Shif et T XA04N2075 NUREG-001 U. S. Nuclear Evnedipation Iteport Regulatory Commission related to operation of Office of Nuclear Reactor Regulation Sequoyah Nuclear Plant Docket Nos. 50-327 Units and 2 50-328 INIS-XA-N--183 March 1979 Tennessee Valley Authority Available from National Technical Information Service Springfield, Virginia 22161 Price: Printed Cpy$11.75 ; Microfiche 3.00 The price of this document for requesters outside of the North American Continent can be obtained from the National Technical Information Service. NUREG-0011 March 1979 SAFETY EVALUATION REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION U.S. NUCLEAR REGULATORY COMMISSION IN THE MATTER OF TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT UNITS AND 2 DOCKET NOS. 50-327 AND 50-328 TABLE OF CONTENTS PAGE 1.0 INTRODUCTION AND GENERAL DESCRIPTION OF PLANT .................................. 1-1 1.1 Introduction .............................................................. 1-1 1.2 General Plant Description ................................................. 1-2 1.3 Comparison with Similar Facility Designs .................................. 1-3 1.4 Identification of Agents and Contractors .................................. 1-4 1.5 Summary of Principal Review Matters ....................................... 1-4 1.6 Outstanding Issues ........................................................ 1-5 1.7 Confirmatory Issues ....................................................... 1-6 1.8 Staff Positions - Licensing Conditions .................................... 1-9 1.9 Generic Issues ............................................................ 1-10 2.0 SITE CHARACTERISTICS ........................................................... 2-1 2.1 Geography and Demography .................................................. 2-1 2.1.1 Site Description and Exclusion Area Control ........................ 2-1 2.1.2 Population and Population Distribution ............................. 2-1 2.1.3 Conclusions ........................................................ 2-4 2.2 Nearby Industrial, Transportation, and Military Facilities ................ 2-4 2.3 Meteorology ............................................................... 2-6 2.3.1 Regional Climatology ............................................... 2-6 2.3.2 Local Meteorology .................................................. 2-6 2.3.3 Onsite Meteorological Measurements Program ......................... 2-7 2.3.4 Short-Term (Accident) Diffusion Estimates .......................... 2-8 2.3.5 Lohg-Term (Routine) Diffusion Estimates ............................ 2-9 2.3.6 Conclusions ........................................................ 2-10 2.4 Hydrologic Engineering .................................................... 2-10 2.4.1 Hydrologic Description ............................................. 2-10 2.4.2 Flood Potential .................................................... 2-13 2.4.3 Low Water Considerations ........................................... 2-15 2.4.4 Groundwater ........................................................ 2-17 2.4.5 Hydrologically-Related Technical Specifications .................... 2-18 2.4.6 Conclusions ........................................................ 2-20 i TABLE OF CONTENTS (Continued) PAGE 2.5 Geology and Seismology .................................................... 2-20 2.5.1 Geology ............................................................ 2-20 2.5.2 Tectonic Setting ................................................... 2-21 2.5.3 Seismology ......................................................... 2-21 3.0 DESIGN CRITERIA FOR STRUCTURES, SYSTEMS AND COMPONENTS ......................... 3-1 3.1 Conformance with General Design Criteria .................................. 3-1 3.2 Classification of Structures, Components, and Systems ..................... 3-1 3.2.1 Seismic Classification ............................................. 3-1 3.2.2 System Quality Group Classification ................................ 3-2 3.3 Wind and Tornado Loading .................................................. 3-2 3.3.1 Wind Loading ....................................................... 3-2 3.3.2 Tornado Loading .................................................... 3-3 3.4 Water Level (Flood) Design ................................................ 3-4 3.5 Missile Protection ........................................................ 3-4 3.5.1 Missile Selection and Description .................................. 3-5 3.5.2 Barrier Design Procedures .......................................... 3-9 3.6 Protection Against Dynamic Effects Associated with the Postulated Rupture of Piping ....................................................... 3-9 3.6.1 Inside Containment ................................................. 3-9 3.6.2 Outside Containment ................................................ 3-10 3.7 Seismic Design ............................................................ 3-11 3.7.1 Seismic Input ...................................................... 3-11 3.7.2 Seismic Analysis ................................................... 3-12 3.7.3 Seismic Instrumentation Program .................................... 3-12 3.8 Design of Seismic Category I Structures ................................... 3-13 3.8.1 Steel Containment .................................................. 3-13 3.8.2 Concrete and Structural Steel Internal Structures .................. 3-14 i i TABLE OF CONTENTS (Continued) PAGE 3.8.3 Other Seismic Category I Structures ................................ 3-14 3.8.4 Foundations ........................................................ 3-15 3.9 Mechanical Systems and Components ......................................... 3-16 3.9.1 Dynamic System Analysis and Testing ................................ 3-16 3.9.2 ASME Code Class 2 and 3 Components ................................. 3-19 3.10 Seismic Qualification of Seismic Category I Intrumentation and Electrical Equipment .................................................... 3-20 3.10.1 Discussion ......................................................... 3-20 3.10.2 Findings ........................................................... 3-21 3.10.3 Qualification Program .............................................. 3-21 3.10.4 Evaluation ........................................... : ............. 3-22 4.0 REACTOR ........................................................................ 4-1 4.1 General ................................................................... 4-1 4.2 Mechanical Design ......................................................... 4-1 4.2.1 Fuel Description ................................................... 4-1 4.2.2 Reactor Vessel Internals ........................................... 4-9 4.3 Nuclear Design ............................................................ 4-11 4.3.1 Design Bases ....................................................... 4-11 4.3.2 Analytical Methods ................................................. 4-15 4.3.3 Summary of Evaluation Findings ..................................... 4-15 4.4 Thermal-Hydraulic Design .................................................. 4-16 5.0 REACTOR COOLANT SYSTEM ......................................................... 5-1 5.1 Summary Description ....................................................... 5-1 5.2 Integrity of Reactor Coolant Pressure Boundary ............................ 5-1 5.2.1 Design of Reactor Coolant Pressure Boundary Components ............. 5-1 5.2.2 Overpressurization Protection ...................................... 5-3 5.2.3 Materials .......................................................... 5-5 iii TABLE OF CONTENTS (Continued) PAGE 5.2.4 Leakage Detection System ........................................... 5-7 5.2.5 Reactor Vessel Integrity ........................................... 5-8 5.2.6 Inservice Inspection Program ....................................... 5-9 5.2.7 Reactor Coolant Pump Flywheel Integrity ............................. 5-11 5.2.8 Loose Parts Monitor ................................................ 5-11 5.3 Component and Subsystem Design ............................................ 5-12 5.3.1 Steam Generator Tube Integrity ..................................... 5-12 5.3.2 Residual Heat Removal System ....................................... 5-12 6.0 ENGINEERED SAFETY FEATURES ..................................................... 6-1 6.1 Design Considerations ..................................................... 6-1 6.1.1 Engineered Safety Features Materials ............................... 6-1 6.1.2 Organic Materials Inside Containment ............................... 6-2 6.2 Containment Systems ....................................................... 6-2 6.2.1 Containment Functional Design ...................................... 6-3 6.2.2 Containment Heat Removal System .................................... 6-16 6.2.3 Containment Air Purification and Cleanup Systems ................... 6-18 6.2.4 Containment Isolation Systems ...................................... 6-20 6.2.5 Combustible Gas Control Systems .................................... 6-22 6.2.6 Containment Leakage Testing Program ................................ 6-23 6.3 Emergency Core Cooling System ............................................ 6-25 6.3.1 Design Basis ....................................................... 6-25 6.3.2 System Design ...................................................... 6-25 6.3.3 Evaluation ........................................................