ML15327A081
| ML15327A081 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/09/2015 |
| From: | Exelon Generation Co |
| To: | Office of Nuclear Reactor Regulation |
| AHUYNH, NRR/DE/ESGB, 415-1137 | |
| References | |
| TAC MF6779 | |
| Download: ML15327A081 (15) | |
Text
TMI T1R21 SG Tube In-service Inspection NRC Call Inspection NRC Call Tim Heindl Tim Heindl Steam Generator Program Engineer November 9, 2015
Agenda Design Overview of TMI-1 Enhanced Once-Through Steam Generator (EOTSG)
T1R21 Steam Generator (SG) Inspection Overview SG Tube Inspection Discussion Points Q&A Acquisition Status:
A OTSG - Acquired 86.0%, Analyzed 82.9%
B OTSG - Acquired 96.0%, Analyzed 95.8%
q y
TMI-1 EOTSG Overview PRIMARY INLET Tube Information Number of Tubes: 15,597 Tube Material: Alloy 690TT PRIMARY INLET Nominal OD: 0.625 inch Nominal Thickness: 0.037 inch Tube Length: 673.375 inch UPPER SHROUD STEAM OUTLET Support Information TSP Material: SA 240 type 410M SS TSP Thickness: 1.18 LOWER SHROUD SHROUD MAIN TSPs Trefoil broached (15th TSP drilled on periphery)
Tubes hydraulically expanded full length of the TS Normal Operating Parameters SHROUD MAIN FEEDWATER HEADER Normal Operating Parameters NOP (Primary) = 2,155 psig NOPD = 1271 psid THot = 603oF The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.
OUTLET NOZZLES OUTLET NOZZLES
T1R21 Steam Generator Inspections Inspection Scope:
100% full-length inspection (bobbin probe) 2-Tube Periphery for Loose Parts (combo array probe) TTS to 01S Di ti E d T b Pl i
d d Diagnostic Exams and Tube Plugging as needed Other Actions Taken:
Revised plant heat-up procedures to equalize temperatures to mitigate wear Met with NRC Region I & Site Residents to achieve alignment on inspection scenarios/strategy inspection scenarios/strategy
- 1. Primary-to-Secondary Leakage No observable primary-to-secondary leakage (PSL) during Cycle 20.
RM-A-5/15 monitor PSLR Continuously.
No observable trends.
- 2. Secondary Side Pressure Tests There were no secondary side pressure tests performed during T1R21.
A drip or bubble test was not required due to the absence of existing primary to secondary leakage existing primary-to-secondary leakage.
- 3. EPRI Guideline Exceptions TMI-1 has not taken any exceptions or deviations from the EPRI SGMP Guidelines.
- 4. Detailed Scope Evaluation
- 100% full length exam of both OTSGs
- 100% full length exam of both OTSGs with bobbin probe
- 2-tube periphery array combo probe exam from TTS to 01S
- All bobbin I codes, PLPs, new DNG /DNT >
1 0V i
d ith DNGs/DNTs >= 1.0V examined with array probe
- Deepest 20 TTW indications in both OTSGs examined with array probe and sample of new and repeat indications for flaw characterization indications for flaw characterization.
- New 20% TW
- Repeat 25% TW
- Growth 12%TW
- Growth 12%TW
- No expansion criteria due to 100%
base scope exam.
- 5. Summary of Inspection Results Tube-to-Tube Wear TSP Wear A
B A
B Number of New 6
6 2023 2132 Number of New 6
6 2023 2132 Number of Repeat 105 276 2502 3282 Total Indications 111 282 4525 5414 Avg. Growth Rate 0.19%/EFPY 0.31%/EFPY 0.54%/EFPY 0.83%/EFPY g
/
/
/
/
95th Percentile 1.06%/EFPY 1.06%/EFPY 3.17%/EFPY 4.23%/EFPY Largest New 10%
10%
33%
35%
Largest Repeat 20%
17%
24%
64%
Location of Largest Flaw 70-100 22-63 137-1 2-4
- 6. Repair/Plugging Plans All tubes repaired will be mechanically roll plugged and stabilized in accordance with stabilization criteria.
All tubes with indications 40% through-wall (TW) will be plugged per Tech Specs.
A total of 25 tubes are currently 40% the Tech Spec Plugging Limit Plugging Limit.
The team has developed a base plugging strategy which p
p gg g gy provides a 99% POS in the W-axis.
- 7. In-situ Pressure Test / Tube Pulls There are currently zero indications that exceed the Condition Monitoring limit (e.g., no in situ pressure testing is required) testing is required).
- 8. Loose Parts Inspections performed to detect loose parts:
- Two (2) tube periphery with array probe - Approximately 902 tubes/SG Loose parts detected to date:
- NONE Loose parts removal plan/damage:
Loose parts removal plan/damage:
- N/A - No loose parts to date 9 Secondary Inspections/Maintenance
- 9. Secondary Inspections/Maintenance No secondary inspections or maintenance planned for T1R21 steam generator inspections T1R21 steam generator inspections Perform sludge mapping with ECT
- 10. Unexpected or Unusual Results There are no unexpected or unusual results from the T1R21 eddy current inspections.
T1R20 Operational Assessment Prediction:
- Median deepest projected indication is 69% TW Median deepest projected indication is 69% TW
- Upper 95th value, max projected depth is 77% TW
- Number of New Flaws Predicted: 3,000 in B OTSG Results of the T1R21 inspection are within the previous OA projections and bounded by T1R20 results.
- 11. Schedule A OTSG - Acquired 86.0%, Analyzed 82.9%
B OTSG - Acquired 96.0%, Analyzed 95.8%
Expected to complete eddy current inspections 11/10 @
Expected to complete eddy current inspections 11/10 @
02:00 Tube Plugging (as needed) window is 11/10/15 - 11/13/15 gg g (
)