ML18295A051

Summary of Meeting with NuScale Power, LLC, to Discuss the Design of Nuscale'S Containment Vessel

ML18295A051
Person / Time
Site:	NuScale
Issue date:	10/24/2018
From:	Tabatabai-Yazdi O NRC/NRO/DLSE/LB1
To:	Samson Lee NRC/NRO/DLSE/LB1
Tabatabai-Yazdi O/NRO/415-6616
References
Download: ML18295A051 (5)

Text

October 24, 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 26, 2018, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS THE DESIGN OF NUSCALES CONTAINMENT VESSEL On September 26, 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 Containment design. Specifically, the meeting participants discussed NuScale designs containment peak pressure calculations basis and design changes to enhance margin; revision to the containments American Society for Mechanical Engineers vessel peak pressure; peak pressure request for addidtional information (RAI) alignment with NuScale analysis and change to the final safety analysis report (FSAR) associated with design changes; and updates related to the staffs RAI No. 9540. 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 under Accession No. ML18247A183.

Docket No.52-048

Enclosures:

1. Meeting Summary

2. Agenda

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

ML18295A051 *via email NRC-001 OFFICE NRO/DLSE/LB1:PM NRO/DLSE/LB1:LA* NRO/DSRA/SCVB:BC* NRO/DLSE/LB1:PM NAME OTabatabai MMoore* DJackson* OTabatabai DATE 10/22/2018 10/23/2018 10/23/2018 10/24/2018 U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE SEPTEMBER 26, 2018, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS THE DESIGN OF NUSCALES CONTAINMENT VESSEL During the September 26, 2018, meeting, the U.S. Nuclear Regulatory Commission (NRC) staff and NuScale representatives discussed NuScale designs containment peak pressure calculations basis. NuScale presented an increase in containment design pressure, design and anaylsis changes to support the modified containment design pressure. NuScale and staff also began discussions on the impact of the design changes, including expected margin for containment design pressure over peak pressure; revisions to the containments American Society for Mechanical Engineers (ASME) vessel peak pressure; peak pressure RAI alignment with NuScale analysis & change to the final safety analysis report (FSAR) associated with design changes; and updates related to the staffs request for additional information (RAI) 9540.

The meeting was closed to public due to the proprietary nature of the information and design.

On September 27, 2018, NuScale submitted a proprietary version of the meeting presentation slides to the NRC. NuScales cover letter and affidavit are available in ADAMS under Acession No. ML18274A078.

The NRC staff had requested NuScale to:

1. Provide a schedule for responding to the staffs RAI Nos. 9304, 9357, 9380, 9482, 9494, and 9549,

2. Explain the differences between the NRELAP5 model used for the post-HP-49 test assessment vis-a-vis the one used for the pre-HP-49 test predictions,

3. Discuss the core heat rod model changes and other changes made in the NRELAP5 model for the post-test assessment that contributed to an increase in the predicted CNV pressure and the fuel rod centerline temperature, as compared to the pre-test predictions,

4. Explain the differences in the containment pressure observed in the unqualified test on 6/22/2018 versus the one observed in the qualified-test performed on 6/26/2018, with both tests using the same test procedures,

5. Describe the slower emergency core cooling system actuation and a smaller break flow with higher peak containment pressure,

6. Discuss the implications of the latest results provided in the HP-49 post-test assessment report, for the other completed test, i.e., HP-06b, HP-07, HP-09, and HP-43, as documented and used in the loss-of-coolant accident (LOCA) topical report (TR) and the other assessments,

7. Discuss the model's capability to predict the peak containment pressure across the full spectrum of break sizes and inadvertent RRV openings in the backdrop of the June 2018 HP-49 NIST test results.

Enclosure

During the meeting, NuScale presented additional or updated analyses and information to respond to the staffs questions. However, the staff stated that additional technical interactions with NuScale are needed for the staff to fully understand the behavior of NuScale containment under various operation and accident scenarios. A follow-up meeting will be scheduled to continue the discussions.

Enclosure

U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE SEPTEMBER 26, 2018, PUBLIC MEETING WITH NUSCALE POWER, LLC, TO DISCUSS TO DISCUSS THE DESIGN OF NUSCALES CONTAINMENT VESSEL MEETING AGENDA Introduction 1:00 - 1:10 pm Discussion of containment design changes (PUBLIC SESSION) 1:10 - 1:20 pm Public Comments 1:20 - 1:30 pm Discussion of containment design changes (CLOSED SESSION) 1:30 - 3:30 pm Enclosure

U.S. NUCLEAR REGULATORY COMMISSION

SUMMARY

OF THE SEPTEMBER 26, 2018, TELECONFERENCE WITH NUSCALE POWER, LLC LIST OF ATTENDEES NuScale Power, LLC Ben Bristol Andy Lingenfelter Meghan McCloskey Greg Myers J.J. Arthur Heqin Xu Jennie Wike Robert Gamble Patrick Byfield Brian Wolf Robert Houser Marty Bryan Karl Gross Kyle Hoover Paul Infanger U.S. Nuclear Regulatory Commission Staff Omid Tabatabai Carl Thurston Alfred Krall (ERI)

Mohsen Khalid-Rahbar (ERI)

Shanlai Lu John Monninger Jeff Schmidt Clint Ashley Kevin Coyne Anne-Marie Grady Alfred Hathaway Peter Lien Weidong Wang Tim Lupold Rebecca Karas Boyce Travis Diane Jackson Syed Haider Jason Thompson Enclosure