ML18059A239

SMR DC RAI - Request for Additional Information No. 373 RAI No. 9406 (04.02)

ML18059A239
Person / Time
Site:	NuScale
Issue date:	02/28/2018
From:	NRC
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Download: ML18059A239 (3)

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NuScaleDCRaisPEm Resource From: Chowdhury, Prosanta Sent: Wednesday, February 28, 2018 9:43 AM To: 'RAI@nuscalepower.com' Cc: Lee, Samuel; Cranston, Gregory; Karas, Rebecca; Schmidt, Jeffrey; Van Wert, Christopher; Bavol, Bruce

Subject:

Request for Additional Information No. 373 RAI No. 9406 (04.02)

Attachments: Request for Additional Information No. 373 (eRAI No. 9406) .pdf Attached please find NRC staffs request for additional information (RAI) 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.

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 301-415-1647 1

Hearing Identifier: NuScale_SMR_DC_RAI_Public Email Number: 401 Mail Envelope Properties (Prosanta.Chowdhury@nrc.gov20180228094200)

Subject:

Request for Additional Information No. 373 RAI No. 9406 (04.02)

Sent Date: 2/28/2018 9:42:56 AM Received Date: 2/28/2018 9:42:00 AM 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 "Schmidt, Jeffrey" <Jeffrey.Schmidt2@nrc.gov>

Tracking Status: None "Van Wert, Christopher" <Christopher.VanWert@nrc.gov>

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

Tracking Status: None

"'RAI@nuscalepower.com'" <RAI@nuscalepower.com>

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 531 2/28/2018 9:42:00 AM Request for Additional Information No. 373 (eRAI No. 9406) .pdf 13886 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Request for Additional Information No. 373 (eRAI No. 9406)

Issue Date: 02/28/2018 Application

Title:

NuScale Standard Design Certification 048 Operating Company: NuScale Power, LLC Docket No.52-048 Review Section: 04.02 - Fuel System Design Application Section:

QUESTIONS 04.02-9 In Appendices A through D of 10 CFR Part 52, the Commission has approved a two-tiered structure to design certifications. Discussions regarding the two-tiered approach can be found in the final rulemaking and various SECY papers and Staff Requirement Memorandums (SRMs). In particular, in the Staff Request Memorandum (SRM) to SECY-94-084 (ML003708098), the Commission instructed the staff to implement the two-tiered design certification rule structure proposed by the staff. The latest guidance is found in SECY-17-0075 (ML16196A321). SRP Section 14.3.4 provides some general guidance regarding the contents of Tier 1 and specifically states that:

Tier 1 should include those SSCs that could affect the operation of the reactor and core cooling systems [e.g., the following chapters of the Standard Review Plan (SRP): Chapter 4- Reactor, Chapter 5-Reactor Coolant Systems and Connected Systems, Chapter 6-Section 6.3 on Emergency Core Cooling Systems, Chapter 9-9.3.6 on the standby liquid control system, Chapter 15-Transients and Accidents Analyses].

The fuel assembly design is a safety significant structure due to (1) the fuel cladding acting as the first fission product barrier, and (2) the direct safety impacts that the fuel assembly design has on the analyses for normal operation, anticipated operational occurrences (AOOs), and postulated accidents (in particular, Chapter 4 and Chapter 15). Additionally, the empirical nature of the fuel design analysis methods means that the approved safety codes and methods are closely tied to the fuel assembly designs upon which they were built. The safe operation of the reactor and core cooling systems can be directly impacted due to the fuel assembly design having direct impacts on thermal-hydraulic and transient performance. Similarly, the burnup limit is safety significant because it has direct implications on the fuel performance and is an important parameter in the design basis accident radiological consequences analyses.

The staff requests NuScale to provide the Tier 1 description for the fuel system design. For example, the Tier 1 description should include the following (or something equivalent):

Section 1.X.X Fuel Assembly Design The fuel assembly is designed to ensure that possible fuel damage would not result in the release of radioactive materials in excess of prescribed limits. The fuel assembly is comprised of fuel rods, grids, guide tubes, top and bottom nozzles, plenum springs, and leaf springs. The fuel assembly design utilized in the NuScale reactor must be approved by the NRC for the NuScale reactor design.