ML18290A860

September 24, 2018, Summary of the Public Meeting with Nuscale Power, LLC, to Discuss Staff'S Review of Nuscale DCA, Chapter 20

ML18290A860
Person / Time
Site:	NuScale
Issue date:	10/18/2018
From:	Tabatabai-Yazdi O NRC/NRO/DLSE/LB1
To:	Samson Lee NRC/NRO/DLSE/LB1
Tabatabai-Yazdi O/NRO/415-6616
References
Download: ML18290A860 (5)

Text

October 18, 2018 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 SEPTEMBER 24, 2018, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS THE U.S.

NUCLEAR REGULATORY COMMISSION STAFFS QUESTIONS RELATED TO NUCALES DESIGN CERTIFICATION APPLICATION, TIER 2, CHAPTER 20, MITIGATION OF BEYOND DESIGN BASIS EXTERNAL EVENTS On September 24, 2018, representatives of the U.S. Nuclear Regulatory Commission (NRC) and NuScale Power, LLC (NuScale) held a public teleconference meeting to discuss staffs questions related to Nucales design certification application, Tier 2, Chapter 20, Mitigation of Beyond Design Basis Events. captures the summary of the topics discussed during the teleconference. 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 (ADAMS) under Accession No. ML18256A302.

Docket No.52-048

Enclosures:

1. Meeting Summary

2. Agenda

3. Attendees CONTACT: Omid Tabatabai, NRO/DLSE 301-415-6616

ML18290A860 *via email NRC-001 OFFICE NRO/DLSE/LB1:PM NRO/DLSE/LB1:LA* NRO/DSRA/SRSB:BC* NRO/DLSE/LB1:PM NAME OTabatabai MMoore* RKaras* OTabatabai DATE 10/17/2018 10/18/2018 10/18/2018 10/18/2018 U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE SEPTEMBER 24, 2018, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS STAFFS QUESTIONS RELATED TO NUCALES DESIGN CERTIFICATION APPLICATION, TIER 2, CHAPTER 20, MITIGATION OF BEYOND DESIGN BASIS EXTERNAL EVENTS At the meeting the U.S. Nuclear Regulatory Commission (NRC) staff provided a status of their review of NuScale Power, LLCs (NuScale) mitigation of beyond design basis external events (MBDBEE) strategy. The NRC staff explained that the they collectively believe that NuScales MBDBEE strategy, up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, can be demonstrated acceptable for maintaining the key safety functions associated with core cooling, containment integrity, and spent fuel pool cooling utilizing onsite installed equipment. Additionally, the batteries are expected to function during the first 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and provide power to instrumentation and enable direct measurement of key safety parameters according to Technical Report TR-0816-50797, Mitigation Strategies for Extended Loss of AC Power Event, (ADAMS Accession No. ML17005A120). Furthermore, for the first 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, operators will have indication of core cooling parameters; such as, core inlet/outlet temperatures, reactor pressure vessel (RPV) and containment water level, and valve position indications. Once the batteries are depleted, at approximately 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> into the extended loss of alternating current (ac) power (ELAP) event, NuScale only relies on the indirect measurement of spent fuel pool level as indication of core cooling. Since NuScale is seeking approval of a 30-day baseline coping strategy for MBDBEE, the NRC staff does not believe this is sufficient for ensuring core cooling is maintained, and does not provide operators with adequate instrumentation to facilitate decision making in response to the event.

NuScale Final Safety Analysis Report, Revision 1, specifies that Nuclear Energy Institute (NEI) 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide," Revision 2 was used as guidance for an ELA) event. Regarding instrumentation, NEI 12-06, Revision 2, states:

The parameters selected must be able to demonstrate the success of the strategies at maintaining the key safety functions as well as indicate imminent or actual core damage to facilitate a decision to manage the response to the event within the Emergency Operating Procedures and FLEX Support Guidelines or within the severe accident management guidelines (SAMGs).

At the conclusion of the meting, the NRC staff proposed the following three options to continue with the review of NuScales 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.

1 Enclosure 1

NuScale requested additional time to internally discuss these options before responding to the NRC staff. The NRC staff will schedule a public meeting to further this topic with NuScale and when NuScale has made a decision.

2

U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE SEPTEMBER 24, 2018, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS STAFFS QUESTIONS RELATED TO NUCALES DESIGN CERTIFICATION APPLICATION, TIER 2, CHAPTER 20, MITIGATION OF BEYOND DESIGN BASIS EVENTS MEETING AGENDA Introduction 11:00 - 11:10 am Staffs Questions Related to NuScale, Tier 2, Chapter 20 11:10 - 11:50 am Public Comments 11:50 - 12:00 pm Enclosure 2

U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE SEPTEMBER 24, 2018, TELECONFERENCE WITH NUSCALE POWER, LLC LIST OF ATTENDEES NuScale Power, LLC Jennie Wike Brain Gardes Doug Bowman Elizabeth English Carrie Fosaaen Chris Maxwell Nadja Joergensen U.S. Nuclear Regulatory Commission Staff Omid Tabatabai Ryan Nolan Rebecca Karas Joe Ashcraft Clint Ashley Ngola Otto Tania Martinez Navedo Diane Jackson Sam Lee Jeremy Bowen John Budzynski Chang Li Sheila Ray Raul Hernandez John Monninger Rob Taylor Kevin Coyne Members of the Public Sarah Fields, Uranium Watch Enclosure 3