ML17258A146

Summary of September 12, 2017, Meeting with Firstenergy Nuclear Operating Company Regarding Its Licensing Amendment Request to Adopt National Fire Protection Association Standard 805 at Davis-Besse Nuclear Power Station, Unit No. 1

ML17258A146
Person / Time
Site:	Davis Besse  (NPF-003)
Issue date:	09/20/2017
From:	Blake Purnell Plant Licensing Branch III
To:	Boles B FirstEnergy Nuclear Operating Co
Purnell B
Shared Package
ML17258A215	List: ML17258A146
References
CAC MF7190
Download: ML17258A146 (4)

Text

LICENSEE:

FACILITY

SUBJECT:

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 20, 2017 FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station, Unit No. 1

SUMMARY

OF SEPTEMBER 12, 2017, MEETING WITH FIRSTENERGY NUCLEAR OPERATING COMPANY REGARDING ITS LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805 AT DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 (CAC NO. MF7190)

On September 12, 2017, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) staff and representatives of FirstEnergy Nuclear Operating Company (FENOC, the licensee) via teleconference. The purpose of the meeting was to discuss FENOC's license amendment request (LAR) to adopt National Fire Protection Association (NFPA) Standard 805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition, as incorporated into Title 10 of the Code of Federal Regulations Section 50.48(c), at Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse). A copy of the meeting notice is available at Agencywide Documents Access and Management System (ADAMS) Accession No. ML17240A356. A list of attendees is enclosed.

BACKGROUND By application dated December 16, 2015 (ADAMS Accession No. ML15350A314), as supplemented by letters dated February 2, March 7, July 28, and December 16, 2016, and January 17 and June 16, 2017 (ADAMS Accession Nos. ML16033A085, ML16067A195, ML16210A422, ML16351A330, ML17017A504, and ML 17170AOOO, respectively), FENOC submitted an LAR to change the current fire protection program at Davis-Besse to one based on NFPA 805. This LAR is currently under review by the NRG staff.

By letter dated April 19, 2017 (ADAMS Accession No. ML17100A173), the NRC staff issued a request for additional information (RAI) regarding the LAR. In safe shutdown analysis (SSA)

RAI 07.01, the staff requested additional information regarding the modeling of reactor coolant pump (RCP) seals in the fire and internal events probabilistic risk assessments (PRAs). The licensee provided its response to SSA RAI 07.01 with its June 16, 2017, letter. The response states that the model assumes a loss-of-coolant accident through the RCP seals will occur if the RCPs are not tripped with 30 minutes of a loss of seal return or within 70 minutes of a loss of all component cooling water. If the RCPs are tripped within these time limits, the model assumes failure of the RCP seals will not occur. The licensee concludes by stating that human failure events are likely to dominate the RCP seal failure sequences in the PRAs; therefore, the RCP seal failure model is sufficient.

DISCUSSION The NRG staff noted during the meeting that the licensee's response to SSA RAI 07.01 did not provide enough information for the staff to perform a review of the technical adequacy of the RCP seal model. The staff asked the licensee to justify that the RCP seal model has no or minimal impact on the NFPA 805 application. The staff also asked the licensee to discuss the potential for conservative modeling assumptions in the compliant plant model to artificially reduce the calculated change in risk associated with the variances from deterministic requirements for RCP seals.

The licensee stated that RCP seal failure accounts for 15 percent of core damage frequency in its PRA. The licensee stated it performed a sensitivity study, with an assumed probability of 2x 10-4 for a seal failure. The sensitivity study indicated that there would be about a 1.6 percent difference in risk if the probability of seal failure is included in the model. The licensee also noted that that the human error probability ranged from approximately 3x10-4 to approximately 2x10-3 _

The licensee stated that the transition and compliant plant models for the RCP seal are the same, except that the compliant plant model assumes no seal failure due to fire. The licensee stated that the treatment of the RCP seal in both the compliant and transition plant models 1s conservative relative to the change in risk.

The licensee agreed to supplement its application to include the information discussed during the meeting. The NRC staff suggested that the discussion focus on the change in risk associated with the RCP seal model, and describe the compliant plant versus the transition plant.

Please direct any inquiries to me at 301-415-1380 or Blake.Purnell@nrc.gov.

Docket No. 50-346

Enclosure:

List of Attendees cc w/encl: Distribution via ListServ Blake Purnell, Project Manager Plant Licensing Branch 111 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

NAME Blake Purnell Todd Hilsmeier J. S. Hyslop Harold Barrett Garill Coles Steve Short Phil Lashley Colin Keller Tony Mangan Aaron Quaderer Matt Murhta Josh Ross Dave McCreary Kathy Nesser Stevie Darr Alan Jelalian Mark Shairer Mat Merriman LIST OF A TIEN DEES SEPTEMBER 12, 2017, PUBLIC MEETING WITH FIRSTENERGY NUCLEAR OPERATING COMPANY AFFILIATION Nuclear Regulatory Commission (NRC)

NRC NRC NRC Pacific Northwest National Laboratory (NRC contractor)

Pacific Northwest National Laboratory (NRC contractor)

FirstEnergy Nuclear Operating Company (FENOC)

FENOC FE NOC FE NOC FE NOC FE NOC FE NOC FE NOC FENOC EPM (FENOC Contractor)

EPM (FENOC Contractor)

ARS (FENOC Contractor)

Enclosure

Package: ML17258A215 Notice: ML17240A356 S

ML17258A146 ummar :

OFFICE DORL/LPL31PM NAME BPurne11 DATE 09118/17 DORL/LPL3/LA SRohrer 09/18117 DORL/LPL3/BC DWrona (KGreen for) 09120/17