ML19238A303

Public Clarification Call with Exelon to Discuss Exelons Response to NRC Requests for Additional Information on Environmental Fatigue

ML19238A303
Person / Time
Site:	Peach Bottom
Issue date:	09/27/2019
From:	Bennett Brady NRC/NRR/DMLR/MRPB
To:	Exelon Generation Co
Brady B, NRR-DMLR 415-2981
Shared Package
ML19255F782	List: ML19238A303 ML19240A300 ML19246A145
References
EPID L-2018-RNW-0012
Download: ML19238A303 (3)

Text

September 27, 2019 U.S. Nuclear Regulatory Commission Public Meeting Summary

Title:

Public clarification call with Exelon to discuss Exelons response to NRC Requests for Additional Information on environmental fatigue Date of Meeting: Wednesday May 29, 2019 Location: Teleconference Type of Meeting: Category 1 Purpose of the Meeting(s):

To provide clarification on Exelon Generation Company, LLCs (Exelon) response to requests for additional information (RAIs) related to the core shroud support fatigue analysis reevaluation.

General Details:

The U.S. Nuclear Regulatory Commission (NRC) staff held a public teleconference with Exelon as part of the safety review of Peach Bottom Atomic Power Station, Units 2 and 3 subsequent license renewal application (SLRA). The meeting started at 1:30 p.m. and ended at approximately 2:30 pm. There were two NRC staff members present in the room and four Exelon staff members on the phone. The meeting began with introductions of NRC staff in the room, and Exelon staff on the phone. No members of the public announced themselves on the phone or informed the NRC staff that they participated in the teleconference.

Phone Participants Affiliations Bennett Brady Nuclear Regulatory Commission (NRC)

Seung Min NRC David Distel Exelon Generation Company, LLC (Exelon)

Leah E. Ritz Exelon Peter Tamburro Exelon Donald B. Warfel Sr.

Exelon Summary of Meeting:

Response to RAI 4.3.6.3-1:

In a letter dated April 10, 2019, the NRC issued a request for additional information, (RAI 4.3.6.3-1) on the core shroud support analysis reevaluation. The NRC staff requested that Exelon compare the projected 80-year CUF and CUFen for the core shroud support in comparison with the 40 -year CUF (0.834) in SLRA Section 4.3.6.3 and the 60-year CUF (0.26) in the 2012 EPU submittal. As part of the response, NRC asked that they confirm that the 80-yesr CUF is a reasonable projection in comparison with the existing estimates of CUF values (40-year and 60-years).

Exelon indicated that the projected 80-year CUFen value for the core shroud support is 0.726 in the fatigue time-limited aging analysis (TLAA). The location is identified as location 22 in SLRA Table 4.3.1-3. Exelon also stated that this projection is based on the projected 80-year cycles described in SLRA Table 4.3.1-1, including the 10 occurrences of the sudden start of pump in cold recirculation loop transient.

The staff noted that SLRA Table 4.3.1-1 addresses the projected 80-year transient cycles for PBAPS Unit 2. In comparison, SLRA Table 4.3.1-2 addresses the PBAPS Unit 3 transient cycles. SLRA Table 4.3.1-2 also projects 16 occurrences of the sudden start of pump in cold recirculation loop transient for 80 years of operation at Unit 3. Given the higher projected cycle number at Unit 3 (16 compared to 10 cycles), the limiting location of the core shroud support may need to be the Unit 3 core shroud support location rather than the Unit 2 location.

The NRC staff proposed the following questions as potential second round RAIs.

1. Whether the Unit 3 core shroud support location is more limiting than the Unit 2 core shroud support location in the TLAA

2. If the Unit 3 location is more limiting, please discuss the projected 80-year CUFen value for the Unit 3 location.

3. Whether the CUFen of the Unit 3 location is close to the CUFen threshold (0.8) for initiation of corrective action as specified in the existing Fatigue Monitoring program. If so, please discuss the potential corrective action.

Public Participation:

No members of the public announced themselves on the phone or informed the NRC staff that they participated in the teleconference.

Action Items/Next Steps:

The NRC staff will issue follow up requests for additional information.

Title:

Public clarification call with Exelon to discuss Exelons response to NRC Requests for Additional Information on environmental fatigue (EPID NO. L-2018-RNW-0012) DATED September 27, 2019 DISTRIBUTION:

PUBLIC RidsNrrDmlr Resource RidsNrrPMPeachBottom Resource Yvonne.Edmonds@nrc.gov NRR/DMLR Bennett.Brady@nrc.gov NRR/DMLR David.Drucker@nrc.gov NRR/DMLR Lauren.Gibson@nrc,gov, NRR/DMLR Angela.Buford@nrc.gov, NRR/DMLR Steven.Bloom@nrc.gov, NRR/DMLR David.Alley@nrc.gov, NRR/DMLR Eric.Oesterle@nrc.gov NRR/DMLR Benjamin.Beasley@nrc.gov NRR/DMLR Meena.Khanna@nrc.gov NRR/DMLR Joseph.Donoghue@nrc.gov NRR/DMLR Jennifer.Tobin@nrc.gov NRR/DORL Justin.Heinly@nrc.gov RI/DRP Brian.Smith2@nrc.gov RI/DRP Mitzi.Young@nrc.gov OGC Kayla.Gamin@nrc.gov OGC Michael.McCoppin@nrc.gov OEDO Scott.Burnell@nrc.gov; HQ/OPA Diane.Screnci@nrc.gov RI/OPA Neil.Sheehan@nrc.gov RI/OPA Darrell.Adams@nrc.gov, OCA David.Decker@nrc.gov, OCA Brice.Bickett@nrc.gov RI/ORA Justin.Heinly@nrc.gov RI/DPR Jonathan.Greives@nrc.gov RI/DPR Kevin.Mangan@nrc.gov RI/DRS David.Distel@exeloncorp.com Paul.Weyhmuller@exeloncorp.com John.Hilditch@exeloncorp.com Donald.Warfel@exeloncorp.com ADAMS Accession Nos:

Meeting Package:ML19255F782 Meeting Notice/Agenda: ML19154A141 Meeting Summary ML19238A303

• concurred via email OFFICE PM:MRPB:DMLR LA:MRPB:DMLR BC:MRPB:DMLR PM:MRPB:DMLR NAME BBrady YEdmonds EOesterle BBrady DATE 9/6/19 9/9/19 9/19/19 9/27/19 OFFICE RECORD COPY