ML20097F192

Nuscale Power, LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: Nuscale Topic - Hydrogen/Oxygen Monitoring, PM-0420-69518, Revision 0

ML20097F192
Person / Time
Site:	NuScale
Issue date:	04/06/2020
From:	Rad Z NuScale
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LO-0420-69819
Download: ML20097F192 (7)

Text

LO-0420-69519 April 6, 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 - Hydrogen/Oxygen Monitoring, PM-0420-69518, 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 hydrogen/oxygen monitoring.

The enclosure to this letter is the nonproprietary presentation entitled ACRS Full Committee Presentation: NuScale Topic - Hydrogen/Oxygen Monitoring, PM-0420-69518, Revision 0.

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

If you have any questions, please contact Matthew Presson at 541-452-7531 or at mpresson@nuscalepower.com.

Sincerely, Zackary W. Rad Director, Regulatory Affairs 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 Getachew Tesfaye, NRC, OEFN-8H12

Enclosure:

ACRS Full Committee Presentation: NuScale Topic - Hydrogen/Oxygen Monitoring, PM-0420-69518, 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-0420-69519

Enclosure:

ACRS Full Committee Presentation: NuScale Topic - Hydrogen/Oxygen Monitoring, PM-0420-69518, 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 Hydrogen/Oxygen Monitoring April 8, 2020 1

PM-0420-69518 Revision: 0 Copyright 2020 by NuScale Power, LLC.

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Presenters Matthew Presson Licensing Project Manager Jim Osborn Licensing Engineer 2

PM-0420-69518 Revision: 0 Copyright 2020 by NuScale Power, LLC.

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Summary and Conclusions

• Core damage accident is a beyond design basis accident

- Consistent with industry practice, allows nonsafety-related SSCs

- A NuScale core damage accident is low frequency

• Bounding analyses shows there is a minimum of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before containment can be threatened

• Decision to place system into service would include precautions and follow RG 1.7 risk-informed process

- There is sufficient time to inspect and evaluate system condition

- If leaks develop, can isolate and repair

• Monitoring path can withstand combustion events

• Containment is well-mixed and representative sampling is required 3

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Containment Isolation Failure

• Chapter 19 documents an assessment of whether a severe core damage event with a containment failure could lead to a large release

• The conclusion is that at the earliest possible time of fuel-coolant interaction (FCI), the airborne fraction of volatile fission product aerosols is less than the calculated threshold for a large release.

- 6.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is the earliest possible time of FCI for intact containment accidents

• Under the bounding assumption that the containment evacuation system (CES) piping were to be completely sheared at the time of unisolation, it is reasonable to conclude this event would not result in a large release or threaten public safety 4

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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 5

PM-0420-69518 Revision: 0 Copyright 2020 by NuScale Power, LLC.

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