ML17363A439

SMR DC RAI - Request for Additional Information No. 315 RAI No. 9237 (15.06.03)

ML17363A439
Person / Time
Site:	NuScale
Issue date:	12/29/2017
From:	NRC
To:	NRC/NRO/DNRL/LB1
References
Download: ML17363A439 (3)

Text

NuScaleDCRaisPEm Resource From: Cranston, Gregory Sent: Friday, December 29, 2017 12:00 PM To: RAI@nuscalepower.com Cc: NuScaleDCRaisPEm Resource; Lee, Samuel; Chowdhury, Prosanta; Karas, Rebecca; Schmidt, Jeffrey; Nolan, Ryan; Franovich, Rani

Subject:

Request for Additional Information No. 315 RAI No. 9237 (15.06.03)

Attachments: Request for Additional Information No. 315 (eRAI No. 9237).pdf Attached please find NRC staffs request for additional information concerning review of the NuScale Design Certification Application.

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

The NRC Staff recognizes that NuScale has preliminarily identified that the response to the question in this RAI is likely to require greater than 60 days.

If you have any questions, please contact me.

Thank you.

Gregory Cranston, Senior Project Manager Licensing Branch 1 (NuScale)

Division of New Reactor Licensing Office of New Reactors U.S. Nuclear Regulatory Commission 301-415-0546 1

Hearing Identifier: NuScale_SMR_DC_RAI_Public Email Number: 342 Mail Envelope Properties (MWHPR09MB1200B4DF0B1B3E140B911EF490050)

Subject:

Request for Additional Information No. 315 RAI No. 9237 (15.06.03)

Sent Date: 12/29/2017 11:59:54 AM Received Date: 12/29/2017 12:00:05 PM From: Cranston, Gregory Created By: Gregory.Cranston@nrc.gov Recipients:

"NuScaleDCRaisPEm Resource" <NuScaleDCRaisPEm.Resource@nrc.gov>

Tracking Status: None "Lee, Samuel" <Samuel.Lee@nrc.gov>

Tracking Status: None "Chowdhury, Prosanta" <Prosanta.Chowdhury@nrc.gov>

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

Tracking Status: None "Schmidt, Jeffrey" <Jeffrey.Schmidt2@nrc.gov>

Tracking Status: None "Nolan, Ryan" <Ryan.Nolan@nrc.gov>

Tracking Status: None "Franovich, Rani" <Rani.Franovich@nrc.gov>

Tracking Status: None "RAI@nuscalepower.com" <RAI@nuscalepower.com>

Tracking Status: None Post Office: MWHPR09MB1200.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 726 12/29/2017 12:00:05 PM Request for Additional Information No. 315 (eRAI No. 9237).pdf 87386 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Request for Additional Information No. 315 (eRAI No. 9237)

Issue Date: 12/29/2017 Application

Title:

NuScale Standard Design Certification 048 Operating Company: NuScale Power, LLC Docket No.52-048 Review Section: 15.06.03 - Radiological Consequences of Steam Generator Tube Failure (PWR) 07/1981 Application Section: 15.6.3 QUESTIONS 15.06.03-3 GDC 1 requires structures, systems, and components important to safety to be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. In addition, 10 CFR 50.2 defines safety-related as structures, systems and components that are relied upon to remain functional during and following design basis events to assure: (1) the integrity of the reactor coolant pressure boundary; (2) the capability to shut down the reactor and maintain it in a safe shutdown condition; or (3) the capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to the applicable guideline exposures set forth in § 50.34(a)(1) or § 100.11 of this chapter, as applicable.

FSAR Tier 2, Section 15.6.3, Steam Generator Tube Failure (Thermal Hydraulic), credits the nonsafety-related secondary main steam isolation valve (MSIV) to provide isolation of the faulted steam generator when single failure criteria is applied (i.e. MSIV fails to close). FSAR Tier 2, Section 10.3.3 states:

The nonsafety-related secondary MSIVs downstream of the MSIVs are credited as backup isolation components in the event that an MSIV fails to close. Although not safety-related, the secondary MSIVs are designed to close under postulated worst-case conditions and are included in technical specification surveillance requirements to ensure their reliability and operability. Thus, consistent with the position established in NUREG-0138, Issue Number 1, the secondary MSIVs ensure that the blowdown is limited if a steamline were to break upstream of the MSIV.

NUREG-0138, Issue Number 1, states that GDC 1 permits flexibility in the acceptance level for safety-related equipment. NUREG-0138, Issue Number 1 also fully documents that its position is only applicable to spontaneous failures of secondary system piping not part of the primary system boundary, and where the potential for a release of fission products is significantly lower compared to a breach of the primary system boundary. As a steam generator tube rupture is a breach of the primary system boundary which bypasses multiple fission product barriers, provide additional justification as to why NUREG-0138, Issue Number 1 applies and/or provide a dose analysis which demonstrates the applicable accident dose limits are met with the single failure of the MSIV and the failure of the secondary, non-safety-related MSIV to close.