ML20097C266
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| ML20097C266 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 04/06/2020 |
| From: | Hicks J Luminant, TXU Energy, Vistra Energy |
| To: | Office of Nuclear Reactor Regulation |
| Galvin D | |
| References | |
| EPID L-2020-LRM-0028 | |
| Download: ML20097C266 (12) | |
Text
Pre-Submittal Meeting for:
COMANCHE PEAK NUCLEAR POWER PLANT DOCKET NO. 50-446 April 6, 2020 License Amendment Request Revise Technical Specification 5.5.9
Participants
- Comanche Peak Participants
- Steven Sewell, CPNPP Sr. Director, Engineering and Regulatory Affairs
- Eric Pace, CPNPP Engineering Manager
- Chung Tran, CPNPP Engineering Manager
- Ashley Birdett, CPNPP Engineering
- Jack Hicks, CPNPP Regulatory Affairs Manager
- Jim Barnette, CPNPP Regulatory Affairs
- Carrie McBeth, CPNPP Regulatory Affairs
- Brad Carpenter, Westinghouse Engineering 2
AGENDA
- Reason for Proposed Amendment
- Description of Current SG Program Technical Specifications and Proposed Changes
- Comanche Peak Unit-2 Steam Generator Information
- Technical Information to be Provided with the LAR
- Summary of recent SG operational experience
- Previous inspection condition monitoring results
- Operational assessment during the additional operating cycle
- Mitigating strategies
- LAR Schedule
- Conclusions
- Questions?
3
Reason for Proposed Amendment
- In response to the 2019 Novel Coronavirus outbreak, the federal government has declared a public health emergency (COVID-19 PHE). Due to the COVID-19 pandemic, Vistra Operations Company LLC (Vistra OpCo) is taking steps to limit the potential of inadvertently spreading the COVOD-19 virus to plant personnel by reducing the numbers of outside contractors and closely following CDC social distancing guidelines.
- The proposed license amendment will revise Technical Specification 5.5.9 in order to defer the CPNPP Unit-2 SG tube inspections from the upcoming 2RF18 refueling outage to 2RF19 (approximately 18 months). The revised SG operational analysis and engineering evaluation will provide for reasonable assurance that the health and safety of the public will not be affected by deferring the tube examination until 2RF19.
4
Description of Current SG Program Technical Specifications and Proposed Changes
- TS 5.5.9.d.2.c currently states, During the remaining life of the SGs, inspect 100% of the tubes every 72 effective full power months. This constitutes the third and subsequent inspection periods.
- 2RF18 is the last outage of the third sequential inspection period of 72 EFPM
- The proposed license amendment will insert a one-time TS change to extend the third sequential inspection period from 72 EFPM to 90 EFPM (from 2RF18 to 2RF19, October 2021) 5
Comanche Peak Unit 2 SG Information CPNPP Unit-2 has four Westinghouse Model D-5 SGs each with 4570 thermally treated Alloy 600 (A600TT) U-tubes. Comanche Peak Unit 2 entered operation in April 1993.
- Summary of previously observed degradation mechanisms
- Anti-vibration bars wear
- Preheater baffle plates (PHB)/tube support plates (TSP) wear
- Foreign object wear
- Channel head indications
- There were no anomalies or degradation in secondary side components reported in prior SG inspections
- Summary of plugged tube information
- SG1 - 23
- SG2 - 33
- SG3 - 21
- SG4 - 19
- Total of 96 plugged tubes (0.53% of the total number of tubes)
- No tubes were required to be plugged during 2RF17
- CPNPP Unit 2 has no primary-to-secondary leakage detected 6
Technical Information to be Provided with the LAR Recent Operational Experience Summary
- Primary-to-secondary leakage trends
- High level summary of the most recent primary and secondary inspections
- Number of tubes plugged and reason for plugging
- Discussion of other relevant operating experience
- Secondary side deposit loading
- Significant chemistry transients
- Introduction of foreign materials 7
Technical Information to be Provided with the LAR Previous Inspection Condition Monitoring
- For each degradation mechanism detected, the most limiting as found condition compared to the tube performance criteria
- Discussion of any tubes that required flaw profiling to demonstrate condition monitoring was met 8
Technical Information to be Provided with the LAR Operational Assessment Including the Additional Operating Cycle
- List of mechanisms considered and reason for consideration
- Strategy for inspecting the mechanisms during the last inspection
- Alloy 600TT Considerations
- How many high stress tubes remain in service
- How tubes that could have remained unidentified as high stress after screening are considered in the inspection strategy
- Operating experience related to high stress tubes
- Predicted margin to the tube integrity performance criteria at the next inspection including flaw growth 9
Technical Information to be Provided with the LAR Mitigating Strategies
- The LAR will include discussion of any mitigating strategies that will be in effect during the upcoming cycle 10
Planned LAR Schedule
- Submittal of LAR by April 10, 2020
- Request approval as soon as practical to limit personnel interaction, or by April 19, 2020
- CPNPP proposes to implement this one time only amendment prior to Unit-2, Mode 4 entry, currently scheduled May 9, 2020 11
Questions?
12