ML24229A157
| ML24229A157 | |
| Person / Time | |
|---|---|
| Issue date: | 08/22/2024 |
| From: | Vivanco R NRC/NRR/DNRL/NRLB |
| To: | |
| References | |
| Download: ML24229A157 (1) | |
Text
Non-Proprietary Presentation to the Advisory Committee on Reactor Safeguards Subcommittee Staff Review of NuScales US460 Standard Design Approval Application Final Safety Analysis Report, Revision 1 August 22nd, 2024 (Open Session) 1 Chapters 7, 9, 12, and 18
Non-Proprietary Acronyms and Definitions ACRS - Advisory Committee on Reactor Safeguards APLB - PRA Licensing Branch B APLC - PRA Licensing Branch C ARCB - Radiation Protection and Consequences Branch CFR - Code of Federal Regulations COL - Combined License COLA - Combined License Application DC - Design Certification (refers to NuScale US600 design)
DCA - Design Certification Application (refers to NuScale US600 design)
DEX - Division of Engineering and External Hazards DNRL - Division of New and Renewed Licenses DRA - Division of Risk Assessment DSS - Division of Safety Systems EEEB - Electrical Engineering Branch EICB - Instrumentation and Controls Branch ELTB - Long Term Operations and Modernization Branch EMIB - Mechanical Engineering and Inservice Testing Branch ESEB - Structural Civil Geotech Engineering Branch FSAR - Final Safety Analysis Report GDC - General Design Criteria NCSG - Corrosion and Steam Generator Branch NLIB - Licensing and Regulatory Infrastructure Branch NPM - NuScale Power Module NRLB - New Reactor Licensing Branch NRR - Office of Nuclear Reactor Regulation PRA - Probabilistic Risk Assessment SCPB - Containment and Plant Systems Branch SDA - Standard Design Approval (refers to NuScale US460 design)
SDAA - Standard Design Approval Application (refers to NuScale US460 design)
SNRB - Nuclear Methods Systems and New Reactors Branch 2
Non-Proprietary Presentation to the ACRS Subcommittee Staff Review of NuScale SDAA FSAR, Revision 1 Chapter 7, Instrumentation and Controls" August 22, 2024 (Open Session) 3
Non-Proprietary NuScale SDAA FSAR Chapter 7 Review NuScale submitted Chapter 7, Instrumentation and Controls, Revision 0 of the SDAA FSAR on December 31, 2022, and Revision 1 on October 31, 2023 NRC regulatory audit of Chapter 7 was performed from March 2023 to August 2023 One audit issue was issued and resolved in the audit The audit issue resulted in NuScale submitting supplemental information to address questions raised during the audit No RAIs issued Staff completed Chapter 7 review and issued an advanced safety evaluation to support todays ACRS Subcommittee meeting 4
Overview
Non-Proprietary NuScale SDAA FSAR Chapter 7 Review Technical Reviewers
- Joseph Ashcraft, NRR/DEX/EICB
- Dinesh Taneja, NRR/DEX/ELTB Project Managers
- Ricky Vivanco, PM, NRR/DNRL/NRLB
- Getachew Tesfaye, Lead PM, NRR/DNRL/NRLB 5
Contributors
Non-Proprietary NuScale SDAA FSAR Chapter 7 Review Section 7.0 - Introduction and Review Process Section 7.1 - Instrumentation and Controls - Fundamental Design Principles Section 7.2 - Instrumentation and Controls - System Characteristics 6
Sections
Non-Proprietary NuScale SDAA FSAR Chapter 7 Review NPM power uprate and safety analysis resulted in changes to Reactor Trip Setpoints & Engineered Safety Feature Actuation System actuation logic and analytical limits Setpoint methodology TR-122844-P documents the new analytical limits and setpoints Common Cause Failure coping analysis revised due to reductions in digital sensors Added Type F Post-Accident Monitoring variables 7
Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 7 Review While there are some differences between the DCA and SDAA, the staff found that the applicant provided sufficient information to support the staffs safety finding The staff found that all applicable regulatory requirements were adequately addressed 8
Conclusion
Non-Proprietary Presentation to the ACRS Subcommittee Staff Review of NuScale SDAA FSAR, Revision 1 Chapter 9, Auxiliary Systems" August 22, 2024 (Open Session) 9
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review NuScale submitted Chapter 9, Auxiliary Systems, Revision 0 of the NuScale SDAA FSAR on December 31, 2022, and Revision 1 on October 31, 2023 NRC regulatory audit of Chapter 9 was performed from March 2023 to August 2023, generating 33 audit issues 23 audit issues were resolved in the audit 10 audit issues resulted in NuScale submitting supplemental information to address questions raised during the audit 13 RAIs were issued Staff completed Chapter 9 review and issued an advanced safety evaluation to support today's ACRS Subcommittee meeting 10 Overview
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review Technical Reviewers Thinh Dinh, NRR/DRA/APLB Daniel Ju, NRR/DRA/APLB Naeem Iqbal, NRR/DRA/APLB Marie Pohida, NRR/DRA/APLC Steven Alfernik, NRR/DRA/APLC Sunwoo Park, NRR/DRA/APLC Edward Stutzcage, NRR/DRA/ARCB Adakou Foli, NRR/DEX/EEEB Sheila Ray, NRR/DEX/EEEB Dinesh Taneja, NRR/DEX/ELTB Joseph Ashcraft, NRR/DEX/EICB Nicholas Hansing, NRR/DEX/EMIB Thomas Scarbrough, NRR/DEX/EMIB Ata Istar, NRR/DEX/ESEB George Wang, NRR/DEX/ESEB Matthew Yoder, NRR/DNRL/NCSG Angelo Stubbs, NRR/DSS/SCPB Brian Lee, NRR/DSS/SCPB David Nold, NRR/DSS/SCPB Gordon Curran, NRR/DSS/SCPB Nageswara Karipineni, NRR/DSS/SCPB Raul Hernandez, NRR/DSS/SCPB Joshua Miller, NRR/DSS/SNRB Ryan Nolan, NRR/DSS/SNRB Zhian Li, NRR/DSS/SNRB Project Managers Greg Cranston, PM, NRR/DNRL/NLIB Getachew Tesfaye, Lead PM, NRR/DNRL/NRLB 11 Contributors
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review 9.1 Fuel Storage and Handling Systems 9.2 Water Systems 9.3 Process Auxiliaries 9.4 Air Conditioning, Heating, Cooling, and Ventilation Systems 9.5 Other Auxiliary Systems Appendix 9A Fire Hazards Analysis 12 Sections
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review Fire barrier rating
- In the DCA steel-composite material was limited to staircase walls with a required 2-hour rated fire barriers.
- In the SDA the reactor building, control building, and radioactive waste building floors, walls and ceilings to be made almost entirely of reinforced concrete or steel composite walls to provide a 3-hour fire barrier rating.
The SDA only houses six NPM and therefore reactor building size reduced compared to that of the 12 NPM DCA design.
- Related parameters used in the analysis of the spent fuel pool (SFP) and ultimate heat sink (UHS) cooling analysis changed accordingly.
Reactor building crane rated capacity increased; modular interface incorporated into crane design; dry dock jib crane added for refueling.
13 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review SDA design
- Consolidated SFP cooling and cleanup system and combined the UHS cooling systems into a single system that cools both the SFP and UHS.
- UHS pool water level is lower
- UHS operating temperatures increased
- Fuel storage rack design and analysis assigned to COL applicant
- Increased core thermal power which will impact SFP and UHS cooling due to increased heat loads associated with the NPMs and the spent fuel assemblies 14 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review SDA Chemical and Volume Control System (CVCS) reconfiguration of certain valves outside containment required compensating design changes. Multiple CVCS valves moved out of NPM bay. Valves included internal restrictions credited for CVCS line breaks outboard of containment isolation valves. Flow restricting venturis added into containment vessel nozzles inside containment for the injection and discharge lines. Flow restricting venturis credited in both Chapter 15 and Chapter 19 events.
15 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review SDA reactor building crane - risk significant design change from DCA to SDA to include a Reactor Building Crane Control System. Reliability of programmable logic controller and associated components results in operator errors being negligible contributors to module drop.
- In DCA, over 95% of the core damage frequency driven by module drop. Calculated drop probability dominated by operator errors of commission (e.g., overspeed, over-raise, overtravel and failure of instrumentation (interlocks/limit switches).
The application does not include specific SFP criticality safety design information and corresponding criticality safety analyses for the SDA. This is addressed with two COL items requiring COL applicants to perform criticality safety analyses for the new fuel and spent fuel pool.
16 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 9 Review While there are some differences between the DCA and the SDA, the staff found that the applicant provided sufficient information to support the staffs safety finding.
The staff found that all applicable regulatory requirements were adequately addressed.
17 Conclusion
Non-Proprietary Presentation to the ACRS Subcommittee Staff Review of NuScale SDAA FSAR, Revision 1 Chapter 12, Radiation Protection" August 22, 2024 (Open Session) 18
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review NuScale submitted Chapter 12, Radiation Protection, Revision 0 of the NuScale SDAA FSAR on December 28, 2022, and Revision 1 on October 31, 2023 NRC regulatory audit of Chapter 12 performed March 2023 to August 2023, generating 13 audit issues 11 audit issues were resolved in the audit 9 audit issues resulted in NuScale submitting supplemental information to address questions raised during the audit 2 RAIs were issued and resolved Staff completed Chapter 12 review and issued an advanced safety evaluation to support today's ACRS Subcommittee meeting 19 Overview
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review Technical Reviewers
- Edward Stutzcage, NRR/DRA/ARCB Project Managers
- Alina Schiller, PM, NRR/DNRL/NRLB
- Getachew Tesfaye, Lead PM, NRR/DNRL/NRLB 20 Contributors
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review Section 12.1 - Assuring that Occupational Radiation Exposures Are As Low As Is Reasonably Achievable Section 12.2 - Radiation Sources Section 12.3 - Radiation Protection Design Features Section 12.4 - Dose Assessment Section 12.5 - Operational Radiation Protection Program 21 Sections
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review Radiological Impacts of Hydrogen and Oxygen Monitoring
- The DCA rule includes an open item to be addressed by the COLA related to the radiological dose consequences to workers performing activities associated with hydrogen and oxygen monitoring following a core damage accident and potential dose consequences to the control room workers and the public resulting from activities associated with hydrogen and oxygen monitoring
- Compliance with 10 CFR 50.34(f)(2)(xxviii), 10 CFR 50.34(f)(2)(vii), and 10 CFR 52.47(a)(2)(iv)
- The SDAA includes a passive autocatalytic recombiner and NuScale has requested an exemption from the combustible gas monitoring requirements of 10 CFR 50.44(c)(4)10 CFR 50.34(f)(2)(xvii)(C)
- The staff is reviewing the exemption under FSAR Chapters 6 and 19
- If the exemption is approved, hydrogen and oxygen monitoring is unnecessary, and the associated radiological implications need not be accessed 22 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review Source terms
- Source terms throughout Chapter 12 were updated to account for changes in reactor power, the number of units, and other less significant design changes
- Methodology for developing source terms remained mostly unchanged
- Shielding and dose rates throughout the facility were adjusted accordingly
- Staff reviewed the updated source terms, shielding, and zoning for significant radiation sources and found them to be acceptable 23 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review Nitrogen-16 (N-16)
- The reactor coolant travels through the RCS significantly faster in the SDAA, impacting the N-16 source term
- Results in significant N-16 concentration remaining in CVCS line exiting the reactor module bays during operation
- NuScale adequately accounted for N-16 in shielding and dose calculations until N-16 reaches 10 half-lives, at which time N-16 doses are insignificant
- Staff reviewed the N-16 concentrations and CVCS system shielding and found them to be acceptable 24 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review Concrete Equivalent Attenuation Shielding
- Radiation shielding is specified in terms of nominal concrete attenuation thicknesses.
- FSAR specifies that materials used in place of the specified concrete provides the equivalent attenuation as the prescribed concrete shielding.
- Alternative radiation shielding must meet the prescribed radiation zoning provided in FSAR Chapter 12 and must be verified to comply with all regulatory requirements.
- Staff reviewed the shielding specifics provided in the FSAR and in audited shielding calculations and found them to be acceptable. Staff found the approach to be acceptable because it ensures that the zoning provided in Chapter 12 and applicable regulatory requirements continue to be met.
25 Significant Changes from DCA to SDA
Non-Proprietary NuScale SDAA FSAR Chapter 12 Review While there are some differences between the DCA and SDAA, the staff found that the applicant provided sufficient information to support the staffs safety findings.
The staff found that all applicable regulatory requirements were adequately addressed for the design.
COL items are provided for programs and site-specific aspects, similar to the DCA application.
26 Conclusion
Non-Proprietary Presentation to the ACRS Subcommittee Staff Review of NuScale SDAA FSAR, Revision 1 Chapter 18, Human Factors Engineering" August 22, 2024 (Open Session) 27
Non-Proprietary NuScale SDAA FSAR Chapter 18 Review Technical Reviewers
- Amy D'Agostino, NRR/DRO/IOLB
- Maurin Scheetz, NRR/DRO/IOLB
- Kamishan Martin, NRR/DRO/IOLB
- Brian Green, NRR/DRO/IOLB Project Managers
- Thomas Hayden, PM, NRR/DNRL/NRLB
- Getachew Tesfaye, Lead PM, NRR/DNRL/NRLB 28 Contributors
Non-Proprietary NuScale SDAA FSAR Chapter 18 Review Section 18.0 - Human Factors Engineering Overview Section 18.1 - Human Factors Engineering Program Management Section 18.2 - Operating Experience Overview Section 18.3 - Functional Requirements Analysis and Function Allocation Section 18.4 - Task Analysis Section 18.5 - Staffing and Qualifications Section 18.6 - Treatment of Important Human Actions Section 18.7 - Human System Interface Design Section 18.8 - Procedure Development Section 18.9 - Training Program Development Section 18.10 - Human Factors Verification and Validation Section 18.11 - Design Implementation Section 18.12 - Human Performance Monitoring 29 Sections
Non-Proprietary NuScale SDAA FSAR Chapter 18 Review NuScale submitted Chapter 18, Human Factors Engineering, Revision 0 of the NuScale SDAA FSAR on December 31, 2022, and Revision 1 on October 31, 2023 NRC regulatory audit of Chapter 18 performed March 2023 to August 2023, generating 20 audit issues All issues were resolved in the audit.
12 issues resulted in NuScale submitting supplemental information to address questions raised during the audit No RAIs were issued Staff completed Chapter 18 review and issued an advanced safety evaluation to support today's ACRS Subcommittee meeting 30 Overview
Non-Proprietary NuScale SDAA FSAR Chapter 18 Review 31 Significant Changes from DCA to SDA Area DCA SDAA Main Control Room 12 units 6 units Staffing 6 operators 3 operators Important Human Actions 2 risk important actions No important human actions Other design changes Remote Shutdown Station No remote shutdown station HFE strategy Results Summary Reports and ITAAC for Design Implementation Implementation Plans for:
Operating Experience Review
Functional Requirements Analysis & Function Allocation
Task Analysis
HSI Design
Verification & Validation
Design Implementation ITAAC for Integrated System Validation and Design Implementation
Non-Proprietary NuScale SDAA FSAR Chapter 18 Review The staff reviewed Implementation Plans for:
Operating Experience Review Functional Requirement Analysis and Function Allocation Task Analysis HSI Design Human Factors Verification and Validation Design Implementation The staff reviewed Result Summary Reports for:
Staffing and Qualifications Treatment of Important Human Actions SDAA includes COL Items for programmatic elements:
Procedure development, training program development and human performance monitoring ITAAC ensure remaining HFE activities are complete No. 03.15.01: the main control room HSI is consistent with design verified and validated by the integrated system validation including any changes reconciled during design implementation No. 03.15.02: for integrated system validation of the main control room design 32 HFE Strategy RSRs will be available before fuel load
Non-Proprietary NuScale SDAA FSAR Chapter 18 Review While there are some differences between the DCA and SDAA, the staff found that the applicant provided sufficient information to support the staffs safety finding.
The staff found that all applicable regulatory requirements were adequately addressed.
33 Conclusion