L-23-058, 180-Day Steam Generator Tube Inspection Report
| ML23087A063 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 03/27/2023 |
| From: | Blair B Energy Harbor Nuclear Corp |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-23-058 | |
| Download: ML23087A063 (1) | |
Text
energy harbor Barry N. Blair Site Vice President, Beaver Valley Nuclear March 27, 2023 L-23-058 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 180-Day Steam Generator Tube Inspection ReportEnergy Harbor Nuclear Corp.
Beaver Valley Power Station P.O. Box 4 Shippingport, PA 15077 724-682-5234 In accordance with Beaver Valley Power Station, Unit No. 1, Technical Specification 5.6.6.1, "Unit 1 SG [Steam Generator] Tube Inspection Report," Energy Harbor Nuclear Corp. hereby submits the steam generator tube inspection results obtained during inspections conducted during the fall 2022 refueling outage.
There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Mr. Phil H. Lashley, Manager -Fleet Licensing, at (330) 696-7208.
Barry N. Blair
Enclosure:
Unit #1 -
1 R28 Steam Generator 180 Day Report cc: NRC Region I Administrator NRC Resident Inspector NRR Project Manager Director BRP/DEP Site BRP/DEP Representative Enclosure L-23-058
Unit #1 - 1R28 Steam Generator 180 Day Report
(18 pages follow)
Unit #1 - 1R28 Steam Generator 180 Day Report Information Required by Technical Specification (TS) 5.6.6.1 Technical Specification 5.6.6.1 requires that a report be submitted to the Nuclear Regulatory Commission (NRC) within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with the Technical Specification 5.5.5.1, Unit 1 SG Program. For the fall 2022 refueling outage (1R28), the initial entry into MODE 4 occurred on November 16, 2022.
NOTE: Refer to the Definitions of Abbreviations, Codes and Reporting Terminology section (Page 17) for abbreviations, 3 letter codes and other nomenclature used throughout this report.
Design and Operating Parameters
Steam Generator Design and Operating Parameters SG Model / Tube Material / # SGs per unit Westinghouse 54F / Alloy 690TT / 3
- of tubes per SG / Nominal Tube Diameter / 3,592, 0.875 inches / 0.050 inches Nominal tube thickness Support Plate Style / Material Broached Quatrefoil / Stainless Steel Last inspection date Fall 2016 (1R24)
EFPM since the last inspection 67.32 Total cumulative SG EFPY at 1R28 15.27 Mode 4 initial entry November 16, 2022 Observed primary to secondary leak rate since None the last inspection and how it trended with time Nominal indicated value of Thot The nominal primary hot leg temperature did not exceed 618°F for any SG during the Cycle 25 through Cycle 28 operating interval Loose parts strainer Each SG has thirty-eight (38) feedwater spray nozzles located on the feedwater ring that is internal to the steam generator. Each spray nozzle has 156 small diameter holes.
Degradation mechanism sub population No degradation mechanism sub populations were used for the purposes of Operational Assessment calculations.
Deviations from SGMP guidelines since the last None inspection Steam Generator Schematic without See Page 18 dimensions
Page 2 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report Per Technical Specification 5.6.6.1.a through 5.6.6.1.f, the following information is to be submitted to the NRC:
TS 5.6.6.1.a The scope of inspections performed on each SG:
1R28 Primary Side Inspection Scope
Exam Probe Extent 100% Full-length (F/L) Bobbin Tube end to tube end, Except Row 1 and 2 U-bends 100% Row 1 and Row 2 U- +POINT TSP 07H to TSP 07C bends TTS Peripheral and Tube Lane +POINT Hot and cold leg TTS inspections (TSH +3/-3 inch) (3 tubes deep) 100% Dents/Dings 1-volt (Historical and newly +POINT Through extent of the dent/ding reported)
All existing TSP/Foreign Object wear and Volumetric indications New AVB/TSP/Foreign Object wear and Volumetric indications wear indications PLP indications and surrounding tubes (1 tubes deep)
Existing foreign objects remaining in the SGs (1-Special Interest (Diagnostic) +POINT tube deep)
Surrounding confirmed foreign objects (2 tubes deep)
All bobbin I-Codes (DNI, NQI, etc.)
New proximity indications (PRO)
All GEO, BLG/OXP(1), OBS, and RRT indications reported from the current inspection.
All PVN 1-volt that may mask a flaw determined by Lead Analyst/Engineering Scale Profiling Bobbin Perform Scale Profiling in 1 SG Plug Visual Inspection Visual All hot leg and cold leg installed plugs Primary Channel Head Visual Visual Hot leg and cold leg channel heads in all SGs Notes:
(1)Inspect BLG/OXP signals that are reported by the bobbin inspection.
There was no eddy current nondestructive examination (NDE) scope expansion of the base inspection programs as required in the 1R28 DA. Targeted diagnostic inspections were performed as part of the special interest programs, such as I-code signals, permeability indications, and possible loose part (PLP) box-ins.
Page 3 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report Secondary Side Visual Examinations:
Secondary side tubesheet cleaning and visual inspections were completed during 1R28. The inspections are summarized below:
- Sludge lancing in all three SGs
- Post sludge lancing cleanliness inspection in all three SGs
- Post sludge lancing FOSAR in all three SGs in the following areas:
o Hot leg and cold leg annulus region o Hot leg and cold leg peripheral tubes o Tube lane and tube lane peripheral tubes o Blowdown pipe and supports
- In-bundle visual inspections of selected hot leg and cold columns from the tube lane in all three SGs
- Feedring and Upper Steam drum inspections in all three SGs:
o Mid-deck Plate o Primary Moisture Separators, including swirl vanes and riser/downcomer barrels o Secondary Moisture Separators o Sludge Collector o Feedring Spray Can Inspection o General area and internal components within the Steam drum
TS 5.6.6.1.b The nondestructive examination techniques utilized for tubes with increased degradation susceptibility:
The top of tubesheet peripheral (3 tubes deep) and tube lane in each steam generator were inspected with a +POINT probe primarily to detect foreign object wear.
100% of dents/dings >= 1-volt (historical and new) were inspected with a +POINT probe through the extent of the dent/ding. The surface riding +POINT probe reduces the influence of the dent/ding signal on flaws at these locations. Although stress corrosion cracking at dents/dings is currently classified as a non-relevant degradation mechanism, the +POINT probe would be expected to provide sufficient detection capabilities at dents/dings.
Page 4 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report
TS 5.6.6.1.c For each degradation mechanism found:
- 1. The nondestructive examination techniques utilized:
1R28 Probes and Techniques for Detection and Sizing of Existing Degradation Mechanisms
Degradation Inspection Detection Detection Sizing Sizing Technique Mechanism Location Program Probe Type Technique Probe ETSS/Revision ETSS/Revision Type Wear AVB Supports 100% F/L Bobbin Bobbin I96041.1, R6 Bobbin I96041.1, R6
+POINT
Wear TSP Supports (Land 100% F/L Bobbin Bobbin I96043.4, R0 Bobbin I96043.4, R0 Wear) +POINT
Wear TSP Supports (Burr 100% F/L Bobbin Bobbin I96043.4, R0 +POINT 21998.1, R4 Wear) +POINT
Wear due to Top of Tubesheet, 100% F/L Bobbin, Bobbin 27091.2, R2 +POINT 21998.1, R4 Foreign Objects Support Structures Special Interest +POINT 21998.1, R4 +POINT and Freespan +POINT +POINT 2790x.1/2(2)
Notes:
(1) No expansion scope required since 100% inspections were performed.
(2) ETSS 2790x series technique, where x is a value of 1-6.
Page 5 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report
- 2. The location, orientation (if linear), measured size (if available), and voltage response for each indication. For tube wear at support structures less than 20 percent through-wall, only the total number of indications needs to be reported:
During 1R28, a total of 17 AVB wear indications were reported in 14 tubes, where 9 new indications were detected. The largest indication measured 14% TW (SG B R39C52) as measured by bobbin probe sizing technique I96041.1. The maximum depth of all indications ranged from 4% TW to 14% TW.
During 1R28, a total of 68 indications of TSP land wear in 64 tubes were detected. There were 44 land wear indications that were newly reported in 1R28. The maximum depths of the TSP land wear indications ranged from 3% TW to 12% TW as measured by sizing technique ETSS I96043.4. The largest indication of TSP land wear had a maximum depth of 12% TW and was in tube R41C52 in SG A. This tube (R41C52 in SG A) contained a 12% TW TSP land wear indication and a 17% TW historical foreign object wear at the same TSP land but at a slightly higher elevation. The flaw depths were similar to prior inspections, but the extent of the land wear was extending close to the foreign object wear indication. Therefore, this tube was preventively plugged. An indication in Tube R6C98 in SG A that was previously classified as TSP burr wear in 1R24 was +POINT probe inspected in 1R28. This examination clearly showed that the flaw is now indicative of traditional tapered TSP land wear. Therefore, this flaw was re-classified as TSP land wear measuring 7% using bobbin technique ETSS I96043.4.
During 1R28, 2 indications in 2 tubes of burr wear were reported in tubes R38C78 in SG B and R1C20 in SG C. Tube R1C20 also contained a TSP land wear at a different land at the same TSP. These indications were historical in nature and were first reported in 1R18. There were no newly reported burr wear indications found in 1R28 and one additional historical burr wear indication that was re-classified as TSP land wear. The maximum depths of the burr wear indications were 26% TW and 17% TW as measured by +POINT probe sizing technique ETSS 21998.1. Historical data reviews of these indications showed no change beyond eddy current variance between inspections. The bobbin and +POINT voltages showed no change between 1R24 and 1R28, thus indicating no change in flaw size.
A total of 4 indications of FO wear were identified during 1R28. Three of the indications were historical in nature and the remaining 1 was newly reported during 1R28. The 3 historical FO wear indications were in 2 tubes. Tube R41C52 in SG A contained a historical FO wear indication along with a TSP land wear indication at the lower edge of the same TSP land. Tube R47C42 in SG B contained 2 FO wear indications. These 3 historical FO wears showed no significant change in eddy current signal response outside of typical eddy current repeatability uncertainty. All FO associated with the historical wear flaws were removed in a prior outage or shown to have no associated FO through bobbin and +POINT probe inspections. Tube R30C59 in SG C contained a newly reported volumetric indication located slightly below TSP 02H and was aligned with the quatrefoil flow hole. Consequently, the indication was not associated with wear from quatrefoil land interaction. The indication had a maximum depth of 29%TW as measured by +POINT sizing technique ETSS 21998.1. The affected tube (Tube R30C59 in SG C) was preventively plugged.
Page 6 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report The tables below summarize all foreign object wear and structure wear that was greater than or equal to 20% TW that was detected in 1R28.
The location, orientation (if linear), measured size (if available), and voltage response for tube wear at support structures (excluding foreign object wear) greater than or equal to 20 percent through-wall.
Axial SG Row Col Volts Location Elevation, Length, inch Degradation %TW inch
B 38 78 0.17 02H 0.44 TSP Burr Wear 26 0.19
Foreign Object Wear Summary
Axial Circumferential SG Row Col Volts Location Elevation, inch %TW Length, Extent, inch inch A 41 52 0.12 02H -0.43 17 0.17 0.16 B 47 42 0.14 FBH 0.29 20 0.16 0.18 B 47 42 0.24 FBH 0.03 30 0.24 0.14 C 30 59 0.19 02H -0.64 29 0.23 0.33
Page 7 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report
- 3. A description of the condition monitoring assessment and results, including the margin to the tube integrity performance criteria and comparison with the margin predicted to exist at the inspection by the previous forward-looking tube integrity assessment:
The methodology for establishing the structural and condition monitoring limits for tube wear and volumetric (pitting) mechanisms was the axial thinning model described in Section 5.3.3 of the EPRI Degradation Specific Management Flaw Handbook. A summary of conditioning monitoring results and 1R28 inspection results in comparison to 1R24 OA projections are contained in the tables below:
1R28 Condition Monitoring Summary
Limiting Condition Degradation Sizing Sizing Flaw Monitoring Margin to Mechanism Technique Probe Depth, Limit, %TW Limit, %TW
%TW
AVB Wear I96041.1 Bobbin 14 53.6 39.6 TSP Land Wear, Flat I96043.4 Bobbin 12(1) 49.5(1) 37.5(1)
TSP Land Wear, I96043.4 Bobbin 12(1) 61.2(1) 49.2(1)
Tapered TSP Burr Wear 21998.1 +POINT 26, 0.19 axial 55.4, 0.25 flaw axial flaw (2) 29.4 Foreign Object Wear 21998.1 +POINT 30, 0.24 axial 55.4, 0.25 flaw axial flaw 25.4 Steam Drum Internal Components Acceptable. No evidence of active degradation.
Notes:
(1) All TSP land wear observed during 1R28 and prior inspections have been tapered. Comparison the CM limit is conservatively done using the Flat Wear CM limits of 49.5%TW for a flaw over the entire TSP width. The Tapered land wear CM limit is 61.2% TW, thus providing even greater margin to the performance criteria.
(2) The CM limit for TSP burr wear used was for a longer axial length flaw, thus providing even greater margin to the performance criteria.
Page 8 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report
Comparison of Prior 1R24 OA Projections to 1R28 Inspection Results
Prior OA Limiting 1R28 Projected Existing Degradation As-Found Bounds Mechanism 1R24 OA Measured 1R28 Projection to Structural As-Found 1R28(1) Parameter(1) Condition?
AVB Wear-Existing Flaws 41% TW 14% TW Yes AVB Wear-Undetected Flaws 57% TW 8% TW Yes TSP Land Wear-Existing Flaws 41% TW 12% TW Yes TSP Land Wear-Undetected Flaws 51% TW 10% TW Yes TSP Burr Wear-Existing Flaws 23% TW(2) (3) 26% TW(2) (3) Yes Foreign Object Wear-Existing 31% TW (2)(3) 30% TW(2) (3) Yes Flaws Notes:
(1) Structural Parameter projections do not include NDE Measurement Uncertainty.
(2) The mechanism for continued growth has been removed or limit has been reached. No growth is predicted. Changes in flaw size from inspection to inspection is due to eddy current variability.
(3) Sized with +POINT probe sizing technique ETSS 21998.1.
It is noted that no tube pulls, or in-situ pressure testing was required in 1R28.
- 4. The number of tubes plugged during the inspection outage:
1R28 Plugging List Plugging Basis1 SG Row Col Location Degradation Mechanism
A 41 52 02H-0.43 Foreign Object Wear 02H-0.69 TSP Land Wear Preventive
C 30 59 02H-0.72 Foreign Object Wear Preventive
Notes:
(1) Additional discussion is contained in the response to TS 5.6.6.1.c.2 above.
Page 9 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report TS 5.6.6.1.d An analysis summary of the tube integrity conditions predicted to exist at the next scheduled inspection (the forward-looking tube integrity assessment) relative to the applicable performance criteria, including the analysis methodology, inputs, and results:
The OA performed for the AVB wear, TSP land wear, TSP burr wear, and FO wear mechanisms demonstrates that the tube structural and leakage integrity performance criteria will be satisfied at the end of a 5-cycle inspection interval until 1R33 for the existing degradation mechanisms at BVPS-1.
Simplified methods of projecting the worst-case degraded tube are designed to provide conservative approximations of fully probabilistic calculations. The mixed arithmetic/monte carlo approach was used to combine uncertainties in projecting end-of-cycle (EOC) flaw size on the worst-case degraded tube.
These calculations are performed for the largest flaw returned to service in all SGs at 1R28, as well as the 95th percentile undetected flaw size from the site-specific POD function. Material property, burst relation, and NDE measurement uncertainties are combined using monte carlo methods for determination of the CM Limits and bounding growth rate values are applied over the OA interval. The maximum EOC flaw size projected deterministically is compared to the CM Limit for the degradation mechanism to determine if the SG performance criteria are met. Deterministic calculations are included for TSP wear and AVB wear. No OA calculation is performed for FO wear as no growth is projected since the wear-initiating mechanism is no longer present for these flaws.
Deterministic Operational Assessment Summary
Degradation 5-Cycle Condition Mechanism Projection, Monitoring(1) 5-Cycle Margin to Limit, %TW
%TW Limit, %TW AVB Wear 35.6 53.6 18.0 TSP Land Wear 33.0 49.5 16.5 29.82, 55.4, 0.25 axial 0.19 axial flaw 25.58 TSP Burr Wear(2) (4) flaw 30, 0.24 55.4, 0.25 axial Foreign Object Wear(3) axial flaw flaw 25.4 Notes:
(1) The CM limit is used to assess the EOC-33 OA projected NDE flaw size since these limits contain all uncertainties, including NDE measurement sizing, uncertainties, at 95/50.
(2) The CM limit for TSP burr limit used was for a longer axial length flaw, thus providing even greater margin to the performance criteria (3) No known foreign objects present. Therefore, there is no mechanism to propagate the flaw. Values listed are the largest flaws left in-service.
(4) Although no TSP burr wear growth is expected, the 5-cycle deterministic worst-case degraded tube OA projection for the largest TSP burr wear flaw left in service used the maximum growth rate observed (0.53% TW/EFPY).
Page 10 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report
In addition to the deterministic worst case degraded tube OA methods, fully probabilistic OA methods were also used for the TSP wear and AVB wear mechanisms. This defense in-depth approach provides added confidence that SG structural and leakage performance criteria will be maintained for the next planned 5-cycle inspection interval from 1R28 to 1R33. While the simplified OA methods provide conservative OA projections through calculations using the worst-case flaw condition and bounding growth, fully probabilistic methods provide a wider range of inputs that includes using distributions of detected and undetected flaws sizes and degradation growth rates, while combining uncertainties for material property, burst relation and NDE measurement. The table below provides a summary of the fully probabilistic OA results for AVB and TSP wear with their margin to the performance criteria.
Fully Probabilistic Operational Assessment Summary
SLB Burst SLB Leak Degradation OA Probability Probability Burst Leak Pressure Rate Mechanism Interval, of of Leak, % Pressure, Rate, Margin to Margin to cycles Burst, % psi gpm Criterion, Criterion, psi gpm
AVB Wear, Site Specific 5 0% 0% 6374 psi 0 gpm 2064 psi 0.1 gpm Growth TSP Wear Site Specific 5 0.0% 0% 6142 psi 0 gpm 1832 psi 0.1 gpm Growth Performance Criterion 5% 5% 4310 psi 0.1 gpm
Page 11 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report As a more refined OA method, the Westinghouse software W-VOL was utilized to further evaluate an inspection interval of 5-cycles for BVPS-1. The W-VOL code applies a volume-based approach towards calculating wear over time. Therefore, this method can project flaw growth that is more realistic to the wear mechanism and provides larger margins to the SG performance criteria than when calculated using wear depth methods. This approach is typically able to demonstrate increased OA intervals in which the SG performance criteria is maintained for a flaw distribution set. The basic concept of the volume-based wear projection OA methodology is to calculate a flaw specific wear rate of volume loss experienced over the prior inspection interval and use it as a basis for projecting volume loss over the next inspection interval for the flaws returned to service at the current inspection as the OA projection. The final wear volumes at the end of the next inspection interval are converted to flaw depths for comparison to the SG performance criteria and for POB calculation. The table below provides a summary of the volume-based OA results for AVB and TSP wear with their margin to the performance criteria.
Volume-Based Operational Assessment Summary
Projected Burst OA 95/50 Margin to 5 Pressure Degradation Interval, Projected, Probability Burst cycle Margin Mechanism cycles %TW of Burst Pressure Limit, to (psi) %TW Criterion, psi AVB Wear 5 25.8 0.00% 6509 31.3 2199 TSP Wear 5 25.9 0.00% 6146 27.4 1836
TS 5.6.6.1.e The number and percentage of tubes plugged to date, and the effective plugging percentage in each SG:
Summary of Tube Plugging
SG A SG B SG C Total No. Tubes Plugged prior to 1R28 0 0 1 1
Total No. Tubes Plugged through 1R28 1 0 2 3
Percent Tubes Plugged through 1R28 0.028% 0% 0.056% 0.028%
Page 12 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report TS 5.6.6.1.f The results of any SG secondary side inspections:
SG secondary side top of tubesheet sludge lancing was performed in each SG during 1R28.
Subsequent post-sludge lance top-of-tubesheet inspections and FOSAR were performed in each SG.
The extent of the visual inspections included the tube lane, annulus, and periphery tubes to at least 3-5 tubes into the tube bundle. At the completion of sludge lancing in each SG, the sludge lance grit tank screen contents were visually inspected for the presence of foreign objects. The table below provides the weights of deposits that were removed from the SGs during 1R28 and during prior outages since SG replacement.
BVPS-1 Sludge Lance Deposit Removal Summary
RSG Outage Date SG A, lbs SG B, lbs SG C, lbs Total
1R17 Feb-2006 SGR SGR SGR SGR
1R18 Sep-2007 5.5 11.0 6.0 22.5
1R19 Apr-2009 6.0 8.5 8.0 22.5
1R20 Oct-2010 12.0 10.5 9.0 31.5
1R21 Apr-2012 7.5 6.5 6.5 20.5
1R22 Sep-2013 4.25 5.25 3.75 13.25
1R23 Apr-2015 - - - -
1R24 Sep-2016 20.5 11.25 11.75 43.5
1R25 Apr-2018 - - - -
1R26 Oct-2019 - - - -
1R27 Apr-2021 - - - -
1R28 Oct-2022 8.33 9.33 7.33 25.0
The contents of the sludge lance grit tank screen were visually inspected for FOs following completion of cleaning each SG. Various gaskets and small bristle wires were found on the SG A, SG B, and SG C grit tank screen. SG B contained the largest amount of removed foreign material from the sludge lancing. The size of all these objects were smaller than the acceptable size limits. The grit tank screen for all SGs also contained deposits and small scale flakes. The hard scale flakes were also smaller than hard sludge/scale size limits. Therefore, no past tube integrity concerns exist from the objects removed from the SGs during sludge lancing.
Page 13 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report A total of 22 FOs in SG A, SG B, and SG C were identified through visual FOSAR inspections during the current outage. The table below lists the FOs found during 1R28 and their status. No tube wear was identified with these objects as determined by +POINT examinations. Eight (8) of the objects were retrieved. Fourteen (14) of the objects found were not retrieved and remain in the SGs. The remaining 14 objects found during 1R28 and not retrieved were small bristle wires, scale, and gasket materials.
An evaluation was performed that shows these objects are smaller than the respective size limits that justifies acceptable operation for 5-cycles.
1R28 Foreign Objects Detected by Visual Inspections
SG/FO Dimensions, inch Fixity ID Retrieved? Foreign Object Description Leg Inspection Elevation Row-Col New/ Legacy
1A001 No Gasket Material CL TTS 1-52 New 0.15 x 0.1 x 0.025 Loose 1A002 No Gasket Material HL TTS 7-48 New 0.35 x 0.2 x 0.025 Fixed 1A003 Yes Wire Bristle CL TTS 44/45-37 New 0.4 x 0.01 diam.
1B001 Yes Gasket Material CL TTS 45/43-38/39 New 2.5 x 0.125 x 0.0625 1B002 Yes Gasket Material HL TTS 27/28-12/13 New 1.3 x 0.125 x 0.05
1B003 No Scale HL TTS 43/44-37/38 New 0.6 x 0.25 x 0.1 Loose
1B004 Yes Wire Bristle HL TTS 40/41-37/38 New 0.5 x 0.02 x 0.02 1B005 Yes Gasket Material HL TTS 42/43-37/38 New 2 x 0.05 x 0.05 1B006 No Machine Turning HL TTS 40/41-43/44 New 0.2 x 0.01 diam. Loose 1B007 Yes Wire Bristle HL TTS 43/42-44/43 New 0.25 x 0.125 x 0.125 1B008 No Wire Bristle HL TTS 39-43/44 New 0.5 x 0.01 diam. Loose 1B009 No Sludge Rock HL TTS 9/10-48/49 New 0.25 x 0.25 x 0.5 Fixed
1B010 No Wire Bristle CL TTS 26/27-60/61 New 0.125 x 0.01 diam. Loose
1B011 No Wire Bristle HL TTS 31/30-60/61 New 0.125 x 0.125 x 0.125 Loose 1B012 No Gasket Material HL TTS 8/9-54/55 New 0.5 x 0.25 x 0.125 Fixed 1B013 No Wire Bristle HL TTS 8/9-54/55 New 0.25 x 0.01 diam. Fixed 1B014 No Wire Bristle HL TTS 8/9-54/55 New 0.03 x 0.01 diam. Fixed 1B015 No Wire Bristle HL TTS 7/8-48/49 New 0.35 x 0.01 diam. Fixed 1B016 No Gasket Material HL TTS 7/8-49/50 New 0.625 x 0.0625 x 0.01 Fixed 1C001 Yes Wire Bristle TL TTS 1-54/55 New 0.2 x 0.01 diam.
1C002 No Sludge Rock CL TTS 19/20-37/38 New 0.25 x 0.1 x 0.1 diam. Loose 1C003 Yes Wire Bristle HL TTS 8-60/61 New 0.2 x 0.1 diam.
Page 14 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report An upper steam drum visual inspection of all SG secondary side internals was performed during 1R28. Visual inspections of the upper steam drum region included the primary and secondary moisture separators, sludge collector, feedring spray cans, and the instrument level tap holes and piping to the isolation valves on each of the SGs. The steam drum inspections focused on the following regions of interest and conditions:
- Mid-deck plate general area.
- Inspection for flow accelerated corrosion (FAC) and erosion-corrosion (E/C) on high flow velocity regions, including the trailing edge of the swirl vanes and adjacent riser barrel surfaces.
- Inspection for deposit buildup at the secondary moisture separator perforated plates, drain channels and drain cups.
No anomalies were noted from any of these inspections. Uniform magnetite coatings were observed on all surfaces, including the highest flow velocity regions. No evidence of FAC or E/C was found on any component. The leading edges of the swirl vanes contained a uniform magnetite coating and no evidence of material thinning.
The sludge collector contained soft and loose deposits ranging from approximately 1/8 inch to 1/2 inch thick for both the upper and lower chambers. The deposits near the spray nozzles were well below the bottom of their fittings. Cleaning of the sludge collector is recommended if the upper and lower chambers of are approximately half full of deposits or if the spray nozzles are completely covered within the sludge pile. This condition was not observed, and cleaning of the sludge deposits is not required in the near term. The drain cups contained a light coating of deposits without substantial piles.
No material or blockage was observed in the feedwater header spray nozzles. FAC or E/C of the perforated spray can holes was not observed. All holes were round with sharp edges with no evidence of hole enlargement.
Based upon the visual inspection results in each of the 3 SGs, it is concluded that there are no active degradation mechanisms of the secondary side SG internals and the inspection results do not alter the planned inspection frequency of the steam drum components.
Tube Plug Visual Inspections
A 100% visual inspection of all previously installed tube plugs (2 Alloy 690 mechanical ribbed plugs) had been performed from the primary side during BVPS 1R28. No anomalous conditions, such as a degraded tube plug or surrounding boron deposits indicating plug degradation, have been reported during performance of these visual inspections. The plug installation parameters of all newly installed Alloy 690 mechanical ribbed plugs (4 plugs) were reviewed and found within the specification.
Page 15 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report Channel Head Bowl Visual Inspections
Each SG primary channel head was visually examined for evidence of cracking and/or breaches in the cladding or divider to channel head weld and for evidence of wastage of the carbon steel channel head. No evidence of cladding or weld cracking and/or breaches or evidence of channel head wastage was identified during 1R28. The examinations performed during 1R28 met the recommendations of NSAL 12-1. During the BVPS 1R24 visual channel head inspection, an anomaly was observed on the divider plate to channel head weld in the hot leg of SG A. The anomaly is located at the toe weld bead (edge of weld) of the divider plate to channel head weld. The anomaly is located approximately 2/3 of the distance from the bottom of the channel head to the tubesheet on the manway side. The anomaly was re-inspected during 1R28. There was no change in the anomaly from 1R21 to 1R28. An evaluation of the condition was previously performed and concluded that the anomaly is an artifact of manufacture and not representative of a crack-like condition created by the operating environment nor a fabrication flaw.
Page 16 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report
Definitions of Abbreviations, Codes, and Reporting Terminology
Term Definition 01C 1st Tube Support Plate on Cold Leg Side 01H 1st Tube Support Plate on Hot Leg Side 95/50 0.95 probability at 50% confidence AVB Anti-Vibration Bar BLG Bulge BVPS Beaver Valley Power Station CL Cold Leg (Outlet)
CM Condition Monitoring DA Degradation Assessment DENT Observed within a Tube Support Plate DING Observed in Free-Span Region of the Tubing DNI Dent/Ding with a Possible Indication E/C Erosion-corrosion EFPM Effective Full Power Months EFPY Effective Full Power Years EOC End of Cycle EPRI Electric Power Research Institute ETSS Examination Technique Specification Sheet FAC Flow Accelerated Corrosion FBH Flow Distribution Baffle Hot Leg Side FO Foreign Object FOSAR Foreign Object Search and Retrieval GEO Geometry Anomaly HL Hot Leg (Inlet)
NQI Non-Quantifiable Indication NSAL Nuclear Safety Advisory Letter OBS Obstructed OA Operational Assessment OXP Over Expansion PLP Possible Loose Part POD Probability of Detection PVN Permeability Variation RRT Retest - Restricted Tube SG Steam Generator SGMP Steam Generator Management Program TL Tube Lane TSH Hot Leg Tubesheet (Secondary Face)
TSP Tube Support Plate TTS Top of Tubesheet TW Through Wall
Page 17 of 18 Unit #1 - 1R28 Steam Generator 180 Day Report
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