ML19130A046
| ML19130A046 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 06/03/2019 |
| From: | Omid Tabatabai NRC/NRO/DLSE/LB1 |
| To: | |
| Tabatabai O / 415-6616 | |
| Shared Package | |
| ML18201A343 | List: |
| References | |
| NuScale Chapter 6 Phase 2 | |
| Download: ML19130A046 (132) | |
Text
Introduction Summary of Application
- Metallic Materials Material Selection and Fabrication
Code of Federal Regulations Composition and Compatibility of Core Cooling Coolants
- Regulatory Basis ******
Technical Evaluation Materials Selection and Fabrication Austenitic Stainless Steel Ferritic Steel Welding Composition and Compatibility of Engineered Safety Feature Fluids Component and System Cleaning Thermal Insulation Branch Technical Position 6-1 Tier 1 and ITAAC Technical Specifications Combined License Information Items Conclusion Introduction Summary of Application ***
Containment Structure Note: Section 6.2.1.1 contains three unresolved issues without a mutually understood and clearly defined path toward resolution. Although these issues are presumptively labeled as Open Items in this section, they are highlighted to differentiate them from the "qualified" Open Items with a path to resolution, recognizing that these issues need to advance in developing a clear path toward resolution. Introduction Summary of Application
Regulatory Basis *
- Technical Evaluation 6.2.1.1.1.1 Peak Calculated Containment Pressure/Temperature (GDC 50, 16, and 38) 6.2.1.1.1.1.1 NuScale Containment Heat Removal System Design 6.2.1.1.1.1.2 Break Spectrum and Single Failures 6.2.1.1.1.1.3 NRELAP5 Design-Basis Modeling Decks 6.2.1.1.1.1.4 Conservatism in the NuScale Power Module Containment Vessel Model and Initial Conditions (Plant-Specific Design Parameters) ***********
6.2.1.1.1.1.5 Test Data Review 6.2.1.1.1.1.5.1
6.2.1.1.1.1.5.2 6.2.1.1.1.1.5.3
6.2.1.1.1.1.6 Liquid Thermal Stratification inside the Containment Vessel 6.2.1.1.1.1.7 Containment Wall Condensation Heat Transfer 6.2.1.1.1.1.8 Effect of Noncondensable Gases on NRELAP5 Model Prediction 6.2.1.1.1.1.9 NRELAP5 Modeling Results 6.2.1.1.1.1.10 Postulated Secondary-System Pipe Ruptures inside the NuScale Containment 6.2.1.1.1.2 External Pressure 6.2.1.1.1.3 Instrumentation and Control (GDC 13) and Monitoring Radioactivity Releases (GDC 64) 6.2.1.1.1.4 Accidents Involving Hydrogen Release and Burning (10 CFR 50.34(f)(3)(v)(A)(1)) 6.2.1.1.1.5 Environmental and Dynamic Effects Design Bases (GDC 4) 6.2.1.1.1.6 Sharing of Structures, Systems, and Components (GDC 5) 6.2.1.1.1.7 Technical Specifications 6.2.1.1.1.8 Combined License Information Items 6.2.1.1.1.9 Conclusion Containment Subcompartments Mass and Energy Release Analysis for Postulated Loss-of-Coolant Accidents Introduction Summary of Application Regulatory Basis *
- Technical Evaluation Energy sources Break spectrum
Blowdown conditions Conclusion Mass and Energy Release Analysis for Postulated Secondary System Pipe Ruptures Inside Containment Introduction Summary of Application Regulatory Basis
- Technical Evaluation Energy sources
Break spectrum
Blowdown conditions
Conclusion Introduction Summary of Application
Regulatory Basis ****
- (i)
- (ii) . *
- Technical Evaluation
Long-Term Cooling
Chemical Effects Introduction
- Applicant's Approach to Addressing Chemical Effects Source Term for Chemical Effects Type and Amount of Chemical Precipitates Capability of Mechanical Equipment in ECCS Flowpath during Post-LOCA OperationChemical Effects Summary Capability of Mechanical Equipment in ECCS Flowpath during Post-LOCA Operation
Mechanical Equipment Evaluation Summary Combined License Information Items ***
- Conclusion Introduction Summary of Application Regulatory Basis *
- Technical Evaluation GDC 1 and GDC 2 General Design Criterion 4 General Design Criterion 5 General Design Criterion 16 General Design Criterion 55
10 CFR 50.34(f)(2)(xiv) Code of Federal Regulations In addition, each applicant for a design certification, design approval, combined license, or manufacturing license under Part 52 of this chapter shall demonstrate compliance with the technically relevant portions of the requirements in paragraphs (f)(1) through (3) of this section-
Federal Register
[d]esign basis events meet their thermal and hydraulic acceptance criteria without reliance on isolating the CES on a high radiation signal. No design basis event results in degraded or damaged core conditions. Section 19.2 analyses demonstrate severe accident conditions, with resultant core damage, also result in generation of reliable containment isolation signals, without reliance on isolation on high containment radiation. An in-containment event resulting in core damage or degradation also results in containment isolation on low low pressurizer level and high containment pressure-These features provide a reliable alternative means to prevent radiological release from the CES to the environs."
In addition, each applicant for a design certification, design approval, combined license, or manufacturing license under Part 52 of this chapter shall demonstrate compliance with the technically relevant portions of the requirements in paragraphs (f)(1) through (3) of this section- Provide a capability for containment purging/venting designed to minimize the purging time consistent with ALARA principles for occupational exposure. Provide and demonstrate high assurance that the purge system will reliably isolate under accident conditions." (II.E.4.4) 10 CFR 50.34(f)(3)(iv) In addition, each applicant for a design certification, design approval, combined license,or manufacturing license under Part 52 of this chapter shall demonstrate compliance with the technically relevant portions of the requirements in paragraphs (f)(1) through (3) of this section-Provide one or more dedicated containment penetrations, equivalent in size to a single 3-foot diameter opening, in order not to preclude future installation of systems to prevent containment failure, such as a filtered vented containment system. (II.B.8) The NuScale CNV [containment vessel] does not include one or more dedicated containment penetrations, equivalent in size to a single 3-foot diameter opening, to accommodate future installation of systems to prevent containment failure. As discussed in this section [Section 6.2], the calculated peak containment pressures for design basis events remain less than the CNV internal design pressure. As discussed in Section 19.2.3, peak containment pressures do not challenge vessel integrity for any analyzed severe accident progression.
Therefore, 10 CFR 50.34(f)(3)(iv) is not technically relevant to the NuScale design. The NRC staff will remain receptive to additional information from NuScale regarding NuScale's position that the regulation is not technically relevant if NuScale can provide technical justification in Tier 2 of the design certification (DC) application that the pressure in containment during beyond design basis accidents cannot exceed the allowable pressure of the containment structure. Federal Register(3)(iv)-Containment Penetration Discussion
10 CFR 50.34(f)(2)(xix) General Design Criterion 54 Station Blackout (10 CFR 50.63) and Appropriate Containment Integrity Reliance on Electrical Power Overpressure Protection Inspections, Tests, Analysis, and Acceptance Criteria Initial Test Program Technical Specifications Combined License Information Items Conclusion Introduction Summary of Application Regulatory Basis
Technical Evaluation *****
Exemption Request for control of hydrogen concentration in containment Equipment Survivability Hydrogen Monitoring Structural Analysis of Containment Integrity Evaluation of Exemption Request #2, 10 CFR 50.44, "Combustible Gas Control for Nuclear Power Reactors" uthorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security. Combined License Information Items Conclusion Introduction Summary of Application
- Technical Specification Bases: 3.6.1," Containment," LCO: The containment is designed to maintain leakage integrity less than or equal to 1.0 La. Leakage integrity is assured by performing local LLRT and containment ISI. Total LLRT leakage is maintained less than or equal to 0.60 (La) in accordance with Appendix J. Satisfactory LLRT and ISI examinations are required for containment OPERABILITY Regulatory Basis **
- Technical Evaluation for Exemption Request No. 7
Authorized by Law No Undue Risk to Public Health and Safety Consistent with Common Defense and Security Special Circumstances Evaluation of Compliance with Containment Leak Rate Testing Regulations and Guidance
Combined License Information Items
Conclusion Introduction Summary of Application Regulatory Basis *
- Technical Evaluation Conclusion
- Functional Design Basis ***Reactor Coolant Pressure Boundary Low Temperature Overpressure Protection GDC 27 Reactivity Control Core Cooling Performance Evaluation 6.3.4.1.1.1 Inadvertent Emergency Core Cooling System Valve Actuation 6.3.4.1.1.2 Secondary System Pipe Break Inside Containment 6.3.4.1.1.3 Loss-of-Coolant Accidents 6.3.4.1.1.4 Long-Term Cooling 6.3.4.1.1.5 In-Vessel Debris Downstream Effects Evaluation *******
- System Design Features Shared Systems Power Requirements Instrumentation System Boundary Testing, Inspection, and Qualification Environmental Requirements System Reliability Technical Specifications Combined License Information Items
Reliability
Control Room Envelope Ventilation System Criteria
Control Room Habitability Is Not a Safety Function Isolation Dampers Occupancy Limitations Pressurization Rate Atmosphere Filtration Control Room Radiological Habitability
Relative Location of Source and Control Room Radiation Sources Toxic Sources Radiation Hazards Radiation Shielding
- Control Room Envelope Unfiltered Inleakage Input Parameters to the Radiological Dose Analysis Radiation Protection Technical Support Center Habitability Toxic Gas Hazards Equipment Qualification ITAAC ***** Technical Specifications Sharing with Multiple Modules
- Components Subject to Inspection **
- Accessibility Examination Techniques and Procedures Inspection Intervals Evaluation of Examination Results System Pressure Tests Code Exemptions Relief Requests Code Cases Inspections, Tests, Analyses, and Acceptance Criteria
- COL Action Items and Certification Requirements and Restrictions
Operational Programs