ML19084A136

Summary of Meeting with NuScale Power, LLC to Discuss Nuclear Regulatory Commission Staff'S Options to Review Nuscale'S Design Certification Application, Tier 2, Chapter 20, Mitigation of Beyond-Design-Basis Events

ML19084A136
Person / Time
Site:	NuScale
Issue date:	03/25/2019
From:	Tabatabai-Yazdi O NRC/NRO/DLSE/LB1
To:	Samson Lee NRC/NRO/DLSE/LB1
Tabatabai-Yazdi O
References
Download: ML19084A136 (6)

Text

March 25, 2019 MEMORANDUM TO: Samuel S. Lee, Chief Licensing Branch 1 Division of Licensing, Siting, and Environmental Analysis Office of New Reactors FROM: Omid Tabatabai, Senior Project Manager /RA/

Licensing Branch 1 Division of Licensing, Siting, and Environmental Analysis Office of New Reactors

SUMMARY

OF THE FEBRUARY 21, 2019, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS THE NUCLEAR REGULATORY COMMISSION STAFFS OPTIONS TO REVIEW NUSCALES DESIGN CERTIFICATION APPLICATION, TIER 2, CHAPTER 20, MITIGATION OF BEYOND-DESIGN-BASIS EVENTS On February 21, 2019, representatives of the U.S. Nuclear Regulatory Commission and NuScale Power, LLC (NuScale) held a public meeting to discuss NuScales mitigation of beyond-design-basis events strategy and staffs options to review NuScales Design Certification Application, Tier 2, Chapter 20, Mitigation of Beyond-Design-Basis Events. captures the summary of the topics discussed during the meeting. The agenda and list of meeting attendees are included in Enclosures 2 and 3, respectively. The meeting notice for this meeting is available in the Agencywide Documents Access and Management System under Accession No. ML19051A036.

Docket No.: 52-048

Enclosures:

1. Meeting Summary

2. Agenda

3. Attendees cc w/encl.: DC NuScale Power, LLC Listserv CONTACT: Omid Tabatabai, NRO/DLSE 301-415-6616

ML19084A136 *via email NRC-001 OFFICE NRO/DLSE/LB1:PM NRO/DLSE/LB1:LA* NRO/DLSE/LB1:PM NAME OTabatabai SGreen* OTabatabai DATE 3/22/2019 3/25/2019 3/25/2019 U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE FEBRUARY 21, 2019, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS NRC STAFFS OPTIONS TO REVIEW NUSCALES DESIGN CERETIFICATION APPLICATION, TIER 2, CHAPTER 20, MITIGATION OF BEYOND-DESIGN-BASIS EVENTS The purpose of this public meeting was to continue discussion from the September 24, 2018 public meeting regarding the Nuclear Regulatory Commission (NRC) staff's review of NuScale Power, LLC (NuScale) design certification application (DCA), Tier 2, Chapter 20, "Mitigation of Beyond-Design-Basis Events (MBDBE)." During the September 24, 2018 public meeting, the NRC staff informed NuScale that based on the docketed information the NRC staff had three options to proceed with the review of NuScales DCA, Chapter 20:

1. Review all of NuScale mitigating strategies during the combined-license (COL) reviews and provide no finality for the design certification.

2. Provide finality for the design certification up to the first 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, and the COL applicant would be responsible for Phase 2 and Phase 3 of the MBDBE strategies.

3. NuScale can address the NRC staffs issue and include appropriate instrumentation beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for ensuring key safety functions are maintained and to facilitate decision making.

A summary of the September 24, 2018, meeting is available in Agencywide Documents Access and Management System (ADAMS) under Accession No. ML18290A860. At the conclusion of September 24, 2018 public meeting, NuScale requested additional time to think about the NRC staffs review options and provide its feedback to the NRC staff at a later time. On October 25, 2018, NuScales Manager of Regulatory Affairs provided NuScales feedback via an electronic mail (e-mail) to the NRC staff. NuScales e-mail is available under ADAMS Accession No. ML18302A151. In its October 25, 2018 e-mail, NuScale informed the NRC staff that NuScale had provided enough information on the docket to allow the NRC staff to make a (favorable) regulatory finding on its MBDBE strategy at the design certification review stage and to provide finality even beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In its October 25, 2018 meeting, NuScale also requested a follow-up public meeting with the staff to further describe its design features and technical information to support its position.

On February 21, 2019, the NRC staff and NuScale representatives met to continue their discussions regarding NRC staff's options to review NuScales MBDBE strategy. The NRC staff informed NuScale that they had received and reviewed NuScales October 25, 2018, e-mail that provided NuScales perspectives on why the NRC staff did not need additional information from NuScale, or a combined license applicant, to make a regulatory finding on its MBDBE strategy beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

The NRC staff also informed NuScale that the Commission had approved the final MBDBE rule, Tite 10 of the Code of Federal Regulations (10 CFR) 50.155, on January 24, 2019 (ADAMS Accession No. ML19023A038), and that the issue of availability of Instrumentation to operators during a beyond-design-basis external event (BDBEE) continues to remain unresolved.

Enclosure 1

Specifically, NuScale believes that instrumentation to monitor the status of the core in a reactor module that is experiencing a BDBEE would not be needed once operators verify that the emergency core cooling system (ECCS) safety functions have been established. The NRC staff believes the regulations contained in 10 CFR 50.155 support the staff position that instrumentation capability must be available to operators throughout a BDBEE, even after operators verify that the ECCS and other safety systems have been established, given uncertainties in thermal hydraulic phenomena and boron distribution during long term cooling.

The staff believes the availability of instrumentation ensures that operators can monitor the status of the modules and facilitate decision making and take actions as needed. The NRC staff also informed NuScale that they had begun drafting a SECY vote paper to seek the Commissions direction on how to proceed with the review of NuScales MBDBE strategy.

In addition, the staff discussed inconsistencies between DCA, Tier 2, Section 20.1 and the supporting technical report, TR-0816-50797, Mitigation Strategies for Extended Loss of AC Power Event, (ADAMS Accession No. ML17005A120). Specifically, the information contained in Section 20.1 indicates that instrumentation is used by the operators only until the safety function has been established, which is in alignment with NuScales position communicated in the October 25, 2018 e-mail. However, the information contained in TR-0816-50797 leads the NRC staff to believe that monitoring instrumentation will be used by the operators for a minimum of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and that it does not make a distinction between establish and maintain like the information in Section 20.1 does.

At the end of the meeting, NuScale informed the NRC staff that they will be submitting a formal letter to address staffs concerns and also to provide its review options for the staff to consider in its SECY paper. NuScale stated that they planned to submit its letter to NRC by March 29, 2019.

2

U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE FEBRUARY 21, 2019, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS NRC STAFFS OPTIONS TO REVIEW NUSCALES DESIGN CERETIFICATION APPLICATION, TIER 2, CHAPTER 20, MITIGATION OF BEYOND-DESIGN-BASIS EVENTS MEETING AGENDA Introduction 1:00 - 1:10 pm Discussions related to DHRS/ECCS actuation logic 1:10 - 2:30 pm Public Comments 2:30 - 2:35 pm Enclosure 2

U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE FEBRUARY 21, 2019, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS NRC STAFFS OPTIONS TO REVIEW NUSCALES DESIGN CERETIFICATION APPLICATION, TIER 2, CHAPTER 20, MITIGATION OF BEYOND-DESIGN-BASIS EVENTS LIST OF ATTENDEES NuScale Power, LLC Carrie Fosaaen Nadja Joergensen Mike Melton Tom Bergman Gary Becker Liz English Doug Bowman Scott Weber Chris Maxwell U.S. Nuclear Regulatory Commission Staff Omid Tabatabai Ryan Nolan Rebecca Karas Boyce Travis Tim Drzewiecki Dinesh Taneja Sam Lee Don Palmrose Raul Hernandez Tania Martinez-Navedo Peter Bamford John Budzynski Clint Ashley Brian Smith Robert Weisman Ann Hove Kevin Coyne Sheila Ray Matthew McConnell Chang Li Members of the Public Sarah Fields Enclosure 3