for | 4.0 Nondestructive examination techniques utilized for each degradation mechanism (5.6.9..c) | ||
Table 1 below identifies NDE examination techniques utilized for each identified degradation mechanism. | Table 1 below identifies NDE examination techniques utilized for each identified degradation mechanism. | ||
4.1 Table I -NDE Techniques Utilized for Sizin Identified De | 4.1 Table I -NDE Techniques Utilized for Sizin Identified De radation Lattice Grid Support Wear Bobbin (%TW depth) 96004.1 MRPC +Point (length) 96910.1 Page 6 of 31 | ||
* The Array probe was the primary means of detecting foreign objects and foreign | * The Array probe was the primary means of detecting foreign objects and foreign object wear during the inspection. | ||
However, the +PointTM probe was used for further characterization and sizing of wear.** There are other EPRI techniques qualified for sizing of foreign object wear depending on the shape of the flaw. ETSS 27901.1 was selected based on the circumferential groove appearance of the foreign object wear indications detected during the U2R1 9 inspection 5.0 Location, orientation (if linear), and measured sizes (if available) of service induced indications (5.6.9.d)5.1 Fan Bar Wear Fan bar wear (FBW) is a mechanical degradation process which produces volumetric tube wear at the interface between the U-bend anti-vibration supports (fan bars) and the tubes. A total of 447 FBW indications were identified in the Calvert Cliffs Unit 2 RSGs during CC2R21. One hundred and four (104) of the 447 indications were newly reported during the CC2R21 outage. There were 44 and 60 new indications in SG21 and SG22, respectively. | |||
and measured sizes (if available) of service induced indications (5.6.9.d) 5.1 Fan Bar | The deepest repeat FBW indication was 30% 1W in 22 SG. Table 2 provides a summary of the fan bar wear indications from CC2R2I. The maximum depth among these indications was 30% TW which is consistent with results from previous inspections. | ||
The deepest repeat FBW indication was 30% 1W in 22 SG. Table 2 provides | Growth of the repeat indications was minimal and consistent with previous results.Figure 1 provides the distribution of fan bar wear depths for both steam generators as reported with the bobbin coil probe. As shown in the figure, SG22 contained more indications. | ||
Growth of the repeat indications was minimal | A majority of the indication in both SG's are less than 20% TW.Figures 2 and 3 provide tube map locations of the reported FBW. Although the tube maps shown in Figures 2 and 3 provide a view of the tubesheet primary face from the hot leg side, both the hot leg and cold leg FBW indications are included on each map. Most of the wear continues to occur in longer tubes (i.e., larger U-bend radius), clustered towards the center-most tube columns.Appendix C provides a complete list of FBW indications. | ||
A majority of the indication in both SG's are less | Page 7 of 31 5.1.1 Table 2 -Fan Bar Wear Indication Summary I 3. S 0 I-I~1 Total Number of In-Service Tubes Prior to CC2R21 8434 8439 Number of FBW Indications 154 293 Maximum Depth of FBW (%TW) 25% 30%Number of TSP Wear Indications | ||
clustered towards the center-most tube columns.Appendix C provides a complete list of FBW indications. | >40%TW 0 0 Number of Newly-Reported Indications 44 60 Number of Tubes Plugged due to FBW 0 0 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth 90 80 IOa 60**SG22 i5020 -........10 .....Q~. 40 40 d~ d~ ~ &., 4' .~' 40 -~~0 ~ 43&~, .'~EL~4o&~, -~'Depth In Percent Tha 11wf Page 8 of 31 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map 140 120 0 0.0o 0 0*00 0 0o°oTubes With Indications | ||
Page 7 of 31 5.1.1 Table 2 -Fan Bar Wear Indication | .. .............. ...........0 0 .. ..... ......... | ||
>40%TW 0 | ..... \ t ...0 60 40 20 0 0 20 40 60 80 100) 120 140 160 Column Number 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map 140 120 E S80 -60 +1 04 i\160O 40 20--0 80 100) 120 140 Column Number 0 20 40 60 Page 9 of 31 5.2 Lattice Grid Support Wear Three indications of wear related to the lattice grid supports were reported during the CC2R21 outage (two indications in SG21 and one indication in SG22). All three of these indications were inspected with +Point T M to confirm that the morphologies of the indications were consistent with lattice grid wear and not some other damage mechanism such as foreign object wear. After confirmation with +PointTM, all three indications were depth sized using the bobbin coil data and length sized with+Point T M .All three indications have a tapered flaw shape.This was the first occurrence of lattice grid wear at Calvert Cliffs Unit 2. However, this is not an unexpected occurrence since lattice grid wear has already been observed at Unit 1. The depths of the Unit 2 indications are consistent with the depths of the indications observed in Unit 1. Table 3 provides a listing of these indications. | ||
.. .............. ........... | 5.2.1 Table 3 -Summary of Lattice Grid Support Wear Indications 5 G22 102 i30 02C -1.74 to -1.24 10% TW 0.5" 5.3 Foreign Object Wear During the CC2R21 inspection, twenty-one (21) foreign object wear indications were detected in 17 tubes. These indications were reported as LPW (Loose Part Wear) in the eddy current database. | ||
..... \ t ... | Four (4) indications in three tubes were newly detected in CC2R21. The remainder were legacy and showed no change in size since previous inspections. | ||
5.2.1 Table 3 -Summary of Lattice Grid Support Wear Indications 5 G22 102 i30 02C -1.74 to -1.24 10% TW 0.5"5.3 Foreign Object | |||
Four (4) indications in three tubes were newly detected | |||
Three (3) of the new indications were identified on two tubes in SG21, these indications were in a cluster about 15 inches above the cold leg tubesheet. | Three (3) of the new indications were identified on two tubes in SG21, these indications were in a cluster about 15 inches above the cold leg tubesheet. | ||
The wear was | The wear was caused by weld slag that was still present at the time of inspection and has since been removed.One (1) of the new indications was on a tube in SG22. This was the deepest new indication detected during the CC2R21 inspections, sized at 36% TW. This indication was near the lower edge of the 04H lattice support. This indication was due to a foreign object based on its location between the contact points of the lattice grid. This indication was caused by a transient loose part which is no longer present based on ET inspection results. The overall deepest indication for SG22 is at Row 126 Col 116, and is 38% TW.This is a previously detected legacy indication. | ||
This indication was due to a | No growth was measured.Page 10 of 31 All LPW indications were sized below the site plugging limit. There were no objects present at non-plugged LPW tube locations from previous outages. Since no objects were present to cause further wear and all LPW %TW were less than the 40% tech spec. plugging limit, all 17 tubes were returned to service.Table 4 provides a summary of the foreign object wear indications seen in the Unit 2 RSGs.5.3.1 Table 4 -Summary of Foreign Object Wear SG1 1 6 TSH -.05to +.19 2724No SG21 12 66 TSH .37 to +.55 24 0.18 No SG21 12 162 TSH -.01to +.17 27 0.18 No SG21 13 65 TSH -.18to +.07 28 0.25 No SG21 14 66 TSH +.36 to +.54 19 0.18 No SG21 14 66 TSH +.36to +.54 17 0.18 No SG21 72 146 TSH +.13to +.31 34 0.18 No SG21 75 147 TSH +17.86 to0+18.09 19 0.23 No SG21 77 147 TSH +17.52 to +17.76 21 0.24 No SG21 77 149 TSH +20.59 to0+20.82 20 0.23 No SG21 137 73 TSC +14.89 to0+15.08 21 0.19 Yes SG21 137 75 TSC +14.4 to +14.58 24 0.18 Yes SG21 137 75 TSC +14.72 to0+14.79 19 0.07 Yes SG22 14 4 TSC +.32 to +.5 24 0.18 No SG22 17 1 TSC -.07to +.13 24 0.2 No SG22 18 2 TSC -.01to +.23 24 0.24 No SG22 82 42 04H -1.76 to -1.47 36 0.29 Yes SG22 112 82 04H +37.63 to +37.82 24 0.19 No SG22 124 116 TSC +12.58 to +12.85 18 0.27 No SG22 126 116 TSCI12.21 to 12.44 24 0.23 No SG22 126 116 TSC 12.52 to 12.76 38 0.24 No 6.0 Number of tubes plugged during the inspection active degradation mechanism (5.6.9.e)Zero (0) tubes were plugged during the CC2R21 outage.outage for each Page 11 of 31 7.0 Total number and percentage of tubes plugged to date and the effective plugging percentage in each steam generator (5,6.9.f)Table 5 provides the post CC2R21 outage tube plugging status of the CCNPP2 SG's.There are currently 37 tubes plugged in SG21 and 32 tubes plugged in SG22.7.1 Table 5 -Tube Plugging Summary SG21 847 37 S(0.437%). | ||
The overall deepest indication for SG22 is at Row 126 Col 116, and is 38% TW.This is a previously detected legacy indication. | SG22 8471 37 (0.4378%)Total 16,942 69 (0.407%)There are no sleeves installed in the CCNPP1 steam generators, therefore the effective plugging percentage is the same as stated Table 5 above.8.0 The results of condition monitoring, including results of tube pulls and in-situ testing (5.6.9.g)The condition monitoring assessment is summarized in Figures 4 through 6. These figures provide the condition monitoring limit curves corresponding to the NDE technique employed for each degradation type. All reported degradation falls below the applicable condition monitoring curve and therefore satisfies the Technical Specification structural performance criteria. | ||
No growth was measured. | No tube-pulls or in-situ pressure testing were required.8.1 Fan Bar Wear Based on the sizing parameters for this technique, the CM curve shown in Figure 4 was generated and documented in the Degradation Assessment (DA). Each of the fan bar wear indications were conservatively plotted at an axial length of 1.8 inches based on current and previous length sizing of the deepest indications. | ||
Page 10 of 31 All LPW indications were sized below the site plugging limit. There were no | As shown, all indications lie well below the CM curve. Hence, structural integrity of the fan bar wear indications is demonstrated. | ||
Since no | 8.2 Foreign Object Wear As documented in the DA, ETSS 27903.1 provides a lower CM limit compared to the other 2790X series of techniques. | ||
Zero (0) tubes were plugged during the CC2R21 outage.outage for | Hence, use of the CM limit curve from the DA is appropriate and conservative for the evaluation of foreign object wear at Calvert Cliffs Unit 2. Figure 5 shows the condition monitoring results for foreign object wear. As shown, all indications lie well below the CM curve. Hence, structural integrity of the foreign object wear indications is demonstrated. | ||
Table 5 provides the post CC2R21 outage tube plugging status of the CCNPP2 SG's.There are currently 37 tubes plugged in SG21 and 32 tubes plugged in SG22.7.1 Table 5 -Tube Plugging | Page 12 of 31 8.3 Lattice Grid Wear Based on the sizing parameters for the bobbin technique, the CM curve shown in Figure 6 was generated and documented in the DA. Since all three of the lattice grid wear indications were inspected with +PointTM, the lengths measured from the +PointTM and depths from bobbin inspections are reflected in the figure. As shown, all indications lie well below the CM curve. Hence, structural integrity of the lattice grid wear indications is demonstrated. | ||
SG22 8471 37 (0.4378%) | Some of the detected flaws had measured axial extents <0.25". For these cases, the flaws were evaluated for leakage integrity using the flaw model for uniform 360 degree thinning of finite axial extent. This is allowed per Section 9.6.3 of the EPRI SG Integrity Assessment Guideline for situations involvng pressure loading only. Using the uniform thinning equation from Section 5.3.2 of the EPRI SG Flaw Handbook the CM limit of a flaw with an axial length of 0.25" is 64.1%TW. Since none of the detected indications approached this depth, accident leakage integrity for these shorter volumetric flaws is also confirmed. | ||
Total 16,942 69 (0.407%)There are no sleeves installed in the CCNPP1 steam generators, therefore the effective plugging percentage is the same as stated Table 5 above.8.0 The results of condition monitoring, including results of | Page 13 of 31 8.3.1 Figure 4- Condition Monitoring Results for Fan Bar Wear 100 SNote: CM limit curve is based on 90structural lengths and depths.9 .....Indication depths are conservatively i plotted using maximum depths.8 0 .. ..... .. ..... ..... ... ........... | ||
The condition monitoring assessment is summarized in Figures 4 through 6. | ... ...... ... .[--Limit (96004.1)Fan Bar Wear Indications 70 -=3*60 60 I-50 -2. 401 S301 20 -10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.82 Page 14 of 31 8.3.2 Figure 5 -Condition Monitoring for Foreign Object Wear 100 90 1 704--...... | ||
No tube-pulls or in-situ pressure testing were required. | Note 1: CM limit curve is based on structural lengths and depths. Indication depths are conservatively plotted using maximum depths.Note 2: CM limit curve shown is for ETSS 27903.1 as documented in the DA.This ETSS gives a lower CM limit that ETSS 27901.1 and is, therefore, conservative for this application. | ||
8.1 Fan Bar | a.*1 60 40 30*20 I-10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.8 2 Page 15 of 31 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear 100 80 -70 I Note: CM limit curve is based on structural lengths and depths.Indication depths are conservatively plotted using maximum depths.Limit (96004.1)* Lattice Grid Wear Indications 360 4J a..,:, 30 I i L 20!10*4 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1,82 8.4 Operational Leakage Criterion and Validation of Previous OA The operational leakage criterion was also satisfied by the absence of any measureable primary to secondary leakage since the previous inspection. | ||
As shown, all indications lie well below the CM curve. Hence, structural integrity of the fan bar wear indications | The results of the 2015 inspection and the condition monitoring assessment confirm that the 2011 operational assessment was appropriately bounding.Page 16 of 31 APPENDIX A -Typical U-Bend Support System CLAMPING BARS*TIE 11UBES TUJBE IN PLANE DIRECION FLAT BAR ThRE OUT OF PLANE DIR.E6rION Page 17 of 31 Appendix B Calvert Cliffs U-2 Tube Support Layout FI N RN 3 c'i ~ ii____C&, !3, I HI ___ ___ __I I I i~ii iI I f-JT"II t i Page 18 of 31 APPENDIX C -002R21 Fan Bar Wear Summary Table C- 1: SG21 Fan Bar Wear Summary 25 163 9 F07 2.00 29 159 13 F06 1.66 30 162 7 F07 -0.93 34 6 15 F06 -1.15 44 6 9 F06 1.70 45 79 7 F07 0.64 48 6 9 F06 1.91 48 8 7 F06 1.86 52 126 10 FO8 -0.75 57 107 14 F08 1.76 58 98 8 F05 -1.79 60 80 7 F06 0.62 63 69 6 F09 2.17 69 115 5 F04 -1.99 74 78 10 FO8 1.00 75 75 9 F08 0.88 76 76 9 F07 -0.78 77 67 7 F08 0.74 77 75 10 F08 0.74 77 79 13 F08 0.74 77 83 11 F08 0.50 80 74 8 F08 1.96 80 76 11 F07 -0.67 80 78 12 FOB 1.92 81 75 7 FO8 0.85 81 79 15 FOB 0.85 81 97 10 FOB 1.75 82 84 5 F06 -1.07 82 94 9 FOB 0.77 83 67 B FOB 0.70 83 79 12 FOB 0.71 83 97 7 FOB 1.91 Page 19 of 31 84 76 11 F07 -0.83 85 75 9 FO8 0.81 85 75 8 F07 1.83 85 79 16 FO8 0.81 85 93 11 FO8 1.77 86 84 10 F06 -0.60 86 88 6 FO8 0.81 86 94 11 F08 0.74 87 67 8 FOB 0.72 87 75 9 FOB 0.84 87 75 5 F07 1.79 87 79 9 F08 0.79 87 83 8 FOB -0.58 87 83 6 F07 -0.05 87 83 7 F06 0.00 87 87 13 F08 1.72 87 93 14 FOB 1.77 87 97 8 FO8 1.98 88 74 7 F08 2.04 88 78 7 F06 1.14 89 75 15 F06 -0.65 89 87 9 F08 1.93 89 87 4 F07 1.16 89 87 7 F06 -1.74 89 93 7 F06 -1.75 89 93 8 F08 1.79 89 101 6 F05 -0.83 90 74 9 F08 1.97 90 76 6 F07 -0.79 91 75 8 FOB 0.79 91 75 7 F06 -0.63 92 78 13 F08 1.81 92 88 8 F06 -0.63 93 73 11 FOB 0.84 93 83 12 F06 -0.44 93 87 8 FOB 1.83 94 74 12 F06 -1.67 94 78 15 FOB 1.65 Page 20Oof 31 94 82 10 F06 -16 95 77 8 F06 -1.55 95 83 9 F08 -0.55 95 87 19 F08 1.89 95 87 10 F09 0.83 95 99 8 F05 -1.48 96 78 8 F08 1.52 96 80 9 F08 -1.97 97 75 10 F06 -0.60 97 75 10 F07 1.50 97 83 5 F07 0.00 97 83 10 F08 0.51 98 74 10 F06 -1.71 98 74 8 F08 1.92 98 76 8 F07 -0.65 98 82 9 F08 1.92 98 82 10 F06 -1.67 98 88 8 F08 0.86 99 75 9 F07 1.76 99 83 9 F06 -0.49 99 83 9 F07 -0.56 99 83 9 F08 -0.56 99 87 18 F06 -1.21 99 87 8 F07 0.77 100 80 8 F06 -1.64 101 75 7 F09 -1.44 101 75 20 F06 -0.58 101 75 15 F07 0.90 101 79 9 F08 0.88 101 79 7 F02 -2.02 101 79 10 F06 -0.65 101 79 7 F07 1.92 101 81 8 F07 -0.79 101 83 5 F06 0.09 101 83 8 F07 0.05 101 83 10 F08 -0.56 101 83 5 FO5 0.00 101 87 11 F06 -1.72 101 87 13 F07 0.72 Page 21 of 31 102 82 5 F07 -13 102 88 8 F06 -0.70 102 90 10 F06 -0.69 103 83 10 F06 0.62 103 87 9 F06 -1.67 103 87 15 F07 0.76 103 91 8 F06 -1.71 104 78 9 F07 0.81 104 78 9 F08 1.85 104 84 9 F06 -0.60 104 86 7 F06 -0.70 104 88 15 FO5 -1.25 104 88 22 F06 -1.11 104 88 7 F07 1.78 105 79 9 F07 1.87 105 83 14 F07 0.00 105 87 9 F07 0.81 106 76 20 F06 1.16 106 76 6 F07 -1.28 106 78 8 F07 0.79 106 88 9 F08 0.79 106 90 10 F06 -0.70 107 75 9 F07 1.72 107 83 10 F06 0.49 107 83 12 F07 0.00 107 85 8 F06 0.74 107 87 19 F07 0.74 108 74 8 F07 0.78 108 76 25 F06 1.25 108 90 12 F06 -0.74 110 76 6 F06 1.20 110 88 9 F06 -0.69 110 90 8 F06 -0.56 111 75 17 F06 -0.79 111 93 7 F07 0.77 112 90 14 F06 -0.67 113 87 10 F07 0.78 114 76 16 F06 -0.81 117 89 18 F06 -1.28 Page 22 of 31 119 87 16 F07 07 122 88 7 F09 1.83 123 89 7 F06 -1.86 132 92 5 F06 1.25 133 91 11 F02 0.88 TotaI:I 154[ I___Page 23 of 31 Table C- 2: SG22 Fan Bar Wear Summary S, StT Se[e _,t 22 6 10 F07 -0.23 37 35 7 F07 1.82 40 28 8 F09 -0.32 44 140 8 F07 -0.72 49 29 8 F07 1.80 61 111 11 F08 1.79 69 83 8 F08 -0.55 70 54 7 F06 -1.64 70 82 8 F07 0.89 70 82 8 F06 -1.82 72 64 8 F08 1.91 72 72 11 F08 2.12 72 82 7 F08 1.94 72 92 11 F08 0.70 73 81 6 F07 0.02 73 91 16 F08 1.65 74 82 8 F06 -1.80 74 82 4 F07 0.81 74 82 8 FOB 1.94 74 94 13 F08 0.80 75 73 8 F08 0.76 75 81 8 F07 -0.78 75 93 7 F08 1.85 76 64 9 F08 1.99 76 72 10 F06 -1.75 76 72 16 FOB 1.89 76 82 8 F07 0.81 76 82 9 FOB 1.92 76 82 9 F06 -1.69 76 98 10 FOB 0.81 77 65 13 FOB 0.79 77 69 8 FOB 0.81 77 73 9 F08 0.79 77 81 8 F07 -0.78 78 64 8 F08 1.88 78 82 13 F06 -1.80 Page 24 of 31 S S~ 656 T l79 81 13 F07 -1.34 79 83 5 F07 -0.24 79 89 8 F07 0.74 79 91 9 F08 1.84 79 93 28 F08 1.42 80 64 8 F08 -1.78 80 64 9 F09 -1.92 80 80 7 F06 -1.74 80 82 8 F06 -1.81 80 82 8 F05 -0.79 81 63 8 F08 -0.91 81 91 10 F08 1.79 82 82 10 F07 0.92 82 82 7 F06 -1.87 82 84 9 F06 1.34 82 84 8 F08 0.82 82 94 9 F08 0.80 83 73 11 F07 1.69 83 73 20 F08 0.70 83 75 14 F02 0.77 83 81 10 F07 -1.27 83 91 13 F08 1.89 84 80 7 F06 -1.68 84 92 19 F08 0.78 84 94 21 F08 0.83 85 65 10 F08 0.79 85 79 11 F08 0.83 85 79 7 F08 -1.24 86 44 7 FO5 1.23 86 72 9 F05 -0.87 86 72 11 F06 -1.69 86 74 11 F06 -1.70 86 92 12 F08 0.78 86 94 16 F08 0.71 87 65 14 F08 0.74 87 83 17 F08 0.00 87 83 8 F06 -0.09 87 83 25 F07 0.05 88 76 9 F06 .1.81 Page 25 of 31 IS~ S S..A "11t I r 88 76 9 F05 1.85 88 78 9 F06 -1.22 88 82 9 EQ5 1.91 88 82 14 F06 1.84 88 84 9 F07 -0.87 88 92 10 F08 0.73 89 65 16 F08 0.79 89 69 12 F08 0.80 89 73 20 F08 0.76 89 81 11 F06 -0.74 89 83 8 F08 -0.56 89 83 10 F06 0.49 89 83 6 F05 0.47 89 83 6 F07 0.54 89 89 12 F08 -1.36 90 82 6 F06 -1.71 91 65 23 F08 0.86 91 81 7 FOG -0.74 91 83 6 F07 0.00 91 103 8 FO5 -0.80 92 76 10 FOG 1.82 92 88 6 F06 0.71 93 73 10 F06 -0.76 93 79 9 FOG -0.74 93 81 9 F06 -0.71 93 83 10 F06 0.45 93 83 9 F07 0.50 93 91 9 F08 1.77 93 93 8 F08 1.77 93 97 8 F08 1.79 94 76 10 FOG 1.77 94 80 9 FOG -1.83 94 82 4 F07 0.78 94 82 19 FOG -1.34 94 86 7 F06 0.62 94 92 12 F08 0.81 94 94 11 F08 0.74 95 81 7 F07 -1.15 95. 83 6 FOG 0.12 Page 26 of 31. | ||
8.2 Foreign Object | 95 83 12 F07 0.42 95 93 7 FO8 1.70 96 80 7 F06 -1.77 96 82 10 F06 1.31 96 82 6 F07 -1.31 96 84 20 F07 1.25 96 86 7 F06 0.00 96 90 5 FOB -1.37 97 25 7 F06 0.81 97 73 9 F06 -0.78 97 75 9 F06 -0.80 97 77 11 F06 -0.78 97 79 11 F06 -0.69 97 81 5 F06 1.34 97 81 4 F08 -1.30 97 81 9 F07 -1.30 98 72 9 F08 1.84 98 76 10 F06 1.67 98 78 13 F08 1.76 98 78 7 F07 0.76 98 82 8 F07 0.81 98 84 6 F06 -0.87 98 94 7 F08 0.76 99 71 14 F08 -0.74 99 77 18 F06 -0.79 99 81 7 F07 -0.81 99 81 7 F06 -0.76 100 76 8 F06 -1.92 100 78 11 F08 -1.90 100 78 8 F07 0.72 100 78 7 F06 -1.81 100 82 14 F07 0.76 100 82 10 FOB 1.89 100 82 16 F06 -1.29 100 84 7 F07 1.34 100 88 10 F07 1.79 101 77 11 F06 -0.77 101 79 10 F07 1.82 101 81 9 F06 -0.62 Page 27 of 31 101 85 9 F09 1.30 101 87 8 F07 0.76 101 89 6 F09 0.66 102 76 13 F06 1.69 102 76 10 F07 -1.23 102 80 7 F08 2.03 102 82 7 F06 -1.69 102 82 10 F09 0.74 102 84 6 F07 1.79 102 86 8 F02 0.78 103 77 14 F06 -0.72 103 79 8 F07 1.73 103 79 11 F06 -0.69 103 81 8 F06 -0.72 103 81 6 F08 -1.18 103 83 15 F06 0.47 103 83 5 F07 -0.09 103 85 12 F08 1.30 103 87 11 F07 0.66 103 87 6 F09 0.71 104 82 11 F07 0.76 104 82 8 F09 0.69 104 82 9 F06 -1.92 104 84 10 F07 1.78 104 94 17 F06 -1.18 105 67 9 F07 -1.20 105 75 13 F06 -0.78 105 77 15 F06 -0.76 105 79 20 F06 -0.71 105 79 13 F07 1.84 105 81 9 F07 1.81 105 81 14 F08 1.39 105 81 11 F06 -0.70 105 83 14 F07 0.45 105 83 9 F06 0.50 105 83 7 FO5 -0.05 105 87 8 F01 0.53 106 80 6 F07 1.20 106 82 13 F06 -1.77 Page 28 of 31 S S 106 82 18 F07 0.71 106 84 5 FO8 -1.45 106 90 22 F07 1.20 107 75 14 F06 -0.77 107 77 12 F06 -0.86 107 79 8 F06 -0.88 107 81 12 FOB -1.40 107 81 21 F06 -0.72 107 83 4 F06 -0.02 107 83 5 FO5 0.02 107 83 12 F07 -0.02 107 85 11 F09 0.83 107 85 8 F06 1.18 107 93 8 F07 0.81 108 74 6 F06 -1.81 108 76 9 F09 0.76 108 76 7 FO8 1.39 108 82 11 F08 1.34 108 82 20 F07 0.76 108 82 11 F09 0.74 108 84 14 F07 1.77 108 84 11 F06 -0.71 108 86 24 F06 -1.18 108 86 6 F08 1.25 108 86 12 F07 1.68 108 90 6 F06 -0.73 109 75 16 F06 -0.86 109 77 22 F06 -0.78 109 79 24 F06 -0.73 109 81 15 F08 -1.18 109 81 8 F07 -1.37 109 81 15 F06 -0.86 109 83 6 F06 0.02 109 83 7 F07 -0.14 109 85 17 F07 -1.35 109 87 12 F07 0.66 110 78 13 F07 0.76 110 82 9 F07 0.73 110 90 8 FOB -1.44 Page 29 of 31. | ||
Hence, use of the CM limit curve from the DA | 111 73 26 F06 -1.39 111 75 22 F06 -0.57 111 77 28 FOG -0.76 111 79 18 FOG -0.69 111 79 9 F07 1.84 111 81 14 FOG -0.76 111 111 9 F03 -1.16 112 72 11 F08 1.33 112 78 13 F07 0.64 112 86 10 F06 -0.69 113 75 12 F06 -0.76 113 77 30 F06 -0.73 113 81 13 FOG -1.30 113 81 9 F08 0.83 113 83 10 F07 0.50 113 83 8 FOG 0.48 113 91 20 F02 -2.18 114 76 4 FOG 1.27 114 78 8 F07 0.72 114 82 9 FOG 1.31 114 84 15 F06 -1.21 114 88 17 F05 1.36 115 73 7 FOG -0.72 115 77 8 FOG -0.76 115 81 7 F06 1.13 115 81 5 F07 -1.29 115 83 7 F07 0.45 115 83 9 FOG 0.45 115 93 10 F07 0.65 116 82 22 F07 1.20 116 84 10 F08 -1.84 117 83 18 F06 0.00 117 83 7 F08 0.14 117 83 7 FO5 0.00 117 91 18 F07 1.29 119 81 13 FOG -0.69 120 82 5 F08 1.35 120 88 12 F08 -1.25 121 75 7 FOG -0.73 Page 30 of 31 121 83 11 F08 0.43 121 87 8 F07 0.71 122 74 9 F07 0.69 123 77 7 F06 -0.81 123 81 11 F07 1.67 123 83 26 F07 0.12 123 83 4 EQ5 -0.07 123 83 11 F06 0.62 124 76 9 F06 0.67 124 82 5 F09 -1.60 124 82 11 F08 -1.46 124 82 13 F06 -1.41 125 91 12 F03 -2.06 126 82 12 F07 1.26 127 83 6 F07 0.07 128 92 12 F08 -1.21 130 92 11 F06 1.74 131 75 9 F06 -0.92 131 83 5 F08 0.09 132 76 6 F08 -1.32 132 80 5 F05 -1.23 132 92 10 F03 -1.83 135 83 12 F07 0.16 Total: 293 Page 31 of 31 | ||
Page 12 of 31 8.3 Lattice Grid | ~Larry D. Smith Exeton Ge e ato ReuaoyAsuac aae 1650 Calvert Cliffs Parkway Lusby, MD 20657 410 495 5219 Office www.exeloncorp.com larry~smith2@exeloncorp.com TS 5.6.9 November 6, 2015 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Calvert Cliffs Nuclear Power Plant, Unit No. 2 Renewed Facility Operating License No. DPR-69 NRC Docket No. 50-318 | ||
Some of the detected flaws had measured axial extents <0.25". For these cases, | |||
Since none of the detected indications approached this depth, accident leakage integrity for these shorter volumetric flaws | |||
Page 13 of 31 8.3.1 Figure 4- Condition Monitoring Results for Fan Bar | |||
... ...... ... .[--Limit (96004.1) | |||
Fan Bar Wear Indications 70 -=3*60 | |||
Note 1: CM limit curve is based | |||
a.* | |||
* Lattice Grid Wear Indications | |||
The results of the 2015 inspection and the condition monitoring assessment confirm | |||
Page 16 of 31 APPENDIX A -Typical U-Bend Support | |||
95 83 12 F07 0. | |||
111 73 26 F06 -1. | |||
~Larry D. | |||
==Subject:== | ==Subject:== | ||
Sprinpq 2015 -180 Day Steam Generator Report | |||
Sprinpq 2015 -180 Day Steam Generator Report | |||
==Reference:== | ==Reference:== | ||
: 1. Calvert Cliffs Nuclear Power Plant Units 1 and 2 Technical Specification 5.6. | : 1. Calvert Cliffs Nuclear Power Plant Units 1 and 2 Technical Specification 5.6.9 In accordance with Reference 1, Attachment (1) provides the results of the steam generator tube inspection conducted on Calvert Cliffs Unit 2 in 2015. This report includes the number and extent of tubes examined and indications identified. | ||
This revision was necessary to correct | This revision was necessary to correct the number of tubes with foreign object wear and to add clarifying information concerning the TW indication. | ||
This issue has been entered into our corrective action program.There are no regulatory commitments contained in this correspondence. | This issue has been entered into our corrective action program.There are no regulatory commitments contained in this correspondence. | ||
Should you have questions regarding this matter, please contact Mr. Larry D. Smith at(410) 495-5219. | Should you have questions regarding this matter, please contact Mr. Larry D. Smith at (410) 495-5219.Respectfully, Larry D. Smith Regulatory Assurance Manager LDS/PSF/bjm | ||
Respectfully, Larry D. | |||
==Attachment:== | ==Attachment:== | ||
(1) Steam Generator Tube Inspection Report, Calvert Cliffs Unit 2, Refueling Outage 21, Revision | (1) Steam Generator Tube Inspection Report, Calvert Cliffs Unit 2, Refueling Outage 21, Revision 1 cc: NRC Project Manager, Calvert Cliffs NRC Resident Inspector, Calvert Cliffs NRC Regional Administrator, Region I S. Gray, MD-DNR ATTACHMENT (1)STEAM GENERATOR TUBE INSPECTION REPORT, CALVERT CLIFFS UNIT 2, REFUELING OUTAGE 21, REVISION 1 Calvert Cliffs Nuclear Power Plant November 6, 2015 Exelon Generation Company, LLC Calvert Cliffs Nuclear Power Plant Unit 2 1650 Calvert Cliffs Parkway Lusby, MD 20657 Calvert Cliffs Unit 2 STEAM GENERATOR TUBE INSPECTION REPORT REFUELING OUTAGE 21 November 2015 Rev. 1 Page Ilof 31 Revisions Minor editorial corrections throughout document 5.3: 21 foreign object wear indications were Rev 1 detected in 14 tubes. This was corrected to 17 tubes.5.3 Clarified that the 36% ITW indication was the deepest new indication. | ||
Added deepest legacy Indication. | |||
Added deepest | Page 2 of 31 TABLE OF CONTENTS | ||
Page 2 of 31 TABLE OF CONTENTS | |||
==1.0 INTRODUCTION== | ==1.0 INTRODUCTION== | ||
................................................................................ | ................................................................................ | ||
4 2.0 THE SCOPE OF THE INSPECTIONS PERFORMED ON EACH SG (5.6.9.A).... | |||
5 3.0 DEGRADATION MECHANISMS FOUND (5.6.9.B)...................................... | |||
6 4.0 NONDESTRUCTIVE EXAMINATION TECIHNIQUES UTILIZED FOR EACH DEGRADATION MECHANISM (5.6.9.C) | |||
.......................................................... | .......................................................... | ||
6 4.1 TABLE 1 -NDE TECHNIQUES UTILIZED FOR IDENT7IFIED DEGRADATION........................................... | |||
6 5.0 LOCATION, ORIENTATION (IF LINEAR), AND MEASURED SIZES (IF AVAILABLE) | |||
AND MEASURED SIZES ( | |||
OF SERVICE INDUCED INDICATIONS (5.6.9.D) | OF SERVICE INDUCED INDICATIONS (5.6.9.D) | ||
..................... | ..................... | ||
7 5.1 FAN BAR WEAR ................................................................................................................. | |||
7 5.1.1 Table 2 -Fan Bar Wear Indication Summary ..................................................................... | |||
8 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth................................................................... | |||
8 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map ..................... | |||
:.......................................................... | :.......................................................... | ||
9 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map ............................................................................... | |||
9 5.2 LATTICE GRID SUPPORT WEAR............................................................................................. | |||
10 5.2.1 Table 3 -Summary of Lattice Grid Support Wear lndications | |||
................................................ | ................................................ | ||
10 5.3 FOREIGN OBJECT WEAR...................................................................................................... | |||
10 5.3.1 Table 4 -Summary of Foreign Object Wear ...................................................................... | |||
11 6.0 NUMBER OF TUBES PLUGGED DURING THE INSPECTION OUTAGE FOR EACH ACTIVE DEGRADATION MECHANISM (5.6.9.E).................................... | |||
11 7.0 TOTAL NUMBER AND PERCENTAGE OF TUBES PLUGGED TO DATE AND THlE EFEECTIVE PLUGGING PERCENTAGE IN EACH STEAM GENERATOR (5.6.9.F) | |||
................................................................................................... | ................................................................................................... | ||
12 7.1 TABLE 5- TUBE PLUGGING | |||
==SUMMARY== | |||
................................................................................... | |||
12 8.0 THE RESULTS OF CONDITION MONITORING, INCLUDING RESULTS OF TUBE PULLS AND IN-SITU TESTING (5.6.9.G) | |||
............................................... | ............................................... | ||
12 8.1 FAN BAR WEAR................................... | |||
............................................................................ | ............................................................................ | ||
12 8.2 FOREIGN OBJECT WEAR...................................................................................................... | |||
12 8.3 LATTICE GRID WEAR......................................................................................................... | |||
13 8.3.1 Figure 4 -Condition Monitoring Results for Fan Bar Wear................................................... | |||
14 8.3.2 Figure 5- Condition Monitoring for Foreign Object Wear ..................................................... | |||
1 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear........................................................ | |||
16 8.4 OPERATIONAL LEAKAGE CRITERION AND VALIDATION OF PREVIOUS OA ........................................ | |||
16 APPENDIX A- TYPICAL U-BEND SUPPORT SYSTEM ..................................... | |||
17 APPENDIX B CAL VERT CLIFFS U-2 TUBE SUPPORT LAYOUT......................... | |||
18 APPENDIX C -CC2R21 FAN BAR WEAR | |||
==SUMMARY== | |||
....................................... | |||
19 TABLE C-i 1:G21 FAN BAR WEAR | |||
==SUMMARY== | |||
.................................................................................... | |||
19 TABLE C- 2: SG22 FAN BAR WEAR | |||
==SUMMARY== | |||
.................................................................................... | |||
24 Page 3 of 31 Calvert Cliffs Nuclear Power Plant Unit 2 CC2R21 Spring 2015 Steam Generator Inspection | |||
==1.0 Introduction== | ==1.0 Introduction== | ||
Calvert Cliffs Nuclear Power Plant Unit 2 (CCNPP2) has two recirculating | Calvert Cliffs Nuclear Power Plant Unit 2 (CCNPP2) has two recirculating steam generators designed and fabricated by Babcock and Wilcox (B&W) of Cambridge, Ontario, Canada. These replacement steam generators (RSG's), SG21 and SG22 were installed in 2003.Each RSG contains 8471 tubes. Three tubes were plugged in SG 21 during manufacturing. | ||
The tubing material is thermally treated Inconel 690 having a nominal outer diameter (OD) of 0.75 inches and a nominal wall thickness of 0.042 inches. The RSG's were designed and fabricated to the ASME Boiler and Pressure Vessel Code, Section III, subsection NB (Class 1), 1989 Edition with no Addenda. All tubes with a bend radius of 12 inches or less (the first 18 rows) were thermally stress-relieved following bending to reduce the residual stress imparted during bending.The straight section of the tube bundle are supported by seven 410 stainless steel (SA-240 Type 410S) lattice grid supports. | |||
SG21 and SG22 | The fan Bar U-Bend support system incorporates sets of SA-240 Type 410S stainless steel Fan Bars on each side of the bundle as shown in Appendix A. Appendix B shows the tube support layout for U-2 Generators. | ||
The tubing material is thermally treated Inconel 690 having a | |||
All tubes with | |||
The fan Bar U-Bend support system incorporates sets of SA-240 Type 410S stainless steel Fan Bars on each side of the bundle | |||
Technical Specification (TS) 5.5.9.d provides the requirements for SG inspection frequencies and requires periodictube inspections be performed. | Technical Specification (TS) 5.5.9.d provides the requirements for SG inspection frequencies and requires periodictube inspections be performed. | ||
TS 5.5.9.d | TS 5.5.9.d requires that 100% of the Unit-2 tubes be inspected at sequential periods of 144, 120, 96, and thereafter 72 effective full power months (EFPM)During the CCNPP2 spring 2015 refueling outage (CC2R21) both Unit 2 steam generators (SG21 and SG22) were inspected in accordance with CCNPP TS 5.5.9. This was the fourth in-service inspection of the replacement steam generators. | ||
The SG's | The SG's had been in operation for 11.205 effective full power years (EFPY) at the time of the inspection. | ||
Below summarizes the results of the inspection in accordance with the 180- | Below summarizes the results of the inspection in accordance with the 180-Day reporting requirements of TS 5.6.9. Bold wording restates the TS requirement, followed by the required CC2R21 information. | ||
A report shall be submitted within 180 days after the initial entry into Mode | A report shall be submitted within 180 days after the initial entry into Mode 4 following completion of an inspection performed in accordance with the Specification 5.5.9, Steam Generator (SG) Program.Page 4 of 31 The report shall include: 2.0 The Scope of the inspections performed on each SG (5.6.9.a)o Eddy Current Bobbin probe examinations (both SG's)* 100% Full Length (FL) of all in-service tubes with a bobbin coil probe for tube-to-support wear at the fan bars and lattice grids and for potential foreign objects and associated wear.o Eddy Current Array Probe (both SG's)* 50% X-Probe examination of all in-service tubes (periphery tubes)from the bottom end of the tube to the 1 st lattice grid on both the HL and CL for potential foreign objects and associated wear.* In addition to the 50% of the in-service tubes that were examined by X-Probe as mentioned above, the following X-probe examinations were performed. | ||
* Inspect all previous PLPs (part not removed) plus a one | * Inspect all previous PLPs (part not removed) plus a one tube bounding examination of such tubes at the elevation of interest not covered by the baseline 50% peripheral X-probe scope* All new PLPs and foreign object wear indications between the tubesheet and first support plus a one-tube bounding examination | ||
* All foreign objects identified by secondary side | * All foreign objects identified by secondary side visual inspection plus a one-tube bounding examination o Special Interest inspection of bobbin and X-Probe indications with+PointTM.* Sizing of all foreign object wear detected by bobbin or X-probe* 10 deepest FBW bobbin indications in each RSG* All 3 wear indications detected at lattice supports in each RSG ( 2 in SG21 and i in SG22)* A sample of MBMs, DNTs, and DNGs as directed by B&W or CCNPP Engineering | ||
* Sizing of all foreign object wear detected by bobbin or X-probe* 10 deepest FBW bobbin indications in each RSG* All 3 wear indications detected at lattice supports in each RSG ( | |||
* All bobbin probe or X-P robe I-codes* Additional bobbin indications as directed by CCNPP Engineering | * All bobbin probe or X-P robe I-codes* Additional bobbin indications as directed by CCNPP Engineering | ||
* Additional indications as needed to meet operational assessment requirements for tube integrity, as identified by B&W Engineering o Visual Examination | * Additional indications as needed to meet operational assessment requirements for tube integrity, as identified by B&W Engineering o Visual Examination | ||
* Visual inspection of all installed tube plugs in both SGs | * Visual inspection of all installed tube plugs in both SGs in accordance with section 6.9 of the EPRI PWR Steam Generator Examination Guidelines, Rev 7. This included both welded and mechanical plugs.Page 5 of 31. | ||
* Visual inspections of the hot and cold leg channel heads including the divider plate/tubesheet interface, the entire bowl | * Visual inspections of the hot and cold leg channel heads including the divider plate/tubesheet interface, the entire bowl per Westinghouse NSAL 12-1 methods for evidence of cladding degradation and/or cracking oThe following secondary side inspections were performed (both SG's)* Secondary side visual inspection of tubesheet ,including the inner bundle passes, the annulus, and the no-tube lane regions* Secondary side visual inspection of the 1 st lattice grid support* Targeted inspection locations identified as PLP (Possible loose Part) by ECT* Visual Upper Bundle inspection | ||
,including the | * Visual inspection of moisture separators 3.0 Degradation mechanisms found (5.6.9.b)Three degradations mechanisms were confirmed to be present in the CCNPP U2 SG's. These are: 1) fan bar wear, 2) lattice grid support wear, and 3) foreign object wear. No other degradation mechanisms, including tube-to-tube wear, were detected.Lattice grid support wear (LGSW) had not been previously detected on U2, however as it has been found on the U1 SG's the presence of LGSW was not unexpected based on the CC2R21 degradation assessment. | ||
* Visual inspection of moisture separators 3.0 Degradation mechanisms found (5.6.9.b) | The visual inspection of the cladding, previously installed plugs, and divider plate found no degradation. | ||
Three degradations mechanisms were confirmed to be present in the CCNPP | |||
Lattice grid support wear (LGSW) had not been previously detected on U2,however as it has been found on the U1 SG's the presence of LGSW was | |||
The visual inspection of the cladding, previously installed plugs, and divider | |||
The secondary side visual inspections of the steam drum, upper bundle,1st lattice grid support, and moisture separators found no degradation. | The secondary side visual inspections of the steam drum, upper bundle,1st lattice grid support, and moisture separators found no degradation. | ||
4.0 Nondestructive examination techniques utilized for | 4.0 Nondestructive examination techniques utilized for each degradation mechanism (5.6.9..c) | ||
Table 1 below identifies NDE examination techniques utilized for each identified degradation mechanism. | Table 1 below identifies NDE examination techniques utilized for each identified degradation mechanism. | ||
4.1 Table I -NDE Techniques Utilized for Sizin Identified De | 4.1 Table I -NDE Techniques Utilized for Sizin Identified De radation Lattice Grid Support Wear Bobbin (%TW depth) 96004.1 MRPC +Point (length) 96910.1 Page 6 of 31 | ||
* The Array probe was the primary means of detecting foreign objects and foreign | * The Array probe was the primary means of detecting foreign objects and foreign object wear during the inspection. | ||
However, the +PointTM probe was used for further characterization and sizing of wear.** There are other EPRI techniques qualified for sizing of foreign object wear depending on the shape of the flaw. ETSS 27901.1 was selected based on the circumferential groove appearance of the foreign object wear indications detected during the U2R1 9 inspection 5.0 Location, orientation (if linear), and measured sizes (if available) of service induced indications (5.6.9.d)5.1 Fan Bar Wear Fan bar wear (FBW) is a mechanical degradation process which produces volumetric tube wear at the interface between the U-bend anti-vibration supports (fan bars) and the tubes. A total of 447 FBW indications were identified in the Calvert Cliffs Unit 2 RSGs during CC2R21. One hundred and four (104) of the 447 indications were newly reported during the CC2R21 outage. There were 44 and 60 new indications in SG21 and SG22, respectively. | |||
and measured sizes (if available) of service induced indications (5.6.9.d) 5.1 Fan Bar | The deepest repeat FBW indication was 30% 1W in 22 SG. Table 2 provides a summary of the fan bar wear indications from CC2R2I. The maximum depth among these indications was 30% TW which is consistent with results from previous inspections. | ||
The deepest repeat FBW indication was 30% 1W in 22 SG. Table 2 provides | Growth of the repeat indications was minimal and consistent with previous results.Figure 1 provides the distribution of fan bar wear depths for both steam generators as reported with the bobbin coil probe. As shown in the figure, SG22 contained more indications. | ||
Growth of the repeat indications was minimal | A majority of the indication in both SG's are less than 20% TW.Figures 2 and 3 provide tube map locations of the reported FBW. Although the tube maps shown in Figures 2 and 3 provide a view of the tubesheet primary face from the hot leg side, both the hot leg and cold leg FBW indications are included on each map. Most of the wear continues to occur in longer tubes (i.e., larger U-bend radius), clustered towards the center-most tube columns.Appendix C provides a complete list of FBW indications. | ||
A majority of the indication in both SG's are less | Page 7 of 31 5.1.1 Table 2 -Fan Bar Wear Indication Summary I 3. S 0 I-I~1 Total Number of In-Service Tubes Prior to CC2R21 8434 8439 Number of FBW Indications 154 293 Maximum Depth of FBW (%TW) 25% 30%Number of TSP Wear Indications | ||
clustered towards the center-most tube columns.Appendix C provides a complete list of FBW indications. | >40%TW 0 0 Number of Newly-Reported Indications 44 60 Number of Tubes Plugged due to FBW 0 0 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth 90 80 IOa 60**SG22 i5020 -........10 .....Q~. 40 40 d~ d~ ~ &., 4' .~' 40 -~~0 ~ 43&~, .'~EL~4o&~, -~'Depth In Percent Tha 11wf Page 8 of 31 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map 140 120 0 0.0o 0 0*00 0 0o°oTubes With Indications | ||
Page 7 of 31 5.1.1 Table 2 -Fan Bar Wear Indication | .. .............. ...........0 0 .. ..... ......... | ||
>40%TW 0 | ..... \ t ...0 60 40 20 0 0 20 40 60 80 100) 120 140 160 Column Number 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map 140 120 E S80 -60 +1 04 i\160O 40 20--0 80 100) 120 140 Column Number 0 20 40 60 Page 9 of 31 5.2 Lattice Grid Support Wear Three indications of wear related to the lattice grid supports were reported during the CC2R21 outage (two indications in SG21 and one indication in SG22). All three of these indications were inspected with +Point T M to confirm that the morphologies of the indications were consistent with lattice grid wear and not some other damage mechanism such as foreign object wear. After confirmation with +PointTM, all three indications were depth sized using the bobbin coil data and length sized with+Point T M .All three indications have a tapered flaw shape.This was the first occurrence of lattice grid wear at Calvert Cliffs Unit 2. However, this is not an unexpected occurrence since lattice grid wear has already been observed at Unit 1. The depths of the Unit 2 indications are consistent with the depths of the indications observed in Unit 1. Table 3 provides a listing of these indications. | ||
.. .............. ........... | 5.2.1 Table 3 -Summary of Lattice Grid Support Wear Indications 5 G22 102 i30 02C -1.74 to -1.24 10% TW 0.5" 5.3 Foreign Object Wear During the CC2R21 inspection, twenty-one (21) foreign object wear indications were detected in 17 tubes. These indications were reported as LPW (Loose Part Wear) in the eddy current database. | ||
..... \ t ... | Four (4) indications in three tubes were newly detected in CC2R21. The remainder were legacy and showed no change in size since previous inspections. | ||
5.2.1 Table 3 -Summary of Lattice Grid Support Wear Indications 5 G22 102 i30 02C -1.74 to -1.24 10% TW 0.5"5.3 Foreign Object | |||
Four (4) indications in three tubes were newly detected | |||
Three (3) of the new indications were identified on two tubes in SG21, these indications were in a cluster about 15 inches above the cold leg tubesheet. | Three (3) of the new indications were identified on two tubes in SG21, these indications were in a cluster about 15 inches above the cold leg tubesheet. | ||
The wear was | The wear was caused by weld slag that was still present at the time of inspection and has since been removed.One (1) of the new indications was on a tube in SG22. This was the deepest new indication detected during the CC2R21 inspections, sized at 36% TW. This indication was near the lower edge of the 04H lattice support. This indication was due to a foreign object based on its location between the contact points of the lattice grid. This indication was caused by a transient loose part which is no longer present based on ET inspection results. The overall deepest indication for SG22 is at Row 126 Col 116, and is 38% TW.This is a previously detected legacy indication. | ||
This indication was due to a | No growth was measured.Page 10 of 31 All LPW indications were sized below the site plugging limit. There were no objects present at non-plugged LPW tube locations from previous outages. Since no objects were present to cause further wear and all LPW %TW were less than the 40% tech spec. plugging limit, all 17 tubes were returned to service.Table 4 provides a summary of the foreign object wear indications seen in the Unit 2 RSGs.5.3.1 Table 4 -Summary of Foreign Object Wear SG1 1 6 TSH -.05to +.19 2724No SG21 12 66 TSH .37 to +.55 24 0.18 No SG21 12 162 TSH -.01to +.17 27 0.18 No SG21 13 65 TSH -.18to +.07 28 0.25 No SG21 14 66 TSH +.36 to +.54 19 0.18 No SG21 14 66 TSH +.36to +.54 17 0.18 No SG21 72 146 TSH +.13to +.31 34 0.18 No SG21 75 147 TSH +17.86 to0+18.09 19 0.23 No SG21 77 147 TSH +17.52 to +17.76 21 0.24 No SG21 77 149 TSH +20.59 to0+20.82 20 0.23 No SG21 137 73 TSC +14.89 to0+15.08 21 0.19 Yes SG21 137 75 TSC +14.4 to +14.58 24 0.18 Yes SG21 137 75 TSC +14.72 to0+14.79 19 0.07 Yes SG22 14 4 TSC +.32 to +.5 24 0.18 No SG22 17 1 TSC -.07to +.13 24 0.2 No SG22 18 2 TSC -.01to +.23 24 0.24 No SG22 82 42 04H -1.76 to -1.47 36 0.29 Yes SG22 112 82 04H +37.63 to +37.82 24 0.19 No SG22 124 116 TSC +12.58 to +12.85 18 0.27 No SG22 126 116 TSCI12.21 to 12.44 24 0.23 No SG22 126 116 TSC 12.52 to 12.76 38 0.24 No 6.0 Number of tubes plugged during the inspection active degradation mechanism (5.6.9.e)Zero (0) tubes were plugged during the CC2R21 outage.outage for each Page 11 of 31 7.0 Total number and percentage of tubes plugged to date and the effective plugging percentage in each steam generator (5,6.9.f)Table 5 provides the post CC2R21 outage tube plugging status of the CCNPP2 SG's.There are currently 37 tubes plugged in SG21 and 32 tubes plugged in SG22.7.1 Table 5 -Tube Plugging Summary SG21 847 37 S(0.437%). | ||
The overall deepest indication for SG22 is at Row 126 Col 116, and is 38% TW.This is a previously detected legacy indication. | SG22 8471 37 (0.4378%)Total 16,942 69 (0.407%)There are no sleeves installed in the CCNPP1 steam generators, therefore the effective plugging percentage is the same as stated Table 5 above.8.0 The results of condition monitoring, including results of tube pulls and in-situ testing (5.6.9.g)The condition monitoring assessment is summarized in Figures 4 through 6. These figures provide the condition monitoring limit curves corresponding to the NDE technique employed for each degradation type. All reported degradation falls below the applicable condition monitoring curve and therefore satisfies the Technical Specification structural performance criteria. | ||
No growth was measured. | No tube-pulls or in-situ pressure testing were required.8.1 Fan Bar Wear Based on the sizing parameters for this technique, the CM curve shown in Figure 4 was generated and documented in the Degradation Assessment (DA). Each of the fan bar wear indications were conservatively plotted at an axial length of 1.8 inches based on current and previous length sizing of the deepest indications. | ||
Page 10 of 31 All LPW indications were sized below the site plugging limit. There were no | As shown, all indications lie well below the CM curve. Hence, structural integrity of the fan bar wear indications is demonstrated. | ||
Since no | 8.2 Foreign Object Wear As documented in the DA, ETSS 27903.1 provides a lower CM limit compared to the other 2790X series of techniques. | ||
Zero (0) tubes were plugged during the CC2R21 outage.outage for | Hence, use of the CM limit curve from the DA is appropriate and conservative for the evaluation of foreign object wear at Calvert Cliffs Unit 2. Figure 5 shows the condition monitoring results for foreign object wear. As shown, all indications lie well below the CM curve. Hence, structural integrity of the foreign object wear indications is demonstrated. | ||
Table 5 provides the post CC2R21 outage tube plugging status of the CCNPP2 SG's.There are currently 37 tubes plugged in SG21 and 32 tubes plugged in SG22.7.1 Table 5 -Tube Plugging | Page 12 of 31 8.3 Lattice Grid Wear Based on the sizing parameters for the bobbin technique, the CM curve shown in Figure 6 was generated and documented in the DA. Since all three of the lattice grid wear indications were inspected with +PointTM, the lengths measured from the +PointTM and depths from bobbin inspections are reflected in the figure. As shown, all indications lie well below the CM curve. Hence, structural integrity of the lattice grid wear indications is demonstrated. | ||
SG22 8471 37 (0.4378%) | Some of the detected flaws had measured axial extents <0.25". For these cases, the flaws were evaluated for leakage integrity using the flaw model for uniform 360 degree thinning of finite axial extent. This is allowed per Section 9.6.3 of the EPRI SG Integrity Assessment Guideline for situations involvng pressure loading only. Using the uniform thinning equation from Section 5.3.2 of the EPRI SG Flaw Handbook the CM limit of a flaw with an axial length of 0.25" is 64.1%TW. Since none of the detected indications approached this depth, accident leakage integrity for these shorter volumetric flaws is also confirmed. | ||
Total 16,942 69 (0.407%)There are no sleeves installed in the CCNPP1 steam generators, therefore the effective plugging percentage is the same as stated Table 5 above.8.0 The results of condition monitoring, including results of | Page 13 of 31 8.3.1 Figure 4- Condition Monitoring Results for Fan Bar Wear 100 SNote: CM limit curve is based on 90structural lengths and depths.9 .....Indication depths are conservatively i plotted using maximum depths.8 0 .. ..... .. ..... ..... ... ........... | ||
The condition monitoring assessment is summarized in Figures 4 through 6. | ... ...... ... .[--Limit (96004.1)Fan Bar Wear Indications 70 -=3*60 60 I-50 -2. 401 S301 20 -10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.82 Page 14 of 31 8.3.2 Figure 5 -Condition Monitoring for Foreign Object Wear 100 90 1 704--...... | ||
No tube-pulls or in-situ pressure testing were required. | Note 1: CM limit curve is based on structural lengths and depths. Indication depths are conservatively plotted using maximum depths.Note 2: CM limit curve shown is for ETSS 27903.1 as documented in the DA.This ETSS gives a lower CM limit that ETSS 27901.1 and is, therefore, conservative for this application. | ||
8.1 Fan Bar | a.*1 60 40 30*20 I-10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.8 2 Page 15 of 31 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear 100 80 -70 I Note: CM limit curve is based on structural lengths and depths.Indication depths are conservatively plotted using maximum depths.Limit (96004.1)* Lattice Grid Wear Indications 360 4J a..,:, 30 I i L 20!10*4 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1,82 8.4 Operational Leakage Criterion and Validation of Previous OA The operational leakage criterion was also satisfied by the absence of any measureable primary to secondary leakage since the previous inspection. | ||
As shown, all indications lie well below the CM curve. Hence, structural integrity of the fan bar wear indications | The results of the 2015 inspection and the condition monitoring assessment confirm that the 2011 operational assessment was appropriately bounding.Page 16 of 31 APPENDIX A -Typical U-Bend Support System CLAMPING BARS*TIE 11UBES TUJBE IN PLANE DIRECION FLAT BAR ThRE OUT OF PLANE DIR.E6rION Page 17 of 31 Appendix B Calvert Cliffs U-2 Tube Support Layout FI N RN 3 c'i ~ ii____C&, !3, I HI ___ ___ __I I I i~ii iI I f-JT"II t i Page 18 of 31 APPENDIX C -002R21 Fan Bar Wear Summary Table C- 1: SG21 Fan Bar Wear Summary 25 163 9 F07 2.00 29 159 13 F06 1.66 30 162 7 F07 -0.93 34 6 15 F06 -1.15 44 6 9 F06 1.70 45 79 7 F07 0.64 48 6 9 F06 1.91 48 8 7 F06 1.86 52 126 10 FO8 -0.75 57 107 14 F08 1.76 58 98 8 F05 -1.79 60 80 7 F06 0.62 63 69 6 F09 2.17 69 115 5 F04 -1.99 74 78 10 FO8 1.00 75 75 9 F08 0.88 76 76 9 F07 -0.78 77 67 7 F08 0.74 77 75 10 F08 0.74 77 79 13 F08 0.74 77 83 11 F08 0.50 80 74 8 F08 1.96 80 76 11 F07 -0.67 80 78 12 FOB 1.92 81 75 7 FO8 0.85 81 79 15 FOB 0.85 81 97 10 FOB 1.75 82 84 5 F06 -1.07 82 94 9 FOB 0.77 83 67 B FOB 0.70 83 79 12 FOB 0.71 83 97 7 FOB 1.91 Page 19 of 31 84 76 11 F07 -0.83 85 75 9 FO8 0.81 85 75 8 F07 1.83 85 79 16 FO8 0.81 85 93 11 FO8 1.77 86 84 10 F06 -0.60 86 88 6 FO8 0.81 86 94 11 F08 0.74 87 67 8 FOB 0.72 87 75 9 FOB 0.84 87 75 5 F07 1.79 87 79 9 F08 0.79 87 83 8 FOB -0.58 87 83 6 F07 -0.05 87 83 7 F06 0.00 87 87 13 F08 1.72 87 93 14 FOB 1.77 87 97 8 FO8 1.98 88 74 7 F08 2.04 88 78 7 F06 1.14 89 75 15 F06 -0.65 89 87 9 F08 1.93 89 87 4 F07 1.16 89 87 7 F06 -1.74 89 93 7 F06 -1.75 89 93 8 F08 1.79 89 101 6 F05 -0.83 90 74 9 F08 1.97 90 76 6 F07 -0.79 91 75 8 FOB 0.79 91 75 7 F06 -0.63 92 78 13 F08 1.81 92 88 8 F06 -0.63 93 73 11 FOB 0.84 93 83 12 F06 -0.44 93 87 8 FOB 1.83 94 74 12 F06 -1.67 94 78 15 FOB 1.65 Page 20Oof 31 94 82 10 F06 -16 95 77 8 F06 -1.55 95 83 9 F08 -0.55 95 87 19 F08 1.89 95 87 10 F09 0.83 95 99 8 F05 -1.48 96 78 8 F08 1.52 96 80 9 F08 -1.97 97 75 10 F06 -0.60 97 75 10 F07 1.50 97 83 5 F07 0.00 97 83 10 F08 0.51 98 74 10 F06 -1.71 98 74 8 F08 1.92 98 76 8 F07 -0.65 98 82 9 F08 1.92 98 82 10 F06 -1.67 98 88 8 F08 0.86 99 75 9 F07 1.76 99 83 9 F06 -0.49 99 83 9 F07 -0.56 99 83 9 F08 -0.56 99 87 18 F06 -1.21 99 87 8 F07 0.77 100 80 8 F06 -1.64 101 75 7 F09 -1.44 101 75 20 F06 -0.58 101 75 15 F07 0.90 101 79 9 F08 0.88 101 79 7 F02 -2.02 101 79 10 F06 -0.65 101 79 7 F07 1.92 101 81 8 F07 -0.79 101 83 5 F06 0.09 101 83 8 F07 0.05 101 83 10 F08 -0.56 101 83 5 FO5 0.00 101 87 11 F06 -1.72 101 87 13 F07 0.72 Page 21 of 31 102 82 5 F07 -13 102 88 8 F06 -0.70 102 90 10 F06 -0.69 103 83 10 F06 0.62 103 87 9 F06 -1.67 103 87 15 F07 0.76 103 91 8 F06 -1.71 104 78 9 F07 0.81 104 78 9 F08 1.85 104 84 9 F06 -0.60 104 86 7 F06 -0.70 104 88 15 FO5 -1.25 104 88 22 F06 -1.11 104 88 7 F07 1.78 105 79 9 F07 1.87 105 83 14 F07 0.00 105 87 9 F07 0.81 106 76 20 F06 1.16 106 76 6 F07 -1.28 106 78 8 F07 0.79 106 88 9 F08 0.79 106 90 10 F06 -0.70 107 75 9 F07 1.72 107 83 10 F06 0.49 107 83 12 F07 0.00 107 85 8 F06 0.74 107 87 19 F07 0.74 108 74 8 F07 0.78 108 76 25 F06 1.25 108 90 12 F06 -0.74 110 76 6 F06 1.20 110 88 9 F06 -0.69 110 90 8 F06 -0.56 111 75 17 F06 -0.79 111 93 7 F07 0.77 112 90 14 F06 -0.67 113 87 10 F07 0.78 114 76 16 F06 -0.81 117 89 18 F06 -1.28 Page 22 of 31 119 87 16 F07 07 122 88 7 F09 1.83 123 89 7 F06 -1.86 132 92 5 F06 1.25 133 91 11 F02 0.88 TotaI:I 154[ I___Page 23 of 31 Table C- 2: SG22 Fan Bar Wear Summary S, StT Se[e _,t 22 6 10 F07 -0.23 37 35 7 F07 1.82 40 28 8 F09 -0.32 44 140 8 F07 -0.72 49 29 8 F07 1.80 61 111 11 F08 1.79 69 83 8 F08 -0.55 70 54 7 F06 -1.64 70 82 8 F07 0.89 70 82 8 F06 -1.82 72 64 8 F08 1.91 72 72 11 F08 2.12 72 82 7 F08 1.94 72 92 11 F08 0.70 73 81 6 F07 0.02 73 91 16 F08 1.65 74 82 8 F06 -1.80 74 82 4 F07 0.81 74 82 8 FOB 1.94 74 94 13 F08 0.80 75 73 8 F08 0.76 75 81 8 F07 -0.78 75 93 7 F08 1.85 76 64 9 F08 1.99 76 72 10 F06 -1.75 76 72 16 FOB 1.89 76 82 8 F07 0.81 76 82 9 FOB 1.92 76 82 9 F06 -1.69 76 98 10 FOB 0.81 77 65 13 FOB 0.79 77 69 8 FOB 0.81 77 73 9 F08 0.79 77 81 8 F07 -0.78 78 64 8 F08 1.88 78 82 13 F06 -1.80 Page 24 of 31 S S~ 656 T l79 81 13 F07 -1.34 79 83 5 F07 -0.24 79 89 8 F07 0.74 79 91 9 F08 1.84 79 93 28 F08 1.42 80 64 8 F08 -1.78 80 64 9 F09 -1.92 80 80 7 F06 -1.74 80 82 8 F06 -1.81 80 82 8 F05 -0.79 81 63 8 F08 -0.91 81 91 10 F08 1.79 82 82 10 F07 0.92 82 82 7 F06 -1.87 82 84 9 F06 1.34 82 84 8 F08 0.82 82 94 9 F08 0.80 83 73 11 F07 1.69 83 73 20 F08 0.70 83 75 14 F02 0.77 83 81 10 F07 -1.27 83 91 13 F08 1.89 84 80 7 F06 -1.68 84 92 19 F08 0.78 84 94 21 F08 0.83 85 65 10 F08 0.79 85 79 11 F08 0.83 85 79 7 F08 -1.24 86 44 7 FO5 1.23 86 72 9 F05 -0.87 86 72 11 F06 -1.69 86 74 11 F06 -1.70 86 92 12 F08 0.78 86 94 16 F08 0.71 87 65 14 F08 0.74 87 83 17 F08 0.00 87 83 8 F06 -0.09 87 83 25 F07 0.05 88 76 9 F06 .1.81 Page 25 of 31 IS~ S S..A "11t I r 88 76 9 F05 1.85 88 78 9 F06 -1.22 88 82 9 EQ5 1.91 88 82 14 F06 1.84 88 84 9 F07 -0.87 88 92 10 F08 0.73 89 65 16 F08 0.79 89 69 12 F08 0.80 89 73 20 F08 0.76 89 81 11 F06 -0.74 89 83 8 F08 -0.56 89 83 10 F06 0.49 89 83 6 F05 0.47 89 83 6 F07 0.54 89 89 12 F08 -1.36 90 82 6 F06 -1.71 91 65 23 F08 0.86 91 81 7 FOG -0.74 91 83 6 F07 0.00 91 103 8 FO5 -0.80 92 76 10 FOG 1.82 92 88 6 F06 0.71 93 73 10 F06 -0.76 93 79 9 FOG -0.74 93 81 9 F06 -0.71 93 83 10 F06 0.45 93 83 9 F07 0.50 93 91 9 F08 1.77 93 93 8 F08 1.77 93 97 8 F08 1.79 94 76 10 FOG 1.77 94 80 9 FOG -1.83 94 82 4 F07 0.78 94 82 19 FOG -1.34 94 86 7 F06 0.62 94 92 12 F08 0.81 94 94 11 F08 0.74 95 81 7 F07 -1.15 95. 83 6 FOG 0.12 Page 26 of 31. | ||
8.2 Foreign Object | 95 83 12 F07 0.42 95 93 7 FO8 1.70 96 80 7 F06 -1.77 96 82 10 F06 1.31 96 82 6 F07 -1.31 96 84 20 F07 1.25 96 86 7 F06 0.00 96 90 5 FOB -1.37 97 25 7 F06 0.81 97 73 9 F06 -0.78 97 75 9 F06 -0.80 97 77 11 F06 -0.78 97 79 11 F06 -0.69 97 81 5 F06 1.34 97 81 4 F08 -1.30 97 81 9 F07 -1.30 98 72 9 F08 1.84 98 76 10 F06 1.67 98 78 13 F08 1.76 98 78 7 F07 0.76 98 82 8 F07 0.81 98 84 6 F06 -0.87 98 94 7 F08 0.76 99 71 14 F08 -0.74 99 77 18 F06 -0.79 99 81 7 F07 -0.81 99 81 7 F06 -0.76 100 76 8 F06 -1.92 100 78 11 F08 -1.90 100 78 8 F07 0.72 100 78 7 F06 -1.81 100 82 14 F07 0.76 100 82 10 FOB 1.89 100 82 16 F06 -1.29 100 84 7 F07 1.34 100 88 10 F07 1.79 101 77 11 F06 -0.77 101 79 10 F07 1.82 101 81 9 F06 -0.62 Page 27 of 31 101 85 9 F09 1.30 101 87 8 F07 0.76 101 89 6 F09 0.66 102 76 13 F06 1.69 102 76 10 F07 -1.23 102 80 7 F08 2.03 102 82 7 F06 -1.69 102 82 10 F09 0.74 102 84 6 F07 1.79 102 86 8 F02 0.78 103 77 14 F06 -0.72 103 79 8 F07 1.73 103 79 11 F06 -0.69 103 81 8 F06 -0.72 103 81 6 F08 -1.18 103 83 15 F06 0.47 103 83 5 F07 -0.09 103 85 12 F08 1.30 103 87 11 F07 0.66 103 87 6 F09 0.71 104 82 11 F07 0.76 104 82 8 F09 0.69 104 82 9 F06 -1.92 104 84 10 F07 1.78 104 94 17 F06 -1.18 105 67 9 F07 -1.20 105 75 13 F06 -0.78 105 77 15 F06 -0.76 105 79 20 F06 -0.71 105 79 13 F07 1.84 105 81 9 F07 1.81 105 81 14 F08 1.39 105 81 11 F06 -0.70 105 83 14 F07 0.45 105 83 9 F06 0.50 105 83 7 FO5 -0.05 105 87 8 F01 0.53 106 80 6 F07 1.20 106 82 13 F06 -1.77 Page 28 of 31 S S 106 82 18 F07 0.71 106 84 5 FO8 -1.45 106 90 22 F07 1.20 107 75 14 F06 -0.77 107 77 12 F06 -0.86 107 79 8 F06 -0.88 107 81 12 FOB -1.40 107 81 21 F06 -0.72 107 83 4 F06 -0.02 107 83 5 FO5 0.02 107 83 12 F07 -0.02 107 85 11 F09 0.83 107 85 8 F06 1.18 107 93 8 F07 0.81 108 74 6 F06 -1.81 108 76 9 F09 0.76 108 76 7 FO8 1.39 108 82 11 F08 1.34 108 82 20 F07 0.76 108 82 11 F09 0.74 108 84 14 F07 1.77 108 84 11 F06 -0.71 108 86 24 F06 -1.18 108 86 6 F08 1.25 108 86 12 F07 1.68 108 90 6 F06 -0.73 109 75 16 F06 -0.86 109 77 22 F06 -0.78 109 79 24 F06 -0.73 109 81 15 F08 -1.18 109 81 8 F07 -1.37 109 81 15 F06 -0.86 109 83 6 F06 0.02 109 83 7 F07 -0.14 109 85 17 F07 -1.35 109 87 12 F07 0.66 110 78 13 F07 0.76 110 82 9 F07 0.73 110 90 8 FOB -1.44 Page 29 of 31. | ||
Hence, use of the CM limit curve from the DA | 111 73 26 F06 -1.39 111 75 22 F06 -0.57 111 77 28 FOG -0.76 111 79 18 FOG -0.69 111 79 9 F07 1.84 111 81 14 FOG -0.76 111 111 9 F03 -1.16 112 72 11 F08 1.33 112 78 13 F07 0.64 112 86 10 F06 -0.69 113 75 12 F06 -0.76 113 77 30 F06 -0.73 113 81 13 FOG -1.30 113 81 9 F08 0.83 113 83 10 F07 0.50 113 83 8 FOG 0.48 113 91 20 F02 -2.18 114 76 4 FOG 1.27 114 78 8 F07 0.72 114 82 9 FOG 1.31 114 84 15 F06 -1.21 114 88 17 F05 1.36 115 73 7 FOG -0.72 115 77 8 FOG -0.76 115 81 7 F06 1.13 115 81 5 F07 -1.29 115 83 7 F07 0.45 115 83 9 FOG 0.45 115 93 10 F07 0.65 116 82 22 F07 1.20 116 84 10 F08 -1.84 117 83 18 F06 0.00 117 83 7 F08 0.14 117 83 7 FO5 0.00 117 91 18 F07 1.29 119 81 13 FOG -0.69 120 82 5 F08 1.35 120 88 12 F08 -1.25 121 75 7 FOG -0.73 Page 30 of 31 121 83 11 F08 0.43 121 87 8 F07 0.71 122 74 9 F07 0.69 123 77 7 F06 -0.81 123 81 11 F07 1.67 123 83 26 F07 0.12 123 83 4 EQ5 -0.07 123 83 11 F06 0.62 124 76 9 F06 0.67 124 82 5 F09 -1.60 124 82 11 F08 -1.46 124 82 13 F06 -1.41 125 91 12 F03 -2.06 126 82 12 F07 1.26 127 83 6 F07 0.07 128 92 12 F08 -1.21 130 92 11 F06 1.74 131 75 9 F06 -0.92 131 83 5 F08 0.09 132 76 6 F08 -1.32 132 80 5 F05 -1.23 132 92 10 F03 -1.83 135 83 12 F07 0.16 Total: 293 Page 31 of 31}} | ||
Page 12 of 31 8.3 Lattice Grid | |||
Some of the detected flaws had measured axial extents <0.25". For these cases, | |||
Since none of the detected indications approached this depth, accident leakage integrity for these shorter volumetric flaws | |||
Page 13 of 31 8.3.1 Figure 4- Condition Monitoring Results for Fan Bar | |||
... ...... ... .[--Limit (96004.1) | |||
Fan Bar Wear Indications 70 -=3*60 | |||
Note 1: CM limit curve is based | |||
a.* | |||
* Lattice Grid Wear Indications | |||
The results of the 2015 inspection and the condition monitoring assessment confirm | |||
Page 16 of 31 APPENDIX A -Typical U-Bend Support | |||
95 83 12 F07 0. | |||
111 73 26 F06 -1. | |||
Revision as of 20:21, 8 July 2018
| ML15314A079 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 11/06/2015 |
| From: | Smith L D Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML15314A079 (33) | |
Text
~Larry D. Smith Exeton Ge e ato ReuaoyAsuac aae 1650 Calvert Cliffs Parkway Lusby, MD 20657 410 495 5219 Office www.exeloncorp.com larry~smith2@exeloncorp.com TS 5.6.9 November 6, 2015 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Calvert Cliffs Nuclear Power Plant, Unit No. 2 Renewed Facility Operating License No. DPR-69 NRC Docket No. 50-318
Subject:
Sprinpq 2015 -180 Day Steam Generator Report
Reference:
- 1. Calvert Cliffs Nuclear Power Plant Units 1 and 2 Technical Specification 5.6.9 In accordance with Reference 1, Attachment (1) provides the results of the steam generator tube inspection conducted on Calvert Cliffs Unit 2 in 2015. This report includes the number and extent of tubes examined and indications identified.
This revision was necessary to correct the number of tubes with foreign object wear and to add clarifying information concerning the TW indication.
This issue has been entered into our corrective action program.There are no regulatory commitments contained in this correspondence.
Should you have questions regarding this matter, please contact Mr. Larry D. Smith at (410) 495-5219.Respectfully, Larry D. Smith Regulatory Assurance Manager LDS/PSF/bjm
Attachment:
(1) Steam Generator Tube Inspection Report, Calvert Cliffs Unit 2, Refueling Outage 21, Revision 1 cc: NRC Project Manager, Calvert Cliffs NRC Resident Inspector, Calvert Cliffs NRC Regional Administrator, Region I S. Gray, MD-DNR ATTACHMENT (1)STEAM GENERATOR TUBE INSPECTION REPORT, CALVERT CLIFFS UNIT 2, REFUELING OUTAGE 21, REVISION 1 Calvert Cliffs Nuclear Power Plant November 6, 2015 Exelon Generation Company, LLC Calvert Cliffs Nuclear Power Plant Unit 2 1650 Calvert Cliffs Parkway Lusby, MD 20657 Calvert Cliffs Unit 2 STEAM GENERATOR TUBE INSPECTION REPORT REFUELING OUTAGE 21 November 2015 Rev. 1 Page Ilof 31 Revisions Minor editorial corrections throughout document 5.3: 21 foreign object wear indications were Rev 1 detected in 14 tubes. This was corrected to 17 tubes.5.3 Clarified that the 36% ITW indication was the deepest new indication.
Added deepest legacy Indication.
Page 2 of 31 TABLE OF CONTENTS
1.0 INTRODUCTION
................................................................................
4 2.0 THE SCOPE OF THE INSPECTIONS PERFORMED ON EACH SG (5.6.9.A)....
5 3.0 DEGRADATION MECHANISMS FOUND (5.6.9.B)......................................
6 4.0 NONDESTRUCTIVE EXAMINATION TECIHNIQUES UTILIZED FOR EACH DEGRADATION MECHANISM (5.6.9.C)
..........................................................
6 4.1 TABLE 1 -NDE TECHNIQUES UTILIZED FOR IDENT7IFIED DEGRADATION...........................................
6 5.0 LOCATION, ORIENTATION (IF LINEAR), AND MEASURED SIZES (IF AVAILABLE)
OF SERVICE INDUCED INDICATIONS (5.6.9.D)
.....................
7 5.1 FAN BAR WEAR .................................................................................................................
7 5.1.1 Table 2 -Fan Bar Wear Indication Summary .....................................................................
8 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth...................................................................
8 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map .....................
- ..........................................................
9 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map ...............................................................................
9 5.2 LATTICE GRID SUPPORT WEAR.............................................................................................
10 5.2.1 Table 3 -Summary of Lattice Grid Support Wear lndications
................................................
10 5.3 FOREIGN OBJECT WEAR......................................................................................................
10 5.3.1 Table 4 -Summary of Foreign Object Wear ......................................................................
11 6.0 NUMBER OF TUBES PLUGGED DURING THE INSPECTION OUTAGE FOR EACH ACTIVE DEGRADATION MECHANISM (5.6.9.E)....................................
11 7.0 TOTAL NUMBER AND PERCENTAGE OF TUBES PLUGGED TO DATE AND THlE EFEECTIVE PLUGGING PERCENTAGE IN EACH STEAM GENERATOR (5.6.9.F)
...................................................................................................
12 7.1 TABLE 5- TUBE PLUGGING
SUMMARY
...................................................................................
12 8.0 THE RESULTS OF CONDITION MONITORING, INCLUDING RESULTS OF TUBE PULLS AND IN-SITU TESTING (5.6.9.G)
...............................................
12 8.1 FAN BAR WEAR...................................
............................................................................
12 8.2 FOREIGN OBJECT WEAR......................................................................................................
12 8.3 LATTICE GRID WEAR.........................................................................................................
13 8.3.1 Figure 4 -Condition Monitoring Results for Fan Bar Wear...................................................
14 8.3.2 Figure 5- Condition Monitoring for Foreign Object Wear .....................................................
1 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear........................................................
16 8.4 OPERATIONAL LEAKAGE CRITERION AND VALIDATION OF PREVIOUS OA ........................................
16 APPENDIX A- TYPICAL U-BEND SUPPORT SYSTEM .....................................
17 APPENDIX B CAL VERT CLIFFS U-2 TUBE SUPPORT LAYOUT.........................
18 APPENDIX C -CC2R21 FAN BAR WEAR
SUMMARY
.......................................
19 TABLE C-i 1:G21 FAN BAR WEAR
SUMMARY
....................................................................................
19 TABLE C- 2: SG22 FAN BAR WEAR
SUMMARY
....................................................................................
24 Page 3 of 31 Calvert Cliffs Nuclear Power Plant Unit 2 CC2R21 Spring 2015 Steam Generator Inspection
1.0 Introduction
Calvert Cliffs Nuclear Power Plant Unit 2 (CCNPP2) has two recirculating steam generators designed and fabricated by Babcock and Wilcox (B&W) of Cambridge, Ontario, Canada. These replacement steam generators (RSG's), SG21 and SG22 were installed in 2003.Each RSG contains 8471 tubes. Three tubes were plugged in SG 21 during manufacturing.
The tubing material is thermally treated Inconel 690 having a nominal outer diameter (OD) of 0.75 inches and a nominal wall thickness of 0.042 inches. The RSG's were designed and fabricated to the ASME Boiler and Pressure Vessel Code,Section III, subsection NB (Class 1), 1989 Edition with no Addenda. All tubes with a bend radius of 12 inches or less (the first 18 rows) were thermally stress-relieved following bending to reduce the residual stress imparted during bending.The straight section of the tube bundle are supported by seven 410 stainless steel (SA-240 Type 410S) lattice grid supports.
The fan Bar U-Bend support system incorporates sets of SA-240 Type 410S stainless steel Fan Bars on each side of the bundle as shown in Appendix A. Appendix B shows the tube support layout for U-2 Generators.
Technical Specification (TS) 5.5.9.d provides the requirements for SG inspection frequencies and requires periodictube inspections be performed.
TS 5.5.9.d requires that 100% of the Unit-2 tubes be inspected at sequential periods of 144, 120, 96, and thereafter 72 effective full power months (EFPM)During the CCNPP2 spring 2015 refueling outage (CC2R21) both Unit 2 steam generators (SG21 and SG22) were inspected in accordance with CCNPP TS 5.5.9. This was the fourth in-service inspection of the replacement steam generators.
The SG's had been in operation for 11.205 effective full power years (EFPY) at the time of the inspection.
Below summarizes the results of the inspection in accordance with the 180-Day reporting requirements of TS 5.6.9. Bold wording restates the TS requirement, followed by the required CC2R21 information.
A report shall be submitted within 180 days after the initial entry into Mode 4 following completion of an inspection performed in accordance with the Specification 5.5.9, Steam Generator (SG) Program.Page 4 of 31 The report shall include: 2.0 The Scope of the inspections performed on each SG (5.6.9.a)o Eddy Current Bobbin probe examinations (both SG's)* 100% Full Length (FL) of all in-service tubes with a bobbin coil probe for tube-to-support wear at the fan bars and lattice grids and for potential foreign objects and associated wear.o Eddy Current Array Probe (both SG's)* 50% X-Probe examination of all in-service tubes (periphery tubes)from the bottom end of the tube to the 1 st lattice grid on both the HL and CL for potential foreign objects and associated wear.* In addition to the 50% of the in-service tubes that were examined by X-Probe as mentioned above, the following X-probe examinations were performed.
- Inspect all previous PLPs (part not removed) plus a one tube bounding examination of such tubes at the elevation of interest not covered by the baseline 50% peripheral X-probe scope* All new PLPs and foreign object wear indications between the tubesheet and first support plus a one-tube bounding examination
- All foreign objects identified by secondary side visual inspection plus a one-tube bounding examination o Special Interest inspection of bobbin and X-Probe indications with+PointTM.* Sizing of all foreign object wear detected by bobbin or X-probe* 10 deepest FBW bobbin indications in each RSG* All 3 wear indications detected at lattice supports in each RSG ( 2 in SG21 and i in SG22)* A sample of MBMs, DNTs, and DNGs as directed by B&W or CCNPP Engineering
- All bobbin probe or X-P robe I-codes* Additional bobbin indications as directed by CCNPP Engineering
- Additional indications as needed to meet operational assessment requirements for tube integrity, as identified by B&W Engineering o Visual Examination
- Visual inspection of all installed tube plugs in both SGs in accordance with section 6.9 of the EPRI PWR Steam Generator Examination Guidelines, Rev 7. This included both welded and mechanical plugs.Page 5 of 31.
- Visual inspections of the hot and cold leg channel heads including the divider plate/tubesheet interface, the entire bowl per Westinghouse NSAL 12-1 methods for evidence of cladding degradation and/or cracking oThe following secondary side inspections were performed (both SG's)* Secondary side visual inspection of tubesheet ,including the inner bundle passes, the annulus, and the no-tube lane regions* Secondary side visual inspection of the 1 st lattice grid support* Targeted inspection locations identified as PLP (Possible loose Part) by ECT* Visual Upper Bundle inspection
- Visual inspection of moisture separators 3.0 Degradation mechanisms found (5.6.9.b)Three degradations mechanisms were confirmed to be present in the CCNPP U2 SG's. These are: 1) fan bar wear, 2) lattice grid support wear, and 3) foreign object wear. No other degradation mechanisms, including tube-to-tube wear, were detected.Lattice grid support wear (LGSW) had not been previously detected on U2, however as it has been found on the U1 SG's the presence of LGSW was not unexpected based on the CC2R21 degradation assessment.
The visual inspection of the cladding, previously installed plugs, and divider plate found no degradation.
The secondary side visual inspections of the steam drum, upper bundle,1st lattice grid support, and moisture separators found no degradation.
4.0 Nondestructive examination techniques utilized for each degradation mechanism (5.6.9..c)
Table 1 below identifies NDE examination techniques utilized for each identified degradation mechanism.
4.1 Table I -NDE Techniques Utilized for Sizin Identified De radation Lattice Grid Support Wear Bobbin (%TW depth) 96004.1 MRPC +Point (length) 96910.1 Page 6 of 31
- The Array probe was the primary means of detecting foreign objects and foreign object wear during the inspection.
However, the +PointTM probe was used for further characterization and sizing of wear.** There are other EPRI techniques qualified for sizing of foreign object wear depending on the shape of the flaw. ETSS 27901.1 was selected based on the circumferential groove appearance of the foreign object wear indications detected during the U2R1 9 inspection 5.0 Location, orientation (if linear), and measured sizes (if available) of service induced indications (5.6.9.d)5.1 Fan Bar Wear Fan bar wear (FBW) is a mechanical degradation process which produces volumetric tube wear at the interface between the U-bend anti-vibration supports (fan bars) and the tubes. A total of 447 FBW indications were identified in the Calvert Cliffs Unit 2 RSGs during CC2R21. One hundred and four (104) of the 447 indications were newly reported during the CC2R21 outage. There were 44 and 60 new indications in SG21 and SG22, respectively.
The deepest repeat FBW indication was 30% 1W in 22 SG. Table 2 provides a summary of the fan bar wear indications from CC2R2I. The maximum depth among these indications was 30% TW which is consistent with results from previous inspections.
Growth of the repeat indications was minimal and consistent with previous results.Figure 1 provides the distribution of fan bar wear depths for both steam generators as reported with the bobbin coil probe. As shown in the figure, SG22 contained more indications.
A majority of the indication in both SG's are less than 20% TW.Figures 2 and 3 provide tube map locations of the reported FBW. Although the tube maps shown in Figures 2 and 3 provide a view of the tubesheet primary face from the hot leg side, both the hot leg and cold leg FBW indications are included on each map. Most of the wear continues to occur in longer tubes (i.e., larger U-bend radius), clustered towards the center-most tube columns.Appendix C provides a complete list of FBW indications.
Page 7 of 31 5.1.1 Table 2 -Fan Bar Wear Indication Summary I 3. S 0 I-I~1 Total Number of In-Service Tubes Prior to CC2R21 8434 8439 Number of FBW Indications 154 293 Maximum Depth of FBW (%TW) 25% 30%Number of TSP Wear Indications
>40%TW 0 0 Number of Newly-Reported Indications 44 60 Number of Tubes Plugged due to FBW 0 0 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth 90 80 IOa 60**SG22 i5020 -........10 .....Q~. 40 40 d~ d~ ~ &., 4' .~' 40 -~~0 ~ 43&~, .'~EL~4o&~, -~'Depth In Percent Tha 11wf Page 8 of 31 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map 140 120 0 0.0o 0 0*00 0 0o°oTubes With Indications
.. .............. ...........0 0 .. ..... .........
..... \ t ...0 60 40 20 0 0 20 40 60 80 100) 120 140 160 Column Number 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map 140 120 E S80 -60 +1 04 i\160O 40 20--0 80 100) 120 140 Column Number 0 20 40 60 Page 9 of 31 5.2 Lattice Grid Support Wear Three indications of wear related to the lattice grid supports were reported during the CC2R21 outage (two indications in SG21 and one indication in SG22). All three of these indications were inspected with +Point T M to confirm that the morphologies of the indications were consistent with lattice grid wear and not some other damage mechanism such as foreign object wear. After confirmation with +PointTM, all three indications were depth sized using the bobbin coil data and length sized with+Point T M .All three indications have a tapered flaw shape.This was the first occurrence of lattice grid wear at Calvert Cliffs Unit 2. However, this is not an unexpected occurrence since lattice grid wear has already been observed at Unit 1. The depths of the Unit 2 indications are consistent with the depths of the indications observed in Unit 1. Table 3 provides a listing of these indications.
5.2.1 Table 3 -Summary of Lattice Grid Support Wear Indications 5 G22 102 i30 02C -1.74 to -1.24 10% TW 0.5" 5.3 Foreign Object Wear During the CC2R21 inspection, twenty-one (21) foreign object wear indications were detected in 17 tubes. These indications were reported as LPW (Loose Part Wear) in the eddy current database.
Four (4) indications in three tubes were newly detected in CC2R21. The remainder were legacy and showed no change in size since previous inspections.
Three (3) of the new indications were identified on two tubes in SG21, these indications were in a cluster about 15 inches above the cold leg tubesheet.
The wear was caused by weld slag that was still present at the time of inspection and has since been removed.One (1) of the new indications was on a tube in SG22. This was the deepest new indication detected during the CC2R21 inspections, sized at 36% TW. This indication was near the lower edge of the 04H lattice support. This indication was due to a foreign object based on its location between the contact points of the lattice grid. This indication was caused by a transient loose part which is no longer present based on ET inspection results. The overall deepest indication for SG22 is at Row 126 Col 116, and is 38% TW.This is a previously detected legacy indication.
No growth was measured.Page 10 of 31 All LPW indications were sized below the site plugging limit. There were no objects present at non-plugged LPW tube locations from previous outages. Since no objects were present to cause further wear and all LPW %TW were less than the 40% tech spec. plugging limit, all 17 tubes were returned to service.Table 4 provides a summary of the foreign object wear indications seen in the Unit 2 RSGs.5.3.1 Table 4 -Summary of Foreign Object Wear SG1 1 6 TSH -.05to +.19 2724No SG21 12 66 TSH .37 to +.55 24 0.18 No SG21 12 162 TSH -.01to +.17 27 0.18 No SG21 13 65 TSH -.18to +.07 28 0.25 No SG21 14 66 TSH +.36 to +.54 19 0.18 No SG21 14 66 TSH +.36to +.54 17 0.18 No SG21 72 146 TSH +.13to +.31 34 0.18 No SG21 75 147 TSH +17.86 to0+18.09 19 0.23 No SG21 77 147 TSH +17.52 to +17.76 21 0.24 No SG21 77 149 TSH +20.59 to0+20.82 20 0.23 No SG21 137 73 TSC +14.89 to0+15.08 21 0.19 Yes SG21 137 75 TSC +14.4 to +14.58 24 0.18 Yes SG21 137 75 TSC +14.72 to0+14.79 19 0.07 Yes SG22 14 4 TSC +.32 to +.5 24 0.18 No SG22 17 1 TSC -.07to +.13 24 0.2 No SG22 18 2 TSC -.01to +.23 24 0.24 No SG22 82 42 04H -1.76 to -1.47 36 0.29 Yes SG22 112 82 04H +37.63 to +37.82 24 0.19 No SG22 124 116 TSC +12.58 to +12.85 18 0.27 No SG22 126 116 TSCI12.21 to 12.44 24 0.23 No SG22 126 116 TSC 12.52 to 12.76 38 0.24 No 6.0 Number of tubes plugged during the inspection active degradation mechanism (5.6.9.e)Zero (0) tubes were plugged during the CC2R21 outage.outage for each Page 11 of 31 7.0 Total number and percentage of tubes plugged to date and the effective plugging percentage in each steam generator (5,6.9.f)Table 5 provides the post CC2R21 outage tube plugging status of the CCNPP2 SG's.There are currently 37 tubes plugged in SG21 and 32 tubes plugged in SG22.7.1 Table 5 -Tube Plugging Summary SG21 847 37 S(0.437%).
SG22 8471 37 (0.4378%)Total 16,942 69 (0.407%)There are no sleeves installed in the CCNPP1 steam generators, therefore the effective plugging percentage is the same as stated Table 5 above.8.0 The results of condition monitoring, including results of tube pulls and in-situ testing (5.6.9.g)The condition monitoring assessment is summarized in Figures 4 through 6. These figures provide the condition monitoring limit curves corresponding to the NDE technique employed for each degradation type. All reported degradation falls below the applicable condition monitoring curve and therefore satisfies the Technical Specification structural performance criteria.
No tube-pulls or in-situ pressure testing were required.8.1 Fan Bar Wear Based on the sizing parameters for this technique, the CM curve shown in Figure 4 was generated and documented in the Degradation Assessment (DA). Each of the fan bar wear indications were conservatively plotted at an axial length of 1.8 inches based on current and previous length sizing of the deepest indications.
As shown, all indications lie well below the CM curve. Hence, structural integrity of the fan bar wear indications is demonstrated.
8.2 Foreign Object Wear As documented in the DA, ETSS 27903.1 provides a lower CM limit compared to the other 2790X series of techniques.
Hence, use of the CM limit curve from the DA is appropriate and conservative for the evaluation of foreign object wear at Calvert Cliffs Unit 2. Figure 5 shows the condition monitoring results for foreign object wear. As shown, all indications lie well below the CM curve. Hence, structural integrity of the foreign object wear indications is demonstrated.
Page 12 of 31 8.3 Lattice Grid Wear Based on the sizing parameters for the bobbin technique, the CM curve shown in Figure 6 was generated and documented in the DA. Since all three of the lattice grid wear indications were inspected with +PointTM, the lengths measured from the +PointTM and depths from bobbin inspections are reflected in the figure. As shown, all indications lie well below the CM curve. Hence, structural integrity of the lattice grid wear indications is demonstrated.
Some of the detected flaws had measured axial extents <0.25". For these cases, the flaws were evaluated for leakage integrity using the flaw model for uniform 360 degree thinning of finite axial extent. This is allowed per Section 9.6.3 of the EPRI SG Integrity Assessment Guideline for situations involvng pressure loading only. Using the uniform thinning equation from Section 5.3.2 of the EPRI SG Flaw Handbook the CM limit of a flaw with an axial length of 0.25" is 64.1%TW. Since none of the detected indications approached this depth, accident leakage integrity for these shorter volumetric flaws is also confirmed.
Page 13 of 31 8.3.1 Figure 4- Condition Monitoring Results for Fan Bar Wear 100 SNote: CM limit curve is based on 90structural lengths and depths.9 .....Indication depths are conservatively i plotted using maximum depths.8 0 .. ..... .. ..... ..... ... ...........
... ...... ... .[--Limit (96004.1)Fan Bar Wear Indications 70 -=3*60 60 I-50 -2. 401 S301 20 -10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.82 Page 14 of 31 8.3.2 Figure 5 -Condition Monitoring for Foreign Object Wear 100 90 1 704--......
Note 1: CM limit curve is based on structural lengths and depths. Indication depths are conservatively plotted using maximum depths.Note 2: CM limit curve shown is for ETSS 27903.1 as documented in the DA.This ETSS gives a lower CM limit that ETSS 27901.1 and is, therefore, conservative for this application.
a.*1 60 40 30*20 I-10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.8 2 Page 15 of 31 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear 100 80 -70 I Note: CM limit curve is based on structural lengths and depths.Indication depths are conservatively plotted using maximum depths.Limit (96004.1)* Lattice Grid Wear Indications 360 4J a..,:, 30 I i L 20!10*4 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1,82 8.4 Operational Leakage Criterion and Validation of Previous OA The operational leakage criterion was also satisfied by the absence of any measureable primary to secondary leakage since the previous inspection.
The results of the 2015 inspection and the condition monitoring assessment confirm that the 2011 operational assessment was appropriately bounding.Page 16 of 31 APPENDIX A -Typical U-Bend Support System CLAMPING BARS*TIE 11UBES TUJBE IN PLANE DIRECION FLAT BAR ThRE OUT OF PLANE DIR.E6rION Page 17 of 31 Appendix B Calvert Cliffs U-2 Tube Support Layout FI N RN 3 c'i ~ ii____C&, !3, I HI ___ ___ __I I I i~ii iI I f-JT"II t i Page 18 of 31 APPENDIX C -002R21 Fan Bar Wear Summary Table C- 1: SG21 Fan Bar Wear Summary 25 163 9 F07 2.00 29 159 13 F06 1.66 30 162 7 F07 -0.93 34 6 15 F06 -1.15 44 6 9 F06 1.70 45 79 7 F07 0.64 48 6 9 F06 1.91 48 8 7 F06 1.86 52 126 10 FO8 -0.75 57 107 14 F08 1.76 58 98 8 F05 -1.79 60 80 7 F06 0.62 63 69 6 F09 2.17 69 115 5 F04 -1.99 74 78 10 FO8 1.00 75 75 9 F08 0.88 76 76 9 F07 -0.78 77 67 7 F08 0.74 77 75 10 F08 0.74 77 79 13 F08 0.74 77 83 11 F08 0.50 80 74 8 F08 1.96 80 76 11 F07 -0.67 80 78 12 FOB 1.92 81 75 7 FO8 0.85 81 79 15 FOB 0.85 81 97 10 FOB 1.75 82 84 5 F06 -1.07 82 94 9 FOB 0.77 83 67 B FOB 0.70 83 79 12 FOB 0.71 83 97 7 FOB 1.91 Page 19 of 31 84 76 11 F07 -0.83 85 75 9 FO8 0.81 85 75 8 F07 1.83 85 79 16 FO8 0.81 85 93 11 FO8 1.77 86 84 10 F06 -0.60 86 88 6 FO8 0.81 86 94 11 F08 0.74 87 67 8 FOB 0.72 87 75 9 FOB 0.84 87 75 5 F07 1.79 87 79 9 F08 0.79 87 83 8 FOB -0.58 87 83 6 F07 -0.05 87 83 7 F06 0.00 87 87 13 F08 1.72 87 93 14 FOB 1.77 87 97 8 FO8 1.98 88 74 7 F08 2.04 88 78 7 F06 1.14 89 75 15 F06 -0.65 89 87 9 F08 1.93 89 87 4 F07 1.16 89 87 7 F06 -1.74 89 93 7 F06 -1.75 89 93 8 F08 1.79 89 101 6 F05 -0.83 90 74 9 F08 1.97 90 76 6 F07 -0.79 91 75 8 FOB 0.79 91 75 7 F06 -0.63 92 78 13 F08 1.81 92 88 8 F06 -0.63 93 73 11 FOB 0.84 93 83 12 F06 -0.44 93 87 8 FOB 1.83 94 74 12 F06 -1.67 94 78 15 FOB 1.65 Page 20Oof 31 94 82 10 F06 -16 95 77 8 F06 -1.55 95 83 9 F08 -0.55 95 87 19 F08 1.89 95 87 10 F09 0.83 95 99 8 F05 -1.48 96 78 8 F08 1.52 96 80 9 F08 -1.97 97 75 10 F06 -0.60 97 75 10 F07 1.50 97 83 5 F07 0.00 97 83 10 F08 0.51 98 74 10 F06 -1.71 98 74 8 F08 1.92 98 76 8 F07 -0.65 98 82 9 F08 1.92 98 82 10 F06 -1.67 98 88 8 F08 0.86 99 75 9 F07 1.76 99 83 9 F06 -0.49 99 83 9 F07 -0.56 99 83 9 F08 -0.56 99 87 18 F06 -1.21 99 87 8 F07 0.77 100 80 8 F06 -1.64 101 75 7 F09 -1.44 101 75 20 F06 -0.58 101 75 15 F07 0.90 101 79 9 F08 0.88 101 79 7 F02 -2.02 101 79 10 F06 -0.65 101 79 7 F07 1.92 101 81 8 F07 -0.79 101 83 5 F06 0.09 101 83 8 F07 0.05 101 83 10 F08 -0.56 101 83 5 FO5 0.00 101 87 11 F06 -1.72 101 87 13 F07 0.72 Page 21 of 31 102 82 5 F07 -13 102 88 8 F06 -0.70 102 90 10 F06 -0.69 103 83 10 F06 0.62 103 87 9 F06 -1.67 103 87 15 F07 0.76 103 91 8 F06 -1.71 104 78 9 F07 0.81 104 78 9 F08 1.85 104 84 9 F06 -0.60 104 86 7 F06 -0.70 104 88 15 FO5 -1.25 104 88 22 F06 -1.11 104 88 7 F07 1.78 105 79 9 F07 1.87 105 83 14 F07 0.00 105 87 9 F07 0.81 106 76 20 F06 1.16 106 76 6 F07 -1.28 106 78 8 F07 0.79 106 88 9 F08 0.79 106 90 10 F06 -0.70 107 75 9 F07 1.72 107 83 10 F06 0.49 107 83 12 F07 0.00 107 85 8 F06 0.74 107 87 19 F07 0.74 108 74 8 F07 0.78 108 76 25 F06 1.25 108 90 12 F06 -0.74 110 76 6 F06 1.20 110 88 9 F06 -0.69 110 90 8 F06 -0.56 111 75 17 F06 -0.79 111 93 7 F07 0.77 112 90 14 F06 -0.67 113 87 10 F07 0.78 114 76 16 F06 -0.81 117 89 18 F06 -1.28 Page 22 of 31 119 87 16 F07 07 122 88 7 F09 1.83 123 89 7 F06 -1.86 132 92 5 F06 1.25 133 91 11 F02 0.88 TotaI:I 154[ I___Page 23 of 31 Table C- 2: SG22 Fan Bar Wear Summary S, StT Se[e _,t 22 6 10 F07 -0.23 37 35 7 F07 1.82 40 28 8 F09 -0.32 44 140 8 F07 -0.72 49 29 8 F07 1.80 61 111 11 F08 1.79 69 83 8 F08 -0.55 70 54 7 F06 -1.64 70 82 8 F07 0.89 70 82 8 F06 -1.82 72 64 8 F08 1.91 72 72 11 F08 2.12 72 82 7 F08 1.94 72 92 11 F08 0.70 73 81 6 F07 0.02 73 91 16 F08 1.65 74 82 8 F06 -1.80 74 82 4 F07 0.81 74 82 8 FOB 1.94 74 94 13 F08 0.80 75 73 8 F08 0.76 75 81 8 F07 -0.78 75 93 7 F08 1.85 76 64 9 F08 1.99 76 72 10 F06 -1.75 76 72 16 FOB 1.89 76 82 8 F07 0.81 76 82 9 FOB 1.92 76 82 9 F06 -1.69 76 98 10 FOB 0.81 77 65 13 FOB 0.79 77 69 8 FOB 0.81 77 73 9 F08 0.79 77 81 8 F07 -0.78 78 64 8 F08 1.88 78 82 13 F06 -1.80 Page 24 of 31 S S~ 656 T l79 81 13 F07 -1.34 79 83 5 F07 -0.24 79 89 8 F07 0.74 79 91 9 F08 1.84 79 93 28 F08 1.42 80 64 8 F08 -1.78 80 64 9 F09 -1.92 80 80 7 F06 -1.74 80 82 8 F06 -1.81 80 82 8 F05 -0.79 81 63 8 F08 -0.91 81 91 10 F08 1.79 82 82 10 F07 0.92 82 82 7 F06 -1.87 82 84 9 F06 1.34 82 84 8 F08 0.82 82 94 9 F08 0.80 83 73 11 F07 1.69 83 73 20 F08 0.70 83 75 14 F02 0.77 83 81 10 F07 -1.27 83 91 13 F08 1.89 84 80 7 F06 -1.68 84 92 19 F08 0.78 84 94 21 F08 0.83 85 65 10 F08 0.79 85 79 11 F08 0.83 85 79 7 F08 -1.24 86 44 7 FO5 1.23 86 72 9 F05 -0.87 86 72 11 F06 -1.69 86 74 11 F06 -1.70 86 92 12 F08 0.78 86 94 16 F08 0.71 87 65 14 F08 0.74 87 83 17 F08 0.00 87 83 8 F06 -0.09 87 83 25 F07 0.05 88 76 9 F06 .1.81 Page 25 of 31 IS~ S S..A "11t I r 88 76 9 F05 1.85 88 78 9 F06 -1.22 88 82 9 EQ5 1.91 88 82 14 F06 1.84 88 84 9 F07 -0.87 88 92 10 F08 0.73 89 65 16 F08 0.79 89 69 12 F08 0.80 89 73 20 F08 0.76 89 81 11 F06 -0.74 89 83 8 F08 -0.56 89 83 10 F06 0.49 89 83 6 F05 0.47 89 83 6 F07 0.54 89 89 12 F08 -1.36 90 82 6 F06 -1.71 91 65 23 F08 0.86 91 81 7 FOG -0.74 91 83 6 F07 0.00 91 103 8 FO5 -0.80 92 76 10 FOG 1.82 92 88 6 F06 0.71 93 73 10 F06 -0.76 93 79 9 FOG -0.74 93 81 9 F06 -0.71 93 83 10 F06 0.45 93 83 9 F07 0.50 93 91 9 F08 1.77 93 93 8 F08 1.77 93 97 8 F08 1.79 94 76 10 FOG 1.77 94 80 9 FOG -1.83 94 82 4 F07 0.78 94 82 19 FOG -1.34 94 86 7 F06 0.62 94 92 12 F08 0.81 94 94 11 F08 0.74 95 81 7 F07 -1.15 95. 83 6 FOG 0.12 Page 26 of 31.
95 83 12 F07 0.42 95 93 7 FO8 1.70 96 80 7 F06 -1.77 96 82 10 F06 1.31 96 82 6 F07 -1.31 96 84 20 F07 1.25 96 86 7 F06 0.00 96 90 5 FOB -1.37 97 25 7 F06 0.81 97 73 9 F06 -0.78 97 75 9 F06 -0.80 97 77 11 F06 -0.78 97 79 11 F06 -0.69 97 81 5 F06 1.34 97 81 4 F08 -1.30 97 81 9 F07 -1.30 98 72 9 F08 1.84 98 76 10 F06 1.67 98 78 13 F08 1.76 98 78 7 F07 0.76 98 82 8 F07 0.81 98 84 6 F06 -0.87 98 94 7 F08 0.76 99 71 14 F08 -0.74 99 77 18 F06 -0.79 99 81 7 F07 -0.81 99 81 7 F06 -0.76 100 76 8 F06 -1.92 100 78 11 F08 -1.90 100 78 8 F07 0.72 100 78 7 F06 -1.81 100 82 14 F07 0.76 100 82 10 FOB 1.89 100 82 16 F06 -1.29 100 84 7 F07 1.34 100 88 10 F07 1.79 101 77 11 F06 -0.77 101 79 10 F07 1.82 101 81 9 F06 -0.62 Page 27 of 31 101 85 9 F09 1.30 101 87 8 F07 0.76 101 89 6 F09 0.66 102 76 13 F06 1.69 102 76 10 F07 -1.23 102 80 7 F08 2.03 102 82 7 F06 -1.69 102 82 10 F09 0.74 102 84 6 F07 1.79 102 86 8 F02 0.78 103 77 14 F06 -0.72 103 79 8 F07 1.73 103 79 11 F06 -0.69 103 81 8 F06 -0.72 103 81 6 F08 -1.18 103 83 15 F06 0.47 103 83 5 F07 -0.09 103 85 12 F08 1.30 103 87 11 F07 0.66 103 87 6 F09 0.71 104 82 11 F07 0.76 104 82 8 F09 0.69 104 82 9 F06 -1.92 104 84 10 F07 1.78 104 94 17 F06 -1.18 105 67 9 F07 -1.20 105 75 13 F06 -0.78 105 77 15 F06 -0.76 105 79 20 F06 -0.71 105 79 13 F07 1.84 105 81 9 F07 1.81 105 81 14 F08 1.39 105 81 11 F06 -0.70 105 83 14 F07 0.45 105 83 9 F06 0.50 105 83 7 FO5 -0.05 105 87 8 F01 0.53 106 80 6 F07 1.20 106 82 13 F06 -1.77 Page 28 of 31 S S 106 82 18 F07 0.71 106 84 5 FO8 -1.45 106 90 22 F07 1.20 107 75 14 F06 -0.77 107 77 12 F06 -0.86 107 79 8 F06 -0.88 107 81 12 FOB -1.40 107 81 21 F06 -0.72 107 83 4 F06 -0.02 107 83 5 FO5 0.02 107 83 12 F07 -0.02 107 85 11 F09 0.83 107 85 8 F06 1.18 107 93 8 F07 0.81 108 74 6 F06 -1.81 108 76 9 F09 0.76 108 76 7 FO8 1.39 108 82 11 F08 1.34 108 82 20 F07 0.76 108 82 11 F09 0.74 108 84 14 F07 1.77 108 84 11 F06 -0.71 108 86 24 F06 -1.18 108 86 6 F08 1.25 108 86 12 F07 1.68 108 90 6 F06 -0.73 109 75 16 F06 -0.86 109 77 22 F06 -0.78 109 79 24 F06 -0.73 109 81 15 F08 -1.18 109 81 8 F07 -1.37 109 81 15 F06 -0.86 109 83 6 F06 0.02 109 83 7 F07 -0.14 109 85 17 F07 -1.35 109 87 12 F07 0.66 110 78 13 F07 0.76 110 82 9 F07 0.73 110 90 8 FOB -1.44 Page 29 of 31.
111 73 26 F06 -1.39 111 75 22 F06 -0.57 111 77 28 FOG -0.76 111 79 18 FOG -0.69 111 79 9 F07 1.84 111 81 14 FOG -0.76 111 111 9 F03 -1.16 112 72 11 F08 1.33 112 78 13 F07 0.64 112 86 10 F06 -0.69 113 75 12 F06 -0.76 113 77 30 F06 -0.73 113 81 13 FOG -1.30 113 81 9 F08 0.83 113 83 10 F07 0.50 113 83 8 FOG 0.48 113 91 20 F02 -2.18 114 76 4 FOG 1.27 114 78 8 F07 0.72 114 82 9 FOG 1.31 114 84 15 F06 -1.21 114 88 17 F05 1.36 115 73 7 FOG -0.72 115 77 8 FOG -0.76 115 81 7 F06 1.13 115 81 5 F07 -1.29 115 83 7 F07 0.45 115 83 9 FOG 0.45 115 93 10 F07 0.65 116 82 22 F07 1.20 116 84 10 F08 -1.84 117 83 18 F06 0.00 117 83 7 F08 0.14 117 83 7 FO5 0.00 117 91 18 F07 1.29 119 81 13 FOG -0.69 120 82 5 F08 1.35 120 88 12 F08 -1.25 121 75 7 FOG -0.73 Page 30 of 31 121 83 11 F08 0.43 121 87 8 F07 0.71 122 74 9 F07 0.69 123 77 7 F06 -0.81 123 81 11 F07 1.67 123 83 26 F07 0.12 123 83 4 EQ5 -0.07 123 83 11 F06 0.62 124 76 9 F06 0.67 124 82 5 F09 -1.60 124 82 11 F08 -1.46 124 82 13 F06 -1.41 125 91 12 F03 -2.06 126 82 12 F07 1.26 127 83 6 F07 0.07 128 92 12 F08 -1.21 130 92 11 F06 1.74 131 75 9 F06 -0.92 131 83 5 F08 0.09 132 76 6 F08 -1.32 132 80 5 F05 -1.23 132 92 10 F03 -1.83 135 83 12 F07 0.16 Total: 293 Page 31 of 31
~Larry D. Smith Exeton Ge e ato ReuaoyAsuac aae 1650 Calvert Cliffs Parkway Lusby, MD 20657 410 495 5219 Office www.exeloncorp.com larry~smith2@exeloncorp.com TS 5.6.9 November 6, 2015 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Calvert Cliffs Nuclear Power Plant, Unit No. 2 Renewed Facility Operating License No. DPR-69 NRC Docket No. 50-318
Subject:
Sprinpq 2015 -180 Day Steam Generator Report
Reference:
- 1. Calvert Cliffs Nuclear Power Plant Units 1 and 2 Technical Specification 5.6.9 In accordance with Reference 1, Attachment (1) provides the results of the steam generator tube inspection conducted on Calvert Cliffs Unit 2 in 2015. This report includes the number and extent of tubes examined and indications identified.
This revision was necessary to correct the number of tubes with foreign object wear and to add clarifying information concerning the TW indication.
This issue has been entered into our corrective action program.There are no regulatory commitments contained in this correspondence.
Should you have questions regarding this matter, please contact Mr. Larry D. Smith at (410) 495-5219.Respectfully, Larry D. Smith Regulatory Assurance Manager LDS/PSF/bjm
Attachment:
(1) Steam Generator Tube Inspection Report, Calvert Cliffs Unit 2, Refueling Outage 21, Revision 1 cc: NRC Project Manager, Calvert Cliffs NRC Resident Inspector, Calvert Cliffs NRC Regional Administrator, Region I S. Gray, MD-DNR ATTACHMENT (1)STEAM GENERATOR TUBE INSPECTION REPORT, CALVERT CLIFFS UNIT 2, REFUELING OUTAGE 21, REVISION 1 Calvert Cliffs Nuclear Power Plant November 6, 2015 Exelon Generation Company, LLC Calvert Cliffs Nuclear Power Plant Unit 2 1650 Calvert Cliffs Parkway Lusby, MD 20657 Calvert Cliffs Unit 2 STEAM GENERATOR TUBE INSPECTION REPORT REFUELING OUTAGE 21 November 2015 Rev. 1 Page Ilof 31 Revisions Minor editorial corrections throughout document 5.3: 21 foreign object wear indications were Rev 1 detected in 14 tubes. This was corrected to 17 tubes.5.3 Clarified that the 36% ITW indication was the deepest new indication.
Added deepest legacy Indication.
Page 2 of 31 TABLE OF CONTENTS
1.0 INTRODUCTION
................................................................................
4 2.0 THE SCOPE OF THE INSPECTIONS PERFORMED ON EACH SG (5.6.9.A)....
5 3.0 DEGRADATION MECHANISMS FOUND (5.6.9.B)......................................
6 4.0 NONDESTRUCTIVE EXAMINATION TECIHNIQUES UTILIZED FOR EACH DEGRADATION MECHANISM (5.6.9.C)
..........................................................
6 4.1 TABLE 1 -NDE TECHNIQUES UTILIZED FOR IDENT7IFIED DEGRADATION...........................................
6 5.0 LOCATION, ORIENTATION (IF LINEAR), AND MEASURED SIZES (IF AVAILABLE)
OF SERVICE INDUCED INDICATIONS (5.6.9.D)
.....................
7 5.1 FAN BAR WEAR .................................................................................................................
7 5.1.1 Table 2 -Fan Bar Wear Indication Summary .....................................................................
8 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth...................................................................
8 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map .....................
- ..........................................................
9 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map ...............................................................................
9 5.2 LATTICE GRID SUPPORT WEAR.............................................................................................
10 5.2.1 Table 3 -Summary of Lattice Grid Support Wear lndications
................................................
10 5.3 FOREIGN OBJECT WEAR......................................................................................................
10 5.3.1 Table 4 -Summary of Foreign Object Wear ......................................................................
11 6.0 NUMBER OF TUBES PLUGGED DURING THE INSPECTION OUTAGE FOR EACH ACTIVE DEGRADATION MECHANISM (5.6.9.E)....................................
11 7.0 TOTAL NUMBER AND PERCENTAGE OF TUBES PLUGGED TO DATE AND THlE EFEECTIVE PLUGGING PERCENTAGE IN EACH STEAM GENERATOR (5.6.9.F)
...................................................................................................
12 7.1 TABLE 5- TUBE PLUGGING
SUMMARY
...................................................................................
12 8.0 THE RESULTS OF CONDITION MONITORING, INCLUDING RESULTS OF TUBE PULLS AND IN-SITU TESTING (5.6.9.G)
...............................................
12 8.1 FAN BAR WEAR...................................
............................................................................
12 8.2 FOREIGN OBJECT WEAR......................................................................................................
12 8.3 LATTICE GRID WEAR.........................................................................................................
13 8.3.1 Figure 4 -Condition Monitoring Results for Fan Bar Wear...................................................
14 8.3.2 Figure 5- Condition Monitoring for Foreign Object Wear .....................................................
1 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear........................................................
16 8.4 OPERATIONAL LEAKAGE CRITERION AND VALIDATION OF PREVIOUS OA ........................................
16 APPENDIX A- TYPICAL U-BEND SUPPORT SYSTEM .....................................
17 APPENDIX B CAL VERT CLIFFS U-2 TUBE SUPPORT LAYOUT.........................
18 APPENDIX C -CC2R21 FAN BAR WEAR
SUMMARY
.......................................
19 TABLE C-i 1:G21 FAN BAR WEAR
SUMMARY
....................................................................................
19 TABLE C- 2: SG22 FAN BAR WEAR
SUMMARY
....................................................................................
24 Page 3 of 31 Calvert Cliffs Nuclear Power Plant Unit 2 CC2R21 Spring 2015 Steam Generator Inspection
1.0 Introduction
Calvert Cliffs Nuclear Power Plant Unit 2 (CCNPP2) has two recirculating steam generators designed and fabricated by Babcock and Wilcox (B&W) of Cambridge, Ontario, Canada. These replacement steam generators (RSG's), SG21 and SG22 were installed in 2003.Each RSG contains 8471 tubes. Three tubes were plugged in SG 21 during manufacturing.
The tubing material is thermally treated Inconel 690 having a nominal outer diameter (OD) of 0.75 inches and a nominal wall thickness of 0.042 inches. The RSG's were designed and fabricated to the ASME Boiler and Pressure Vessel Code,Section III, subsection NB (Class 1), 1989 Edition with no Addenda. All tubes with a bend radius of 12 inches or less (the first 18 rows) were thermally stress-relieved following bending to reduce the residual stress imparted during bending.The straight section of the tube bundle are supported by seven 410 stainless steel (SA-240 Type 410S) lattice grid supports.
The fan Bar U-Bend support system incorporates sets of SA-240 Type 410S stainless steel Fan Bars on each side of the bundle as shown in Appendix A. Appendix B shows the tube support layout for U-2 Generators.
Technical Specification (TS) 5.5.9.d provides the requirements for SG inspection frequencies and requires periodictube inspections be performed.
TS 5.5.9.d requires that 100% of the Unit-2 tubes be inspected at sequential periods of 144, 120, 96, and thereafter 72 effective full power months (EFPM)During the CCNPP2 spring 2015 refueling outage (CC2R21) both Unit 2 steam generators (SG21 and SG22) were inspected in accordance with CCNPP TS 5.5.9. This was the fourth in-service inspection of the replacement steam generators.
The SG's had been in operation for 11.205 effective full power years (EFPY) at the time of the inspection.
Below summarizes the results of the inspection in accordance with the 180-Day reporting requirements of TS 5.6.9. Bold wording restates the TS requirement, followed by the required CC2R21 information.
A report shall be submitted within 180 days after the initial entry into Mode 4 following completion of an inspection performed in accordance with the Specification 5.5.9, Steam Generator (SG) Program.Page 4 of 31 The report shall include: 2.0 The Scope of the inspections performed on each SG (5.6.9.a)o Eddy Current Bobbin probe examinations (both SG's)* 100% Full Length (FL) of all in-service tubes with a bobbin coil probe for tube-to-support wear at the fan bars and lattice grids and for potential foreign objects and associated wear.o Eddy Current Array Probe (both SG's)* 50% X-Probe examination of all in-service tubes (periphery tubes)from the bottom end of the tube to the 1 st lattice grid on both the HL and CL for potential foreign objects and associated wear.* In addition to the 50% of the in-service tubes that were examined by X-Probe as mentioned above, the following X-probe examinations were performed.
- Inspect all previous PLPs (part not removed) plus a one tube bounding examination of such tubes at the elevation of interest not covered by the baseline 50% peripheral X-probe scope* All new PLPs and foreign object wear indications between the tubesheet and first support plus a one-tube bounding examination
- All foreign objects identified by secondary side visual inspection plus a one-tube bounding examination o Special Interest inspection of bobbin and X-Probe indications with+PointTM.* Sizing of all foreign object wear detected by bobbin or X-probe* 10 deepest FBW bobbin indications in each RSG* All 3 wear indications detected at lattice supports in each RSG ( 2 in SG21 and i in SG22)* A sample of MBMs, DNTs, and DNGs as directed by B&W or CCNPP Engineering
- All bobbin probe or X-P robe I-codes* Additional bobbin indications as directed by CCNPP Engineering
- Additional indications as needed to meet operational assessment requirements for tube integrity, as identified by B&W Engineering o Visual Examination
- Visual inspection of all installed tube plugs in both SGs in accordance with section 6.9 of the EPRI PWR Steam Generator Examination Guidelines, Rev 7. This included both welded and mechanical plugs.Page 5 of 31.
- Visual inspections of the hot and cold leg channel heads including the divider plate/tubesheet interface, the entire bowl per Westinghouse NSAL 12-1 methods for evidence of cladding degradation and/or cracking oThe following secondary side inspections were performed (both SG's)* Secondary side visual inspection of tubesheet ,including the inner bundle passes, the annulus, and the no-tube lane regions* Secondary side visual inspection of the 1 st lattice grid support* Targeted inspection locations identified as PLP (Possible loose Part) by ECT* Visual Upper Bundle inspection
- Visual inspection of moisture separators 3.0 Degradation mechanisms found (5.6.9.b)Three degradations mechanisms were confirmed to be present in the CCNPP U2 SG's. These are: 1) fan bar wear, 2) lattice grid support wear, and 3) foreign object wear. No other degradation mechanisms, including tube-to-tube wear, were detected.Lattice grid support wear (LGSW) had not been previously detected on U2, however as it has been found on the U1 SG's the presence of LGSW was not unexpected based on the CC2R21 degradation assessment.
The visual inspection of the cladding, previously installed plugs, and divider plate found no degradation.
The secondary side visual inspections of the steam drum, upper bundle,1st lattice grid support, and moisture separators found no degradation.
4.0 Nondestructive examination techniques utilized for each degradation mechanism (5.6.9..c)
Table 1 below identifies NDE examination techniques utilized for each identified degradation mechanism.
4.1 Table I -NDE Techniques Utilized for Sizin Identified De radation Lattice Grid Support Wear Bobbin (%TW depth) 96004.1 MRPC +Point (length) 96910.1 Page 6 of 31
- The Array probe was the primary means of detecting foreign objects and foreign object wear during the inspection.
However, the +PointTM probe was used for further characterization and sizing of wear.** There are other EPRI techniques qualified for sizing of foreign object wear depending on the shape of the flaw. ETSS 27901.1 was selected based on the circumferential groove appearance of the foreign object wear indications detected during the U2R1 9 inspection 5.0 Location, orientation (if linear), and measured sizes (if available) of service induced indications (5.6.9.d)5.1 Fan Bar Wear Fan bar wear (FBW) is a mechanical degradation process which produces volumetric tube wear at the interface between the U-bend anti-vibration supports (fan bars) and the tubes. A total of 447 FBW indications were identified in the Calvert Cliffs Unit 2 RSGs during CC2R21. One hundred and four (104) of the 447 indications were newly reported during the CC2R21 outage. There were 44 and 60 new indications in SG21 and SG22, respectively.
The deepest repeat FBW indication was 30% 1W in 22 SG. Table 2 provides a summary of the fan bar wear indications from CC2R2I. The maximum depth among these indications was 30% TW which is consistent with results from previous inspections.
Growth of the repeat indications was minimal and consistent with previous results.Figure 1 provides the distribution of fan bar wear depths for both steam generators as reported with the bobbin coil probe. As shown in the figure, SG22 contained more indications.
A majority of the indication in both SG's are less than 20% TW.Figures 2 and 3 provide tube map locations of the reported FBW. Although the tube maps shown in Figures 2 and 3 provide a view of the tubesheet primary face from the hot leg side, both the hot leg and cold leg FBW indications are included on each map. Most of the wear continues to occur in longer tubes (i.e., larger U-bend radius), clustered towards the center-most tube columns.Appendix C provides a complete list of FBW indications.
Page 7 of 31 5.1.1 Table 2 -Fan Bar Wear Indication Summary I 3. S 0 I-I~1 Total Number of In-Service Tubes Prior to CC2R21 8434 8439 Number of FBW Indications 154 293 Maximum Depth of FBW (%TW) 25% 30%Number of TSP Wear Indications
>40%TW 0 0 Number of Newly-Reported Indications 44 60 Number of Tubes Plugged due to FBW 0 0 5.1.2 Figure 1 -Distribution of Fan Bar Wear Depth 90 80 IOa 60**SG22 i5020 -........10 .....Q~. 40 40 d~ d~ ~ &., 4' .~' 40 -~~0 ~ 43&~, .'~EL~4o&~, -~'Depth In Percent Tha 11wf Page 8 of 31 5.1.3 Figure 2 -SG 21 Fan Bar Wear Map 140 120 0 0.0o 0 0*00 0 0o°oTubes With Indications
.. .............. ...........0 0 .. ..... .........
..... \ t ...0 60 40 20 0 0 20 40 60 80 100) 120 140 160 Column Number 5.1.4 Figure 3 -SG 22 Fan Bar Wear Map 140 120 E S80 -60 +1 04 i\160O 40 20--0 80 100) 120 140 Column Number 0 20 40 60 Page 9 of 31 5.2 Lattice Grid Support Wear Three indications of wear related to the lattice grid supports were reported during the CC2R21 outage (two indications in SG21 and one indication in SG22). All three of these indications were inspected with +Point T M to confirm that the morphologies of the indications were consistent with lattice grid wear and not some other damage mechanism such as foreign object wear. After confirmation with +PointTM, all three indications were depth sized using the bobbin coil data and length sized with+Point T M .All three indications have a tapered flaw shape.This was the first occurrence of lattice grid wear at Calvert Cliffs Unit 2. However, this is not an unexpected occurrence since lattice grid wear has already been observed at Unit 1. The depths of the Unit 2 indications are consistent with the depths of the indications observed in Unit 1. Table 3 provides a listing of these indications.
5.2.1 Table 3 -Summary of Lattice Grid Support Wear Indications 5 G22 102 i30 02C -1.74 to -1.24 10% TW 0.5" 5.3 Foreign Object Wear During the CC2R21 inspection, twenty-one (21) foreign object wear indications were detected in 17 tubes. These indications were reported as LPW (Loose Part Wear) in the eddy current database.
Four (4) indications in three tubes were newly detected in CC2R21. The remainder were legacy and showed no change in size since previous inspections.
Three (3) of the new indications were identified on two tubes in SG21, these indications were in a cluster about 15 inches above the cold leg tubesheet.
The wear was caused by weld slag that was still present at the time of inspection and has since been removed.One (1) of the new indications was on a tube in SG22. This was the deepest new indication detected during the CC2R21 inspections, sized at 36% TW. This indication was near the lower edge of the 04H lattice support. This indication was due to a foreign object based on its location between the contact points of the lattice grid. This indication was caused by a transient loose part which is no longer present based on ET inspection results. The overall deepest indication for SG22 is at Row 126 Col 116, and is 38% TW.This is a previously detected legacy indication.
No growth was measured.Page 10 of 31 All LPW indications were sized below the site plugging limit. There were no objects present at non-plugged LPW tube locations from previous outages. Since no objects were present to cause further wear and all LPW %TW were less than the 40% tech spec. plugging limit, all 17 tubes were returned to service.Table 4 provides a summary of the foreign object wear indications seen in the Unit 2 RSGs.5.3.1 Table 4 -Summary of Foreign Object Wear SG1 1 6 TSH -.05to +.19 2724No SG21 12 66 TSH .37 to +.55 24 0.18 No SG21 12 162 TSH -.01to +.17 27 0.18 No SG21 13 65 TSH -.18to +.07 28 0.25 No SG21 14 66 TSH +.36 to +.54 19 0.18 No SG21 14 66 TSH +.36to +.54 17 0.18 No SG21 72 146 TSH +.13to +.31 34 0.18 No SG21 75 147 TSH +17.86 to0+18.09 19 0.23 No SG21 77 147 TSH +17.52 to +17.76 21 0.24 No SG21 77 149 TSH +20.59 to0+20.82 20 0.23 No SG21 137 73 TSC +14.89 to0+15.08 21 0.19 Yes SG21 137 75 TSC +14.4 to +14.58 24 0.18 Yes SG21 137 75 TSC +14.72 to0+14.79 19 0.07 Yes SG22 14 4 TSC +.32 to +.5 24 0.18 No SG22 17 1 TSC -.07to +.13 24 0.2 No SG22 18 2 TSC -.01to +.23 24 0.24 No SG22 82 42 04H -1.76 to -1.47 36 0.29 Yes SG22 112 82 04H +37.63 to +37.82 24 0.19 No SG22 124 116 TSC +12.58 to +12.85 18 0.27 No SG22 126 116 TSCI12.21 to 12.44 24 0.23 No SG22 126 116 TSC 12.52 to 12.76 38 0.24 No 6.0 Number of tubes plugged during the inspection active degradation mechanism (5.6.9.e)Zero (0) tubes were plugged during the CC2R21 outage.outage for each Page 11 of 31 7.0 Total number and percentage of tubes plugged to date and the effective plugging percentage in each steam generator (5,6.9.f)Table 5 provides the post CC2R21 outage tube plugging status of the CCNPP2 SG's.There are currently 37 tubes plugged in SG21 and 32 tubes plugged in SG22.7.1 Table 5 -Tube Plugging Summary SG21 847 37 S(0.437%).
SG22 8471 37 (0.4378%)Total 16,942 69 (0.407%)There are no sleeves installed in the CCNPP1 steam generators, therefore the effective plugging percentage is the same as stated Table 5 above.8.0 The results of condition monitoring, including results of tube pulls and in-situ testing (5.6.9.g)The condition monitoring assessment is summarized in Figures 4 through 6. These figures provide the condition monitoring limit curves corresponding to the NDE technique employed for each degradation type. All reported degradation falls below the applicable condition monitoring curve and therefore satisfies the Technical Specification structural performance criteria.
No tube-pulls or in-situ pressure testing were required.8.1 Fan Bar Wear Based on the sizing parameters for this technique, the CM curve shown in Figure 4 was generated and documented in the Degradation Assessment (DA). Each of the fan bar wear indications were conservatively plotted at an axial length of 1.8 inches based on current and previous length sizing of the deepest indications.
As shown, all indications lie well below the CM curve. Hence, structural integrity of the fan bar wear indications is demonstrated.
8.2 Foreign Object Wear As documented in the DA, ETSS 27903.1 provides a lower CM limit compared to the other 2790X series of techniques.
Hence, use of the CM limit curve from the DA is appropriate and conservative for the evaluation of foreign object wear at Calvert Cliffs Unit 2. Figure 5 shows the condition monitoring results for foreign object wear. As shown, all indications lie well below the CM curve. Hence, structural integrity of the foreign object wear indications is demonstrated.
Page 12 of 31 8.3 Lattice Grid Wear Based on the sizing parameters for the bobbin technique, the CM curve shown in Figure 6 was generated and documented in the DA. Since all three of the lattice grid wear indications were inspected with +PointTM, the lengths measured from the +PointTM and depths from bobbin inspections are reflected in the figure. As shown, all indications lie well below the CM curve. Hence, structural integrity of the lattice grid wear indications is demonstrated.
Some of the detected flaws had measured axial extents <0.25". For these cases, the flaws were evaluated for leakage integrity using the flaw model for uniform 360 degree thinning of finite axial extent. This is allowed per Section 9.6.3 of the EPRI SG Integrity Assessment Guideline for situations involvng pressure loading only. Using the uniform thinning equation from Section 5.3.2 of the EPRI SG Flaw Handbook the CM limit of a flaw with an axial length of 0.25" is 64.1%TW. Since none of the detected indications approached this depth, accident leakage integrity for these shorter volumetric flaws is also confirmed.
Page 13 of 31 8.3.1 Figure 4- Condition Monitoring Results for Fan Bar Wear 100 SNote: CM limit curve is based on 90structural lengths and depths.9 .....Indication depths are conservatively i plotted using maximum depths.8 0 .. ..... .. ..... ..... ... ...........
... ...... ... .[--Limit (96004.1)Fan Bar Wear Indications 70 -=3*60 60 I-50 -2. 401 S301 20 -10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.82 Page 14 of 31 8.3.2 Figure 5 -Condition Monitoring for Foreign Object Wear 100 90 1 704--......
Note 1: CM limit curve is based on structural lengths and depths. Indication depths are conservatively plotted using maximum depths.Note 2: CM limit curve shown is for ETSS 27903.1 as documented in the DA.This ETSS gives a lower CM limit that ETSS 27901.1 and is, therefore, conservative for this application.
a.*1 60 40 30*20 I-10 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1.8 2 Page 15 of 31 8.3.3 Figure 6 -Condition Monitoring for Lattice Grid Wear 100 80 -70 I Note: CM limit curve is based on structural lengths and depths.Indication depths are conservatively plotted using maximum depths.Limit (96004.1)* Lattice Grid Wear Indications 360 4J a..,:, 30 I i L 20!10*4 0 0.2 0.4 0.6 0.8 1 1.2 Structural Length (Inches)1.4 1.6 1,82 8.4 Operational Leakage Criterion and Validation of Previous OA The operational leakage criterion was also satisfied by the absence of any measureable primary to secondary leakage since the previous inspection.
The results of the 2015 inspection and the condition monitoring assessment confirm that the 2011 operational assessment was appropriately bounding.Page 16 of 31 APPENDIX A -Typical U-Bend Support System CLAMPING BARS*TIE 11UBES TUJBE IN PLANE DIRECION FLAT BAR ThRE OUT OF PLANE DIR.E6rION Page 17 of 31 Appendix B Calvert Cliffs U-2 Tube Support Layout FI N RN 3 c'i ~ ii____C&, !3, I HI ___ ___ __I I I i~ii iI I f-JT"II t i Page 18 of 31 APPENDIX C -002R21 Fan Bar Wear Summary Table C- 1: SG21 Fan Bar Wear Summary 25 163 9 F07 2.00 29 159 13 F06 1.66 30 162 7 F07 -0.93 34 6 15 F06 -1.15 44 6 9 F06 1.70 45 79 7 F07 0.64 48 6 9 F06 1.91 48 8 7 F06 1.86 52 126 10 FO8 -0.75 57 107 14 F08 1.76 58 98 8 F05 -1.79 60 80 7 F06 0.62 63 69 6 F09 2.17 69 115 5 F04 -1.99 74 78 10 FO8 1.00 75 75 9 F08 0.88 76 76 9 F07 -0.78 77 67 7 F08 0.74 77 75 10 F08 0.74 77 79 13 F08 0.74 77 83 11 F08 0.50 80 74 8 F08 1.96 80 76 11 F07 -0.67 80 78 12 FOB 1.92 81 75 7 FO8 0.85 81 79 15 FOB 0.85 81 97 10 FOB 1.75 82 84 5 F06 -1.07 82 94 9 FOB 0.77 83 67 B FOB 0.70 83 79 12 FOB 0.71 83 97 7 FOB 1.91 Page 19 of 31 84 76 11 F07 -0.83 85 75 9 FO8 0.81 85 75 8 F07 1.83 85 79 16 FO8 0.81 85 93 11 FO8 1.77 86 84 10 F06 -0.60 86 88 6 FO8 0.81 86 94 11 F08 0.74 87 67 8 FOB 0.72 87 75 9 FOB 0.84 87 75 5 F07 1.79 87 79 9 F08 0.79 87 83 8 FOB -0.58 87 83 6 F07 -0.05 87 83 7 F06 0.00 87 87 13 F08 1.72 87 93 14 FOB 1.77 87 97 8 FO8 1.98 88 74 7 F08 2.04 88 78 7 F06 1.14 89 75 15 F06 -0.65 89 87 9 F08 1.93 89 87 4 F07 1.16 89 87 7 F06 -1.74 89 93 7 F06 -1.75 89 93 8 F08 1.79 89 101 6 F05 -0.83 90 74 9 F08 1.97 90 76 6 F07 -0.79 91 75 8 FOB 0.79 91 75 7 F06 -0.63 92 78 13 F08 1.81 92 88 8 F06 -0.63 93 73 11 FOB 0.84 93 83 12 F06 -0.44 93 87 8 FOB 1.83 94 74 12 F06 -1.67 94 78 15 FOB 1.65 Page 20Oof 31 94 82 10 F06 -16 95 77 8 F06 -1.55 95 83 9 F08 -0.55 95 87 19 F08 1.89 95 87 10 F09 0.83 95 99 8 F05 -1.48 96 78 8 F08 1.52 96 80 9 F08 -1.97 97 75 10 F06 -0.60 97 75 10 F07 1.50 97 83 5 F07 0.00 97 83 10 F08 0.51 98 74 10 F06 -1.71 98 74 8 F08 1.92 98 76 8 F07 -0.65 98 82 9 F08 1.92 98 82 10 F06 -1.67 98 88 8 F08 0.86 99 75 9 F07 1.76 99 83 9 F06 -0.49 99 83 9 F07 -0.56 99 83 9 F08 -0.56 99 87 18 F06 -1.21 99 87 8 F07 0.77 100 80 8 F06 -1.64 101 75 7 F09 -1.44 101 75 20 F06 -0.58 101 75 15 F07 0.90 101 79 9 F08 0.88 101 79 7 F02 -2.02 101 79 10 F06 -0.65 101 79 7 F07 1.92 101 81 8 F07 -0.79 101 83 5 F06 0.09 101 83 8 F07 0.05 101 83 10 F08 -0.56 101 83 5 FO5 0.00 101 87 11 F06 -1.72 101 87 13 F07 0.72 Page 21 of 31 102 82 5 F07 -13 102 88 8 F06 -0.70 102 90 10 F06 -0.69 103 83 10 F06 0.62 103 87 9 F06 -1.67 103 87 15 F07 0.76 103 91 8 F06 -1.71 104 78 9 F07 0.81 104 78 9 F08 1.85 104 84 9 F06 -0.60 104 86 7 F06 -0.70 104 88 15 FO5 -1.25 104 88 22 F06 -1.11 104 88 7 F07 1.78 105 79 9 F07 1.87 105 83 14 F07 0.00 105 87 9 F07 0.81 106 76 20 F06 1.16 106 76 6 F07 -1.28 106 78 8 F07 0.79 106 88 9 F08 0.79 106 90 10 F06 -0.70 107 75 9 F07 1.72 107 83 10 F06 0.49 107 83 12 F07 0.00 107 85 8 F06 0.74 107 87 19 F07 0.74 108 74 8 F07 0.78 108 76 25 F06 1.25 108 90 12 F06 -0.74 110 76 6 F06 1.20 110 88 9 F06 -0.69 110 90 8 F06 -0.56 111 75 17 F06 -0.79 111 93 7 F07 0.77 112 90 14 F06 -0.67 113 87 10 F07 0.78 114 76 16 F06 -0.81 117 89 18 F06 -1.28 Page 22 of 31 119 87 16 F07 07 122 88 7 F09 1.83 123 89 7 F06 -1.86 132 92 5 F06 1.25 133 91 11 F02 0.88 TotaI:I 154[ I___Page 23 of 31 Table C- 2: SG22 Fan Bar Wear Summary S, StT Se[e _,t 22 6 10 F07 -0.23 37 35 7 F07 1.82 40 28 8 F09 -0.32 44 140 8 F07 -0.72 49 29 8 F07 1.80 61 111 11 F08 1.79 69 83 8 F08 -0.55 70 54 7 F06 -1.64 70 82 8 F07 0.89 70 82 8 F06 -1.82 72 64 8 F08 1.91 72 72 11 F08 2.12 72 82 7 F08 1.94 72 92 11 F08 0.70 73 81 6 F07 0.02 73 91 16 F08 1.65 74 82 8 F06 -1.80 74 82 4 F07 0.81 74 82 8 FOB 1.94 74 94 13 F08 0.80 75 73 8 F08 0.76 75 81 8 F07 -0.78 75 93 7 F08 1.85 76 64 9 F08 1.99 76 72 10 F06 -1.75 76 72 16 FOB 1.89 76 82 8 F07 0.81 76 82 9 FOB 1.92 76 82 9 F06 -1.69 76 98 10 FOB 0.81 77 65 13 FOB 0.79 77 69 8 FOB 0.81 77 73 9 F08 0.79 77 81 8 F07 -0.78 78 64 8 F08 1.88 78 82 13 F06 -1.80 Page 24 of 31 S S~ 656 T l79 81 13 F07 -1.34 79 83 5 F07 -0.24 79 89 8 F07 0.74 79 91 9 F08 1.84 79 93 28 F08 1.42 80 64 8 F08 -1.78 80 64 9 F09 -1.92 80 80 7 F06 -1.74 80 82 8 F06 -1.81 80 82 8 F05 -0.79 81 63 8 F08 -0.91 81 91 10 F08 1.79 82 82 10 F07 0.92 82 82 7 F06 -1.87 82 84 9 F06 1.34 82 84 8 F08 0.82 82 94 9 F08 0.80 83 73 11 F07 1.69 83 73 20 F08 0.70 83 75 14 F02 0.77 83 81 10 F07 -1.27 83 91 13 F08 1.89 84 80 7 F06 -1.68 84 92 19 F08 0.78 84 94 21 F08 0.83 85 65 10 F08 0.79 85 79 11 F08 0.83 85 79 7 F08 -1.24 86 44 7 FO5 1.23 86 72 9 F05 -0.87 86 72 11 F06 -1.69 86 74 11 F06 -1.70 86 92 12 F08 0.78 86 94 16 F08 0.71 87 65 14 F08 0.74 87 83 17 F08 0.00 87 83 8 F06 -0.09 87 83 25 F07 0.05 88 76 9 F06 .1.81 Page 25 of 31 IS~ S S..A "11t I r 88 76 9 F05 1.85 88 78 9 F06 -1.22 88 82 9 EQ5 1.91 88 82 14 F06 1.84 88 84 9 F07 -0.87 88 92 10 F08 0.73 89 65 16 F08 0.79 89 69 12 F08 0.80 89 73 20 F08 0.76 89 81 11 F06 -0.74 89 83 8 F08 -0.56 89 83 10 F06 0.49 89 83 6 F05 0.47 89 83 6 F07 0.54 89 89 12 F08 -1.36 90 82 6 F06 -1.71 91 65 23 F08 0.86 91 81 7 FOG -0.74 91 83 6 F07 0.00 91 103 8 FO5 -0.80 92 76 10 FOG 1.82 92 88 6 F06 0.71 93 73 10 F06 -0.76 93 79 9 FOG -0.74 93 81 9 F06 -0.71 93 83 10 F06 0.45 93 83 9 F07 0.50 93 91 9 F08 1.77 93 93 8 F08 1.77 93 97 8 F08 1.79 94 76 10 FOG 1.77 94 80 9 FOG -1.83 94 82 4 F07 0.78 94 82 19 FOG -1.34 94 86 7 F06 0.62 94 92 12 F08 0.81 94 94 11 F08 0.74 95 81 7 F07 -1.15 95. 83 6 FOG 0.12 Page 26 of 31.
95 83 12 F07 0.42 95 93 7 FO8 1.70 96 80 7 F06 -1.77 96 82 10 F06 1.31 96 82 6 F07 -1.31 96 84 20 F07 1.25 96 86 7 F06 0.00 96 90 5 FOB -1.37 97 25 7 F06 0.81 97 73 9 F06 -0.78 97 75 9 F06 -0.80 97 77 11 F06 -0.78 97 79 11 F06 -0.69 97 81 5 F06 1.34 97 81 4 F08 -1.30 97 81 9 F07 -1.30 98 72 9 F08 1.84 98 76 10 F06 1.67 98 78 13 F08 1.76 98 78 7 F07 0.76 98 82 8 F07 0.81 98 84 6 F06 -0.87 98 94 7 F08 0.76 99 71 14 F08 -0.74 99 77 18 F06 -0.79 99 81 7 F07 -0.81 99 81 7 F06 -0.76 100 76 8 F06 -1.92 100 78 11 F08 -1.90 100 78 8 F07 0.72 100 78 7 F06 -1.81 100 82 14 F07 0.76 100 82 10 FOB 1.89 100 82 16 F06 -1.29 100 84 7 F07 1.34 100 88 10 F07 1.79 101 77 11 F06 -0.77 101 79 10 F07 1.82 101 81 9 F06 -0.62 Page 27 of 31 101 85 9 F09 1.30 101 87 8 F07 0.76 101 89 6 F09 0.66 102 76 13 F06 1.69 102 76 10 F07 -1.23 102 80 7 F08 2.03 102 82 7 F06 -1.69 102 82 10 F09 0.74 102 84 6 F07 1.79 102 86 8 F02 0.78 103 77 14 F06 -0.72 103 79 8 F07 1.73 103 79 11 F06 -0.69 103 81 8 F06 -0.72 103 81 6 F08 -1.18 103 83 15 F06 0.47 103 83 5 F07 -0.09 103 85 12 F08 1.30 103 87 11 F07 0.66 103 87 6 F09 0.71 104 82 11 F07 0.76 104 82 8 F09 0.69 104 82 9 F06 -1.92 104 84 10 F07 1.78 104 94 17 F06 -1.18 105 67 9 F07 -1.20 105 75 13 F06 -0.78 105 77 15 F06 -0.76 105 79 20 F06 -0.71 105 79 13 F07 1.84 105 81 9 F07 1.81 105 81 14 F08 1.39 105 81 11 F06 -0.70 105 83 14 F07 0.45 105 83 9 F06 0.50 105 83 7 FO5 -0.05 105 87 8 F01 0.53 106 80 6 F07 1.20 106 82 13 F06 -1.77 Page 28 of 31 S S 106 82 18 F07 0.71 106 84 5 FO8 -1.45 106 90 22 F07 1.20 107 75 14 F06 -0.77 107 77 12 F06 -0.86 107 79 8 F06 -0.88 107 81 12 FOB -1.40 107 81 21 F06 -0.72 107 83 4 F06 -0.02 107 83 5 FO5 0.02 107 83 12 F07 -0.02 107 85 11 F09 0.83 107 85 8 F06 1.18 107 93 8 F07 0.81 108 74 6 F06 -1.81 108 76 9 F09 0.76 108 76 7 FO8 1.39 108 82 11 F08 1.34 108 82 20 F07 0.76 108 82 11 F09 0.74 108 84 14 F07 1.77 108 84 11 F06 -0.71 108 86 24 F06 -1.18 108 86 6 F08 1.25 108 86 12 F07 1.68 108 90 6 F06 -0.73 109 75 16 F06 -0.86 109 77 22 F06 -0.78 109 79 24 F06 -0.73 109 81 15 F08 -1.18 109 81 8 F07 -1.37 109 81 15 F06 -0.86 109 83 6 F06 0.02 109 83 7 F07 -0.14 109 85 17 F07 -1.35 109 87 12 F07 0.66 110 78 13 F07 0.76 110 82 9 F07 0.73 110 90 8 FOB -1.44 Page 29 of 31.
111 73 26 F06 -1.39 111 75 22 F06 -0.57 111 77 28 FOG -0.76 111 79 18 FOG -0.69 111 79 9 F07 1.84 111 81 14 FOG -0.76 111 111 9 F03 -1.16 112 72 11 F08 1.33 112 78 13 F07 0.64 112 86 10 F06 -0.69 113 75 12 F06 -0.76 113 77 30 F06 -0.73 113 81 13 FOG -1.30 113 81 9 F08 0.83 113 83 10 F07 0.50 113 83 8 FOG 0.48 113 91 20 F02 -2.18 114 76 4 FOG 1.27 114 78 8 F07 0.72 114 82 9 FOG 1.31 114 84 15 F06 -1.21 114 88 17 F05 1.36 115 73 7 FOG -0.72 115 77 8 FOG -0.76 115 81 7 F06 1.13 115 81 5 F07 -1.29 115 83 7 F07 0.45 115 83 9 FOG 0.45 115 93 10 F07 0.65 116 82 22 F07 1.20 116 84 10 F08 -1.84 117 83 18 F06 0.00 117 83 7 F08 0.14 117 83 7 FO5 0.00 117 91 18 F07 1.29 119 81 13 FOG -0.69 120 82 5 F08 1.35 120 88 12 F08 -1.25 121 75 7 FOG -0.73 Page 30 of 31 121 83 11 F08 0.43 121 87 8 F07 0.71 122 74 9 F07 0.69 123 77 7 F06 -0.81 123 81 11 F07 1.67 123 83 26 F07 0.12 123 83 4 EQ5 -0.07 123 83 11 F06 0.62 124 76 9 F06 0.67 124 82 5 F09 -1.60 124 82 11 F08 -1.46 124 82 13 F06 -1.41 125 91 12 F03 -2.06 126 82 12 F07 1.26 127 83 6 F07 0.07 128 92 12 F08 -1.21 130 92 11 F06 1.74 131 75 9 F06 -0.92 131 83 5 F08 0.09 132 76 6 F08 -1.32 132 80 5 F05 -1.23 132 92 10 F03 -1.83 135 83 12 F07 0.16 Total: 293 Page 31 of 31