ML18324A551

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Audit Plan for Regulatory Audit of Nuscale Design Certification Application, Final Safety Analysis Report, Tier 2, Section 3.7 Seismic Design and Section 3.8 Design of Category I Structures
ML18324A551
Person / Time
Site: NuScale
Issue date: 11/26/2018
From: Amadiz Marieliz Vera
NRC/NRO/DLSE/LB1
To: Samson Lee
NRC/NRO/DLSE/LB2
Vera A M/NRO/5861
References
Download: ML18324A551 (8)
v • d • e


Text

November 26, 2018 MEMORANDUM TO: Samuel S. Lee, Chief Licensing Branch 1 Division of Licensing, Siting, and Environmental Assessment Office of New Reactors FROM: Marieliz Vera, Project Manager /RA/

Licensing Branch 1 Division of Licensing, Siting, and Environmental Assessment Office of New Reactors

SUBJECT:

AUDIT PLAN FOR REGULATORY AUDIT OF NUSCALE POWER, LLC DESIGN CERTIFICATION APPLICATION, FINAL SAFETY ANALYSIS REPORT, TIER 2, SECTION 3.7, SEISMIC DESIGN AND SECTION 3.8 DESIGN OF CATEGORY I STRUCTURES On January 6, 2017, NuScale Power, LLC (NuScale) submitted a design certification application (DCA) for a small modular reactor to the U.S. Nuclear Regulatory Commission (NRC)

(Agencywide Documents Access and Management System Accession No. ML17013A229).

The NRC staff started its detailed technical review of NuScales DC application on March 15, 2017.

The purpose of the subject audit to be conducted by the NRC staff is to: (1) gain a better understanding of the NuScale design of the Category I Structures and Seismic Design; (2) verify information provided in the DCA; (3) identify information that may require docketing to support the basis of the licensing or regulatory decision; and (4) review related documentation and non-docketed information to evaluate conformance with regulatory guidance and compliance with NRC regulations.

The audit will take place at NuScales offices in Rockville, Maryland. The audit is currently scheduled to start on December 3, 2018, and end on December 7, 2018. The audit plan is enclosed.

Docket No.52-048

Enclosure:

1. Audit Plan cc w/encl.: DC NuScale Power, LLC Listserv CONTACT: Marieliz Vera, NRO/ DLSE 301-415-5861

ML18324A551 OFFICE NRO/DLSE/LB1: PM NRO/DLSE/LB1: LA NRO/DLSE/LB1: PM NAME MVera MMoore MVera DATE 11/20/2018 11/20/2018 11/26/2018 U.S. NUCLEAR REGULATORY COMMISSION REGULATORY AUDIT OF NUSCALE DESIGN CERTIFICATION APPLICATION, FINAL SAFETY ANALYSIS REPORT, TIER 2, SECTION 3.7, SEISMIC DESIGN AND SECTION 3.8, DESIGN OF CATEGORY I STRUCTURES DOCKET NO.52-048 AUDIT PLAN APPLICANT: NuScale Power, LLC (NuScale)

APPLICANT CONTACTS: Marty Bryan, NuScale DURATION: December 3, 2018 to December 7, 2018 LOCATION: NuScale Rockville Office AUDIT TEAM: Manas Chakravorty, Senior Structural Engineer (NRC),

Audit Lead Robert Roche-Rivera, Structural Engineer (NRC)

Sunwoo Park, Structural Engineer (NRC)

Ata Istar, Structural Engineer (NRC)

Pravin Patel, Structural Engineer (NRC)

John Ma, Senior Structural Engineer (NRC)

Vaughn Thomas, Acting Branch Chief (NRC)

Marieliz Vera, Project Manager (NRC)

I. BACKGROUND On January 6, 2017, NuScale submitted to the U.S. Nuclear Regulatory Commission (NRC) a Final Safety Analysis Report (FSAR) for its Design Certification Application (DCA) of the NuScale design (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML17013A229) (Reference 1).

On March 15, 2017, the NRC staff accepted the DCA for docketing and initiated its licensing review. The applicant has performed seismic analysis and design evaluation of NuScale Seismic Category I (SC-I) structures in support of its DCA and in response to the NRC staffs request for additional information (RAIs) pertaining to FSAR Sections 3.7.1, 3.7.2, 3.7.3, 3.8.4, and 3.8.5. During the audit, the NRC staff will review pertinent technical information including calculations, engineering drawings, and supporting documentations and confirm their consistency with the information in FSAR Sections 3.7 and 3.8. The audit will be conducted at NuScales facility.

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II. PURPOSE The purpose of this audit is for the NRC staff to review primarily non-docketed information to examine and verify the analyses and calculations, engineering drawings, and related documentations that support the NuScale DCA FSAR Sections 3.7 and 3.8 and confirm their consistency with the information in the FSAR Sections 3.7 and 3.8 and the related RAI responses.

III. REGULATORY BASIS Title 10 of the Code of Federal Regulations (CFR), Part 50, Appendix A, General Design Criterion (GDC) 1, as it relates to structures, systems, and components being designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety function to be performed.

GDC 2, as it relates to the design of the safety-related structures being able to withstand the most severe natural phenomena such as wind, tornadoes, hurricanes, floods, and earthquakes and the appropriate combination of all loads.

GDC 4, as it relates to safety-related structures being appropriately protected against dynamic effects, including the effects of missiles, pipe whipping, and discharging fluids, that may result from equipment failures and from events and conditions outside the nuclear power unit.

10 CFR Part 50, Appendix S as it relates to structures, systems, and components (SSCs) remaining functional and within applicable stress, strain, and deformation limits, for safe shutdown earthquake (SSE) ground motions. The required safety functions of these SSCs must be assured during and after the vibratory ground motion associated with the SSE ground motion through design, testing, or qualification methods. The evaluation must take into account SSI effects and the expected duration of the vibratory motion.

IV. REGULATORY AUDIT SCOPE The scope of this audit is to review information on the analyses, calculations, engineering drawings, procedures, computational tools, and associated documentations which support FSAR Sections 3.7.1, Seismic Design Parameters, 3.7.2, Seismic System Analysis, 3.7.3, Seismic Subsystem Analysis, 3.8.4, Other Seismic Category I Structures, and 3.8.5, Foundations, and related RAI responses docketed prior to the beginning of the audit.

Attachments A and B specify the scope of the audit.

In support of this Audit, NuScale should identify the pertinent calculations and documents that are used in establishing the seismic demand and the capacity of the seismic Category I structures in the NuScale design control document (DCD) scope as well as the responses to the related RAIs. A list of the calculations and the supporting documents directly related to Audit scope items should be provided to the NRC staff prior to the start of the audit.

V. SPECIAL REQUESTS The NRC staff requests that NuScale provide the following:

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  • Calculations and supporting documents should also be made available for review during the audit.
  • A work space for the duration of the audit.
  • A private conference room for NRC staffs internal discussions.
  • A teleconference line for the audit entrance and exit meetings.
  • An internet connection to be used by NRC staff to access the NRC systems.

VI. AUDIT ACTIVITIES AND DELIVERABLES The NRC audit team will review selected portions of the analyses and calculations and associated documentations that were performed or prepared in support of the information provided in the NuScale DCA and in response to NRC staffs RAIs, as detailed in Attachments A and B. The NRC staff will conduct this audit in accordance with the guidance provided in NRO-REG-108, Regulatory Audits (Reference 2), Appendix A to DSRS Section 3.7.2, Seismic System Analysis and Appendix B to DSRS Section 3.8.4, Other Seismic Category I Structures as applicable. The NRC staff acknowledges the proprietary nature of certain information requested and will handle it appropriately throughout the audit. While the NRC staff will take notes, the NRC staff will not remove hard copies or electronic files from the audit site(s).

The audit entrance and exit briefings will be scheduled at the beginning and conclusion of the audit. The entrance and exit briefings will not be noticed or conducted as public meetings. As needed, the audit lead may consider periodic status briefings with the applicant during the audit to discuss progress and potential issues identified.

The audit will allow the NRC staff to examine and verify the analyses, calculations, engineering drawings, and related documentation that support the NuScale DCA FSAR Sections 3.7 and 3.8 and confirm their consistency with the information in FSAR Sections 3.7 and 3.8. Further the audit will allow the NRC staff to identify information, if any, that should be docketed to support the staffs licensing decision. The audit will also assist the NRC staff in determining if additional RAIs will be needed to obtain information necessary to complete its licensing review.

Within 90 days of completion of the audit, the audit team will generate a regulatory audit summary which will include a list of documents audited by the team, a description of audit activities, and a description of any new technical issues identified during the audit and proposed closure paths. The staff does not make safety findings in an audit summary; however, the staff may refer to the audit summary in a safety evaluation.

Any questions or concerns related to the conduct of the audit will be communicated to Marieliz Vera (NRC) at 301-415-5861 or Marieliz.Vera@nrc.gov.

VII. REFERENCES

1. NuScale Power, LLC Letter to the NRC, NuScale Power, LLC Submittal of the NuScale Standard Plant Design Certification Application, December 31, 2016 (ADAMS Accession No. ML17013A229).

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2. NuScale Design-Specific Review Standard Section 3.7.1, Seismic Design Parameters, April 2017, (ADAMS Accession No. ML15355A384).
3. NuScale Design-Specific Review Standard Section 3.7.2, Seismic System Analysis, April 2017, (ADAMS Accession No. ML15355A389).
4. NuScale Design-Specific Review Standard Section 3.7.3, Seismic Subsystem Analysis, April 2017, (ADAMS Accession No. ML15355A402).
5. NuScale Design-Specific Review Standard Section 3.8.4, Other Seismic Category I Structures, April 2017, (ADAMS Accession No. ML15355A444).
6. NuScale Design-Specific Review Standard Section 3.8.5, Foundations, April 2017, (ADAMS Accession No. ML15355A451).
7. NRO-REG-108, Regulatory Audits, April 2, 2009 (ADAMS Accession No. ML081910260).

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Attachment A - FSAR 3.7 Areas of the Audit FSAR Section 3.7.1 (Seismic Design Parameters)

1. CSDRS and CSDRS-HF (FSAR Section 3.7.1.1.1).

CSDRS and the CSDRS compatible time histories:

  • Basis of the CSDRS for the standard design.
  • Development of time histories based on the CSDRS.

CSDRS-HF:

  • Basis of the CSDRS-HF for the hard rock sites.
  • Development of time histories based on the CSDRS-HF.

FSAR Section 3.7.2 (Seismic System Analysis)

1. SSI, SSSI, and the Sensitivity Analyses Analysis Models (RAI Nos. 3.7.2-1, 3.7.2-4, 3.7.2-6, 3.7.2-8, 3.7.2-15, 3.7.2-31)
  • Model consistency and ESM Benchmarking results, adequacy of number of layers, excavated volume and structural element mesh size, passing frequency, Poissons ratio, water table, element aspect ratio, model depth, transfer functions, analysis frequencies, etc.
  • Consideration of structural stiffness variation in the model.
  • Validation of the simplified NPM beam model against the detailed NPM 3D model.
  • ANSYS 3D Fluid-Structure Interaction (FSI) model to account for the FSI effect.
  • Model used for the study of the soil separation sensitivity effect.
  • Modeling of potential operating conditions with less than 12 NPMs.

Analysis Results (RAI Nos. 3.7.2-10, 3.7.2-20, 3.7.2-25)

  • Bounding structural seismic demand at critical locations including NPM lug and skirt supports, RBC support, Bioshield, etc.
  • Bounding equipment seismic demand (ISRS) at critical locations including the RBC support, Bioshield, RFT, CB emergency equipment room, etc.
  • Lateral soil pressures at below grade walls.

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  • Plan for addressing in the design basis any exceedances from the sensitivity studies.
2. Status Briefing on the RAIs waiting for initial response.

FSAR Section 3.7.3 (Seismic Subsystem Analysis)

1. Bioshields seismic input, analysis, and design (RAI No. 8928, Questions 03.07.03-2 to 03.07.03-4; RAI No. 8838, Question 03.08.04-1).

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Attachment B - FSAR 3.8 Areas of the Audit FSAR Section 3.8.4 (Other Seismic Category I Structures)

1. SAP2000 Analysis Models (RAIs 3.8.4-2, 3.8.4-5, 3.8.4-19, 3.8.4-28)
  • Boundary conditions
  • Finite element and material properties
2. Implementation of Structural Design Criteria Design loads (static and dynamic loads) and Load Combinations (RAIs 3.8.4-6, 3.8.4-7, 3.8.4-11, 3.8.4-13, 3.8.4-14, 3.8.4-20, 3.8.4-37)
  • Implementation of normal, severe, extreme, and abnormal loads in SAP2000
  • Method for checking the ACI 349 and AISC N690 critical load combination(s)

Member capacity calculations and calculations of demand/capacity ratios for Critical Sections (RAI 3.8.4-26)

  • Microsoft Excel spreadsheet(s) and Mathcad files - Implementation of ACI 349 and AISC N690 design provisions Design calculations for NPM supports (RAI 3.8.4-10, 3.8.4-21, 3.8.4-31)
  • Local lug restraint SAP2000 analysis
  • Calculations for design basis demand, capacity, and respective D/C ratios RFT/CFT analysis and design report (RAI 3.8.4-1)

Engineering drawings including plans, elevations, cross-sections, reinforcement details, and details of connections and joints (RAIs 03.08.04-15 to -18)

3. Status Briefing on the RAIs waiting for initial response FSAR Section 3.8.5 (Foundations)
1. Calculations related to the stability checks (uplifting, sliding and overturning) for RXB and CRB.
2. Calculations related to the settlement checks (maximum vertical settlement, maximum tilting settlement, maximum allowable differential settlement between buildings and maximum angular distortion) for RXB and CRB (tunnel area).
3. Calculations related to the bearing pressure (average, localized and toe) checks for RXB and CRB (tunnel area) foundations.
4. Calculations for the designs of RXB and CRB (tunnel area) foundations.
5. Calculations that considers the reduction of 50 percent of soft soil stiffness (Soil Type
11) in the design of RXB and CRB foundations.
6. Standalone and triple building models used in the RXB and CRB foundation designs.
7. Examples of how the governing load combination 10 from Table 3.8.4-1 (Equation 9-6 of ACI 349) was used for the design of RXB and CRB foundations.
8. Engineering drawings with reinforcements of RXB and CRB foundations.

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