ML18090A011

SMR TR RAIs - Request for Additional Information Letter No. 9438 (Erai No. 9438) Topical Report, Thermal Hydraulic Stability, 15.09, Srsb

ML18090A011
Person / Time
Site:	PROJ0769
Issue date:	03/31/2018
From:	NRC
To:	NRC/NRO/DNRL/LB1
References
Download: ML18090A011 (3)

Text

NuScaleTRRaisPEm Resource From: Chowdhury, Prosanta Sent: Saturday, March 31, 2018 2:26 PM To: Request for Additional Information Cc: Lee, Samuel; Cranston, Gregory; Karas, Rebecca; Skarda, Raymond; Bavol, Bruce; NuScaleTRRaisPEm Resource

Subject:

Request for Additional Information Letter No. 9438 (eRAI No. 9438) Topical Report, Thermal Hydraulic Stability, 15.09, SRSB Attachments: Request for Additional Information No. 9438 (eRAI No. 9438).pdf Attached please find NRC staffs request for additional information (RAI) concerning review of the NuScale Topical Report.

Please submit your technically correct and complete response within 60 days of the date of this RAI to the NRC Document Control Desk.

If you have any questions, please contact me.

Thank you.

Prosanta Chowdhury, Project Manager Licensing Branch 1 (NuScale)

Division of New Reactor Licensing Office of New Reactors U.S. Nuclear Regulatory Commission 301-415-164 1

Hearing Identifier: NuScale_SMR_DC_TR_Public Email Number: 78 Mail Envelope Properties (BN7PR09MB2609A1E12C54277B0C51A0B69EA00)

Subject:

Request for Additional Information Letter No. 9438 (eRAI No. 9438) Topical Report, Thermal Hydraulic Stability, 15.09, SRSB Sent Date: 3/31/2018 2:25:31 PM Received Date: 3/31/2018 2:25:37 PM From: Chowdhury, Prosanta Created By: Prosanta.Chowdhury@nrc.gov Recipients:

"Lee, Samuel" <Samuel.Lee@nrc.gov>

Tracking Status: None "Cranston, Gregory" <Gregory.Cranston@nrc.gov>

Tracking Status: None "Karas, Rebecca" <Rebecca.Karas@nrc.gov>

Tracking Status: None "Skarda, Raymond" <Raymond.Skarda@nrc.gov>

Tracking Status: None "Bavol, Bruce" <Bruce.Bavol@nrc.gov>

Tracking Status: None "NuScaleTRRaisPEm Resource" <NuScaleTRRaisPEm.Resource@nrc.gov>

Tracking Status: None "Request for Additional Information" <RAI@nuscalepower.com>

Tracking Status: None Post Office: BN7PR09MB2609.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 531 3/31/2018 2:25:37 PM Request for Additional Information No. 9438 (eRAI No. 9438).pdf 85375 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Request for Additional Information No. 9438 (eRAI No. 9438)

Issue Date: 04/02/2018 Application

Title:

NuScale Topical Report Operating Company: NuScale Docket No. PROJ0769 Review Section: 15.09 - A.DSRS NuScale Thermal Hydraulic Stability Application Section:

QUESTIONS 15.09-5 In accordance with 10 CFR 50 Appendix A GDC 10, Reactor design, the reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that specified acceptable fuel design limits are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences. Appendix A GDC 12, "Suppression of reactor power oscillations," requires that oscillations be either not possible or reliably detected and suppressed. The SRP 15.0.2 acceptance criteria with respect to evaluation models includes the requirement that the chosen mathematical models and the numerical solution of those models must be able to predict the important physical phenomena reasonably well from both qualitative and quantitative points of view.

The staff reviewed the response to the original RAI, RAI 8870, and found that the response was insufficient for the staff to reach a conclusion regarding the adequacy of the stability analysis methodology. The following supplemental information is therefore requested:

x Provide a summary listing of the numerical results of the sensitivity studies described by the original RAI response. It is acceptable to respond to this request by providing these results as a table that in one column indicates the user input parameter for the subcooled boiling and a second column that provides the decay ratio.

x Explain how the variation in the input parameter for subcooled boiling covers a sufficient range to account for the impact of bypass flow.

x Compare the sensitivity of the decay ratio to the decay ratio uncertainty.