10 CFR 50 Appendix S, General Information

Appendix S to Part 50-Earthquake Engineering Criteria for Nuclear Power Plants General Information This appendix applies to applicants for a construction permit or operating license under part 50, or a design certification, combined license, design approval, or manufacturing license under part 52 of this chapter, on or after January 10, 1997. However, for either an operating license applicant or holder whose construction permit was issued before January 10, 1997, the earthquake engineering criteria in Section VI of appendix A to 10 CFR part 100 continue to apply. Paragraphs IV.a.1.i, IV.a.1.ii, IV.4.b, and IV.4.c of this appendix apply to applicants for an early site permit under part 52.
I. Introduction

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(a) Each applicant for a construction permit, operating license, design certification, combined license, design approval, or manufacturing license is required by §§ 50.34(a)(12), 50.34(b)(10), or 10 CFR 52.47, 52.79, 52.137, or 52.157, and General Design Criterion 2 of appendix A to this part, to design nuclear power plant structures, systems, and components important to safety to withstand the effects of natural phenomena, such as earthquakes, without loss of capability to perform their safety functions. Also, as specified in § 50.54(ff), nuclear power plants that have implemented the earthquake engineering criteria described herein must shut down if the criteria in paragraph IV(a)(3) of this appendix are exceeded.

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(b) These criteria implement General Design Criterion 2 insofar as it requires structures, systems, and components important to safety to withstand the effects of earthquakes. II. Scope The evaluations described in this appendix are within the scope of investigations permitted by § 50.10(c)(1).

III. Definitions As used in these criteria: Combined license means a combined construction permit and operating license with conditions for a nuclear power facility issued under subpart C of part 52 of this chapter.

Design Approval means an NRC staff approval, issued under subpart E of part 52 of this chapter, of a final standard design for a nuclear power reactor of the type described in 10 CFR 50.22.

Design Certification means a Commission approval, issued under subpart B of part 52 of this chapter, of a standard design for a nuclear power facility.

Manufacturing license means a license, issued under subpart F of part 52 of this chapter, authorizing the manufacture of nuclear power reactors but not their installation into facilities located at the sites on which the facilities are to be operated.

Operating basis earthquake ground motion (OBE) is the vibratory ground motion for which those features of the nuclear power plant necessary for continued operation without undue risk to the health and safety of the public will remain functional. The operating basis earthquake ground motion is only associated with plant shutdown and inspection unless specifically selected by the applicant as a design input.

Response spectrum is a plot of the maximum responses (acceleration, velocity, or displacement) of idealized single-degree-of-freedom oscillators as a function of the natural frequencies of the oscillators for a given damping value. The response spectrum is calculated for a specified vibratory motion input at the oscillators' supports.

Safe-shutdown earthquake ground motion (SSE) is the vibratory ground motion for which certain structures, systems, and components must be designed to remain functional.

Structures, systems, and components required to withstand the effects of the safe-shutdown earthquake ground motion or surface deformation are those necessary 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 that could result in potential offsite exposures comparable to the guideline exposures of § 50.34(a)(1).

Surface deformation is distortion of geologic strata at or near the ground surface by the processes of folding or faulting as a result of various earth forces. Tectonic surface deformation is associated with earthquake processes.

IV. Application To Engineering Design The following are pursuant to the seismic and geologic design basis requirements of § 100.23 of this chapter:

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(a) Vibratory Ground Motion.

(1) Safe Shutdown Earthquake Ground Motion.

(i) The Safe Shutdown Earthquake Ground Motion must be characterized by free-field ground motion response spectra at the free ground surface. In view of the limited data available on vibratory ground motions of strong earthquakes, it usually will be appropriate that the design response spectra be smoothed spectra. The horizontal component of the Safe Shutdown Earthquake Ground Motion in the free-field at the foundation level of the structures must be an appropriate response spectrum with a peak ground acceleration of at least 0.1g.

(ii) The nuclear power plant must be designed so that, if the Safe Shutdown Earthquake Ground Motion occurs, certain structures, systems, and components will remain functional and within applicable stress, strain, and deformation limits. In addition to seismic loads, applicable concurrent normal operating, functional, and accident-induced loads must be taken into account in the design of these safety-related structures, systems, and components. The design of the nuclear power plant must also take into account the possible effects of the Safe Shutdown Earthquake Ground Motion on the facility foundations by ground disruption, such as fissuring, lateral spreads, differential settlement, liquefaction, and landsliding, as required in § 100.23 of this chapter.

(iii) The required safety functions of structures, systems, and components must be assured during and after the vibratory ground motion associated with the Safe Shutdown Earthquake Ground Motion through design, testing, or qualification methods.

(iv) The evaluation must take into account soil-structure interaction effects and the expected duration of vibratory motion. It is permissible to design for strain limits in excess of yield strain in some of these safety-related structures, systems, and components during the Safe Shutdown Earthquake Ground Motion and under the postulated concurrent loads, provided the necessary safety functions are maintained.

(2) Operating Basis Earthquake Ground Motion.

(i) The Operating Basis Earthquake Ground Motion must be characterized by response spectra. The value of the Operating Basis Earthquake Ground Motion must be set to one of the following choices:

(A) One-third or less of the Safe Shutdown Earthquake Ground Motion design response spectra. The requirements associated with this Operating Basis Earthquake Ground Motion in Paragraph (a)(2)(i)(B)(I ) can be satisfied without the applicant performing explicit response or design analyses, or

(B) A value greater than one-third of the Safe Shutdown Earthquake Ground Motion design response spectra. Analysis and design must be performed to demonstrate that the requirements associated with this Operating Basis Earthquake Ground Motion in Paragraph (a)(2)(i)(B)(I) are satisfied. The design must take into account soil-structure interaction effects and the duration of vibratory ground motion.

(I) When subjected to the effects of the Operating Basis Earthquake Ground Motion in combination with normal operating loads, all structures, systems, and components of the nuclear power plant necessary for continued operation without undue risk to the health and safety of the public must remain functional and within applicable stress, strain, and deformation limits.

(3) Required Plant Shutdown. If vibratory ground motion exceeding that of the Operating Basis Earthquake Ground Motion or if significant plant damage occurs, the licensee must shut down the nuclear power plant. If systems, structures, or components necessary for the safe shutdown of the nuclear power plant are not available after the occurrence of the Operating Basis Earthquake Ground Motion, the licensee must consult with the Commission and must propose a plan for the timely, safe shutdown of the nuclear power plant. Prior to resuming operations, the licensee must demonstrate to the Commission that no functional damage has occurred to those features necessary for continued operation without undue risk to the health and safety of the public and the licensing basis is maintained.

(4) Required Seismic Instrumentation. Suitable instrumentation must be provided so that the seismic response of nuclear power plant features important to safety can be evaluated promptly after an earthquake.

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(b) Surface Deformation. The potential for surface deformation must be taken into account in the design of the nuclear power plant by providing reasonable assurance that in the event of deformation, certain structures, systems, and components will remain functional. In addition to surface deformation induced loads, the design of safety features must take into account seismic loads and applicable concurrent functional and accident-induced loads. The design provisions for surface deformation must be based on its postulated occurrence in any direction and azimuth and under any part of the nuclear power plant, unless evidence indicates this assumption is not appropriate, and must take into account the estimated rate at which the surface deformation may occur.

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(c) Seismically Induced Floods and Water Waves and Other Design Conditions. Seismically induced floods and water waves from either locally or distantly generated seismic activity and other design conditions determined pursuant to § 100.23 of this chapter must be taken into account in the design of the nuclear power plant so as to prevent undue risk to the health and safety of the public.

Federal Register

72 FR 49508, Aug. 28, 2007]

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NRC website 10 CFR 50 Appendix S

v t e Code of Federal Regulations
Title 10 Part 50 - DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES
10 CFR: 1 2 4 5 7 9 10 11 12 13 14 15 16 19 20 21 25 26 30 31 32 33 34 35 36 37 39 40 50 51 52 54 55 60 61 62 63 70 71 72 73 74 75 76 81 95 100 140 150 160 170 171
1, General Provisions, Basis, purpose, and procedures applicable 2, Definitions 3, Interpretations 4, Written communications 5, Deliberate misconduct 7, Employee protection 8, Information collection requirements: OMB approval 9, Completeness and accuracy of information 10, Requirement of License, Exceptions, License required; limited work authorization 11, Exceptions and exemptions from licensing requirements 12, Specific exemptions 13, Attacks and destructive acts by enemies of the United States; and defense activities 20, Classification and Description of Licenses, Two classes of licenses 21, Class 104 licenses; for medical therapy and research and development facilities 22, Class 103 licenses; for commercial and industrial facilities 23, Construction permits 30, Applications for Licenses, Certifications, and Regulatory Approvals; Form; Contents; Ineligibility of Certain Applicants, Filing of application for licenses; oath or affirmation 31, Combining applications 32, Elimination of repetition 33, Contents of applications; general information 34, Contents of applications; technical information 36, Technical specifications 37, Agreement limiting access to Classified Information 38, Ineligibility of certain applicants 39, Public inspection of applications 40, Standards for Licenses, Certifications, and Regulatory Approvals, Common standards 41, Additional standards for class 104 licenses 42, Additional standard for class 103 licenses 43, Additional standards and provisions affecting class 103 licenses and certifications for commercial power 44, Combustible gas control for nuclear power reactors 45, Standards for construction permits, operating licenses, and combined licenses 46, Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors 47, Emergency plans 48, Fire protection 49, Environmental qualification of electric equipment important to safety for nuclear power plants 50, Issuance, Limitations, and Conditions of Licenses and Construction Permits, Issuance of licenses and construction permits 51, Continuation of license 52, Combining licenses 53, Jurisdictional limitations 54, Conditions of licenses 55, Conditions of construction permits, early site permits, combined licenses, and manufacturing licenses 56, Conversion of construction permit to license; or amendment of license 57, Issuance of operating license 58, Hearings and report of the Advisory Committee on Reactor Safeguards 59, Changes, tests and experiments 60, Acceptance criteria for fracture prevention measures for lightwater nuclear power reactors for normal operation 61, Fracture toughness requirements for protection against pressurized thermal shock events 62, Requirements for reduction of risk from anticipated transients without scram (ATWS) events for light-water-cooled nuclear power plants 63, Loss of all alternating current power 64, Limitations on the use of highly enriched uranium (HEU) in domestic non-power reactors 65, Requirements for monitoring the effectiveness of maintenance at nuclear power plants 66, Requirements for thermal annealing of the reactor pressure vessel 67, Accident source term 68, Criticality accident requirements 69, Inspections, Records, Reports, Notifications, Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors 70, Inspections 71, Maintenance of records, making of reports 72, Immediate notification requirements for operating nuclear power reactors 73, Licensee event report system 74, Notification of change in operator or senior operator status 75, Reporting and recordkeeping for decommissioning planning 76, . Licensee's change of status; financial qualifications 78, US/IAEA Safeguards Agreement, Facility information and verification 80, Transfers of Licenses--Creditors' Rights--Surrender of Licenses, Transfer of licenses 81, Creditor regulations 82, Termination of license 83, Release of part of a power reactor facility or site for unrestricted use 90, Amendment of License or Construction Permit at Request of Holder, Application for amendment of license, construction permit, or early site permit 91, Notice for public comment; State consultation 92, Issuance of amendment 100, Revocation, Suspension, Modification, Amendment of Licenses and Construction Permits, Emergency Operations by the Commission, Revocation, suspension, modification of licenses, permits, and approvals for cause 101, Retaking possession of special nuclear material 102, Commission order for operation after revocation 103, Suspension and operation in war or national emergency 109, Backfitting 110, Enforcement, Violations 111, Criminal penalties 120, Additional Standards for Licenses, Certifications, and Regulatory Approvals, Training and qualification of nuclear power plant personnel 150, Aircraft impact assessment Appendices: 10 CFR 50 Appendix A, Appendix a to Part 50-General Design Criteria for Nuclear Power Plants 10 CFR 50 Appendix B, Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants 10 CFR 50 Appendix C, Appendix C to Part 50-A Guide for the Financial Data and Related Information Required to Establish Financial Qualifications for Construction Permits and Combined Licenses 10 CFR 50 Appendix D, Appendix D to Part 50--Reserved 10 CFR 50 Appendix E, Appendix E to Part 50-Emergency Planning and Preparedness for Production and Utilization Facilities 10 CFR 50 Appendix F, Appendix F to Part 50--Policy Relating to the Siting of Fuel Reprocessing Plants and Related Waste Management Facilities 10 CFR 50 Appendix G, Appendix G to Part 50-Fracture Toughness Requirements 10 CFR 50 Appendix H, Appendix H to Part 50-Reactor Vessel Material Surveillance Program Requirements 10 CFR 50 Appendix I, Appendix I to Part 50-Numerical Guides for Design Objectives and Limiting Conditions for Operation to Meet the Criterion "As Low As Is Reasonably Achievable" for Radioactive Material In Light-Water-Cooled Nuclear Power Reactor E 10 CFR 50 Appendix J, Appendix J to Part 50-Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors 10 CFR 50 Appendix K, Appendix K to Part 50-Eccs Evaluation Models 10 CFR 50 Appendix L, Appendix L to Part 50--Reserved 10 CFR 50 Appendix M, Appendix M to Part 50--Reserved 10 CFR 50 Appendix N, Appendix N to Part 50-Standardization of Nuclear Power Plant Designs: Permits to Construct and Licenses to Operate Nuclear Power Reactors of Identical Design At Multiple Sites 10 CFR 50 Appendix O, Appendix O to Part 50-Reserved 10 CFR 50 Appendix P, Appendix P to Part 50--Reserved 10 CFR 50 Appendix Q, Appendix Q to Part 50--Pre-Application Early Review of Site Suitability Issues 10 CFR 50 Appendix R, Appendix R to Part 50-Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979 10 CFR 50 Appendix S, General Information

10 CFR 50 Appendix S, General Information

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