ML20094H674

LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation NuScale Topic-Probabilistic Risk Assessment with a Focus on Emergency Core Cooling System Analysis PM-0420-69559, Revision 0

ML20094H674
Person / Time
Site:	NuScale
Issue date:	04/03/2020
From:	Rad Z NuScale
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LO-0420-69560
Download: ML20094H674 (9)

Text

LO-0420-69560 April 3, 2020 Docket No.52-048 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738

SUBJECT:

NuScale Power, LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Probabilistic Risk Assessment, with a Focus on Emergency Core Cooling System Analysis, PM-0420-69559, Revision 0 The purpose of this submittal is to provide presentation materials to the NRC for use during the upcoming Advisory Committee on reactor Safeguards (ACRS) NuScale Full Committee Meeting on April 8, 2020. The materials support NuScales presentation of the probabilistic risk assessment.

The enclosure to this letter is the nonproprietary presentation entitled ACRS Full Committee Presentation: NuScale Topic - Probabilistic Risk Assessment, with a Focus on Emergency Core Cooling System Analysis, PM-0420-69559, Revision 0.

This letter makes no regulatory commitments and no revisions to any existing regulatory commitments.

If you have any questions, please contact Rebecca Norris at 541-602-1260 or at RNorris@nuscalepower.com.

Sincerely, y

Zackary W. Rad

Director, Di t R Regulatory l t Affairs Aff i NuScale Power, LLC Distribution: Robert Taylor, NRC, OWFN-8H12 Michael Snodderly, NRC, OWFN-8H12 Christopher Brown, NRC, OWFN-8H12 Gregory Cranston, NRC, OWFN-8H12 Michael Dudek, NRC, OWFN-8H12 Marieliz Johnson, NRC, OWFN, 8H12

Enclosure:

ACRS Full Committee Presentation: NuScale Topic - Probabilistic Risk Assessment, with a Focus on Emergency Core Cooling System Analysis, PM-0420-69559, Revision 0 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

LO-0420-69560

Enclosure:

ACRS Full Committee Presentation: NuScale Topic - Probabilistic Risk Assessment, with a Focus on Emergency Core Cooling System Analysis, PM-0420-69559, Revision 0 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

NuScale Nonproprietary ACRS Full Committee Presentation NuScale Topic Probabilistic Risk Assessment, with a Focus on Emergency Core Cooling System Analysis April 8, 2020 1

PM-0420-69559 Revision: 0 Copyright 2020 by NuScale Power, LLC.

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Presenters Rebecca Norris Licensing Project Manager Sarah Bristol Probabilistic Risk Assessment Supervisor 2

PM-0420-69559 Revision: 0 Copyright 2020 by NuScale Power, LLC.

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ACRS Interactions

• March and October 2018 - Overview of NuScale PRA for selected members (Ref. LO-1018-62248, 10/30/18)

- PRA methods, quality process, passive features modeling, human error, multi-module risk

• May-June 2019 -FSAR Chapter 19 Subcommittee and Full Committee (Ref. LO-0519- 65373, 5/09/19; LO-0519-65769, 5/31/19)

- Multiple topics including full committee discussion of passive system reliability

• July 2019 -NuScale site (Corvallis, OR) meeting.

- Multiple topics including results of intermediate ECCS valve testing

• March, 2020 - Phase 5 focus area Subcommittee (Ref. LO-0220-69047, 2/28/20)

- Discussion of ECCS operation 3

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Focus Area Review Topics

• ECCS mechanical configuration

• ECCS valve and inadvertent actuation block (IAB) operation

• ECCS valve testing

• ECCS valve failure modes and probability

• ECCS logic

• ECCS valve generic data sensitivity

- Evaluated the impact of ECCS reliability on select support systems 4

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Outstanding Subcommittee Questions

• Units in sample fault trees (Ref. slide ECCS Valve Logic (Spurious Opening)) are per year

• Fussell-Vesely values (Ref. slide Generic Data Sensitivity): In a sensitivity study including generic data for ECCS valves, there were no new support system risk insights, including consideration for human action risk significance (i.e., FV importance measures)

Reference slides are contained in the presentations submitted as LO-0220-69047, 2/28/20 5

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Acronyms ACRS Advisory Committee on Reactor Safeguards DCA Design Certification Application ECCS emergency core cooling system FSAR Final Safety Analysis Report FV Fussell-Vesely IAB inadvertent actuation block NRC Nuclear Regulatory Commission PRA probabilistic risk assessment 6

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Portland Office Richland Office 6650 SW Redwood Lane, 1933 Jadwin Ave., Suite 130 Suite 210 Richland, WA 99354 Portland, OR 97224 541.360.0500 971.371.1592 Charlotte Office Corvallis Office 2815 Coliseum Centre Drive, 1100 NE Circle Blvd., Suite 200 Suite 230 Corvallis, OR 97330 Charlotte, NC 28217 541.360.0500 980.349.4804 Rockville Office 11333 Woodglen Ave., Suite 205 Rockville, MD 20852 301.770.0472 http://www.nuscalepower.com Twitter: @NuScale_Power 7

PM-0420-69559 Revision: 0 Copyright 2020 by NuScale Power, LLC.

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