ML21043A355
| ML21043A355 | |
| Person / Time | |
|---|---|
| Issue date: | 02/16/2021 |
| From: | Burton M NRC/NRR/DNRL/NCSG |
| To: | |
| Matthew Burton-NRR/DNRL 301-415-0647 | |
| Shared Package | |
| ML21025A072 | List: |
| References | |
| 20210037 | |
| Download: ML21043A355 (5) | |
Text
February 16, 2021 U.S. Nuclear Regulatory Commission Public Meeting Summary
Title:
Meeting with the Industry Steam Generator Task Force Meeting Identifier: 20210037 Date of Meeting: January 26, 2021 Location: Webinar Type of Meeting: Category 2 Purpose of the Meeting: The purpose of this meeting was for the U.S. Nuclear Regulatory Commission (NRC) staff to discuss steam generator (SG) issues with the industry Steam Generator Task Force (SGTF).
General Details: The industry SGTF met with NRC staff on January 26, 2021, by Webinar.
The purpose of the meeting was to discuss a variety of SG issues. The meeting consisted of open and closed portions during which public and proprietary information was discussed, respectively. The public industry slides are available in the Agencywide Documents Access and Management System (ADAMS) under Package Accession No. ML21025A072. This meeting was noticed as a public meeting and the agenda is available in ADAMS under Accession No. ML21015A002.
2 LISTING OF ATTENDEES U.S. NRC MEETING WITH THE INDUSTRY STEAM GENERATOR TASK FORCE January 26, 2021 Participant Affiliation Participant Affiliation Bill Cullen EPRI Mo Uddin Engineering Mech Corp.
Brent Capell EPRI Patrick Fabian PSEG Nuclear Brian Mann EXCEL Services Corp. Phil Rush MPR Brian Thomas PSEG Nuclear Rich Guill EPRI Craig Kelley Framatome Russell Cipolla Intertek Damian Testa Westinghouse Russ Wells TVA Daniel Folsom TVA Scott Redner Xcel Energy, Inc.
Dan Mayes Duke Energy Sean Kil EPRI Fred Madden Certrec Steve Brown Entergy Gary Alberti Energy Harbor Tim Thulien Duke Energy Helen Cothron EPRI Thomas Bipes Zetec James Skirpan Westinghouse Al Butcavage NRC Jana Bergman Curtiss-Wright Allen Hiser NRC Jay Smith Westinghouse Andrew Johnson NRC Jeff Lanum Entergy Brendan Collins NCC Jeff Raschiatore Westinghouse Elise Burket NRC Jeremy Mayo TVA Greg Makar NRC Jesse Baron TVA Jennifer Tobin NRC James Benson EPRI John Bozga NRC John Arhar PG&E Leslie Terry NRC Kent Colgan Framatome Mat Burton NRC Kester Thompson FPL Patrick Purtscher NRC Lee Friant Exelon Nuclear Paul Klein NRC Michael Stark Dominion Energy Steven Bloom NRC
3 Summary of Presentations: During the meeting, industry representatives discussed and made presentations on their draft template for reporting SG inspection results to the NRC as required by the technical specifications (TS), loose parts strategy, enhanced probe inspections, and the status of high stress tube re-analysis. A summary of the information exchanged during the meeting is discussed below.
TS Reporting Requirements Template The industry discussed the contents of their draft TS reporting requirements template and highlighted changes since it was last discussed with the NRC staff.
With regards to reporting the design and operating parameters, the NRC staff noted that it would be helpful for plants to identify if there is a loose parts strainer in the feed water system.
The NRC staff noted that if an indication was not in-situ pressure tested but further analyses were performed (e.g., flaw profiling) to demonstrate that the tube met the structural and leakage performance criteria, then a description of the further analyses performed should be included as part of the of the description of the condition monitoring assessment and results.
With regards to reporting a summary of the forward-looking tube integrity assessment, the NRC staff noted that it would be helpful to include a discussion of how the growth rates for each degradation mechanism were determined.
The NRC staff stated that whenever statements are made about primary- or secondary-side inspections being performed, the statement should include the scope of the inspections and the inspection results (e.g., no degradation detected).
The NRC staff shared an example of a deposit loading table received as part of a license amendment request. The staff noted that a similar table being submitted as part of the SG tube inspection report would help the staff understand the extent of deposit loading at a given plant.
Industry Plans for Loose Parts Strategy Both the NRC staff and Industry SGTF agree that longer inspection intervals may increase SG tube susceptibility to loose parts damage.
The Industry SGTF described their approach for an industry loose parts strategy and discussed requirements related to loose parts that are currently in the Electric Power and Research Institute (EPRI) SG Integrity Assessment Guidelines. Additional requirements will be included in the EPRI SG Integrity Assessment Guidelines.
The Industry SGTF is considering a graded approach based on SG design and operating experience. In addition, plants would assess their current loose parts management
4 activities. The Industry SGTF noted that the additional requirements may only be required by plants that are operating for longer periods.
The NRC staff stated that they are aligned with the direction of the Industry SGTF; however, even plants that are not running longer can benefit from best practices.
Enhanced Probe Inspections During the January 7, 2021, meeting, the NRC staff presented its position on Technical Specification Task Force (TSTF) submitted TSTF-577, Revision 0, Revised Frequencies for Steam Generator Tube Inspections, (ADAMS Accession No. ML21012A322). The Industry SGTF asked for clarification of the staffs Conditional 72 EFPM for Alloy 600TT SG tubing and further explanation of no cracking history. The NRC staff stated that all requirements contained in the Conditional 72 EFPM must be met and that the statements listed should be read with an AND (NOT an OR). The staff clarified that no cracking history means that there have been no cracks detected throughout the entire inspection history (with the exception of the portion of the tube below the H* distance in the tubesheet according to the H* alternate repair criteria).
The Industry SGTF stated that TS wording about eddy current probe technology requirements needs to be open and not specific to probe type. The NRC staff commented that the wording related to use of enhanced probes is intended to give plants flexibility and indicate that for SGs with A600TT tubes, the staff considers inspections performed primarily with bobbin probes insufficient extending the inspection interval to 72 EFPM.
High Stress Tube Rescreening Status During the October 28, 2020, meeting, Westinghouse informed NRC staff that a high stress tube was not identified in the original screening for long row tubes in 2004 for one plant, Plant D2 (ADAMS Package Accession No. ML20300A215).
Westinghouse stated that the high stress tube was not identified due to a miscommunication regarding the LAR code definition between Engineering and the Data Analyst.
Westinghouse is performing Extent of Condition (EOC) reviews; rescreening all eight of the plants for which they performed long row high stress tube eddy current screening.
2 out of 8 EOC reviews are In-Progress 4 out of 8 EOC reviews are Complete (Pending Review / Verification) 2 out of 8 EOC reviews are Complete (Results Final)
Completed (Results Final) EOC Reviews identified 14 in-service tubes to be added to the high stress tube list for Plant D2. All 14 tubes were associated with the LAR code.
5 Open Discussion During the open discussion portion of the meeting, the Industry SGTF voiced concerns regarding the timeline of TSTF-577 issuance and asked about the potential to coordinate TSTF-577 issuance with plant outages planned for fall 2021. The NRC staff discussed the need to coordinate the timeline internally but clarified that completion dates will be contingent upon submittal of the final version of TSTF-577 for NRC review. The TSTF approximated that the circulation of the final version to EPRI and throughout the Industry -
prerequisite to final submittal to NRC -- could be completed before the end of February 2021 (approximately 3 weeks).
The Industry SGTF answered an inquiry regarding typical design and locations of loose parts strainers. Locations include, but are not limited to:
Feedring with Perforated Spray Cans to Distribute Feed Water (On Newer SG Design with Thermally Treated Alloy 690)
Internal SG Screens Pre-Heater Design, Small Holes in the Heater Box before the SG Bulk Flow Feedwater Pump Inlet Strainers Flexitallic Gaskets with Internal Retaining Rings Closed Discussion The final portion of the meeting was closed due to proprietary information related to EPRI SG guideline revisions, AP1000, and in-progress high stress tube screening extent of condition reviews.
If you have any questions regarding this meeting summary, please feel free to contact me by phone at 301-415-1167, or by email at Leslie.Terry@nrc.gov.
Attachments:
- 1. Meeting Notice: ML21015A002
- 2. Industry Slides: ML21025A074
- 3. Package: ML21025A072