Text

Redacted - Updated Final Safety Analysis Report (UFSAR) Part 1 - November 2015
	ML16083A448
Person / Time
Site:	Pilgrim
Issue date:	11/30/2015
From:	; Entergy Nuclear Operations
To:	Booma Venkataraman; Plant Licensing Branch 1
	Ventkataraman V, DORL/LPLI-I, 415-2934
Shared Package
ML16083A494	List: ML16083A448; ML16083A453; ML16083A461; ML16083A464; ML16083A469; ML16083A471;
References
	CAC MF7229
	Download: ML16083A448 (782)
	v • d • e

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS Section Title Volume Section 1 Introduction and Summary 1 1.1 Project Identification 1 1.2 Definitions 1 1.3 Methods of Technical Presentation 1 1.4 Classification of BWR Systems, Criteria, 1 and Requirements for Safety Evaluation 1.5 Principal Design Criteria 1 1.6 Station Description 1 1.7 Comparison of Principal Design Characteristics 1 1.8 Summary of Radiation Effects 1 1.9 Station Management 1 1.10 Quality Assurance Program 1 1.11 Station Research, Development, and Further Information Requirements and Resolutions Summary 1 Section 2 Station Site and Environs 1 2.1 Introduction 1 2.2 Site Description 1 2.3 Meteorology 1 2.4 Hydrology 1 2.5 Geology and Seismology 1 2.6 Environs Radiation Surveillance Program 1 Section 3 Reactor 1 3.1 Summary Description 1 3.2 Fuel Mechanical Design 1 3.3 Reactor Vessel Internals Mechanical Design 1 3.4 Reactivity Control Mechanical Design 1 3.5 Control Rod Drive Housing Supports 1 3.6 Nuclear Design 1 3.7 Thermal and Hydraulic Design 1 3.8 Standby Liquid Control System 1 3.9 Recirculation Pump Trip, Alternate Rod Insertion, and Feedwater Pump Trip Systems 1 Section 4 Reactor Coolant System 2 4.1 Summary Description 2 4.2 Reactor Vessel and Appurtenances Mechanical Design 2 4.3 Recirculation System 2 4.4 Nuclear System Pressure Relief System 2 4.5 Main Steam Line Flow Restrictor 2 Summ T of C-i Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 4.6 Main Steam Line Isolation Valves 2 4.7 Reactor Core Isolation Cooling System 2 4.8 Residual Heat Removal System 2 4.9 Reactor Water Cleanup System 2 4.10 Nuclear System Leakage Rate Limits 2 4.11 Main Steam Lines and Feedwater Piping 2 Section 5 Containment 2 5.1 Summary Descriptions 2 5.2 Primary Containment System 2 5.3 Secondary Containment System 2 5.4 Control of Combustible Gas Concentrations in Containment 2 Section 6 Core Standby Cooling Systems 2 6.1 Safety Objective 2 6.2 Safety Design Bases 2 6.3 Summary Description - Core Standby Cooling Systems 2 6.4 Description 2 6.5 Safety Evaluation 2 6.6 Inspection and Testing 2 6.7 The Nuclear Safety Requirements for Plant Operation 2 6.8 Current Technical Specifications 2 Section 7 Control and Instrumentation 3 7.1 Summary Description 3 7.2 Reactor Protection System 3 7.3 Primary Containment and Reactor Vessel Isolation Control System 3 7.4 Core Standby Cooling Systems Control and Instrumentation 3 7.5 Neutron Monitoring System 3 7.6 Refueling Interlocks 3 7.7 Reactor Manual Control System 3 7.8 Reactor Vessel Instrumentation 3 7.9 Recirculation Flow Control System 3 7.10 Feedwater Control System 3 7.11 Turbine Generator Control System 3 7.12 Process Radiation Monitoring 3 7.13 Area Radiation Monitoring System 3 7.14 Environs Radiation Monitors 3 7.15 Health Physics and Laboratory Analysis Radiation Monitors 3 Summ T of C-ii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 7.16 Process Computer System 3 7.17 Nuclear System Stability Analysis for Initial Core 3 7.18 Reactor Building Isolation and Control System 3 7.19 RHR Service Water System (SSW, RBCCW) 3 7.20 Equipment Area Cooling System 3 7.21 Meteorological Instrumentation 3 Section 8 Electrical Power System 4 8.1 Summary Description 4 8.2 Unit and Preferred AC Power Sources 4 8.3 Secondary AC Power Source 4 8.4 Auxiliary Power Distribution System 4 8.5 Standby AC Power Source 4 8.6 125 and 250 Volt DC Power Systems 4 8.7 24 Volt DC Power System 4 8.8 120 Volt AC Power Systems 4 8.9 Cable Installation Criteria 4 8.10 Blackout AC Power Source 4 Section 9 Radioactive Waste Systems 4 9.1 Summary Description 4 9.2 Liquid Radwaste System 4 9.3 Solid Radwaste System 4 9.4 Gaseous Radwaste System 4 9.5 Trash Compaction and Decontamination Facilities 4 Section 10 Auxiliary Systems 4 10.1 Summary Description 4 10.2 New Fuel Storage 4 10.3 Spent Fuel Storage 4 10.4 Fuel Pool Cooling and Cleanup System 4 10.5 Reactor Building Closed Cooling Water System 4 10.6 Turbine Building Closed Cooling Water System 4 10.7 Salt Service Water System 4 10.8 Fire Protection System 4 10.9 HVAC Systems 4 10.10 Makeup Water Treatment System 4 10.11 Instrument and Service Air Systems 4 10.12 Potable and Sanitary Water System 4 10.13 Equipment and Floor Drainage Systems 4 10.14 Process Sampling Systems 4 10.15 Communications Systems 4 10.16 Station Lighting System 4 10.17 Main Control Room Environmental Control System 4 10.18 Equipment Area Cooling System 4 10.19 Post Accident Sampling System 4 Summ T of C-iii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 10.20 Crack Arrest Verification System 4 10.21 Hydrogen Water Chemistry Extended Test System 4 10.22 Electrolytic Hydrogen Water Chemistry System 4 10.23 Mitigation Monitoring System 4 Section 11 Power Conversion Systems 4 11.1 Summary Description 4 11.2 Turbine-Generator 4 11.3 Main Condenser 4 11.4 Main Condenser Gas Removal and Turbine Sealing Systems 4 11.5 Turbine Bypass System 4 11.6 Circulating Water System 4 11.7 Condensate Demineralizer System 4 11.8 Condensate and Feedwater System 4 11.9 Condensate Storage System 4 Section 12 Structures and Shielding 4 12.1 Summary Description 4 12.2 Structural Design 4 12.3 Shielding and Radiation Protection 4 12.4 Radioactive Materials Safety 4 Section 13 Conduct of Operations 5 13.1 Introduction and Summary 5 13.2 Organization and Responsibilities 5 13.3 Training 5 13.4 Preoperational Test Program 5 13.5 Reactor Startup and Power Test Program 5 13.6 Station Procedures 5 13.7 Records 5 13.8 Operational Review and Audits 5 Section 14 Station Safety Analysis 5 14.1 Introduction 5 14.2 Reactor Limits 5 14.3 Method of Approach 5 14.4 Abnormal Operational Transients 5 14.5 Postulated Design Basis Accidents 5 14.6 Special Events 5 14.7 References 5 Summ T of C-iv Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix A Pressure Integrity of Piping and Equipment Pressure Parts 5 A.1 Scope 5 A.2 Classification of Piping and Equipment Pressure Parts 5 A.3 Design Requirements 5 A.4 Materials 5 A.5 Fabrication and Installation Requirements 5 A.6 Testing and Inspection Requirements 5 A.7 Final Cleaning and Protection 5 A.8 F1, F2, F3, and F4 Fabrication and Erection Schedule 5 A.9 M1, M2, and M3 Material Schedules 5 A.10 T1, T2, T3, T4, and T5 Inspection and Testing Schedules 5 Appendix B Technical Specifications 5 B.1 Technical Specifications 5 B.2 Technical Specifications Relocated to the FSAR 5 B.3 Relocated Technical Specifications and Related 5 Bases 5 B.4 References 5 Appendix C Structural Loading Criteria 5 C.1 Scope 5 C.2 Concrete and Steel Structures 5 C.3 Components 5 Appendix D Quality Assurance Program 5 D.1 General 5 D.2 Program Organization and Responsibility 5 D.3 Quality Surveillance and Auditing 5 D.4 Quality Controls and Assurance Measures 5 D.5 QC-QA Documentation and Records 5 D.6 Project Communications 5 Attachment D.I General Electric Quality System for BWR Nuclear Steam Supply Projects 5 Attachment D.II Bechtel Quality Assurance Program, Pilgrim Nuclear Power Station 5 Attachment D.III Site Handling and Storage of Nuclear Steam Supply System Equipment, Pilgrim Nuclear Power Station 5 Summ T of C-v Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix E Stack Release Limit Calculations for Pilgrim Station Site 5 E.1 Analytical Model 5 E.2 Verification of Analytical Model 5 E.3 Stack Release Limit Calculations for Pilgrim Station Site 5 E.4 Building Exhaust Vent Release 5 E.5 Summary 5 E.6 References 5 Appendix F Comparison of Pilgrim Nuclear Power Station with the Proposed General Design Criteria Published by the AEC for Public Comment in The Federal Register July 11, 1967 6 F.1 Summary Description 6 F.2 Criteria Conformance 6 Appendix G Station Nuclear Safety Operation Analysis Supporting Nuclear Safety Requirements for Plant Operation 6 G.1 Analytical Objective 6 G.2 Bases for Selecting Operation Requirements for Plant Operation 6 G.3 Bases for Selecting Surveillance Test Frequencies for Nuclear Safety Systems and Engineered Safeguards for Plant Operation 6 G.4 Method of Analysis 6 G.5 Analysis and Results 6 G.6 Conclusion 6 Appendix H Tornado Criteria for Nuclear Power Plants 6 H.0 Foreword 6 H.1 Introduction 6 H.2 Characteristics of Tornadoes 6 H.3 Tornado Probability 6 H.4 Wind Loading 6 H.5 Pressure Differential 6 H.6 Water Loss 6 H.7 Tornado Missiles 6 H.8 References 6 Summ T of C-vi Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Appendix I Site Investigation of the Seabreezes 6 I.1 Introduction 6 I.2 Results and Conclusions 6 Section Title Volume I.3 Discussion 6 I.4 Data and Calculations 6 I.5 References 6 Appendix J Station Research, Development, and Further Information Requirements and Resolution 6 J.1 Resolution of ACRS Concerns 6 J.2 Areas Specified in the ACRS Construction Permit Letter for Pilgrim Nuclear Power Station 6 J.3 Areas Specified in the AEC Staff Construction Permit - Safety Evaluation Report for Pilgrim Nuclear Power Station 6 J.4 Areas Specified in Recent, Related ACRS Construction and Operating Permit Letters 6 J.5 Summary Conclusions 6 J.6 References 6 Appendix K Inservice Inspection Program 6 K.1 General 6 K.2 Inspection Program Development 6 K.3 Inspection Program Implementation 6 K.4 Reference Base Examinations 6 K.5 Documentation and Records 6 Appendix L Containment Report 7 L.1 Introduction and Summary 7 L.2 Basis for Containment Design 7 L.3 Containment System Design 7 L.4 Initial Overload and Leakage Rate Test 7 L.5 Manufacturer's Data Report for Nuclear Vessels 7 Appendix M Reactor Pressure Vessel Design Report 7 M.1 Introduction to the Report 7 M.2 Summary 7 Appendix N Emergency Plan 7 Summ T of C-vii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix O Analysis of the Consequences of High Energy Piping Failures Outside The Primary Containment 7 O.1 Introduction 7 O.2 Analysis Assumptions 7 O.3 Analysis Approach 7 O.4 Structural Loading Analytical Technique 7 O.5 Jet and Fluid Forces Analytical Techniques 7 O.6 Detailed System Analyses 7 O.7 Environmental Qualification of Electrical Equipment 7 Appendix P Deleted 7 Appendix Q Supplemental Reload Submittal 7 Q.1 Introduction 7 Appendix R Initial Core Station Safety Analysis 7 R.1 Introduction 7 R.2 Analyses of Abnormal Operational Transients (Initial Core) 7 R.3 Analysis of Design Basis Accidents (Initial Core) 7 R.4 Special Events (Initial Core) 7 R.5 Analytical Methods (Initial Core) 7 R.6 Evaluation Using Standard NRC Approach (Initial Core) 7 Appendix S License Renewal Commitments 7 S.1 Supplement for Renewed Operating License 7 S.2 Aging Management programs and Activities 7 Transients (Initial Core) 7 S.3 Evaluation of Time-Limited Aging Analyses 7 S.4 References 7 Summ T of C-viii Rev. 30 - Nov. 2015

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PNPS-FSAR SECTION 1 INTRODUCTION AND

SUMMARY

TABLE OF CONTENTS 1.1 PROJECT IDENTIFICATION 1.1-1 1.1.1 Identification and Qualification of Contractors 1.1-1 1.1.1.1 Applicant 1.1-1 1.1.1.2 Engineering Constructor 1.1-2 1.1.1.3 Nuclear Steam Supply System Supplier 1.1-3 1.1.1.4 Turbine Generator Supplier 1.1-3 1.2 DEFINITIONS 1.2-1 1.3 METHODS OF TECHNICAL PRESENTATION 1.3-1 1.3.1 Purpose 1.3-1 1.3.2 Radioactive Material Barrier Concept 1.3-1 1.3.3 Organization of Contents 1.3-1 1.3.4 Format Organization of Sections 1.3-2 1.3.5 Power Level Basis for Analysis of Abnormal Transients and Accidents 1.3-3 1.4 CLASSIFICATION OF BWR SYSTEMS, CRITERIA, AND REQUIREMENTS FOR SAFETY EVALUATION 1.4-1 1.4 1 Introduction 1.4-1 1.4.2 Classification Plan 1.4-3 1.4.3 Use of the Classification Plan 1.4-4 1.5 PRINCIPAL DESIGN CRITERIA 1.5-1 1.5.1 Principal Design Criteria Classifica-tion By Classification 1.5-1 1.5.1.1 General Criteria 1.5-1 1.5.1.2 Power Generation Design Criteria (Planned Operation) 1.5-2 1.5.1.3 Power Generation Design Criteria (Abnormal Operation Transients 1.5-2 1.5.1.4 Nuclear Safety Design Criteria Planned Operation) 1.5-3 1.5.1.5 Nuclear Safety Design Criteria (Abnormal Operation Transients) 1.5-3 1.5.1.6 Nuclear Safety Design Criteria (Accidents) 1.5-3 1.5.1.7 Nuclear Safety Design Criteria (Special Events 1.5-6 1.5.1.8 Nuclear Safety Design Criteria (Special Event) 1.5-6 1.5.2 Principal Design Criteria, System By System 1.5-7 1.5.2.1 General Criteria 1.5-7 1.5.2.2 Nuclear System Criteria 1.5-7 1.5.2.3 Power Conversion System Criteria 1.5-8 1-i Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 1 INTRODUCTION AND

SUMMARY

TABLE OF CONTENTS 1.5.2.4 Electric Power System Criteria 1.5-8 1.5.2.5 Radioactive Waste Disposal Criteria 1.5-9 1.5.2.6 Nuclear Safety Systems and Engineering Safeguards Criteria 1.5-9 1.5.2.6.1 General 1.5-9 1.5.2.6.2 Containment and Isolation Criteria 1.5-10 1.5.2.6.3 Core Standby Cooling Criteria 1.5-10 1.5.2.6.4 Standby Power Criteria 1.5-11 1.5.2.7 Reactivity Control Criteria 1.5-11 1.5.2.8 Process Control Systems Criteria 1.5-11 1.5.2.8.1 Nuclear System Process Control Criteria 1.5-11 1.5.2.8.2 Power Conversion Systems Process Control Criteria 1.5-11 1.5.2.8.3 Electrical Power System Process Control Criteria 1.5-12 1.5.2.9 Auxiliary Systems Criteria 1.5-12 1.5.2.10 Shielding and Access Control Criteria 1.5-12 1.5.2.11 Structural Loading Criteria 1.5-13 1.6 STATION DESCRIPTION 1.6-1 1.6.1 General 1.6-1 1.6.1.1 Site and Environs 1.6-1 1.6.1.1.1 Site Ownership 1.6-1 1.6.1.1.2 Activities at the Site 1.6-1 1.6.1.1.3 Access to Site 1.6-1 1.6.1.1.4 Description of the Environs 1.6-1 1.6.1.1.5 Geology and Seismology 1.6-2 1.6.1.1.6 Hydrology 1.6-2 1.6.1.1.7 Meteorology 1.6-2 1.6.1.1.8 Station Design Bases Dependent Upon The Station Site and Environs 1.6-3 1.6.1.1.9 Environs Radiation Surveillance Program 1.6-3 1.6.1.2 Facility Arrangement 1.6-4 1.6.1.3 Nuclear System 1.6-4 1.6.1.3.1 Reactor Core and Control Rods 1.6-4 1.6.1.3.2 Reactor Vessel and Internals 1.6-4 1.6.1.3.3 Reactor Recirculation System 1.6-5 1.6.1.3.4 Residual Heat Removal System 1.6-5 1.6.1.3.5 Reactor Water Cleanup System 1.6-5 1.6.1.4 Power Conversion Systems 1.6-6 1.6.1.4.1 Turbine Generator 1.6-6 1.6.1.4.2 Turbine Bypass System 1.6-6 1.6.1.4.3 Main Condenser 1.6-6 1.6.1.4.4 Main Condenser Air Ejector and Turbine Steam Sealing Systems 1.6-6 1.6.1.4.5 Circulating Water System 1.6-7 1.6.1.4.6 Condensate Demineralizer System 1.6-7 1.6.1.4.7 Condensate and Reactor Feedwater Systems 1.6-7 1-ii Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 1 INTRODUCTION AND

SUMMARY

TABLE OF CONTENTS 1.6.1.5 Electrical Power System 1.6-7 1.6.1.6 Radioactive Waste Systems 1.6-8 1.6.1.6.1 Liquid Radwaste System 1.6-8 1.6.1.6.2 Solid Radwaste System 1.6-8 1.6.1.6.3 Gaseous Radwaste System 1.6-9 1.6.2 Nuclear Safety Systems and Engineered Safeguards 1.6-9 1.6.2.1 Reactor Protection System 1.6-9 1.6.2.2 Neutron Monitoring System 1.6-10 1.6.2.3 Control Rod Drive System 1.6-10 1.6.2.4 Nuclear System Pressure Relief System 1.6-10 1.6.2.5 Reactor Core Isolation Cooling System 1.6-10 1.6.2.6 Primary Containment 1.6-10 1.6.2.7 Primary Containment and Reactor Vessel Isolation Control System 1.6-11 1.6.2.8 Secondary Containment 1.6-11 1.6.2.9 Main Steam Line Isolation Valves 1.6-11 1.6.2.10 Main Steam Line Flow Restrictors 1.6-12 1.6.2.11 Core Standby Cooling Systems 1.6-12 1.6.2.12 Residual Heat Removal System (Containment Spray, Suppression Pool Cooling, LPCI with Heat Rejection) 1.6-13 1.6.2.13 Control Rod Velocity Limiter 1.6-14 1.6.2.14 Control Rod Drive Housing Supports 1.6-14 1.6.2.15 Standby AC Power Supply 1.6-14 1.6.2.16 DC Power Supply 1.6-14 1.6.2.17 Salt Water Service System 1.6-15 1.6.2.18 Reactor Building Closed Cooling Water System 1.6-15 1.6.2.19 Main Steam Line Radiation Monitoring System 1.6-15 1.6.2.20 Refueling Ventilation Exhaust Radiation Monitoring System 1.6-15 1.6.2.21 Main Control Room Environmental Control System 1.6-15 1.6.2.22 Equipment Area Cooling System 1.6-15 1.6.3 Special Safety Systems 1.6-16 1.6.3.1 Standby Liquid Control System 1.6-16 1.6.3.2 Station Equipment Outside the Control Room 1.6-16 1.6.3.3 Recirculation Pump Trip System 1.6-16 1.6.4 Process Control and Instrumentation 1.6-16 1.6.4.1 Nuclear System Process Control and Instrumentation 1.6-16 1.6.4.1.1 Reactor Manual Control System 1.6-16 1.6.4.1.2 Recirculation Flow Control System 1.6-16 1.6.4.1.3 Neutron Monitoring System 1.6-16 1.6.4.1.4 Refueling Interlocks 1.6-17 1.6.4.1.5 Reactor Vessel Instrumentation 1.6-17 1.6.4.1.6 Process Computer System 1.6-17 1-iii Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 1 INTRODUCTION AND

SUMMARY

TABLE OF CONTENTS 1.6.4.2 Power Conversion Systems Process Control and Instrumentation 1.6-17 1.6.4.2.1 Pressure Regulator and Turbine Control 1.6-17 1.6.4.2.2 Feedwater System Control 1.6-18 1.6.4.3 Electrical Power System Process Control 1.6-18 1.6.4.4 Radiation Monitoring and Control 1.6-18 1.6.4.4.1 Process Radiation Monitoring 1.6-18 1.6.4.4.2 Area Radiation Monitors 1.6-18 1.6.4.4.3 Liquid Radwaste System Control 1.6-18 1.6.4.4.4 Solid Radwaste Control 1.6-19 1.6.4.4.5 Gaseous Radwaste System Control 1.6-19 1.6.5 Auxiliary Systems 1.6-19 1.6.5.1 Auxiliary AC Power 1.6-19 1.6.5.2 Turbine Building Closed Cooling Water System 1.6-19 1.6.5.3 Fire Protection System 1.6-19 1.6.5.4 Heating, Ventilation, and Air Conditioning Systems 1.6-20 1.6.5.5 New and Spent Fuel Storage 1.6-20 1.6.5.6 Fuel Pool Cooling and Filtering System 1.6-20 1.6.5.7 Service and Instrument Air System 1.6-20 1.6.5.8 Makeup Water Treatment System 1.6-20 1.6.5.9 Potable and Sanitary Water Systems 1.6-20 1.6.5.10 Equipment and Floor Drainage Systems 1.6-20 1.6.5.11 Process Sampling System 1.6-20 1.6.5.12 Station Communication Systems 1.6-21 1.6.5.13 Technical Support Center 1.6-21 1.6.6 Shielding 1.6-21 1.6.7 Implementation of Loading Criteria 1.6-21 1.6.8 Independent Spent Fuel Storage Installation 1.6-22 1.7 COMPARISON OF PRINCIPAL DESIGN CHARACTERISTICS 1.7-1 1.8

SUMMARY

OF RADIATION EFFECTS 1.8-1 1.8.1 Planned Operations 1.8-1 1.8.2 Abnormal Operational Transients 1.8-1 1.8.3 Accidents 1.8-1 1.9 STATION MANAGEMENT 1.9-1 1.9.1 Organizational Structure 1.9-1 1.9.2 Operator Training 1.9-1 1.9.3 Safety Responsibilities 1.9-1 1.9.4 Emergency Plans 1.9-1 1.9.5 Cooperation with Other Agencies 1.9-1 1.10 QUALITY ASSURANCE PROGRAM 1.10-1 1-iv Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 1 INTRODUCTION AND

SUMMARY

TABLE OF CONTENTS 1.10.1 Introduction 1.10-1 1.10.2 QA Program Objectives 1.10-1 1.10.3 QA Program Organization 1.10-1 1.10.4 Quality Control and Assurance Measures 1.10-1 1.10.5 Quality Records and Documentation 1.10-2 1.10.6 Quality Requirements Review 1.10-2 1.10.7 QA Program Update 1.10-3 1.11 STATION RESEARCH, DEVELOPMENT, AND FURTHER INFORMATION REQUIREMENTS AND RESOLUTION

SUMMARY

1.11-1 1.11.1 Reference 1.11-2 1-v Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 1 LIST OF TABLES Table Title 1.2-1 Classification of BWR Systems, Criteria, and Requirements for Safety Evaluation 1.4-1 Concept for Classification of BWR Systems, Criteria, and Requirements for Safety Evaluation 1.5-1 Station Shielding Design Basis Limitations 1.8-1 Summary of Maximum Offsite Effects of Design Basis Accidents 1.11-1 Pilgrim Nuclear Power Station - ACRS Concerns - Resolutions 1.11-2 Pilgrim Nuclear Power Station - AEC-Staff Concerns-Resolutions 1.11-3 Pilgrim Nuclear Power Station - ACRS Concerns on Other Recent, Related Dockets - Pilgrim Capability for Resolution 1.11-4 Pilgrim Nuclear Power Station Topical Reports Submitted to the AEC in Support of Docket 1-vi Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 1 LIST OF FIGURES Figure Title 1.2-1 Relationship Between Safety Action and Protective Action 1.2-2 Relationship Between Different Types of Systems, Actions, and Objectives 1.2-3 Relationship Between Protective Functions and Protective Actions 1.3-1 Deleted 1.3-2 Piping and Instrumentation Symbols (Drawing M200) 1.3-3,4,5 Functional Control Diagram Symbols 1.3-6 Instrument Symbols 1.6-1 Plot Plan (Drawing C2) 1.6-2 Deleted 1.6-3 Exclusion Area 1.6-4 Reactor Heat Balance, Design Power 1.6-5 Turbine-Generator Heat Balance, Design Power 1-vii Rev. 30 - Nov. 2015

PNPS-FSAR 1.6 STATION DESCRIPTION 1.6.1 General 1.6.1.1 Site and Environs The site is located on the western shore of Cape Cod Bay in the Town of Plymouth, Plymouth County, Massachusetts. It is 38 mi southeast of Boston, Massachusetts and 44 mi east of Providence, Rhode Island.

Section 2 discusses the site locations with respect to the surrounding communities.

1.6.1.1.1 Site Ownership The 517 acre plant site is wholly owned by Entergy.

1.6.1.1.2 Activities at the Site The Applicant intends to develop the site solely for the purpose of generating and transmitting electrical energy in support of its normal business activities.

Provisions have been made for controlled public access to the shorefront breakwater area. This area is shown on Figures 1.6-1 and 1.6-2. The exclusion area is depicted on Figure 1.6-3.

1.6.1.1.3 Access to Site Direct access to the site is available by road and sea. Normal land access is by a two lane paved road built across the site to Route 3A, leading to either Plymouth or nearby Route 3. Alternate access from the site to Plymouth and Route 3 via Route 3A is provided by Rocky Hill Road.

1.6.1.1.4 Description of the Environs Population The area within 3 mi of the site is sparsely developed having an estimated 2,358 permanent residents. The number of residents is estimated to increase to 3,301 within this radius due to the seasonal residence along Priscilla and White Horse Beaches.

Brockton is the nearest densely populated center with more than 25,000 residents, with the nearest boundary about 23 mi from the site.

Land Use (Refer to Section 2)

The site is located along the coast with approximately 60 percent of the area within a 50 mi radius open water. Approximately 85 percent of the land area within a 10 mi radius is open space and vacant.

The area within 2 mi of the site is sparsely developed with the exception of the seasonal residences along Priscilla Beach and White Horse Beach.

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PNPS-FSAR An estimate of the present land use for the towns of Plymouth, Carver, and Kingston is presented in Section 2. Portions of these towns constitute approximately 90 percent of the land area within a 10 mi radius of the site. The data indicates that over 85 percent of the land is categorized as open space and vacant.

Approximately 7 percent of the land use is agricultural, the major portion of which is cranberry bogs. The adjacent waters are used for commercial fishing, shell fishing, and sport fishing.

1.6.1.1.5 Geology and Seismology The surface stratum in the station area consists of approximately 20 ft of silty and clayey fine sands with scattered boulders. The stratum is moderately compact. The soils underlying the upper stratum are moderately compact to compact, poorly to well graded sands with some gravel and cobbles. Boulders are scattered throughout the overburden soil, and a discontinuous thin layer of small boulders overlies bedrock. Bedrock is approximately 60 to 70 ft below msl. There are no known faults at or near the station site.

It is indicated from geologic and tectonic history that the region is relatively quiescent. Low magnitude seismic events can occur, but should be infrequent. The horizontal ground acceleration at the site due to maximum expected earthquake would be less than 8 percent of gravity, and this magnitude has been used for design purposes.

Structures and equipment have been examined for an acceleration of 15 percent of gravity to ascertain that no failure could occur that would prevent safe shutdown of the station.

1.6.1.1.6 Hydrology Surface drainage at the site is entirely within the Applicant's property and toward Cape Cod Bay. The ground water table has fairly steep gradients which generally follow the topography with ground water flow toward the bay. Ground water usage in the area is limited to a few locations since most of the residences are supplied with water from the Town of Plymouth. The closest Plymouth water supply source is 2 3/4 mi from the site and there is no current or proposed ground water development in the vicinity of the site.

Circulation off the site is a result of the combined effects of tidal and wind driven currents. Studies indicate that coastal upwelling also occurs at the site. These three processes, plus the momentum mixing of the circulating water discharge with the waters of the bay, will provide efficient mixing of waters discharged during station operation. Prevailing littoral drift is to the southeast (downcoast) from the site. The net effect of all circulation factors will result in the transport of discharged waters either offshore or parallel to shore.

1.6.1.1.7 Meteorology The main features of the weather in eastern Massachusetts are its variety and changeability. The site meteorology is influenced by the coastal location on Cape Cod Bay. Present data indicates that 1.6-2 Rev. 30 - Nov. 2015

PNPS-FSAR favorable atmospheric dilution conditions prevail. The annual average wind velocity is approximately 6 mph with the most frequent wind directions offshore. There are no long periods of light winds or calms. The high monthly average temperature of 72F occurs in July and a low of 31F in January and February. The storm cycle in the area consists of "northeasters" in the winter and spring, thunderstorms in late spring and summer, and hurricanes in the late summer and fall. Tornado activity in eastern Massachusetts is uncommon.

1.6.1.1.8 Station Design Bases Dependent upon the Station Site and Environs Offgas System A stack is provided for the continuous dispersal of gaseous effluent to the atmosphere. Height and location of the stack took into consideration such factors as station operational characteristics and site meteorological conditions. Gaseous releases shall be in compliance with 10CFR20 and 10CFR50 Appendix I.

Wind Loading Design All station structures have been designed to withstand wind velocities in accordance with ASCE Paper 3269. Structures whose failure could affect the operations, functions, and integrity of the Primary Containment System have been designed to assure that safe shutdown of the reactor can be achieved when these structures are subjected to the effects of a tornado.

Seismic Design The station seismic design criteria for Class I structure and equipment, important to safety, are based on dynamic analyses using acceleration or velocity response spectrum curves which are based on a ground horizontal acceleration of 8 percent of gravity. As an additional requirement, the design is such that a safe shutdown of the station can be made based on a ground acceleration of 15 percent of gravity. All structures not Class I have been designed to meet applicable codes.

Shoreline Protection The station site will be protected from storm waves by rubble breakwaters and a stone revetment which also stabilizes the shoreline by preventing erosion.

1.6.1.1.9 Environs Radiation Surveillance Program A study of preoperational environmental radiation levels was initiated in August 1969, which includes sampling and laboratory radioactivity analyses of airborne particulates, airborne iodine, fresh water, sea water, marine life, marine sediments, milk, and crops. Background radiation levels were established. Sampling activities are concentrated within a few miles of the station; however, in addition, selected sampling is also conducted at control 1.6-3 Rev. 30 - Nov. 2015

PNPS-FSAR locations over 20 mi from the station. These studies are being continued after station startup. Comparison of the operational and preoperational data permits detection of any significant increase in radiation levels in the environment.

1.6.1.2 Facility Arrangement The station is arranged such that the turbine-generator axis is oriented parallel to the shoreline of Cape Cod Bay, and the Reactor Building is located on the north or seaward side of the Turbine Building. Auxiliary bays are located between and adjacent to the Reactor Building and Turbine Building and house the main control room, the radwaste and machine shop equipment, and other service equipment and systems. The Old Administration Building is to the west of the Turbine Building, the New Administration/Service Building is to the east of the Turbine Building, and the Trash Compaction Building is to the North-East of the Turbine Building.

The Diesel Generator Building is adjacent to the north side of the Reactor Building.

The main offgas stack is located about 700 ft to the west of the centerline of the station.

1.6.1.3 Nuclear System The nuclear system includes a single cycle, forced circulation, General Electric Boiling Water Reactor producing steam for direct use in the steam turbine. A heat balance showing the major parameters of the nuclear system for the design power condition is shown on Figure 1.6-4.

1.6.1.3.1 Reactor Core and Control Rods The fuel for the reactor core consists of slightly enriched uranium dioxide pellets contained in sealed Zircaloy 2 tubes. These fuel rods are assembled into individual fuel assemblies, each containing 64 rods or more. The number of fuel assemblies in the complete core is 580.

Gross control of the core is achieved by movable, bottom-entry control rods, supplemented in the initial fuel load with temporary control curtains. The control rods are of cruciform shape and are dispersed throughout the lattice of fuel assemblies. The rods are controlled by individual hydraulic drives.

1.6.1.3.2 Reactor Vessel and Internals The reactor vessel contains the core and supporting structure; the steam separators and dryers; the jet pumps; the control rod guide tubes; distribution lines for the feedwater, core spray, and standby liquid control; the incore instrumentation; and other components.

The main connections to the vessel include the steam lines, the coolant recirculation lines, feedwater lines, control rod drive housings, and core standby cooling lines.

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PNPS-FSAR The reactor vessel is designed and fabricated in accordance with applicable codes for a pressure of 1,250 psig. The nominal operating pressure ranges from 1,020 to 1,050 psia in the steam space above the separators. The vessel is fabricated of carbon steel and is clad internally with stainless steel.

The reactor core is cooled by demineralized water which enters the lower portion of the core and boils as it flows upward around the fuel rods. The steam leaving the core is dried by steam separators and dryers, located in the upper portion of the reactor vessel. The steam is then directed to the turbine through the main steam lines.

Each steam line is provided with two isolation valves in series; one on each side of the primary containment barrier.

1.6.1.3.3 Reactor Recirculation System The Reactor Recirculation System pumps reactor coolant through the core to remove the energy generated in the fuel. This is accomplished by two recirculation loops external to the reactor vessel but inside the primary containment. Each loop has one motor driven recirculation pump. Recirculation pump speed can be varied to allow some control of reactor power level through the effects of coolant flow rate on moderator void content.

1.6.1.3.4 Residual Heat Removal System The Residual Heat Removal System (RHRS) is a system of pumps, heat exchangers, and piping that fulfills the following functions:

1. Removal of decay heat during and after station shutdown.

2. Injection of water into the reactor vessel following a loss of coolant accident (LOCA) rapidly enough to reflood the core, and prevent fuel clad melting independent of other Core Cooling Systems. This is discussed in Section 1.6.2 under Engineered Safeguards.

3. Removal of heat from the primary containment following a LOCA to limit the increase in primary containment pressure. This is accomplished by cooling and recirculating the water inside the primary containment.

The redundancy of the equipment provided for containment cooling is further extended by a separate part of the RHRS which sprays cooling water into the containment.

This latter capability is discussed in Section 1.6.2.12.

1.6.1.3.5 Reactor Water Cleanup System A Reactor Water Cleanup System, which includes a filter-demineralizer arrangement, is provided to clean up the reactor cooling water, reduce the amounts of activated corrosion products in the water, and to remove reactor coolant from the nuclear system under controlled conditions.

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PNPS-FSAR 1.6.1.4 Power Conversion Systems To produce electrical power the station utilizes a power conversion system which includes turbine-generator, main condenser, air ejector, air ejector condensers, turbine gland seal condenser, condensate demineralizers, and a feedwater heating system. See Figure 1.6-5. The steam comes from the reactor, drives the turbine generator and is exhausted to the condenser. The deaerated condensate is demineralized prior to regenerative heating necessary for its return as feedwater to the reactor. The heat dumped to the main condenser is removed by the Circulating Water System.

1.6.1.4.1 Turbine Generator The turbine is a General Electric 1,800 rpm tandem compound, four-flow, non reheat unit with 43 in last stage buckets. It has a double flow high pressure cylinder and two double flow low pressure cylinders. Exhaust steam from the high pressure unit passes through moisture separators before entering the low pressure units. The turbine has five extraction stages for reactor feedwater system heating. Turbine controls include a speed governor, steam admission (control) valves, emergency stop valves, crossover intercept valves, and a pair of initial pressure regulators. The generator is a direct coupled, 60 cycle, 24,000 V synchronous unit, with a liquid cooled stator and hydrogen cooled rotor.

1.6.1.4.2 Turbine Bypass System A Bypass System is provided to allow passing of the steam from the reactor directly to the main condenser under control of the pressure regulator. Steam is bypassed to the condenser whenever the reactor steam rate exceeds that corresponding to the load connected to the turbine generator at that time. For example, the bypass system would be used during generator synchronization or rejection of a large electrical load. The system has the capacity to pass 25 percent of turbine design steam flow.

1.6.1.4.3 Main Condenser The main condenser is of the single pass, divided water box, deaerating type. It consists of two shells, one for each low pressure turbine cylinder. Each half capacity condenser has two feedwater heaters located in its neck. The hotwells of each condenser are designed to provide a minimum condensate retention time of 2 min, permitting decay of short lived radioactive isotopes.

Deaeration is provided in the condensers for removal of dissolved gases from the condensate.

1.6.1.4.4 Main Condenser Air Ejector and Turbine Steam Sealing Systems One twin element (100 percent spare capacity) two stage steam jet air ejector complete with inter and after condensers are provided for evacuating gases from the turbine and main condenser. One mechanical vacuum pump is provided to remove gases from the main condenser during startup and shutdown when steam is not available for the air ejectors.

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PNPS-FSAR The Turbine Sealing System provides steam to the seals on the turbine valve glands and the turbine shaft glands at a pressure slightly above atmospheric. This system collects and condenses sealing steam and discharges air leakage through the Gland Seal Holdup System to the main stack. The Holdup System serves mainly to allow short half life radioactive gases to decay before discharge to the main stack.

1.6.1.4.5 Circulating Water System Two vertical, removable element circulating water pumps located in the intake structure will provide a continuous supply of condenser cooling water. The water is pumped from and returned to Cape Cod Bay. Trash racks, and traveling water screens will protect the circulating water pump from debris. The screens are kept clean by a screen wash system.

1.6.1.4.6 Condensate Demineralizer System The Condensate Demineralizer System consists of seven parallel circuit purifying vessels to maintain reactor feedwater of required purity. Ionic and particulate materials from the reactor, main steam line, turbine, main condenser, etc., are removed from the condensate in this system.

1.6.1.4.7 Condensate and Reactor Feedwater Systems The Condensate and Reactor Feedwater System will take condensate from the main condenser and after five stages of heating deliver it to the reactor.

Condensate will be pumped by three, motor driven, vertical pumps through the steam jet air ejector inter and after condensers, and the gland seal condenser. After leaving the gland seal condenser, it will pass through the condensate deep bed demineralizers. The purified flow will then combine into two parallel streams, each with three stages of low pressure feedwater heating. Feedwater will then be boosted in pressure by the reactor feed pumps. There will be no regulating valves in the piping between the condensate pumps and the reactor feed pumps. The flow from the three centrifugal, motor driven reactor feedwater pumps will be combined into two parallel streams, each with two stages of high pressure feedwater heating.

The feedwater will then flow to the reactor. Control valves will be located in the piping between the high pressure feedwater heaters and the reactor for regulation of feedwater flow.

1.6.1.5 Electrical Power System The station main generator feeds electrical power at 24 kV via an isolated phase bus into the main transformer which steps the voltage up to 345 kV. A 345 kV power connection is made between the main transformer and the 345 kV switchyard ring bus. The 345 kV switchyard ring bus is connected to the startup transformer. Power from the station is transmitted to the Boston Edison System at 345 kV through transmission lines which are interconnected with the major power systems in the New England area.

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PNPS-FSAR Station auxiliary power during startup will be from the startup transformer connected to the 345 kV switchyard ring bus. In addition, power for station emergency shutdown will be from two standby diesel generators or from the shutdown transformer fed from a 24 kV line which is connected to the New England grid by an independent 115 kV line. In the unlikely event these shutdown power sources are unavailable, a non-safety related, Blackout AC Power Source is provided to supply power to the 4.16kV emergency service buses.

1.6.1.6 Radioactive Waste Systems The Radioactive Waste Systems are designed to control the release of station produced radioactive material to within the limits specified in 10CFR20, and to meet the design objectives of 10CFR50, Appendix I. This is done by various methods such as collection, drumming, filtration, holdup for decay, and dilution. The methods employed for the controlled release of these contaminants are dependent primarily upon the state of the material: liquid, solid, or gaseous.

1.6.1.6.1 Liquid Radwaste System The Liquid Radioactive Waste Control System collects, treats, stores, and disposes of all radioactive liquid wastes. These wastes are collected in sumps at various locations throughout the station and then transferred to the appropriate collection tanks in the Radwaste Building for treatment, storage, dilution, and disposal as necessary. Wastes are processed on a batch basis. Processed liquid wastes may be returned to the Condensate System or discharged to the environs through the circulating water discharge canal. The liquid wastes in the discharge canal are diluted with condenser effluent circulating water to achieve a permissible concentration at the site boundary.

Equipment is selected, arranged, and shielded to permit operation, inspection, and maintenance with minimum personnel exposure. For example, tanks and processing equipment which are expected to contain significant radiation sources are located behind shielding.

Similarly, sumps, pumps, instruments, and valves are located in controlled access rooms or shielded spaces. Processing equipment is designed to require a minimum of maintenance.

Protection against accidental discharge of liquid radioactive waste is provided by radiation monitoring and procedural controls.

1.6.1.6.2 Solid Radwaste System With the Solid Radwaste System, solid radioactive wastes are collected, processed, and packaged for storage, shipment, and offsite disposal. Process solid wastes are collected, dewatered, and containerized for offsite shipment. Examples of these solid wastes are filter residue, spent resins, paper, air filter elements and non-reusable contaminated clothing. Solid wastes from equipment originating in the nuclear system are stored for radioactive decay in the fuel storage pool and prepared for offsite shipment in approved shipping containers.

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PNPS-FSAR 1.6.1.6.3 Gaseous Radwaste System The Gaseous Radwaste System collects, processes, and delivers to the main stack, for elevated release to the atmosphere, gases from the main condenser air ejector, startup vacuum pump, and gland seal condenser.

Non-condensible radioactive offgas is continuously removed from the main condenser by the air ejector during plant operation. The air ejector offgas normally contains activation gases, principally, N-16, 0-19, and N-13. The N-16 and 0-19 have short half lives and quickly decay. The 10 min N-13 is present in small amounts which are further reduced by decay. The air ejector offgas also contains the radioactive noble gas parents of biologically significant Sr-89, Sr-90, Ba-140, and Cs-137. The concentration of these noble gases depends upon the amount of tramp urainum in the coolant and on the reactor fuel cladding surfaces (usually extremely small), and the number and size of fuel cladding leaks. After hydrogen/oxygen recombination and chilling to strip the condensibles to reduce the volume, the remaining non-condensibles (principally kryptons, xenons and air) are delayed in a 30 min holdup system before reaching the adsorption bed. Radioactive particulate daughters of the noble gases are retained on the HEPA filters and on the charcoal. The charcoal adsorption bed, operating in a constant temperature vault, selectively adsorbs and delays the xenons and kryptons from the bulk carrier gas (principally air). This delay on the charcoal permits the Xe and Kr to decay in place. The offgas is discharged to the environs via the main stack. The activity of the gas entering and leaving the Offgas Treatment System is continuously monitored. This system results in a reduction of the offgas activity (curies) released by a factor of approximately 185 relative to a 30 min holdup system.

Holdup in this system provides ample time to prevent release of fission product gases in excess of the permissible main stack release rate limits. When concentrations which would cause the stack release rate limits to be exceeded are detected, the holdup line is automatically isolated after a 15 min delay, unless corrective action has been taken to obviate station shutdown.

The system is designed to accommodate the possible explosive hazard due to the hydrogen and oxygen present from the radiolytic decomposition of reactor coolant.

The gland seal condenser is exhausted by a blower into shielded piping which provides 1.75 min holdup to reduce the activity of short lived radioactive gases (N-16 and O-19) which are then discharged to the main stack.

1.6.2 Nuclear Safety Systems and Engineered Safeguards 1.6.2.1 Reactor Protection System The Reactor Protection System (RPS) initiates a rapid, automatic shutdown (scram) of the reactor. This action is taken in time to 1.6-9 Rev. 30 - Nov. 2015

PNPS-FSAR prevent fuel cladding damage and any nuclear system process barrier damage following abnormal operational transients. The RPS overrides all operator actions and process controls.

1.6.2.2 Neutron Monitoring System Although not all of the Neutron Monitoring System qualifies as a nuclear safety system, those portions that provide high neutron flux signals to the RPS do. The intermediate range monitors (IRM) and average power range monitors (APRM), which monitor neutron flux via incore detectors, signal the RPS to scram in time to prevent excessive fuel cladding damage as a result of overpower transients.

1.6.2.3 Control Rod Drive System When a scram is initiated by the RPS it is the Control Rod Drive System that inserts the negative reactivity necessary to shut down the reactor. Each control rod is controlled individually by a hydraulic control unit. When a scram signal is received, high pressure water from an accumulator for each rod inserts each control rod rapidly into the core.

1.6.2.4 Nuclear System Pressure Relief System A Pressure Relief System consisting of relief and safety valves mounted on the main steam lines is provided to prevent excessive pressure inside the nuclear system following either abnormal operational transients or accidents.

1.6.2.5 Reactor Core Isolation Cooling System The Reactor Core Isolation Cooling System (RCICS) provides makeup water to the reactor vessel whenever the vessel is isolated. The RCICS uses a steam driven turbine-pump unit and operates automatically in time and with sufficient coolant flow to maintain adequate reactor vessel water level.

1.6.2.6 Primary Containment The design employs a pressure suppression primary containment inerted with nitrogen during normal operation which houses the reactor vessel, the reactor coolant recirculating loops, and other branch connections of the Reactor Primary System. The Primary Containment System consists of a drywell, a pressure suppression chamber which stores a large volume of water, a connecting vent system between the drywell and the water pool, Venting and Vacuum Relief System, isolation valves, Containment Cooling Systems, and other service equipment. In the event of a Process System piping failure within the drywell, reactor water and steam would be released into the drywell air space. The resulting increased drywell pressure would then force a mixture of nitrogen, steam, and water through the vent system into the pool of water which is stored in the suppression chamber. The steam would condense in the suppression pool, resulting in a rapid pressure reduction in the drywell. Nitrogen which was transferred to the suppression chamber pressurizes the suppression chamber, and is subsequently vented to 1.6-10 Rev. 30 - Nov. 2015

PNPS-FSAR the drywell to equalize the pressure between the two vessels.

Cooling systems are provided to remove heat from the reactor core, the drywell, and from the water in the suppression chamber and thus provide continuous cooling of the primary containment under accident conditions. Appropriate isolation valves are actuated during this period to ensure containment of radioactive materials within the primary containment which otherwise might be released from the reactor during the course of the accident.

1.6.2.7 Primary Containment and Reactor Vessel Isolation Control System The Primary Containment and Reactor Vessel Isolation Control System automatically initiates closure of isolation valves to close off all potential leakage paths for radioactive material to the environs.

This action is taken upon indication of a potential breach in the nuclear system process barrier.

1.6.2.8 Secondary Containment The design employs a low inleakage, elevated release point secondary containment system which houses the Primary Containment System, refueling facilities, and most of the components of the Nuclear Steam Supply System. The Secondary Containment System provides secondary containment when the Primary Containment System is closed and in service, and it provides primary containment when the Primary Containment System is open, as in refueling. The Secondary Containment System consists of the Reactor Building, Standby Gas Treatment System, Reactor Building Isolation Control System, and main stack.

In the event of a postulated pipe break inside the drywell or a fuel handling accident, the Reactor Building is isolated by the Reactor Building Isolation Control System to provide a low leakage barrier.

The Standby Gas Treatment System is initiated by the same conditions that isolate the Reactor Building. The Standby Gas Treatment System exhausts air from the Reactor Building to maintain a reduced pressure within the Reactor Building relative to the outside atmosphere, treats the air to remove particulates and iodines, and releases the air through the elevated release point, the main stack.

1.6.2.9 Main Steam Line Isolation Valves Although all pipelines which both penetrate the primary containment and offer a potential release path for radioactive material are provided with redundant isolation capabilities, the main steam lines, because of their large size and large mass flow rates, are given special isolation consideration. Two automatic isolation valves, each powered by both air pressure and spring force, are provided in each main steam line. These valves fulfill the following objectives:

1. Prevent excessive damage to the fuel barrier by limiting the loss of reactor coolant from the reactor vessel resulting from either a major leak from the steam piping outside the primary containment, or a malfunction of the 1.6-11 Rev. 30 - Nov. 2015

PNPS-FSAR pressure control system resulting in excessive steam flow from the reactor vessel

2. Limit the release of radioactive materials by closing the primary containment barrier in case of a major leak from the nuclear system inside the primary containment 1.6.2.10 Main Steam Line Flow Restrictors A venturi type flow restrictor is installed in each steam line close to the reactor vessel. These devices limit the loss of coolant from the reactor vessel before the main steam line isolation valves are closed in case of a main steam line break outside the primary containment and prevent uncovering of the core.

1.6.2.11 Core Standby Cooling Systems A number of Standby Cooling Systems are provided to prevent fuel clad melting in the event of a breach in the nuclear system process barrier, that results in a loss of reactor coolant.

The four core standby cooling systems are:

High Pressure Coolant Injection System (HPCI)

Automatic Depressurization System Core Spray System Low Pressure Coolant Injection (LPCI) (an operating mode of the RHR)

The core standby cooling system's initiation and control instrumentation is divided in two parts, the incident detection circuitry (IDC) and the control instrumentation. The IDC includes those channels which detect a need for core cooling systems operation and the corresponding trip systems which initiate the proper core standby cooling system response.

1. High Pressure Coolant Injection System The HPCI provides and maintains an adequate coolant inventory inside the reactor vessel to prevent fuel clad melting as a result of postulated small breaks in the nuclear system process barrier. A high pressure system is needed for such breaks because the reactor vessel depressurizes slowly, preventing low pressure systems from injecting coolant. The HPCI includes a turbine pump powered by reactor steam. The system is designed to accomplish its function on a short term basis without reliance on station auxiliary power supplies other than the dc power supply.

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PNPS-FSAR

2. Automatic Depressurization System The automatic depressurization system acts to rapidly reduce reactor vessel pressure during postulated accident situations in which the HPCI fails to automatically maintain reactor vessel water level. The depressurization provided by the system enables the low pressure standby cooling systems to deliver cooling water to the reactor vessel. The automatic depressurization system uses some of the relief valves which are part of the nuclear system pressure relief system. The automatic relief valves are arranged to open upon conditions indicating both that a break in the nuclear system process barrier has occurred, and that the HPCI is not delivering sufficient cooling water to the reactor vessel to maintain the water level above a pre-selected value. The automatic depressurization system will not be activated unless either the core spray or LPCI cooling is available.

3. Core Spray System The core spray system consists of two independent pump loops that deliver cooling water to spray spargers over the core. The system is actuated by conditions indicating that a breach exists in the nuclear system process barrier, but water is delivered to the core only after reactor vessel pressure is reduced. This system provides the capability to cool the fuel by spraying water onto the core.

4. Low Pressure Coolant Injection LPCI is an operating mode of the RHR but is discussed here because the LPCI mode acts as an engineered safeguard in conjunction with the other standby cooling systems. LPCI uses the pump loops of the RHR to inject cooling water at low pressure into an undamaged reactor recirculation loop. LPCI is actuated by conditions indicating a breach in the nuclear system process barrier, but water is delivered to the core only after reactor vessel pressure is reduced. LPCI operation, together with the core shroud and jet pump arrangement, provides the capability of core reflooding following a LOCA in time to prevent fuel clad melting.

1.6.2.12 Residual Heat Removal System (Containment Spray, Suppression Pool Cooling, LPCI with Heat Rejection)

The suppression pool (torus) cooling subsystem is placed in operation to limit the temperature of the water in the suppression pool following a design basis LOCA. In the suppression pool cooling mode of operation the RHR main system pumps take suction from the suppression pool, and pump the water through the RHR heat exchangers where cooling takes place by transferring heat to the station 1.6-13 Rev. 30 - Nov. 2015

PNPS-FSAR cooling systems. The fluid is then discharged back to the suppression pool.

Long-term core and suppression pool cooling can be performed by use of the LPCI with Heat Rejection mode for liquid breaks inside primary containment of sufficient size to support continuous recirculation as described below including the design basis LOCA.

In the LPCI with Heat Rejection Mode, the RHR pumps take suction from the suppression pool, and pump the water through the RHR heat exchanger where cooling takes place by transferring heat to the station cooling water systems. The fluid is then discharged back to the reactor vessel where sensible and decay heat is absorbed. The fluid returns to the suppression pool by flowing out the pipe break, into the drywell, and back to the suppression pool through the drywell to wetwell vent system. This method of cooling sets up a recirculation loop including the suppression pool, RHR heat exchanger, and reactor vessel.

Another portion of the RHR is provided to spray water into the containment as an augmented means of removing energy from the containment following a LOCA. This capability is in excess of the required energy removal capability for a design basis LOCA and can be placed into service at the discretion of the operator.

1.6.2.13 Control Rod Velocity Limiter A control rod velocity limiter is attached to each control rod to limit the velocity at which a control rod can fall out of the core should it become detached from its control rod drive. The rate of reactivity insertion resulting from a rod drop accident is limited by this action. The limiters contain no moving parts.

1.6.2.14 Control Rod Drive Housing Supports Control rod drive housing supports are located underneath the reactor vessel near the control rod housings. The supports limit the travel of a control rod in the event that a control rod housing is ruptured.

The supports prevent a nuclear excursion as a result of a housing failure, thus protecting the fuel barrier.

1.6.2.15 Standby AC Power Supply The Standby AC Power Supply System consists of two diesel generators capable of providing electrical power that is self-contained within the station and is independent of normal sources of supply. Each of the diesel generators is of sufficient capacity to carry the essential loads of their respective buses.

1.6.2.16 DC Power Supply The Station Battery System, consisting of three batteries, each with its own charger is sized to supply emergency DC power for a time period adequate to safeguard the station. The three batteries, two 125V DC for control, one 250V DC for power are each connected to 1.6-14 Rev. 30 - Nov. 2015

PNPS-FSAR their associated DC power distribution buses to supply uninterrupted power to vital loads.

1.6.2.17 Salt Water Service System The Salt Water Service System supplies coolant to the secondary sides of the heat exchangers of the Reactor Building and Turbine Building Closed Cooling Water Systems to remove heat produced during normal operation, shutdown, and accident conditions. Cooling water is taken at the intake structure by the five service water pumps and discharged with the condenser circulating water.

1.6.2.18 Reactor Building Closed Cooling Water System The Reactor Building Closed Cooling Water System is provided to supply self-contained coolant to the Reactor Auxiliary Systems equipment (potentially radioactive) and accessories, and to the RHRS to remove heat during normal operation, shutdown, and accident conditions. The system consists of two independent loops, each with three pumps, one heat exchanger, and associated piping and valves.

The loops are cross tied to permit operation with various combinations of equipment.

1.6.2.19 Main Steam Line Radiation Monitoring System The Main Steam Line Radiation Monitoring System consists of gamma radiation monitors located external to the main steam lines just outside of the primary containment. The monitors are designed to detect a gross release of fission products from the fuel.

1.6.2.20 Refueling Ventilation Exhaust Radiation Monitoring System The Refueling Ventilation Exhaust Monitoring System consists of a number of radiation monitors arranged to monitor the activity level of the ventilation exhaust from the refueling area of the Reactor Building. The monitors are designed to detect gross release of fission products from the spent fuel stored and handled in the refueling area. Upon detection of high radiation, the trip signals generated by the monitors are used to isolate the Reactor Building and to actuate the Standby Gas Treatment System.

1.6.2.21 Main Control Room Environmental Control System The Main Control Room Environmental Control System consists of two fans and filter trains to supply filtered air to the main control room upon detection of high radiation in the normal ventilation air.

1.6.2.22 Equipment Area Cooling System The Equipment Area Cooling System consists of a number of fan cooling units provided to remove heat from the pump room compartments in the Reactor Building that house Core Standby Cooling Systems.

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PNPS-FSAR 1.6.3 Special Safety Systems 1.6.3.1 Standby Liquid Control System Although not intended to provide prompt reactor shutdown, the Standby Liquid Control System provides a redundant, independent, and different way from the control rods to bring the nuclear fission reaction to subcriticality, and to maintain subcriticality as the reactor cools. The system makes possible an orderly and safe shutdown in the event that not enough control rods can be inserted into the reactor core to accomplish shutdown in the normal manner.

The system is sized to counteract the positive reactivity effect from full power to the cold shutdown condition.

1.6.3.2 Station Equipment Outside the Control Room Sufficient equipment and controls are available outside the control room to enable an operator to shut down the reactor and maintain it in a safe condition if access to the control room is lost.

1.6.3.3 Recirculation Pump Trip System In accordance with NUREG 0460, independent and diverse means are provided to introduce negative reactivity to the reactor core in the event of failure of the reactor to scram from power. The Recirculating Pump Trip (RPT) System is discussed in Section 3.9.

1.6.4 Process Control and Instrumentation 1.6.4.1 Nuclear System Process Control Instrumentation 1.6.4.1.1 Reactor Manual Control System The Reactor Manual Control System provides the means by which control rods are manipulated from the control room for gross power control.

The system controls valves in the Control Rod Drive Hydraulic System. Only one control rod can be manipulated at a time. The Reactor Manual Control system includes the controls that restrict control rod movement (rod block) under certain conditions as a backup to procedural controls.

1.6.4.1.2 Recirculation Flow Control System The Recirculation Flow Control System controls the speed of the reactor recirculation pumps. Adjusting the pump speed changes the coolant flow rate through the core. This effects changes in core power level.

1.6.4.1.3 Neutron Monitoring System The Neutron Monitoring System is a system of incore neutron detectors and out of core electronic monitoring equipment. The system provides indication of neutron flux, which can be correlated to thermal power level, for the entire range of flux conditions that 1.6-16 Rev. 30 - Nov. 2015

PNPS-FSAR may exist in the core. The source range monitors (SRM) and the intermediate range monitors (IRM) provide flux level indications during reactor startup and low power operation. The local power range monitors (LPRM) and average power range monitors (APRM) allow assessment of local and overall flux conditions during power range operation. Rod block monitors (RBM) are provided to prevent rod withdrawal when reactor power should not be increased at the existing reactor coolant flow rate. The Traversing Incore Probe System (TIPS) provides a means to calibrate the individual neutron monitoring sensors.

1.6.4.1.4 Refueling Interlocks A system of interlocks that restricts the movements of refueling equipment and control rods when the reactor is in the refuel mode is provided to prevent an inadvertent criticality during refueling operations. The interlocks back up procedural controls that have the same objective. The interlocks affect the refueling platform, the refueling platform hoists, the fuel grapple, control rods, and the service platform hoist.

1.6.4.1.5 Reactor Vessel Instrumentation In addition to instrumentation provided for the nuclear safety systems and engineered safeguards, instrumentation is provided to monitor and transmit information that can be used to assess conditions existing inside the reactor vessel and the physical condition of the vessel itself. The instrumentation provided monitors reactor vessel pressure, water level, surface temperature, internal differential pressures and coolant flow rates, and top head flange leakage.

1.6.4.1.6 Process Computer System An online process computer is provided to monitor and log process variables, and to make certain analytical computations. The rod worth minimizer function of the computer prevents rod withdrawal under low power conditions if the rod to be withdrawn is not in accordance with a preplanned pattern. The effect of the rod block is to limit the reactivity worth of the control rods by enforcing adherence to the preplanned rod pattern.

1.6.4.2 Power Conversion Systems Process Control and Instrumentation 1.6.4.2.1 Pressure Regulator and Turbine Control The pressure regulator controls both the turbine admission (control) valves and the turbine bypass valves and maintains constant reactor pressure. Pressure regulation is coordinated with the turbine speed and Load Control Systems. The turbine control utilizes a mechanical Hydraulic Control System arranged for remote operation.

1.6-17 Rev. 30 - Nov. 2015

PNPS-FSAR 1.6.4.2.2 Feedwater System Control A three element controller is used to regulate the feedwater system so that proper water level is maintained in the reactor vessel. The controller uses main steam flow rate, reactor vessel water level, and feedwater flow rate signals. The feedwater control signal is used to regulate the feedwater valves to adjust flow.

1.6.4.3 Electrical Power System Process Control High speed protective relaying is provided on the generator, station buses, and lines to isolate and disconnect faulted equipment in event of a failure and maintain system integrity. Relay types employed are impedance, ground differential, voltage, overcurrent, overexcitation, and negative sequence. Generator voltage, load frequency, metering, and telemetering systems are also used.

1.6.4.4 Radiation Monitoring and Control 1.6.4.4.1 Process Radiation Monitoring Radiation monitors are provided on various lines to monitor either for radioactive materials released to the environs via process liquids and gases or for process system malfunctions. The following monitors are provided:

Main Steam Lines Air Ejector Offgas Main Stack Reactor Building Exhaust Vent Drywell Airborne Activity Standby Gas Treatment Exhaust Drywell Atmosphere High Range Control Room Ventilation Intake Torus Atmosphere High Range Main Stack High Range Refueling Floor Exhaust Reactor Building Exhaust Vent High Range Turbine Building Roof Vent Exhaust High Range Radwaste Liquid Discharge RBCCW 1.6.4.4.2 Area Radiation Monitors A number of radiation monitors are provided to monitor for abnormal radiation at various locations in the Reactor Building, Turbine Building, Radwaste Building, and main control room. These monitors annunciate alarms when abnormal radiation levels are detected.

1.6.4.4.3 Liquid Radwaste System Control The Liquid Radwaste System collects, treats, and stores liquid radioactive wastes on a batch basis with protection against accidental discharge provided by the design, supplemented by procedural controls. Liquid wastes are discharged on a batch basis at a controlled rate after sampling and laboratory analysis.

1.6-18 Rev. 30 - Nov. 2015

PNPS-FSAR Instrumentation with alarms to detect abnormal radioactivity concentration in the liquid radwaste discharges is provided.

1.6.4.4.4 Solid Radwaste Control The Solid Radwaste System collects, treats, and packages solid radioactive wastes for offsite shipment. Wastes are handled on a batch basis. Radiation levels of the various batches are determined by the operator.

1.6.4.4.5 Gaseous Radwaste System Control The Gaseous Radwaste System is continuously monitored by the main stack radiation monitor. A high level signal from the Air Ejector Offgas Radiation Monitoring System will automatically isolate the Offgas System by closing a valve between the Air Ejector System and the stack. A main steam line high radiation condition will automatically close a valve on the mechanical vacuum pump discharge line and trip the pump. A shutoff valve between the main condenser and air ejector is closed upon high temperature or pressure signals in the offgas line.

1.6.5 Auxiliary Systems 1.6.5.1 Auxiliary AC Power Normal auxiliary power is supplied from the main generator to the auxiliary buses via the unit auxiliary transformer. The startup transformer can also supply auxiliary power during operation.

Either the unit auxiliary transformer or startup transformer can be connected to all auxiliary buses in the plant. Also, the shutdown transformer is available as an independent offsite power source to provide power to the emergency buses. Each offsite source has capacity for operation of all systems required to shut down the station and maintain it in a safe condition.

1.6.5.2 Turbine Building Closed Cooling Water System The Turbine Building Closed Cooling Water System supplies self-contained coolant to equipment located in the Turbine and Auxiliary Building to remove heat produced during station operation.

1.6.5.3 Fire Protection System The Fire Protection System consisting of fire pumping equipment and an underground water loop provides an adequate supply of water throughout the station. Carbon dioxide and chemical fire fighting equipment is also provided for selected areas.

1.6.5.4 Heating, Ventilation, and Air Conditioning Systems The Station Heating, Ventilating, and Air Conditioning Systems provide appropriate ambient temperature environmental conditions for station operating personnel and equipment. Normal air flow is routed from nonradioactive areas to areas of progressively greater contamination potential prior to final exhaust.

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PNPS-FSAR 1.6.5.5 New and Spent Fuel Storage New fuel is stored in a dry storage vault located adjacent to the spent fuel pool area in the Reactor Building. Transport of spent fuel and irradiated channels during refueling is handled underwater.

Spent fuel is stored underwater in the spent fuel pool in the Reactor Building and in dry storage casks at the Independent Spent Fuel Storage Installation until prepared for shipment from the site.

1.6.5.6 Fuel Pool Cooling and Filtering System The Spent Fuel Pool Cooling and Demineralizer System is provided to clean the pool water and remove decay heat from the spent fuel stored in the spent fuel storage pool.

1.6.5.7 Service and Instrument Air Systems Three non-lubricated, reciprocating, double acting compressors (in long term layup) and the two non-lubricated, screw, compound compressors supply the station with oil free air for instrument air, and high pressure service air. The compressors each take a suction from El 23 ft lower switch gear room through a dry type filter, and discharge through an after cooler with an integral moisture separator to an air receiver.

1.6.5.8 Makeup Water Treatment System The Makeup Water System is provided to maintain a supply of treated water suitable as makeup for the station. Water from the Town of Plymouth water system is processed through a demineralization system and stored in an onsite storage tank.

1.6.5.9 Potable and Sanitary Water Systems Water for drinking and sanitary use is supplied from the Town of Plymouth Water System. Shower and lavatory waste water that does not contain radioactive material is directed to sewage disposal facilities.

1.6.5.10 Equipment and Floor Drainage Systems Station Equipment and Floor Drainage Systems will handle radioactive and nonradioactive drains. Drainage which may contain potentially radioactive materials is pumped to the Radwaste System for determination of radioactivity followed by cleanup, decay, or discharge directly to the condenser circulating water discharge.

Nonradioactive drains will be disposed of through storm sewers.

1.6.5.11 Process Sampling System The station Process Sampling System is provided to monitor the quality of station process flows. Information required for making operational decisions is obtained from analysis of samples from pertinent system streams.

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PNPS-FSAR 1.6.5.12 Station Communication Systems Separate external and internal communication systems are provided.

The external system provides typical telephone communications. The internal system consists of several party channels and a central paging channel providing effective operational communication between various locations at the station site.

1.6.5.13 Technical Support Center (TSC)

In conformance with NUREG-0737, Supplement 1, Section 8.2, a closed circuit television (CCTV) camera is located in the main control room to record and transmit the following types of information to the TSC:

1. panel meter readings

2. annunciator window displays

3. plant computer video data

4. trend recorder readings In addition, the following equipment is provided to further enhance the access ability of information at the TSC:

1. A functional duplicate of the plant computer input/output printer is installed at the TSC to allow access to the computer data.

2. Independent reliable voice communication is provided between the TSC and the main control room.

Refer to the Emergency Plan (Appendix N) for further information concerning the use of this facility.

1.6.6 Shielding Shielding implemented by occupancy requirements in the various areas of the station is provided to meet the limits of applicable regulations. Access limits are given on Table 1.5-1.

1.6.7 Implementation of Loading Criteria Structures and equipment are designed to resist structural and mechanical damage due to loads produced by environmental thermal forces. For the purpose of categorizing mechanical strength designs for these loads, the following definitions are established:

a. Class I This class includes those structures, equipment, and components whose failure or malfunction might cause or increase severity of an accident which would endanger the public health and safety. This category includes those structures, equipment, and components required for safe shutdown and isolation of the reactor 1.6-21 Rev. 30 - Nov. 2015

PNPS-FSAR

b. Class II This class includes those structures, equipment, and components which are important to reactor operation, but are not essential for preventing an accident which would endanger the public health and safety, and are not essential for the mitigation of the consequences of these accidents. A Class II designated item shall not degrade the integrity of any item designated Class I.

1.6.8 Independent Spent Fuel Storage Installation The PNPS site contains an Independent Spent Fuel Storage Installation inside the plant protected area as shown on Figure 1.6-1. The ISFSI consists of a concrete pad with space for 40 natural convection air-cooled, HI-STORM shielded dry spent fuel storage casks, each capable of storing 68 spent nuclear fuel assemblies in a welded multi-purpose container.

1.6-22 Rev. 30 - Nov. 2015

PNPS-FSAR Figure 1.6-1 has been removed.

Please refer to BECo Controlled Drawing C2 1 of 1 Rev. 30 - Nov. 2015

PNPS-FSAR Figure 1.6-2 has been deleted See Figure 1.6-1 1 of 1 Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 3 REACTOR TABLE OF CONTENTS Section Title Page 3.1

SUMMARY

DESCRIPTION 3.1-1 3.2 FUEL MECHANICAL DESIGN 3.2-1 3.2.1 Fuel System Damage 3.2-1 3.2.1.1 Stress/Strain 3.2-1 3.2.1.2 Fatigue 3.2-2 3.2.1.3 Fretting Wear 3.2-2 3.2.1.4 Oxidation, Hydriding, and Corrosion Products 3.2-3 3.2.1.4.1 Oxidation and Corrosion Products 3.2-3 3.2.1.4.2 Hydriding 3.2-3 3.2.1.5 Dimensional Changes 3.2-3 3.2.1.6 Internal Gas Pressure 3.2-4 3.2.1.7 Hydraulic Loads 3.2-4 3.2.1.8 Control Rod Reactivity 3.2-5 3.2.2 Fuel Rod Failure 3.2-5 3.2.2.1 Hydriding 3.2-5 3.2.2.2 Cladding Collapse 3.2-5 3.2.2.3 Fretting Wear 3.2-5 3.2.2.4 Overheating of Cladding 3.2-5 3.2.2.5 Overheating of Pellets 3.2-6 3.2.2.6 Excessive Fuel Enthalpy 3.2-6 3.2.2.7 Pellet-Cladding Interaction 3.2-6 3.2.2.8 Bursting 3.2-6 3.2.2.9 Mechanical Fracturing 3.2-6 3.2.3 Fuel Coolability 3.2-7 3.2.3.1 Cladding Embrittlement 3.2-7 3.2.3.2 Violent Expulsion of Fuel 3.2-7 3.2.3.3 Generalized Cladding Melting 3.2-7 3.2.3.4 Fuel Rod Ballooning 3.2-7 3.2.3.5 Structural Deformation 3.2-7 3.2.4 Description and Design Drawings 3.2-7 3.2.4.1 Control Rods 3.2-9 3.2.4.2 Velocity Limiter 3.2-9 3.2.5 Testing, Inspection and Surveillance Plans 3.2-9 3.2.6 References 3.2-10 3.3 REACTOR VESSEL INTERNALS MECHANICAL DESIGN 3.3-1 3.3.1 Power Generating Objective 3.3-1 3.3.2 Power Generation Design Basis 3.3-1 3.3.3 Safety Design Basis 3.3-1 3.3.4 Description 3.3-1 3.3.4.1 Core Structure 3.3-2 3.3.4.1.1 Core Shroud 3.3-2 3-i Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 3.3.4.1.2 Shroud Head and Steam Separator Assembly 3.3-4 3.3.4.1.3 Core Support (Core Plate) 3.3-4 3.3.4.1.4 Top Guide 3.3-5 3.3.4.2 Fuel Support Pieces 3.3-5 3.3.4.3 Control Rod Guide Tubes 3.3-5 3.3.4.4 Jet Pump Assemblies 3.3-5 3.3.4.5 Steam Dryers 3.3-7 3.3.4.6 Feedwater Spargers 3.3-7 3.3.4.7 Core Spray Lines 3.3-8 3.3.4.8 (Deleted) 3.3-8 3.3.4.9 Differential Pressure and Liquid Control Line 3.3-8 3.3.4.10 Incore Flux Monitor Guide Tubes 3.3-8 3.3.4.11 Startup Neutron Sources 3.3-9 3.3.4.12 Surveillance Holders 3.3-9 3.3.5 Vibration 3.3-9 3.3.5.1 Vibration Analysis 3.3-9 3.3.5.2 Vibration Testing 3.3-9 3.3.5.3 Increased Core Flow Vibration Analysis 3.3-11 3.3.6 Safety Evaluation 3.3-11 3.3.6.1 Evaluation Methods 3.3-11 3.3.6.2 Plant Conditions 3.3-11 3.3.6.2.1 Normal Condition 3.3-11 3.3.6.2.2 Upset Condition 3.3-11 3.3.6.2.3 Emergency Condition 3.3-12 3.3.6.2.4 Faulted Condition 3.3-12 3.3.6.2.5 Correlation of Plant Condition with Event Probability 3.3-12 3.3.6.3 Special Events to be Evaluated 3.3-13 3.3.6.4 Pressure Differentials During Rapid Depressurization 3.3-14 3.3.6.5 Recirculation Line Break 3.3-15 3.3.6.5.1 Accident Definition 3.3-15 3.3.6.5.2 Jet Pump Joints 3.3-15 3.3.6.6 Steam Line Break Accident 3.3-16 3.3.6.6.1 Accident Definition 3.3-16 3.3.6.6.2 Effects of Initial Reactor Power and Core Flow 3.3-16 3.3.6.7 Reactor Internals Pressure Differences at Normal, Upset, Emergency and Faulted Condition 3.3-17 3.3.6.7.1 Core Support 3.3-17 3.3.6.7.2 Guide Tubes 3.3-18 3.3.6.7.3 Fuel Channels 3.3-18 3.3.6.8 Thermal Shock 3.3-19 3.3.6.9 Earthquake 3.3-20 3.3.6.10 Impact of Increased Core Flow (ICF) and Final Feedwater Temperature Reduction (FFWTR) on Reactor Internal Components 3.3-22 3.3.6.10.1 Reactor Internals 3.3-23 3.3.6.10.2 Fuel Channels 3.3-23 3-ii Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 3.3.6.10.3 Fuel Bundles 3.3-23 3.3.6.11 Conclusion 3.3-23 3.3.7 Inspection and Testing 3.3-23 3.3.8 References 3.3-24 3.4 REACTIVITY CONTROL MECHANICAL DESIGN 3.4-1 3.5 CONTROL ROD DRIVE HOUSING SUPPORTS 3.5-1 3.5.1 Safety Objective 3.5-1 3.5.2 Safety Design Basis 3.5-1 3.5.3 Description 3.5-1 3.5.4 Safety Evaluation 3.5-2 3.5.5 Inspection and Testing 3.5-3 3.5.6 (Deleted) 3.5-3 3.5.7 Current Operational Nuclear Safety Requirements 3.5-4 3-iii Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 3.6 NUCLEAR DESIGN 3.6-1 3.6.1 Design Bases 3.6-1 3.6.1.1 Safety Design Bases 3.6-1 3.6.1.1.1 Reactivity Basis 3.6-1 3.6.1.1.2 Overpower Bases 3.6-1 3.6.1.2 Plant Performance Design Bases 3.6-1 3.6.2 Description 3.6-2 3.6.2.1 Nuclear Design Description 3.6-2 3.6.2.2 Power Distribution 3.6-2 3.6.2.2.1 Power Distribution Calculations 3.6-2 3.6.2.2.2 Power Distribution Measurements 3.6-2 3.6.2.2.3 Power Distribution Accuracy 3.6-3 3.6.2.2.4 Power Distribution Anomalies 3.6-3 3.6.2.3 Reactivity coefficients 3.6-3 3.6.2.4 Control Requirements 3.6-5 3.6.2.4.1 Shutdown Reactivity 3.6-5 3.6.2.4.2 Reactivity Variations 3.6-5 3.6.2.5 Control Rod Patterns and Reactivity Worths 3.6-5 3.6.2.6 Criticality of Reactor During Refueling 3.6-5 3.6.2.7 Stability 3.6-6 3.6.2.7.1 Xenon Transients 3.6-6 3.6.2.7.2 Thermal Hydraulic Stability 3.6-6 3.6.2.8 Vessel Irradiations 3.6-6 3.6.3 Analytical Methods 3.6-6 3.6.4 Changes 3.6-6 3.6.5 References 3.6-6 3.7 THERMAL AND HYDRAULIC DESIGN 3.7-1 3.7.1 Design Bases 3.7-1 3.7.1.1 Safety Design Bases 3.7-1 3.7.1.2 Power Generation Design Bases 3.7-1 3.7.1.3 Requirements for Steady-State Conditions 3.7-1 3.7.1.4 Requirements for Transient Conditions 3.7-2 3.7.1.5 Summary of Design Bases 3.7-2 3.7.2 Description of Thermal-Hydraulic Design of the Reactor Core 3.7-2 3.7.2.1 Summary Comparison 3.7-2 3.7.2.2 Critical Power Ratio 3.7-2 3.7.2.3 Linear Heat Generation Rate (LHGR) 3.7-2 3.7.2.4 Void Fraction Distribution 3.7-2 3.7.2.5 Core Coolant Flow Distribution and Orificing Pattern 3.7-3 3.7.2.6 Core Pressure Drop and and Hydraulic Loads 3.7-3 3.7.2.7 Correlation and Physical Data 3.7-3 3.7.2.8 Thermal Effects of Operational Transients 3.7-3 3-iv Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 3.7.2.9 Uncertainties in Estimates 3.7-3 3.7.2.10 Flux Tilt Considerations 3.7-3 3.7.3 Description of the Thermal and Hydraulic Design of the Reactor Coolant System 3.7-4 3.7.3.1 Plant Configuration Data 3.7-4 3.7.3.2 Operating Restrictions on Pumps 3.7-4 3.7.3.3 Power-Flow Operating Map 3.7-4 3.7.3.4 Temperature-Power Operating Map (PWR) 3.7-5 3.7.3.5 Load-Following Characteristics 3.7-5 3.7.3.6 Thermal and Hydraulic Characteristics Summary Table 3.7-7 3.7.4 Evaluation 3.7-7 3.7.4.1 Critical Power 3.7-7 3.7.4.2 Core Hydraulics 3.7-7 3.7.4.3 Influence of Power Distributions 3.7-7 3.7.4.4 Core Thermal Response 3.7-7 3.7.4.5 Analytical Methods 3.7-7 3.7.4.6 Thermal-Hydraulic Stability Analysis 3.7-7 3.7.5 Testing and Verification 3.7-10 3.7.6 Instrumentation Requirements 3.7-10 3.7.7 References 3.7-10 3.8 STANDBY LIQUID CONTROL SYSTEM 3.8-1 3.8.1 Safety Objective 3.8-1 3.8.2 Safety Design Basis 3.8-1 3.8.3 Description 3.8-1 3.8.4 Safety Evaluation 3.8-4 3.8.5 Inspection and Testing 3.8-6 3.8.6 Compliance With 10CFR50.62 3.8-7 3.8.7 Current Operation Nuclear Safety Require-ments 3.8-7 3.8.8 References 3.8-7 3.9 RECIRCULATION PUMP TRIP, ALTERNATE ROD INSERTION, AND FEEDWATER PUMP TRIP SYSTEMS 3.9-1 3.9.1 Design Objective 3.9-1 3.9.2 Design Basis 3.9-1 3.9.3 Description 3.9-1 3.9.3.1 Recirculation Pump Trip System 3.9-1 3.9.3.2 Alternate Rod Insertion System 3.9-2 3.9.3.3 Feedwater Pump Trip System 3.9-2 3.9.3.4 System Trip Logic 3.9-2 3.9.4 References 3.9-3 3-v Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 3 LIST OF TABLES Table Title 3.2-1 Fuel Data GE11 and GE14 Fuel Designs 3.2-2 (Deleted) 3.2-3 (Deleted) 3.2-4 (Deleted) 3.3-1 Reactor Vessel Internals, Design Data 3.3-2 Reactor Internal Pressure Differences for Rated Flow Operation 3.3-3 Reactor Internal Pressure Differences for Increased Core Flow Operation 3.7-1 Thermal and Hydraulic Analysis Parameters 3.8-1 (Deleted) 3.8-2 (Deleted) 3-vi Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 3 LIST OF FIGURES Figure Title 3.2-1 Typical Core Cel1 3.2-2 Typical GE11 Fuel Bundle Design 3.2-3 Typical GE14 Fuel Assembly 3.3-1 Reactor Vessel Internals (Drawing M1A48-4) 3.3-2 Reactor Vessel Internal Flow - Schematic 3.3-3 Steam Separator 3.3-4 Fuel Support Piece 3.3-5 Jet Pump (Drawing M1E44-1) 3.3-6 Steam Dryer 3.3-7 Pressure Nodes Used for Depressurization Analysis 3.3-8 Thermal Shock Transient Analysis Zones 3.3-9 Material Behavior Graph - Cycles versus Stress for Stainless Steel 3.3-10 Pictorial View of Pilgrim Shroud Repair Hardware 3.4-1 (Deleted) 3.4-2 Control Rod - Isometric 3.4-3 Control Rod to Control Rod Drive Coupling - Isometric 3.4-4 Control Rod Velocity Limiter - Isometric 3.4-5 Control Rod Drive, Simplified Component Illustration 3.4-6 Control Rod Drive, Schematic Diagram 3.4-7 Control Rod Unit Drive Cutway Illustration 3.4-8 Inner Filter Arrangement 3.4-9 Control Rod Drive Hydraulic System, Piping and Instrumentation Diagram (Drawing M250) 3.4-10 Control Rod Drive Hydraulic System, Process Diagram (Drawing M1D12-4) 3.4-11 (Deleted) 3-vii Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 3.4-12 (Deleted) 3.4-13 Control Rod Hydraulic Control Unit, Isometric 3.4-14 Hybrid Control Rod Blade Design 3.4-15 Control Rod Duralife 230 (Drawing M1D-86) 3.5-1 Control Rod Drive Housing Support - Isometric 3.7-1 Power/Flow Operating Map 3.7-2 (Deleted) 3.8-1 Standby Liquid Control System (Drawing M249) 3.8-2 Standby Liquid Control System, Process Diagram (Drawing M1F2-3) 3.8-3 (Deleted) 3.8-4 Standby Liquid Control System, Functional Control Diagram (Drawing M1F1-2) 3.8-5 (Deleted) 3.8-6 Sodium Pentaborate Solution Volume and Concentration Requirements 3.9-1 Elementary Diagram ATWS System Power Supply (Drawing M1Y-4) 3.9-2 Elementary Diagram ATWS System (Drawing M1Y-6) 3.9-3 Elementary Diagram ATWS System Logic (Drawing M1Y-9) 3.9-4 Air Dump Systems and ATWS Air Dump System 3-viii Rev. 30 - Nov. 2015

PNPS-FSAR Table 3.2-1 FUEL DATA GE11, AND GE14, AND GNF2 FUEL DESIGNS Fuel Assembly GE11

GE14 GNF2 Geometry 9x9 10x10 10x10 Rod Pitch (in.) 0.566 0.510 0.510 Active Fuel Length (in.) 141.24 145.24 145.24 Heat Transfer Area (ft2) 95.5 109 110 Debris Filter No Yes Yes Fuel Rods Fill Gas helium helium helium Fill Pressure (atm) 10 10 10 Getter yes No No Number of Fuel Rods 74 92 92 Fuel Material sintered UO2 sintered UO2 sintered UO2 Pellet Diameter (in.) 0.376 0.345 0.3496 Pellet Length (in.) 0.380 0.350 0.375 Pellet Immersion Density (%TD) 96.5 97 97 Cladding Material Zr-2+ Zr-2+ Zr-2+

Zirconium Zirconium Zirconium Outside Diameter (in.) 0.440 0.404 0.4039 Total Thickness (in.) 0.028 0.026 0.0236 Barrier Thickness (in.) 0.0035 0.0035 0.0035 Water Rod Material Zr-2 Zr-2 Zr-2 Outside Diameter (in.) 0.980 0.980 0.980 Thickness (in.) 0.030 0.030 0.030 Number of Water Rods 2 2 2 Number of Fuel Rods Displaced 7 8 8 Spacers Material Zr-2 with Zr-2 with Alloy-X-750 Alloy X-750 Alloy X-750 Springs Springs Number per Bundle 7 8 8 Fuel Channel Material Zr-2 Zr-2 ZRY-2/ZRY-4/NSF Inside Dimension (in.) 5.278 5.278 5.283 Equivalent** Wall Thickness (in.) 0.0745 0.0745 Flow Trippers Yes No No

In cycle 17 core, there is no GE11 fuelCycle 21 has a full core of GNF2 Fuel bundles..

The information in this table is maintained as legacy information as GE11 and GE14 fuels are is in the spent fuel pool.

- Based on cross-sectional area.

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PNPS-FSAR 3.3 REACTOR VESSEL INTERNALS MECHANICAL DESIGN 3.3.1 Power Generation Objective Reactor vessel internals (exclusive of fuel, control rods, and incore flux monitors) are provided to achieve the following objectives:

1. Maintain partitions between regions within the reactor vessel to provide proper coolant distribution, thereby allowing power operation without fuel damage due to inadequate cooling

2. Provide positioning and support for the fuel assemblies, control rods, incore flux monitors, and other vessel internals to assure that control rod movement is not impaired 3.3.2 Power Generation Design Basis

1. The reactor vessel internals shall be designed to provide proper coolant distribution during all anticipated normal operating conditions to allow power operation of the core without fuel damage.

2. The reactor vessel internals shall be arranged to facilitate refueling operations.

3. The reactor vessel internals shall include devices that permit assessment of the core reactivity condition during periods of low power and subcritical operations.

4. Adequate working space and access shall be provided to permit adequate inspection of reactor vessel internals.

3.3.3 Safety Design Basis

1. The reactor vessel internals shall be arranged to provide a floodable volume in which the core can be adequately cooled in the event of a breach in the nuclear system process barrier external to the reactor vessel.

2. Deflections and deformation of reactor vessel internals shall be limited to assure that the control rods and the core standby cooling system (CSCS) can perform their safety functions during abnormal operational transients and accidents.

3. The reactor vessel internals mechanical design shall assure that safety design bases 1 and 2 are satisfied in accordance with the loading criteria of Appendix C, so that the safe shutdown of the station and removal of decay heat are not impaired.

3.3.4 Description The reactor vessel internals are installed inside the reactor vessel to properly distribute the flow of coolant delivered to the vessel, to locate and support the fuel assemblies, and to provide an inner volume containing the core that can be flooded following a break in the nuclear system process barrier external to the reactor vessel. The reactor vessel internals described include the following components:

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PNPS-FSAR Core shroud Shroud stabilizers Shroud head and steam separator assembly Core support (core plate)

Top guide Fuel support pieces Control rod guide tubes Jet pump assemblies Steam dryers Feedwater spargers Core spray lines Vessel head cooling spray nozzle Differential pressure and liquid control line Incore flux monitor guide tubes The overall arrangement of the internals within the reactor vessel is shown on Figure 3.3-1. Table 3.3-1 gives detailed design data for the various reactor vessel internals.

Although not mandatory, the design of the reactor vessel internals is in accordance with the intent of Section III of the ASME Boiler and Pressure Vessel Code. The material used for fabrication of most of the reactor vessel internals is solution heat treated, unstabilized Type 304 austenitic stainless steel, conforming to ASTM specifications. Weld procedures and welders are qualified in accordance with the intent of Section IX of the ASME Boiler and Pressure Vessel Code. The floodable inner volume of the reactor vessel is shown on Figure 3.3-1. It is the volume inside the core shroud up to the level of the jet pump nozzles. The boundary of the inner volume consists of the following:

1. The jet pumps from the jet pump nozzles down to the shroud support

2. The shroud support, which forms a barrier between the outside of the shroud and the inside of the reactor vessel

3. The reactor vessel wall below the shroud support

4. The core shroud up to the level of the jet pump nozzles 3.3.4.1 Core Structure The core structure surrounds the active core of the reactor and consists of the core shroud, shroud head and steam separator assembly, core support, and top guide. This structure is used to form partitions within the reactor vessel, to sustain pressure differentials across the partitions, to direct the flow of the coolant water, and to laterally locate and support the fuel assembles, control rod guide tubes, and steam separators. Figure 3.3-2 shows the reactor vessel internal flow paths. The core structure is designed in accordance with the loading criteria of Appendix C.

3.3.4.1.1 Core Shroud The core shroud is a stainless steel cylindrical assembly which provides a partition to separate the upward flow of coolant through the core from the downward recirculation flow. This partition separates the core region from 3.3-2 Rev. 30 - Nov. 2015

PNPS-FSAR the downcomer annulus, thus providing a floodable region following a recirculation line break. The volume enclosed by the core shroud is characterized by three regions, each with a different shroud diameter. The upper shroud has the largest diameter and surrounds the core discharge plenum, which is bounded by the shroud head on top and the top fuel guide below. The central portion of the shroud surrounds the active fuel and forms the longest section of the shroud. This section has the intermediate diameter and is bounded at the bottom by the core support assembly. The lower shroud, surrounding part of the lower plenum, has the smallest diameter and at the bottom is welded to the reactor vessel shroud support. See Section 4.2, Reactor Vessel and Appurtenances Mechanical Design.

NRC Generic Letter GL94-03 was issued regarding intergranular stress corrosion cracking (IGSCC) of the circumferential girth welds for core shrouds in boiling water reactors (BWRs). Pilgrim chose to install a preemptive repair that provides structural replacement for all the shroud circumferential girth welds in lieu of continued inspection and analysis for these welds.

In RFO #10, a design change was implemented that provided a permanent repair for the core shroud in the Pilgrim reactor pressure vessel (RPV). This repair was classified as a repair by replacement per the ASME Code Section XI. The repair structurally replaces all of the shroud circumferential girth welds by installing vertical tie rod and lateral spring arrangement at each of four locations on the outside of the shroud in the jet pump annulus.

The shroud repair was designed to replace the structural function of the circumferential girth welds. These welds were required to maintain shroud structural integrity for providing vertical and horizontal support to the shroud head, core top guide, and core support plate, and to prevent core flow bypass to the downcomer region. The core top guide and core support plate act together to laterally support the fuel assemblies and maintain the correct fuel channel spacing to permit control rod insertion.

The repair consists of four shroud stabilizer assemblies, each comprised of a vertical tie rod with radially acting springs, installed 90 degrees apart around the perimeter of the shroud (reference Figure 3.3-10). Each stabilizer assembly consists of a tie rod, an upper bracket and a lateral spring, a lower tie rod extension and a lateral spring, two intermediate supports, and other minor parts. The tie rod provides the vertical load carrying ability from the stabilizer upper bracket to the RPV gusset attachment.

The upper spring provides radial load carrying ability from the shroud, at the core top guide elevation, to the RPV. The lower spring provides radial load carrying ability from the shroud, at the core support plate elevation, to the RPV. Two intermediate supports are provided for the tie rod so that its natural frequency is higher than the forcing frequency for flow induced vibration.

Each cylindrical section of the shroud is prevented from unacceptable horizontal motion by the stabilizers for all potential combinations of cracking in the circumferential welds. The upper stabilizer assembly restrains the shroud upper ring, upper cylinder, top guide support ring, and central upper cylinder. The intermediate supports restrain the central mid-cylinder and the upper core support plate ring. The lower stabilizer assembly restrains the central lower cylinder, the core support plate ring, and lower cylinder.

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PNPS-FSAR In addition, core plate wedge devices were installed in the annular gap between the top of the core plate and the inside of the shroud. Two such wedges were installed at the same azimuth locations as the four shroud stabilizers (total of eight wedges). These wedges prevent relative motion between the core plate and the shroud.

As a result of the shroud repair, there is no theoretical need for any structural integrity in the circumferential girth welds in the shroud (referred to as welds H1 through H10). The repair design is based on the possibility that these welds all have 360 degree through-wall cracks. The shroud stabilizer design also considered that welds H1 through H10 were intact as well as other bounding cases that produce greater shroud stresses or greater stress on the new shroud repair hardware.

The shroud stabilizer springs are made from nickel-chrome-iron Inconel Alloy X-750. The tie rod material is Type XM-19 austenitic stainless steel. Other small parts of the stabilizers are made from Type 316L stainless steel.

There are no welded components in the new shroud hardware. The new materials are highly resistant to intergranular stress corrosion cracking (IGSCC) compared to welded Type 304 stainless steel and are at relatively low stress levels during normal operating conditions. As a result, the principal contributors to IGSCC are minimized in this design.

3.3.4.1.2 Shroud Head and Steam Separator Assembly The shroud head and steam separator assembly is bolted to the top of the upper shroud to form the top of the core discharge plenum. This plenum provides a mixing chamber for the steam water mixture before it enters the steam separators. The individual stainless steel axial flow steam separators shown on Figure 3.3-3 are attached to the top of standpipes which are welded into the stainless steel shroud head.

The steam separators have no moving parts. In each separator, the steam water mixture rising through the standpipe passes vanes which impart a spin to establish a vortex separating the water from the steam. The steam exits from the top of the separator and rises up to the dryers. The separated water exits from under the separator cap and flows out between the standpipes, draining into the recirculation flow downcomer annulus.

3.3.4.1.3 Core Support (Core Plate)

The core support assembly consists of a circular stainless steel plate stiffened with a rim and beam structure. Perforations in the plate provide lateral support and guidance for the control rod guide tubes, peripheral fuel support pieces, and incore flux monitor guide tubes, and locations for startup neutron sources. The entire assembly is bolted to a support ledge between the central and lower portions of the core shroud after proper positioning has been assured by alignment pins which fit into slots in the ledge.

Core support plugs have been fitted into bypass flow holes in the core support plate to limit flow and thus reduce movement of the incore neutron monitors to acceptable levels. The bases used in the development of the plug design are discussed in the SR on the Pilgrim Channel Wear Investigation(1) and the second reload licensing submittal(9) Evaluations of the mechanical performance are presented in References 2, 8 and 10.

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PNPS-FSAR 3.3.4.1.4 Top Guide The top fuel guide is formed by a series of stainless steel beams joined at right angles to form square openings. Each opening provides lateral support and guidance for four fuel assemblies. Holes are provided at the bottom of the beams to anchor the incore flux monitor guide tubes and neutron sources.

The top fuel guide is positioned by alignment pins which fit into radial slots in the top of the shroud.

3.3.4.2 Fuel Support Pieces The fuel support pieces, shown on Figure 3.3-4, are of two basic types -

peripheral and four lobed. The peripheral fuel support pieces, which are welded to the core support assembly, are located at the outer edge of the active core and are not adjacent to control rods. Each peripheral fuel support piece will support one fuel assembly and contains a replaceable orifice assembly designed to assure proper coolant flow to the fuel assembly. The four lobed fuel support pieces will each support four fuel assemblies, and are provided with orifice plates to assure proper coolant flow distribution to each fuel assembly. The four lobed fuel support pieces rest in the top of the control rod guide tubes and are supported laterally by the core support. The control rods pass through slots in the center of the four lobed fuel support pieces. A control rod and the four fuel assemblies which immediately surround it represent a core cell. See Section 3.2, Fuel Mechanical Design.

3.3.4.3 Control Rod Guide Tubes The control rod guide tubes, located inside the vessel, extend from the top of the control rod drive (CRD) housings up through holes in the core support.

Each tube is designed as the lateral guide for a control rod and as the vertical support for a four lobed fuel support piece and the four fuel assemblies surrounding the control rod. The bottom of the guide tube is supported by the CRD housing which in turn transmits the weight of the guide tube, fuel support piece, and fuel assemblies to the reactor vessel bottom head. See Section 4.2, Reactor Vessel and Appurtenances Mechanical Design. A thermal sleeve is inserted into the CRD housing from below and is rotated to lock the control rod guide tube in place. A key is inserted into a locking slot in the bottom of the CRD housing to hold the thermal sleeve in position.

3.3.4.4 Jet Pump Assemblies The jet pump assemblies are located in two semicircular groups in the downcomer annulus between the core shroud and the reactor vessel wall. Each stainless steel jet pump consists of a driving nozzle, suction inlet, throat or mixing section, and diffuser. See Figure 3.3-5. The driving nozzle, suction inlet, and throat are joined together as a removable unit and the diffuser is permanently installed. High pressure water from the recirculation pumps is supplied to each pair of jet pumps through a riser pipe welded to the recirculation inlet nozzle thermal sleeve. See Section 4.3, Reactor Recirculation System. A riser brace is welded to cantilever beams extending from pads on the reactor vessel wall.

The jet pump diffuser is a gradual conical section changing to a straight cylindrical section at the lower end. The diffuser is supported vertically 3.3-5 Rev. 30 - Nov. 2015

PNPS-FSAR by the shroud support, a flat ring which is welded to the reactor vessel wall, and to which is welded the shroud support cylinder. The joint between the throat and the diffuser is a slip fit. A metal to metal spherical to conical seal joint is used between the nozzle entry section and riser with firm contact maintained by a clamp arrangement which fits under posts on the riser, and utilizes a bolt to provide a downward force on a pad on top of the nozzle entry section. The inlet-mixer section is supported laterally by a bracket attached to the riser pipe. The bracket assembly has swing gates with an adjustable wedge and set screws to provide a mid-span piping restraint for the inlet-mixers. Observed gaps between the restrainer bracket set screws and the inlet-mixers as well as swing gates in which the lock pin is not seated have been evaluated and acceptance criteria for these conditions have been incorporated into the jet pump design documents, drawings, and the reactor in-vessel inspection program. Where necessary, replacement restrainer bracket swing gates and restrainer bracket auxiliary wedges will be installed.

The replacement restrainer bracket swing gates and restrainer bracket auxiliary wedges were designed and fabricated in accordance with GE Specifications that are consistent with the original design requirements for all reactor internals. The fit-up and function of these replacement swing gates is identical to the original design and they are fabricated from upgraded material. Also, instead of a welded keeper, the replacement swing gates have a weldless style keeper with a mechanical ratchet lock, which will reduce installation time.

The auxiliary wedges fit around the set screws and provide a solid load path between the restrainer bracket and the inlet-mixer. The wedges are designed to self-adjust to accommodate alignment variations in the system and to compensate for any wear after installation. These new components were designed to maintain the jet pumps within their original design requirements and do not have any adverse effect on the overall function of the jet pumps.

The materials used for the new components are Type 316 stainless steel with a maximum carbon content of 0.02% and Ni-Cr-Fe Inconel Alloy X-750. These materials are resistant to Intergranular Stress Corrosion Cracking (IGSCC) in the BWR environment. No Stellite or cobalt hardfacing or alloys are used in the construction.

The potential effects of Thermal Power Optimization (TPO, 2028 MWt maximum normal operating power) on jet pump integrity were considered and found to be acceptable. There is no increase in core flow or recirculation jet pump drive flow associated with TPO conditions.

The cumulative effects of potential vibratory fatigue on the jet pumps were investigated and it was determined that the riser brace is the limiting component. The design basis criteria for the jet pump restrainer bracket maximum allowable set screw gap is based on riser brace fatigue. The allowable deflection of the jet pump riser brace that adversely affects the cumulative fatigue usage for the riser brace. Since this criteria is based on a simple maximum deflection, it is independent of the source, amplitude, or frequency for the equivalent dynamically applied load. The alternating stresses associated with vibratory fatigue within the allowable deflection criteria thereby do not adversely affect the cumulative fatigue usage for the riser brace.

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PNPS-FSAR The inlet mixer section of each jet pump is held in place by a beam-bolt assembly located in the riser transition piece. The beam ends are positioned within packets in the transition piece, and the beam load is transferred to the elbow through a bolt located in the center of the beam. See view D-D of Figure 3.3-5 (BECo MIE44-1). A preload is applied to the beam when it is installed to ensure enclosure integrity of the joint between the riser and the inlet mixer assemblies. Ultrasonic testing in mid-1979 and early 1980 detected cracking in some beams in certain BWR/3s. To preclude failure by intergranular stress corrosion cracking which has been observed in jet pump beams in some BWR plants, the existing Pilgrim jet pump beams that were of BWR-3 design have been replaced by improved BWR-4 beam bolt assemblies.

These replacement beam bolt assemblies are different in four aspects:

o The beam depth has been increased o The Inconel material heat treatment has been changed o The beam bolt material has been changed to 316L o The retaining device design has been changed Beams reflecting these design changes are not expected to crack.

These improvements are discussed further in the GE NEDE report of December 1981 (Reference 5), which also presents a recommended schedule for inservice inspection of the replacement beams.

3.3.4.5 Steam Dryers The steam dryers remove moisture from the wet steam which exits from the steam separators. The wet steam leaving the steam separators flows across the dryer vanes and the moisture flows down through collecting troughs and tubes to the water above the downcomer annulus. See Figure 3.3-6. A skirt extends down into the water to form a seal between the wet steam plenum and the dry steam flowing out the top of the dryers to the steam outlet nozzles. Vertical guide rods facilitate positioning the dryer and shroud head in the vessel. The dryers rest on steam dryer support brackets attached to the reactor vessel wall, and are restricted from lifting by steam dryer hold-down brackets, which are attached to the reactor vessel closure head over the top of the steam dryer lifting lugs when the head is in place.

3.3.4.6 Feedwater Spargers The feedwater spargers are stainless steel headers located in the mixing plenum above the downcomer annulus. A separate sparger is fitted to each of four feedwater nozzles and is shaped to conform to the curve of the vessel wall. Sparger end brackets are attached to vessel brackets to support the weight of the spargers, and wedge blocks position the spargers away from the vessel wall. Feedwater flow enters the center of the spargers and is discharged through top mounted elbows, each with a converging discharge nozzle. The cooler feedwater blows downward to mix with the downcomer flow from the steam separators before it contacts the vessel wall. The feedwater also serves to collapse any steam voids and to subcool the water flowing to the jet pumps and recirculation pumps.

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PNPS-FSAR 3.3.4.7 Core Spray Lines The two 100 percent capacity carbon steel core spray lines separately enter the reactor vessel through the two core spray nozzles as shown on Figure 4.2-

2. See Section 4.2, Reactor Vessel and Appurtenances Mechanical Design. The lines divide immediately inside the reactor vessel. The two halves are routed to opposite sides of the reactor vessel and are supported by clamps attached to the vessel wall. The header halves are then routed downward into the downcomer annulus and pass through the upper shroud immediately below the flange. The flow divides again as it enters the center of the semicircular sparger ring which is routed halfway around the inside of the upper shroud.

The ends of the two sparger rings for each line are supported by slip-fit brackets designed to accommodate thermal expansion of the rings. The header routing and supports are designed to accommodate differential movement between the shroud and the vessel. The other core spray line is identical except that the header enters the opposite side of the vessel and the sparger rings are at a slightly different elevation in the shroud. The proper spray distribution pattern is provided by a combination of distribution nozzles pointed radially inward and downward from the sparger rings. See Section 6, Core Standby Cooling Systems.

3.3.4.8 Deleted 3.3.4.9 Differential Pressure and Liquid Control Line The stainless steel differential pressure and liquid control line serves a dual function within the reactor vessel. It injects liquid control solution into the coolant stream as discussed in Section 3.8, Standby Liquid Control System, and senses the differential pressure across the core support assembly, as discussed in Section 4.2, Reactor Vessel and Appurtenances Mechanical Design. The line enters the reactor vessel at a point below the core shroud as two concentric pipes. In the lower plenum, the two pipes separate. The inner pipe terminates near the lower shroud with a perforated length below the core support assembly. It is used to sense the pressure below the core support during normal operation and to inject liquid control solution when required. This location assures that good mixing and dispersion are facilitated. The use of the inner pipe also reduces the thermal shock to the vessel nozzle should the Standby Liquid Control System (SLCS) ever be used.

The outer pipe terminates immediately above the core support assembly and senses the pressure in the region outside the fuel assembly channels.

3.3.4.10 Incore Flux Monitor Guide Tubes The incore flux monitor guide tubes are welded to the top of the incore flux monitor housings in the lower plenum and extend up to the top of the core support. See Section 4.2, Reactor Vessel and Appurtenances Mechanical Design.

The power range detectors for the power range monitoring units and the dry tubes for the source range monitoring/intermediate range monitoring (SRM/IRM) detectors are inserted through the guide tubes, and are held in place below the top guide by spring tension. A latticework of clamps, tie bars, and spacers give lateral support and rigidity to the guide tubes. The bolts and clamps are welded after assembly to prevent loosening during reactor operation.

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PNPS-FSAR 3.3.4.11 Startup Neutron Sources The startup neutron sources are required during the first startup of the reactor. At the end of the first operating cycle, the neutron sources can be removed since the reactor has adequate neutron source in the form of fuel carried to the subsequent operating cycle. Neutron sources have been removed after four operating cycles since experience on other BWR plants has shown that startup neutron source holders left in the core longer than one operating cycle have a tendency to become brittle and are subject to cracking and separation. Cores with an average exposure of 5,000 MWd/t will emit enough neutrons to permit startup following a 120 day outage. Higher core average exposure will allow longer outage periods. For an extended outage, where neutron startup sources would be required, new antimony rods would have to be irradiated and installed in new holders.

To allow full core discharge and reloading without the startup neutron sources and without meeting the activity requirements of the fuel, a spiral reloading and unloading pattern is followed.

3.3.4.12 Surveillance Holders The surveillance sample holders are welded baskets containing impact and tensile specimen capsules. See Section 4.2, Reactor Vessel and Appurtenances Mechanical Design. The baskets hang from brackets on the inside wall of the reactor vessel at the midheight of the active core, and at radial positions chosen to expose the specimens to the same environment and maximum neutron fluxes experienced by the reactor vessel itself, while at the same time avoiding jet pump removal interference or damage.

3.3.5 Vibration 3.3.5.1 Vibration Analysis A vibration analysis of reactor vessel internals was performed in the design to determine any potential hydraulically induced equipment vibrations and to check that the structures do not fail due to fatigue. The structures were analyzed for natural frequencies, mode shapes, and vibrational magnitudes that could lead to fatigue at these frequencies. The cyclic loadings were evaluated using the cyclic stress criteria of the ASME Code,Section III as a guide.

3.3.5.2 Vibration Testing The criteria for selecting BWR plants to be vibration tested is to test each new plant which contains a significant design departure from a plant that has been previously vibration tested (e.g., the first plant of each standard plant design). Since all jet pump plants are geometrically quite similar, it is not expected that there will be a great deal of difference in the vibration response of the various plants of approximately the same size. However, where vessel diameters changed significantly, or where flow velocities increased significantly, vibration tests were scheduled.

3.3-9 Rev. 30 - Nov. 2015

PNPS-FSAR Depending on the reactor vessel manufacturer, BWRs are equipped with two types of shroud support structures. Reactors such as Dresden 2 and 3, Peach Bottom 2 and 3, Brunswick, and Zimmer are equipped with a stilt-type shroud support.

Reactors such as Fermi 2, Cooper, Millstone 1, and Pilgrim are equipped with a gusset-type shroud support. Pilgrim differs from Millstone 1 in the area of jet pump riser support, both at the inlet thermal sleeve attachment and at the riser brace elevation. Because of these design differences, confirmatory vibration tests were conducted on Pilgrim plant to ensure that the flow induced vibrations do not jeopardize the integrity of internal structure of the reactor vessel. This program supplemented the first of a kind data obtained from the Millstone 1 tests. The vessel internal components monitored were:

1. Shroud - to measure horizontal displacements

2. Jet Pump Assembly Riser Brace - to measure strain in the braces of the riser pipe for two jet pumps

3. Jet Pumps - to measure horizontal radial motion of two pumps with respect to the reactor pressure vessel The vibration of the various reactor internal components were detected by sensors mounted directly on those components. The vibration amplitude signals from these sensors were amplified and displayed by an oscillograph type recorder and also recorded on magnetic tape. Data were obtained from operable sensors during the power test program and periodically during steady state operation throughout the first operating cycle.

The operating conditions established for the vibration measurements during the power test program are listed below. These operating conditions are indicative of the range of operating conditions applicable for variations in vibration excitations. Actual test points are designed to cover this range of variations in steam and coolant flow.

Operating Conditions

1. 75 percent Thermal Power Line

2. 100 percent Thermal Power Line Measurements were monitored for each of the above power levels at the following conditions:

1. Four approximately equally spaced flow points from minimum flow to 100 percent flow

2. With 100 percent core flow trip Pump A

3. With Pump B only operating, open equalizer

4. With 100 percent core flow trip Pump B

5. With Pump A only operating, open equalizer

6. With 100 percent core flow trip both pumps simultaneously 3.3-10 Rev. 30 - Nov. 2015

PNPS-FSAR 3.3.5.3 Increased Core Flow Vibration Analysis The increased core flow vibration analysis was performed by analyzing the startup test vibration data for Millstone 1 and Pilgrim. The vibration levels for 100% flow operation were conservatively extrapolated by the ratio of flow velocity squared for each of the instrumented reactor internal components.

The jet pump riser braces showed the highest vibration response (32.4% of acceptance criteria) at 112.5% of rated core flow. In addition to analyzing the startup test data, an evaluation of the riser brace structural natural frequency was performed to determine if an excitation phenomena exists because of increased recirculation pump speed (blade passing frequency). The results show the riser brace natural frequency is high enough (169% of blade passing) to avoid such an excitation. This riser brace excitation would be most limiting as a result of an increase in pump speed and flow. Based on the results of these analyses and a review of test data it is apparent that operation with increased core flow does not result in flow-induced vibrations of reactor internals which exceed acceptable mechanical design limits (Reference 6).

3.3.6 Safety Evaluation 3.3.6.1 Evaluation Methods To determine that the safety design basis is satisfied, the responses of the reactor vessel internals to loads imposed during normal operation, abnormal operational transients, and accidents are examined. Determination of these effects on the ability to insert control rods, cool the core, and flood the inner volume of the reactor vessel are made. The various structural loading combinations assumed to be imposed on the reactor vessel internals are as described in Appendix C for Class I equipment. These loading combinations include upset loads, emergency loads, and faulted loads.

The ASME Boiler and Pressure Code,Section III for Class A vessels, is used as a guide to determine limiting stress intensities and cyclic loadings for the reactor vessel internals. For those components for which buckling is not a possible failure mode and stresses are within those stated in the ASME Code, it is concluded that the safety design basis is satisfied. For those components, for which either buckling is a possible failure mode or stresses exceed those presented in the ASME Code, either the elastic stability of the structure or the resulting deformation is examined to determine if the safety design basis is satisfied.

3.3.6.2 Plant Conditions All events that the plant might credibly experience are evaluated to establish a design basis for plant equipment. These events are divided into four plant conditions. The plant conditions described in the following paragraphs are based on event probability (i.e., frequency of occurrence) and correlated design conditions as defined in the ASME B&PV Code,Section III.

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PNPS-FSAR 3.3.6.2.1 Normal Condition Normal conditions are any conditions in the course of system startup, operation in the design power range, normal hot standby (with condenser available), and system shutdown other than upset, emergency, faulted, or testing. For this condition, structural loadings on the reactor vessel internals are evaluated at 100% power and 100% recirculation flow.

3.3.6.2.2 Upset Condition Upset conditions are any deviations from normal conditions which are anticipated to occur often enough that the design should include a capability to withstand the conditions without operational impairment. The upset conditions include those transients which result from any single operator error or control malfunction, transients caused by a fault in a system component requiring its isolation from the system, and transients due to loss of load or power. For this condition, the analysis is based on a reactor power corresponding to 105% of related steam flow and 100% recirculation flow.

3.3.6.2.3 Emergency Condition Emergency conditions are those deviations from normal conditions which require shutdown to correct the conditions or to repair damage in the reactor pressure coolant boundary (RCPB). These conditions have a low probability of occurrence, but are included to provide assurance that no gross loss of structural integrity results as a concomitant effect of any damage developed in the system. Emergency condition events include, but are not limited to, transients caused by one or more of the following: a multiple valve blow down of the reactor vessel; loss of reactor coolant from a small break or crack which does not depressurize the reactor system, nor result in leakage beyond normal makeup system capacity, but which does require the safety functions of containment isolation and reactor shutdown. The reactor is analyzed at core power corresponding to 102% of rated power and 100% recirculation flow. For Pilgrim the limiting event for this plant condition is an unintentional actuation of the Automatic Depressurization System (ADS). This event results in a sudden depressurization of the reactor system, similar to but less severe than the design basis LOCA.

3.3.6.2.4 Faulted Condition Faulted conditions are those combinations of conditions associated with extremely unlikely postulated events, with consequences such that the integrity and operability of the system may be so impaired that considerations of public health and safety are involved. Faulted conditions encompass events that are postulated because their consequences include the potential for releasing significant amounts of radioactive material. These postulated events are the most drastic that must be designed against, and thus represent limiting design bases. Faulted condition events include, but are not limited to, one or more the following: a control rod drop accident; a fuel-handling accident; a main steam line break; a recirculation loop break; the combination of small break/large break accident.

3.3-12 Rev. 30 - Nov. 2015

PNPS-FSAR For Pilgrim, the reactor is analyzed at two states; 1) 100% recirculation flow and 102% of rated power and 2) 110% recirculation flow and 23% of rated power (the lowest power at which 110% recirculation flow is permissible). The limiting events are an instantaneous circumferential break of a main steam line upstream of the main steam line flow limiters and the instantaneous circumferential break of a recirculation line.

3.3.6.2.5 Correlation of Plant Conditions with Event Probability The probabilities per reactor year, P, of normal, upset, emergency and faulted events are listed below. These probabilities can be used to identify the appropriate plant condition for any hypothesized event or sequence of events.

Events Encountered (probability per Plant Conditions reactor year)

Normal (planned) 1.0 Upset (moderate probability) 1.0>P>10-2 Emergency (low probability) 10-2>P>10-4 Faulted (extremely low probability) 10-4>P>10-6 3.3.6.3 Specific Events To Be Evaluated Examination of the spectrum of conditions for which the safety design basis must be satisfied reveals four significant events:

1. Loss of coolant accident: This accident is a break in a recirculation line. The accident results in some pressure differentials across the reactor vessel internals which exceed normal loads

2. Steam line break accident: This accident is a break in one main steam line between the reactor vessel and the flow restrictor. The accident results in significant pressure differentials across the reactor vessel internals

3. Thermal shock: The most severe thermal shocks to the reactor vessel internals occur when low pressure coolant injection (LPCI) operations or high pressure coolant injection (HPCI) operations reflood the reactor vessel inner volume following either a recirculation line break or a main steam line break. See Section 6, Core Standby Cooling System

4. Earthquake: This event subjects the reactor vessel internals to significant forces as a result of ground motion. These seismic loads are combined with other transients loads such as ADS loads or LOCA loads to demonstrate the structural integrity of the reactor components under such combined events.

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PNPS-FSAR Analysis of other conditions existing during normal operation, abnormal operational transients, and accidents show that the loads affecting the reactor vessel internals are less severe than the four postulated events.

Hence, the design bases for structural stress evaluations are based on the above limiting events.

3.3.6.4 Pressure Differentials During Rapid Depressurization A digital computer code (Reference 7) is used to analyze the transient conditions within the reactor vessel following the recirculation line break accident and the steam line break accident. The analytical model of the vessel consists of nine spatial nodes with their boundaries located at interfaces defined by physical restrictions in the reactor system. Each node is connected to the necessary adjoining nodes by flow paths having the required resistance and inertial characteristics. The reactor system model is designed for short-term transients where there is rapid system depressurization. Its calculations typically include the first 30 to 45 seconds of the blowdown. The program solves the energy and mass conservation equations for each node, giving the depressurization rates and pressure in the various regions of the reactor. The flow resistances are evaluated from the irreversible pressure drops associated with known flow rates. Momentum effects are considered for all flow paths. Figure 3.3-7 shows the nine reactor nodes in the model. They are: 1) the subcooled lower plenum, 2) the core, 3) the upper plenum, 4) the mixing region, 5) the downcomer, 6) and 7) the two recirculation loops, 8) the core bypass region, and 9) the steam dome.

This computer code is approved for use in ECCS conformance evaluation under 10CFR 50, Appendix K. In order to adequately predict the blowdown pressure effect on individual reactor assembly components, three features are included in the model that are not applicable to the ECCS analysis and are, therefore, not described in Reference 5. These additional features are:

1. The liquid level in the steam separator region, and in the annulus between the dryer skirt and the pressure vessel, is tracked to determine more accurately the flow and mixture quality in the steam dryer and the steam line.

2. The flow path between the bypass region and the shroud head is more accurately modeled for a steam line break since the fuel assembly pressure differential is influenced by flashing in the guide tubes and the bypass region. In the ECCS analysis, the momentum equation is solved in this flow path but its irreversible loss coefficient is conservatively set at an arbitrary low value.

3. The enthalpies in the guide tubes and the bypass region are calculated separately since the fuel assembly differential pressure is influenced by flashing in these regions. In the ECCS analysis, these regions are lumped together.

3.3-14 Rev. 30 - Nov. 2015

PNPS-FSAR 3.3.6.5 Recirculation Line Break 3.3.6.5.1 Accident Definition This accident is the same design basis LOCA as described in Section 6, Core Standby Cooling Systems, and Section 14, Station Safety Analysis. It is assumed that an instantaneous, circumferential break occurs in one recirculation loop (the largest liquid break).

As detailed in Section 3.3.6.5.1, the vessel depressurization rate is less for liquid breaks (recirculation line breaks) than for steam breaks (steam line breaks). Therefore the postulated recirculation line break accident is not the design basis for internal pressure loads. Maximum loads occur following the postulated steam line break and are discussed in Section 3.3.6.5.

3.3.6.5.2 Jet Pump Joints An analysis has been performed to evaluate the potential leakage from within the floodable inner volume of the reactor vessel during the recirculation line break and subsequent reflooding. The two possible sources of leakage are:

1. Jet pump throat to diffuser joint

2. Jet pump nozzle to riser joint The jet pump to shroud support joint is welded and therefore is not a possible source of leakage. The throat to diffuser joints for all jet pumps leak no more than a total of 225 gal/min. The jet pump nozzle to riser joint by analysis is shown to leak no more than a total of 225 gal/min. The jet pump nozzle to riser joint analysis is shown to leak no more than 582 gal/min for the pumps through which the vessel is being flooded.

The summary of maximum leakage is then:

Total leakage through all throat to diffuser joints . . . . . . . . . . . .. . . . 225 gpm Total leakage through all operational nozzle to riser joints. . . . . . . . . . . 582 gpm TOTAL MAXIMUM RATE .. 807 gpm CSCS capacity is sized to accommodate 3,000 gal/min leakage at these locations. It is concluded that the reactor vessel internals retain sufficient integrity during the recirculation line break accident to allow reflooding the inner volume of the reactor vessel.

3.3-15 Rev. 30 - Nov. 2015

PNPS-FSAR 3.3.6.6 Steam Line Break Accident 3.3.6.6.1 Accident Definition The analysis of this accident assumes an instantaneous circumferential break of one main steam line between the reactor vessel and the main steam line flow restrictor. This is not the same accident as described in Section 14, Station Safety Analysis, because greater differential pressures across the reactor vessel internals result from this accident. It is noteworthy that this accident results in greater loading of the reactor vessel internals and a higher depressurization rate than does the recirculation line break. The steam line break accident is more severe because the depressurization rate is proportional to the mass flow rate and the difference between the fluid escape enthalpy, he, and the saturated water enthalpy, hf. However, mass flow rate is inversely proportional to escape enthalpy he; therefore, depressurization rate is proportional to 1 - hf/he. Consequently, depressurization rate decreases as he decreases. That is, depressurization is less for mixture flow (recirculation line break) than for steam flow (steam line break).

A steam line break upstream of the flow restrictors produces a larger blowdown area, and thus a faster depressurization rate, than a break downstream of the restrictors. A faster depressurization rate results in greater pressure differentials across the reactor internal structures.

To add conservatism to the analysis it is assumed that only steam is discharged through the break; this maximizes the vessel depressurization rate and the resultant loadings on the vessel internals.

The steam line break accident produces significantly higher pressure differentials across the reactor internal structures than does the recirculation line break. This fact results from the greater reactor depressurization rate associated with the steam line break. Therefore, the steam line break is the design basis accident for internal pressure differentials.

3.3.6.6.2 Effects of Initial Reactor Power and Core Flow The maximum internal pressure loads can be considered to be composed of two parts: a steady-state part and a transient part. For a given plant, the core flow and the core power are the two major factors which influence the reactor internal pressure differentials. The core flow essentially affects only the steady-state part. For a fixed power, the greater the core flow, the larger the steady-state pressure differentials. The core power affects both the steady-state and the transient parts. As the power is decreased, there is less steam generation rate and, consequently, the steady-state core pressure differential is less. However, less voiding in the core also means that less steam is generated to replace steam flow out of the broken steam line, thus increasing the depressurization rate and the transient part of the maximum pressure load. As a result, the total loads on some components are higher at low power.

3.3-16 Rev. 30 - Nov. 2015

PNPS-FSAR To ensure that the calculated pressure differences are bounding, an analysis is conducted at a low power/high recirculation flow combination in addition to the standard safety analysis combination of high power/rated recirculation flow. The power chosen for the low power/high recirculation flow combination is the minimum value permitted by the recirculation system controls at rated recirculation drive flow (that is, the drive flow necessary to achieve rated core flow at rated power). This condition maximizes those loads which are inversely proportional to power. It must be noted that this condition, while possible, is unlikely; the reactor generally operates at or near full power and, at reduced power, high core flow is neither required nor desirable.

3.3.6.7 Reactor Internals Pressure Differences at Normal, Upset, Emergency and Faulted Condition Table 3.3-2 summarizes the pressure differentials across the reactor internal components for the limiting plant configuration/transient for normal, upset, emergency and faulted conditions. As shown, the maximum pressure loads acting on the reactor internals result from a steam line break (a faulted condition).

On most components the loads are maximum when operating at the minimum power associated with the maximum core flow. This observation is substantiated by the analytical comparison of liquid breaks versus steam breaks, and by the investigation of the effects of core power and core flow.

As discussed earlier, it is possible but not probable that the reactor is operating at this rather abnormal condition of minimum power and maximum core flow. More realistically, the reactor is at or near a full power condition.

Thus, use of the pressure loads associated with this abnormal condition, where maximum, introduces additional conservatism in the analysis.

The maximum differential pressures in Table 3.3-2 are used, in combination with other assumed structural loads as described in Appendix C, to determine the total loading on the various reactor vessel internals. The various internals are then examined to assess the extent of deformation and collapse, if any. Of particular interest are the responses of the core support assembly, the guide tubes, and the channels around the fuel bundles.

Reference 12 reevaluated pressure differences across reactor internals for maximum extended load line limit (MELLL) region operation. The results were bound by the design limits and have adequate design margin for operation in the MELLL region.

3.3.6.7.1 Core Support The core support assembly sustains the maximum net force, which is an upward force following the steam line break accident, so the effect on the core support holddown bolts must be established. Analysis shows that the applied stresses are about 1/2 of yield strength for the bolts, indicating that the core support can withstand the effects of the accident.

3.3-17 Rev. 30 - Nov. 2015

PNPS-FSAR In RFO #10 a reactor shroud repair was implemented as described in Section 3.3.4.1.1. The design loads for the shroud stabilizers included seismic plus main steam line break accidents. The effect of the shroud repair on the reactor pressure vessel was analyzed and the results included in a stress report that is an addendum to the original design stress report for the reactor pressure vessel. The shroud stabilizers change the points of application of the forces applied to the vessel from the shroud. There are new forces applied to the pressure vessel from the shroud stabilizer springs and a change in the forces applied from the existing shroud support plate and gussets to the vessel wall. These new and revised forces were combined with the forces defined in the original vessel design stress report and analyzed per the original reactor pressure vessel Code of Construction. The analysis concluded that all stresses within the reactor pressure vessel remain within their allowable limits.

3.3.6.7.2 Guide Tubes Because of the externally applied pressure, the guide tube is examined for collapse. As in the case of the lower shroud and core support assembly, a number of formulae are utilized to calculate the collapse pressure.

Unfortunately, the Winderberg test is not applicable because the geometry of the guide tube is outside of the test range. Use of ASME curves indicates the extreme sensitivity to wall thickness. For the minimum wall thickness for a 10 in Schedule 10 pipe, the ASME curves give a collapse load of 45 psi. Using the average wall thickness, the collapse pressure is increased to over 70 psi.

Using empirical relations for tubes over the critical length, the calculated collapse pressure is over 100 psi. The ASME curves calculate that the collapse pressure is reached at 54 psi for a wall thickness of 0.150 in, which is 6 mils over the minimum for a 10 in Schedule 10 pipe. The calculated total loading for the guide tubes is considerably below the collapse loading, and it can be concluded that no failure occurs. The analysis also indicates that the control rods are 70 percent to 80 percent inserted at the time the maximum external pressure is applied to the guide tubes.

3.3.6.7.3 Fuel Channels The BWR fuel channel performs the following functions:

a. forms the fuel bundle flow path outer periphery for bundle coolant flow;

b. provides surfaces for control rod guidance in the reactor core;

c. provides structural stiffness to the fuel bundle during lateral loadings applied from fuel rods through the fuel spacers;

d. minimizes, in conjunction with the finger springs and bundle lower tie plate, coolant bypass flow at the channel/lower tie plate interface;

e. transmits fuel assembly seismic loadings to the top guide and fuel support of the core internal structures; 3.3-18 Rev. 30 - Nov. 2015

PNPS-FSAR

f. provides a heat sink during loss-of-coolant accident (LOCA); and

g. provides a stagnation envelope for in-core fuel slipping.

The channel is open at the bottom and makes a sliding seal fit on the lower tie plate surface. The upper end of the fuel assemblies in a four-bundle cell are positioned in the corners of the cell against the top guide beams by the channel fastener springs. At the top of the channel, two diagonally opposite corners have welded tabs, one of which supports the weight of the channel from a threaded raised post on the upper tie plate. One of these raised posts has a threaded hole. The channel is attached using the threaded channel fastener assembly, which also includes the fuel assembly positioning spring. Channel-to-channel spacing is provided for by means of spacer buttons located on the upper portion of the channel adjacent to the control rod passage area.

Reference 4 provides a complete description and analytical results for channels supplied by the General Electric Company (GE). The channels supplied by other vendors have been evaluated and are predicted to behave in a similar fashion as GE supplied channels. NSF is also zirconium alloy containing a approx. 1% of nickel, Tin, and Iron. Channels made from NSF are introduced into PNPS core as a part of a special Lead Use Channel Program approved by the NRC (Reference 16) for up to 8% of the core in Cycle 21 (Reference 17). NSF is known to be more resistant to bowing compared to Zr-2 and Zr-4 alloy channels.

3.3.6.8 Thermal Shock The most severe thermal shock effects for the reactor vessel internals result from the reflooding of the reactor vessel inner volume. For some vessel internals, the limiting thermal shock occurs from LPCI operation and for others HPCI operation is controlling, dependent upon the location of the component. These effects occur as a result of any large LOCA, such as the recirculation line break and the steam line break accidents previously described.

The locations are as follows:

1. Shroud support plate The peak strain resulting in the shroud support plate is about 6.5 percent.

This strain is higher than the 5.0 percent strain permitted by the ASME Code,Section III, for 10 cycles, but the 1 cycle, peak strain corresponds to about 6 allowable cycles of an extended ASME Code curve as applied to less than 10 cycles.

Figure 3.3-9 illustrates both the ASME Code curve and the basic material curves from which it was established (with the safety factor of 2 on strain or 20 on cycles, whichever is more conservative). The extension of the ASME Code curve represents a similar criteria to that used in the ASME Code,Section III, but applied to fewer than 10 cycles of loading. For this Type 304 stainless steel material, a 10 percent peak strain corresponds to one allowable cycle of loading. Even a 10 percent strain for a single cycle loading represents a very conservative suggested limit because this has a large safety margin below the point at which even minor cracking is expected to begin. Because the conditions which lead to the calculated peak strain of 6.5 percent are not expected to occur even once during the entire reactor lifetime, the peak strain is considered tolerable.

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2. Shroud to shroud support plate discontinuity The results of the analysis of the shroud to shroud support plate discontinuity region are as follows:

Amplitude of alternating stress. 180,000 psi Peak strain. 1.34 percent The ASME Code,Section III, allows 220 cycles of this loading, thus no significant deformations result.

3. Shroud inner surfaces at highest irradiation zone By the end of station life, the peak thermal shock stress is 155,700 psi, corresponding to a peak strain of 0.57 percent. The shroud material is Type 304 stainless steel, which is not significantly affected by irradiation. The material does experience a loss in reduction of area. Because reduction of area is the property which determines tolerable local strain, irradiation effects can be neglected. The peak strain resulting from thermal shock at the inside of the shroud represents no loss of integrity of the reactor vessel inner volume.

3.3.6.9 Earthquake The seismic loads on the RPV and internals, due to horizontal motion, are based on a dynamic analysis of the RPV and internals model. Seismic analysis is performed by coupling this lumped mass model of the RPV, and internals with the building soil structure model to determine the system natural frequencies and mode shapes. The relative displacement, acceleration, and load response of the RPV and internals are then determined by either the time history method or the response spectrum method. In the time history method, the dynamic response is determined for each mode of interest and added algebraically for each instant of time. Resulting response time histories are then examined and the maximum value of displacement, acceleration, shears, and moments are used for design calculations. In the response spectrum method, the relative displacements, accelerations, shears, and moments are determined for each mode of interest. The square root of the sum of squares (SRSS) of these individual responses is then used for design calculations. Since the RPV and its internal system are made up of many separate components, there are many natural frequencies spaced closer than the natural frequencies of single component structures. When the time history method of seismic analysis is used as it is on Pilgrim, the physical displacements, accelerations, shears, and moments due to each mode are added algebraically at each instant of time and, hence, no criteria concerning the method of combining loads due to closely spaced modal frequencies needs to be set. When the response spectrum method of seismic analysis is used, it can be argued that, for very closely spaced frequencies, the peak modal response may occur at practically the same time and hence, the absolute sum (instead of SRSS) of the contributions from each mode should be taken. However, this argument overlooks the fact that signs of the mode shapes and participation factors of two neighboring modes, may be such that the load contribution from these modes subtract from one another instead of reinforcing one another, in parts of the structure. If this occurs, the loads would be definitely lower than the loads from an absolute sum.

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PNPS-FSAR The best indication of the adequacy of the SRSS method of combining modal load contributions is a comparison of the results from time history methods, and from response spectrum methods with SRSS load combinations and smoothed spectra. Such comparisons for the RPV and internals in BWR plants generally show that the loads determined by both methods are comparable in magnitude with the loads determined by the response spectrum method, being generally on the high side. Therefore, it may be concluded that the SRSS method of combining loads is adequate even for closely spaced modes.

The natural frequencies of the reactor internals, reactor vessel, and pedestal system in the vertical direction have been found to be approximately 20 Hz.

Examination of the response spectra shows no significant amplification at this frequency. Hence, omitting the vertical motion from seismic analysis to reduce the analytical complexities is acceptable. The effects of vertical excitations are accounted for by increasing or decreasing (whichever causes higher stress) the weight of the various components by a percentage equal to the vertical acceleration expressed in percent g.

The coupling of the vertical and lateral motions will cause an extremely small change in the bending moment experienced by some components. Since this change is a very small fraction of the moment caused by lateral moment, it can be neglected.

The stresses caused by the combined Safe Shutdown Earthquake and the LOCA conditions have been compared with and found to be within the Appendix C primary stress limits for faulted conditions.

To demonstrate that the reactor vessel internals can adequately resist the stresses resulting from an earthquake, a 1.0g lateral force was assumed. This does not mean that the Operating Basis Earthquake, which is used in combination with the accident loadings described (see Appendix C) is of this magnitude, but that the assumption of 1.0g lateral force is more than adequate to demonstrate the capabilities of the reactor vessel internals. For the reactor shroud, this analysis was superseded by the stress and seismic analyses performed subsequently as part of the shroud repair.

In RFO #10, a reactor shroud repair was implemented as described in Section 3.3.4.1.1. The design loads for the shroud stabilizers included seismic plus main steam line break accidents. The seismic analysis was done with a lumped mass and beam element two-dimensional finite element model of the entire reactor building and reactor vessel structure. To be consistent with the original design basis seismic analysis, the model has a single horizontal translational degree of freedom for each node. The model included in the reactor internals with elements to represent the fuel, guide tubes and shroud.

The model was first benchmarked against the original GE seismic analysis. The shroud repair was then added to the model by inserting two linear spring elements representing the upper and lower shroud stabilizer springs and a single rotational spring element to represent the four tie rods by an equivalent restraint against the shroud horizontal (overturning) movement.

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PNPS-FSAR The seismic analysis was done via the time history with modal superposition method. The ground motion input was done using both a Housner Response Spectrum synthetic time history per FSAR requirements shown in FSAR Figures 2.5-5 (OBE) and 2.5-6 (SSE), and a Taft earthquake time history consistent with the original seismic analysis. The shroud stabilizer design loads conservatively bound the higher of either the Housner or Taft responses.

The shroud stabilizers limit the displacement of the top guide and core support plates in the horizontal and vertical directions. The displacement limits were specified by General Electric based on analytical and empirical data on the ability to insert control rods with both transient and permanent displacements of the top guide and core support plate. The safety factors from Table C.3-6 were applied to the maximum displacement limits for the upset, emergency, and faulted conditions.

It can be concluded that earthquake forces do not cause deformations of the reactor vessel internals sufficient to prevent the insertion of control rods, the proper operation of the CSCS, or the proper flooding of the inner volume of the reactor vessel.

3.3.6.10 Impact of Increased Core Flow (ICF) and Final Feedwater Temperature Reduction (FFWTR) on Reactor Internal Components To support plant operation at 107.5% of rated recirculation flow, a safety analysis of the reactor internal components was performed to verify that the expected structural loading increases remain within the safety design bases limits. The analysis includes ICF with both normal feedwater temperature Feedwater temperature affects the steady state and transient components of the pressure differentials differently. A reduction in feedwater temperature decreases the steady state component due to a reduced void fraction and a corresponding reduction in two-phase friction effects. However, a reduction in feedwater temperature increases the transient portion of the pressure differentials due to the reduced steam generation rate and the corresponding increase in the depressurization rate during a LOCA event (see Section 3.3.6.5.2). When effects on the steady state and transient components are combined, it turns out that the reduced feedwater temperature increases the overall pressure differential across the reactor components located in high steam environments, i.e. above the core region. These reactor internals are typically the top guide, upper shroud, shroud head and steam dryer. The loads for these components are limiting at the reduced feedwater temperature condition. At or below the core region, where the environment is mostly in a liquid or low steam quality state, the reduced feedwater temperature has negligible overall impact on the reactor components. These components include the shroud support, core plate, and fuel channels. For these components, the limiting loads are still experienced at normal feedwater temperatures.

A review was made of the effect of 75F feedwater temperature reduction on reactor internals pressure differentials (RIPDs). The conclusion was that normal and upset RIPDs were not adversely affected, and the increase on LOCA RIPDs (<2%) over the 43F case was very small relative to the margin existing, in the design. This review is documented in General Electrics design record file (J11-02368, Reference 11).

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PNPS-FSAR 3.3.6.10.1 Reactor Internals The reactor internals most affected by pressure differences under increased core flow conditions are the core plate, guide tube, shroud support, shroud and top guide. These components were evaluated under normal, upset, emergency, and faulted conditions. The pressure differentials for these components during increased core flow operation were found to produce stresses that are within the allowable limits of the safety design bases.

3.3.6.10.2 Fuel Channels The fuel channels were also evaluated under normal, upset, emergency and faulted conditions for increased core flow and/or FFWTR. The channel wall pressure differentials were found to be within the allowable design values.

3.3.6.10.3 Fuel Bundles The margin to fuel bundle lift was re-evaluated for increase core flow operation and/or FFWTR. The analysis considered the added bundle lift component due to increased core flow, with and without FFWTR, in addition to the effect of the design basis LOCA, the control rod friction force due to scram and the design-basis earthquake. The fuel bundle minimum lift margin was found to be 135 pounds (net downward force on fuel bundle) during the worst-case faulted event from rated operating conditions (a steamline break at 102% power, 107.5% flow). This analysis found the effect of increased core flow with or without FFWTR to yield acceptable results in terms of avoiding fuel bundle lift.

3.3.6.11 Conclusions The analyses of the responses of the reactor vessel internals to situations imposing various loading combinations on the internals show that deformations are sufficiently limited to allow both adequate control rod insertion, and proper operation of the CSCS. Sufficient integrity of the internals is retained in such situations to allow successful reflooding of the reactor vessel inner volume. The analyses considered various loading combinations, including loads imposed by external forces. Thus, safety design bases 1, 2, and 3 are satisfied.

These conclusions extend to plant operation at rated core flow and increased core flow with and without final feedwater temperature reduction.

3.3.7 Inspection and Testing Quality control methods are used during the fabrication and assembly of reactor vessel internals to assure that the design specifications are met.

The Reactor Coolant System (RCS), which includes the reactor vessel internals, is thoroughly cleaned and flushed before fuel is loaded initially.

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PNPS-FSAR During the preoperational test program, operational readiness tests are performed on various systems. In the course of these tests such reactor vessel internals as the feedwater spargers, the core spray lines, the vessel head cooling spray nozzle, and the SLCS line are functionally tested.

A vibration analysis of reactor vessel internals was performed in the design to reduce failures due to vibration. With this analysis as a guide, the reactor internals are instrumented and tested to ascertain that there are no gross instabilities. Field test data are correlated with the analysis to ensure validity of the analytical techniques on a continuing basis. For vibration testing of reactor vessel internals, refer to Section 3.3.5.2.

The reactor vessel and internals are designed to assure adequate working space and access for inservice inspection. The criteria for selecting the components and locations to be inspected are based on the probability of a defect occurring or enlarging at a given location, and includes areas of known stress concentrations and locations where cyclic strain or thermal stress might occur. When practical, 100 percent inspection is planned at these locations; however, in cases where access is difficult, hazardous, or limited, it is planned to inspect a statistically significant portion. The type of inspection planned at each location is dependent on the type and location of defects anticipated.

3.3.8 References

1. NEDC-20259, "Summary Report on the Pilgrim Channel Wear Investigation and Corrective Measures Taken", January 1974.

2. NEDE-24323-P, "Core Support Plate Plug Service Life", March 1981.

3. "Design and Performance of G.E. BWR Jet Pumps", General Electric Co.,

Atomic Power Equipment Department, APED-5460, July 1968.

4. "General Electric Standard Application for Reactor Fuel," NEDE-24011-P-A, Revision Number Listed in Latest Supplemental Reload Submittal in Appendix Q.

5. NEDE-24362-1, "Improvements in Jet Pump Hold-Down Beam Service Life",

December 1981.

6. NEDO-30242, "Safety Review of Pilgrim Nuclear Power Station, Unit No. 1 at Core Flow Conditions Above Rated Flow Throughout Cycle 6", August 1983.

7. NEDE-20566-P, "Analytical Model for Loss-of-Coolant Accident in Accordance with 10CFR50, Appendix K", General Electric Company.

8. NEDC-32120P, "Revision of Core Support Plate Plug Service Life", General Electric Nuclear Energy, July 1992.

9. NEDO-20855-01, "GE BWR Reload No. 2 Licensing Submittal for PNPS, Unit 1 with Bypass Flow Holes Plugged", GE Boiling Water Reactor Projects Department, September, 1975.

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PNPS-FSAR

10. M-2-ER-Q-EO "Engineering Report for Core Support Plate Plug Life Extension", March 1994.

11. General Electric (D.C. Serell) to Boston Edison (B. Hagemeier), January 16, 1997, "Pilgrim Cycle 11 Reactor Internal Pressure Differences for Increased Core Flow with 75 F Feedwater Temperature Reduction".

12. NEDC-32306P, Maximum Extended Load Line Limit Analyses for Pilgrim Nuclear Power Station Reload 9 Cycle 10, General Electric Company, March 1994 (SUDDS/RF94-042)

13. SE3084, "Various jet pumps have mixer swing gates that do not have the latch pins engaged in their associated holes and restrainer bracket set screws not in contact with the inlet mixer", April 4, 1997. [Includes SUDDS/RF 97-41, SIA Report No. SIR-97-028, "Evaluation of the Pilgrim Jet Pumps with and without Gaps at Set Screws and Wedges" dated April 1997]

14. SUDDS/RF 97-41 Rev. 1 of vendor report SIR 97-028 Rev. 2.

15. SUDDS/RF 03-036 SIA Calculation PNPS-10Q-313 Jet Pump Gap Analysis dated 3/7/03.

16. MFN12-074, Enclosure 1, Proprietary, NRC SER on Enhanced NSF LUC Program.

17. EC47671, Pilgrim Cycle 21 Fuel Receipt.

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PNPS-FSAR 3.7 THERMAL AND HYDRAULIC DESIGN 3.7.1 Design Basis 3.7.1.1 Safety Design Bases Thermal-hydraulic design of the core shall establish:

(1) Actuation limits for the devices of the nuclear safety systems such that no fuel damage occurs as a result of moderate frequency transient events.

(2) The thermal-hydraulic safety limits for use in evaluating the safety margin relating the consequences of fuel barrier failure to public safety.

(3) That the nuclear system exhibits no inherent tendency toward divergent or limit cycle oscillations which would compromise the integrity of the fuel or nuclear system process barrier.

3.7.1.2 Power Generation Design Bases The thermal-hydraulic design of the core shall provide the following operational characteristics:

(1) The ability to achieve rated core power output throughout the design life of the fuel without sustaining premature fuel failure.

(2) Flexibility to adjust core output over the range of plant load and load maneuvering requirements in a stable, predictable manner without sustaining fuel damage.

3.7.1.3 Requirements for Steady-State Conditions For purposes of maintaining adequate thermal margin during normal steady-state operation, the MCPR must not be less than the required MCPR operating limit, and the LHGR must be maintained below the maximum LHGR for the fuel type. This does not specify the operating power nor does it specify peaking factors. These parameters are determined subject to a number of constraints including the thermal limits given previously. The core and fuel design basis for steady-state operation (i.e., MCPR and LHGR limits) have been defined to provide margin between the steady-state operating conditions and any fuel damage condition to accommodate uncertainties and to assure that no fuel damage results even during the worst anticipated transient condition at any time in life. During SLO the MCPR thermal limit is adjusted to account for increased uncertainties (Reference 5).

The design steady-state MCPR operating limit and the peak LHGR are referenced in Table 3.7-1.

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PNPS-FSAR 3.7.1.4 Requirements for Transient Conditions The transient thermal limits are established such that no safety limit is expected to be exceeded during the most severe moderate frequency transient event as defined in Reference 1.

3.7.1.5 Summary of Design Bases In summary, the steady-state operating limits have been established to assure that the design basis is satisfied for the most severe moderate frequency transient event. There is no steady-state design overpower basis. An overpower which occurs during an incident of a moderate frequency transient event must meet the plant transient MCPR limit. Demonstration that the transient limits are not exceeded is sufficient to conclude that the design basis is satisfied.

3.7.2 Description of Thermal-Hydraulic Design of the Reactor Core 3.7.2.1 Summary Comparison An evaluation of plant performance from a thermal and hydraulic standpoint is provided in Subsection 3.7.3.

A tabulation of core parameters used in the thermal and hydraulic calculation is provided in Table 3.7-1.

3.7.2.2 Critical Power Ratio The critical power ratio is defined as the ratio of the critical power (bundle power at which some point within the assembly experiences onset of boiling transition) to the operating bundle power. The minimum critical power ratio (MCPR) ensures that fuel damage resulting from severe overheating of the fuel rod cladding caused by inadequate cooling is avoided. The minimum critical power ratio corresponds to the most limiting fuel assembly in the core.

Further description of the critical power ratio and model used to calculate this ratio is provided in Reference 1.

3.7.2.3 Linear Heat Generation Rate (LHGR)

A value of 1% plastic strain of the Zircaloy cladding has been established as the safety limit below which fuel damage due to overstraining of the fuel cladding is not expected to occur. The linear heat generation rate required to cause this amount of cladding strain is given in Reference 1. The models used to calculate this transient LHGR safety limit are also described in this reference.

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PNPS-FSAR 3.7.2.4 Void Fraction Distribution The void fraction distribution is calculated using the core average axial power distribution.

3.7.2.5 Core Coolant Flow Distribution and Orificing Pattern Correct distribution of core coolant flow among the fuel assemblies is accomplished by the use of an accurately calibrated fixed orifice at the inlet of each fuel assembly. The orifice is located in the fuel support piece. The orifices serve to control the flow distribution and, hence, the coolant conditions within prescribed bounds throughout the design range of core operation.

The core is divided into two orificed flow zones. The outer zone is a narrow, reduced power region around the periphery of the core; the inner zone consists of the core center region. No other control of flow and steam distribution, other than that incidentally supplied adjustment of the power distribution with the control rod is employed or needed. The orifices can be removed for changes during refueling operations if necessary.

The sizing and design of the orifices ensures that the flow in each fuel assembly is stable during all phases of operation at normal operating conditions. Hydraulic models including core coolant flow distribution and bypass, are included in Reference 1.

3.7.2.6 Core Pressure Drop and Hydraulic Loads The flow distribution to the fuel assemblies and bypass flow paths is calculated on the assumption that the pressure drop across all fuel assemblies and bypass flow paths is the same. This assumption has been confirmed by measuring the flow distribution in boiling water reactors. The components of bundle pressure drop considered are friction, local, elevation, and acceleration.

Models for pressure drop across the core are given in Reference 1.

3.7.2.7 Correlation and Physical Data General Electric has obtained substantial amounts of physical data in support of the pressure drop and thermal-hydraulic loads. This information is provided in Reference 1.

3.7.2.8 Thermal Effects of Operational Transients The evaluation of the core's capability to withstand the thermal effects resulting from anticipated operational transients is covered in Section 14.

3.7.2.9 Uncertainties in Estimates Uncertainties in thermal-hydraulic parameters are considered in the statistical analysis which is performed to establish the fuel cladding integrity safety limit documented in Reference 1.

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PNPS-FSAR 3.7.2.10 Flux Tilt Considerations For flux tilt considerations, refer to Subsection 3.6.2.2.4.

3.7.3 Description of the Thermal and Hydraulic Design of the Reactor Coolant System The thermal and hydraulic design of the reactor coolant system is described in this section.

3.7.3.1 Plant Configuration Data Reactor coolant system geometric data is provided in Section 4.

3.7.3.2 Operating Restrictions on Pumps Recirculation pump operational requirements are discussed in Subsection 7.9, Recirculation Flow Control System.

3.7.3.3 Power-Flow Operating Map A BWR must operate with certain restrictions because of pump net positive suction head (NPSH) requirements, overall plant control characteristics, core thermal power limits, core thermal-hydraulic stability considerations, etc. The power-flow operating map for PNPS is shown in Figure 3.7-1. Constraints imposed by equipment, alarms or reactor scrams initiated by protective instrumentation, and operator actions based upon written operating procedures maintain operations within the embolded boundary lines shown on this map for normal operating conditions.

The current operating map depicted in Figure 3.7-1 evolved from an original region that has both expanded and contracted over several iterations. References 2 through 6, and 11 through 13 provide the bases for each change. The original operating region was enclosed by the natural circulation line, the 100% load line, and a constant recirculation pump speed line which intersects 100% rated core power at 100% rated core flow (not shown on Figure 3.7-1).

Normal reactor operation would also effectively be restricted to the minimum pump speed (approximately 26%) line. An interlock prevents low power, high recirculation flow combinations which may create recirculation NPSH problems as depicted by the minimum power line.

The analyses in references 2 through 6, and 11 through 13 altered the operating region boundaries as summarized below:

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PNPS-FSAR Core power cannot exceed 100% rated core power or 2028 megawatts thermal. The maximum core flow at 100% rated power is 107.5% of rated core flow (69 mlb/hr). Below 100% core power, the core flow limit increases linearly to 112.5% of rated core flow at 78.8% rated core power. Between 78.8% and 49.3% rated core power, the maximum core flow allowed is 112.5% of rated core flow. Below 49.3% rated core power, the maximum allowed core flow drops to 100% rated core flow. See References 3, 4 and 13.

100% rated core power continues as the maximum core power limit as core flow decreases from 107.5% to 76.7% rated core flow. Below 76.7% rated core flow, the maximum allowed core power decreases along the 119.3% load line toward its intersection with the natural circulation line at approximately 56.9% rated core power. See Reference 6. There are 2 regions of the operating domain where administrative controls are enforced to provide defense-in-depth protection for the occurrence of thermal hydraulic instability. The Exclusion Region is part of the Option 1-D Stability Solution. It is annotated as a shaded section. The flow range is from natural circulation to a cycle dependent core flow value. The boundary is non linear based on the calculation of core decay ratio intercept values on the natural circulation and MELLLA rod lines in Reference

11. The Buffer Zone is defined as a region in the operating domain with a parallel boundary to the Exclusion Region. The intercept point on the natural circulation line is 5% lower in power that the Exclusion Region intercept. The Buffer Zone intercept on the high rod line is 5% greater in flow than the Exclusion Region. These regions are validated for each fuel cycle and included in the COLR.

Cycle 18 ATWS Analysis required imposing a P-F map boundary different from MELLLA boundary from 0 to 5000 MWD/ST in order to limit the peak reactor pressure to 1500 psig. Power-Flow Map will show this boundary as documented in Appendix H to Supplemental Reload Licensing Report (Reference 17, Appendix Q). This boundary changes the minimum core flow to 78.5% at 100% power and has a different slope than the MELLLA line. It intersects the MELLLA line at 94.7% power, 70.6% flow. This boundary is specific to Cycle 18 and was selected to maximize the operating domain. After 5000 MWD/ST there is no restriction due to ATWS and Power-Flow Map reverts back to using MELLLA boundary.

Cycle 18 stability analysis requires use of the flow clamp from 0 to 2000 MWD/ST cycle exposure in order to prove that core wide mode is the dominant mode of oscillations, as required to use Stability Option 1-D. For cycle exposure greater than 2000 MWD/ST, flow clamp is not required (Reference 17, Appendix Q).

These regions are illustrated on Figures 3.7-1. See also the discussion in Section 3.7.4.6 and References 8 through 12. Froom Cycle 19 oonwards, the use flow clamp is not required. Also, the ATWS analysis became Cycle independent again and did noot require P-F map restrictions too meet ATWS analysis criteria. Ref. 18 and Cycle 20 SRLR doocument these conclusions.

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PNPS-FSAR During Single Loop Operation the acceptable boundaries of reactor operation are reduced from normal two-loop operation. Core flow is limited to 52% of rated and core power is limited to 65% of rated.

The administrative controls of the stability regions are also enforced in SLO (Reference 5).

3.7.3.4 Temperature-Power Operating Map (PWR)

Not applicable.

3.7.3.5 Load-Following Characteristics The following simple description of BWR operation with recirculation flow control summarizes the principal modes of normal power range operation. Assuming the plant to be initially hot with the reactor critical, full power operation can be approached following the sequence shown as points 1 to 7 in Figure 3.7-1. The first part of the sequence (1 to 3) is achieved with control rod withdrawal and manual, individual recirculation pump control. Individual pump startup procedures are provided that achieve 26% of full pump speed in each loop. Power, steam flow, and feedwater flow are increased as control rods are manually withdrawn until the feedwater flow has reached approximately 20%. An interlock prevents low power-high recirculation flow combinations that create recirculation pump and jet pump NPSH problems.

Control rods are withdrawn causing reactor thermal power and core flow to increase along the pump minimum speed line. Once the feedwater interlock is cleared, the operator can manually increase recirculation flow in each loop until the operating state reaches point 3.

Thermal output can then be increased by either control rod withdrawal or recirculation flow increase. For example, the operator can reach 50% power in the ways indicated by points 4 or 5.

With a slight rod withdrawal and an increase of recirculation flow to rated flow, point 4 can be achieved. If, however, it is desired to maintain lowest recirculation flow, 50% power can be reached by withdrawing control rods until point 5 is reached.

The curve labeled "100% load line" represents a typical steady-state power flow characteristic for a fixed rod pattern. It is slightly affected by xenon, core leakage flow assumptions, and reactor vessel pressure variations; however, for this example, these effects have been neglected.

To optimize load following capabilities, power range operation should be near or below the "100% load line." If load following response is desired in either direction, plant operation near 90%

power provides the most capability. If maximum load pickup capability is desired, the nuclear system can be operated near point 6, with load response available all the way up to point 7, rated power.

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PNPS-FSAR The large negative operating coefficients, which are inherent in the BWR, provide important advantages as follows:

1. Good load following with well damped behavior and little undershoot or overshoot in the heat transfer response.

2. Load following with recirculation flow control.

3. Strong damping of spatial power disturbances.

Design of this single cycle BWR plant includes the ability to follow load demand over a reasonable range without requiring operator action.

Load following is accomplished by varying the recirculation flow to the reactor. This method of power level control takes advantage of the reactor negative void coefficient. To increase reactor power, it is necessary only to increase the recirculation flow rate which sweeps some of the voids from the moderator, causing an increase in core reactivity. As the reactor power increases, more steam is formed and the reactor stabilizes at a new power level with the transient excess reactivity balanced by the new void formation. No control rods are moved to accomplish this power level change.

Conversely, when a power reduction is required, it is necessary only to reduce the recirculation flow rate. When this is done, more voids are formed in the moderator, and the reactor power output automatically decreases to a new power level commensurate with the new recirculation flow rate. No control rods are moved to accomplish the power reduction.

Load following through the use of variations in the recirculation flow rate (flow control) is advantageous relative to load following by control rod positioning. Flow variations perturb the reactor uniformly in the horizontal planes, and thus allow operation with flatter power distribution and reduced transient allowances. As the flow is varied, the power and void distributions remain approximately constant at the steady state and points for a wide range of flow variations. These constant distributions provide the important advantage that the operator can adjust the power distribution at a reduced power, and flow by movement of control rods and then bring the reactor to full power conditions by increasing flow, with the assurance that the power distributions will remain approximately constant. Section 7.9, Recirculation Flow Control System, describes the means by which recirculation flow is varied.

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PNPS-FSAR 3.7.3.6 Thermal and Hydraulic Characteristics Summary Table The thermal-hydraulic characteristics are provided in Table 3.7-1 for the core and Section 4.0 for other portions of the reactor coolant system.

3.7.4 Evaluation The design basis employed for the thermal and hydraulic characteristics incorporated in the core design, in conjunction with the plant equipment characteristics, nuclear instrumentation, and the reactor protection system, is given in Reference 1.

3.7.4.1 Critical Power The GEXL-Plus critical power correlation utilized in thermal-hydraulic evaluations is discussed in Reference 1.

3.7.4.2 Core Hydraulics Core hydraulic models and correlations are discussed in Reference 1.

3.7.4.3 Influence of Power Distributions The influence of power distributions on the thermal-hydraulic design is discussed in Reference 1. The local, radial, and axial peaking factors used in the analysis are listed in the supplemental reload licensing report found in Appendix Q.

3.7.4.4 Core Thermal Response The thermal response of the core for accidents and expected transient conditions is discussed in Section 14.

3.7.4.5 Analytical Methods The analytical methods, thermodynamic data, and hydrodynamic data used in determining the thermal and hydraulic characteristics of the core are documented in Reference 1.

3.7.4.6 Thermal-Hydraulic Stability Analysis Light water reactors, including boiling water reactors, inherently include a stabilizing negative moderator density reactivity coefficient. Fuel power increases are limited by corresponding coolant density decreases that constrain further moderation of the thermal neutron flux and subsequent power production. This feedback mechanism between the fuel and core coolant is reversible.

Perturbations of fuel power by control rod motion or the core coolant density by compression/rarefaction waves passing through the vapor phase are characterized by damped oscillations of the neutron flux density. At normal power operating conditions, the reactor core coolant is the recipient of a continuous bombardment of internally and externally generated small perturbations, manifested in the electronic signal data representing neutron flux density as 3.7-8 Rev. 30 - Nov. 2015

PNPS-FSAR mid-range frequency (0.5 to 2 Hz) components of the total signal "noise".

At low reactor coolant flow conditions, the effectiveness of the feedback between fuel power production and coolant moderation to dampen neutron flux density oscillations will degrade. Moderator density changes originating in the lower elevations of the fuel assembly coolant channel are reflected later in the upper elevations of the fuel assembly coolant, the time lag determined by the velocity of the coolant flow. Reactor coolant velocities associated with forced convection flow near rated conditions incur a very short time lag, assuring that the fuel power feedback to core coolant density changes (and the reverse effect) are nearly "in phase" and result in the highly dampened oscillatory behavior response of both variables desired. The "decay ratio" of the response is much less than 1.0, i.e., the ratio of the offset from average of the variables (e.g., neutron flux density) peak value to the offset from average of the preceding peak value of that variable. However, at much lower coolant velocities near and below 40% rated core flow rate, the time lag increases; and the power feedback to the coolant from the fuel in the upper elevation of the fuel assembly associated with a coolant density change will increase or decrease partially "out of phase" with the coolant density increase or decrease that occurred earlier upstream in the fuel channel. The oscillations become less damped, and, if the time lag increases significantly, even undamped. Undamped, growing oscillations have a "decay ratio" greater than 1.0. This is known as a "dynamic density-wave" instability.

Higher core void fractions associated with increased core power can aggravate the marginal stability or instability associated with low coolant flow rate alone. As power increases in the bottom of the core, the onset of boiling moves further upstream, and the "boiling length" increases, further increasing the magnitude of the time lag that a coolant density compression/rarefaction wave can experience traveling up the fuel channel flow path. As power increases overall, both the coolant void fractions and fuel power density increase in the upper elevations of the fuel assembly channels, adding greater potential for "out-of-phase" thermal-hydraulic feedback to accelerate the effects of destabilizing low coolant flow. Therefore, while core instability may occur over a wide range of core power at low flow condition, it is at the upper portion of that range where decay ratios are expected to be significantly greater than 1.0.

While the increased delay in void propagation up a fuel channel at low reactor coolant flow conditions is the most common cause for instability in BWRs, it is but one of several reactor and fuel characteristics that may interact to lead to unstable conditions of the same or different types. One characteristic that has changed significantly since early BWR designs is a decrease in fuel pin diameter. This results in less lag between power production changes in the smaller fuel pin and the consequential thermal heat changes to the surrounding coolant/moderator. This has reduced the margin to instability previously available in the larger fuel pin designs 3.7-9 Rev. 30 - Nov. 2015

PNPS-FSAR under conditions of reduced coolant flow. The various phenomena of thermo hydraulic instability are described in NUREG/CR-6003 (Reference 7).

Thermo hydraulic density-wave instabilities do not pose a significant threat to nuclear fuel or clad failure in most cases.

When the reactor core remains thermo hydraulically and neutronically coupled, core thermal-hydraulic instability quickly results in reactor scram on high neutron flux via the APRMs input to the Reactor Protection System. This is due to the essentially "in phase" response of all LPRMs feeding in to a common APRM. Even if crediting only the 120% of rated power trip setpoint to terminate reactor operation, unstable operation would incur only mild thermal cycling of the fuel before a reactor scram. However, reactor conditions may favor a neutronically and thermo hydraulically uncoupled response, resulting in "out-of-phase" LPRM neutron flux indications. Their summations in their associated APRM could "mask" the severity of local power oscillations by partially canceling out each others' oscillatory extremes. If uncoupled power oscillations were to persist without intervention, local fuel cladding may experience cycling periods of departure from nucleate boiling conditions. In the rarely experienced or expected case of single channel thermo hydraulic instability, detection is also made difficult by the APRMs representation of global, rather than local, core power.

General Design Criterion 10 of Appendix A, 10 CFR 50 precludes normal operation or anticipated transients that would lead to departure of nucleate boiling conditions, a fuel design limit.

General Design Criterion 12 requires that undamped power oscillations either be automatically detected and suppressed, or that either the design or automatic actions preclude the possibility of operation at the conditions which create core power oscillations.

While core thermo hydraulic instabilities have never been experienced at PNPS their possibility cannot be precluded based upon the design of the reactor core and fuel. The option of "detecting and suppressing" power oscillations was selected for PNPS beginning in Cycle 16 (Reference 11).

The PNPS Long Term Stability Solution is known as Option 1-D. PNPS has a relatively small core and small inlet orifice diameter compared to other BWR plants. These design features result in a 95%

confidence that if unstable oscillations occur at PNPS, they will be global or core wide. Based on cycle dependent stability analysis the APRM scram setpoint is positioned to prevent operation in regions of the power-flow map where a 95% confidence or core wide oscillation is not ensured by the small core and small inlet orifice diameter. For core wide oscillations the LPRMs will respond in phase, which means the APRM signals will be indicative of core power conditions. The flow biased APRM scram setpoint can be used to detect and suppress the undamped oscillations. The APRM flow biased scram is the license basis feature that protects the SLMCPR limit.

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PNPS-FSAR The cycle specific flow biased APRM setpoint may be exposure dependent and is documented in the supplemental reload licensing report found in Appendix Q. However, there are defense-in-depth restrictions that are part of Option 1-D to provide prevention against onset of a thermal-hydraulic instability event. Option 1-D is an NRC approved methodology (References 8 through 12).

EXCLUSION REGION The implementation of Option 1-D identified the Exclusion Region.

This is an area within the operating domain where the possibility exists for the occurrence of thermal-hydraulic oscillations. See References 10 and 11. The Exclusion Region is validated for each core and cycle design. Normal operation is prohibited within the Exclusion Region. If the region is entered as a result of a transient, then immediate exit is required. Cycle 18 stability analysis requires use of the flow clamp from 0 to 2000 MWD/S cycle exposure in order to prove that core wide is the dominant mode of oscillations as required to use stability Option 1-D. For cycle exposure greater than 2000 MWD/S flow clamp is not required (Reference 17, Appendix Q). Hence, for the first 2000 MWD/S cycle exposure the APRM flow biased scram setpoint is inside the operating domain. Normally, the APRM flow biased scram setpoint is closer to the operating domain above this region to provide protection for the MCPR in case of the occurrence of an unstable oscillation. The APRM flow biased rod block is positioned parallel to the APRM scram and lower by 5% of rated power. It provides a warning prior to reaching the APRM Scram setpoint.

BUFFER ZONE A Buffer Zone, which is parallel to the Exclusion Region, adds additional margin to prevent occurrence of thermal hydraulic instabilities. Normal and transient operation in the Buffer Zone is permitted with availability of on-line stability monitoring. The primary means of performing on-line stability monitoring is the SOLOMON program, which is part of the process computer. This feature is described in Section 7.16. The alternate means of on-line stability monitoring is the Period Based Detection System (PBDS). This feature is described in Section 7.5.

The required Stability Option 1-D limits are defined in the core operating limits report (COLR).

3.7.5 Testing and Verification The reload core startup physics and core verification programs are contained in the Technical Specifications.

3.7.6 Instrumentation Requirements The reactor vessel instrumentation monitors the key reactor vessel operating parameters, during planned operations. This ensures sufficient control of the parameters. The reactor vessel sensors are discussed in Subsection 7.8, Reactor Vessel Instrumentation.

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PNPS-FSAR 3.7.7 References

1. "General Electric Standard Application for Reactor Fuel," NEDE-24011-P-A, Revision Number Listed in Latest Supplemental Reload License Submittal in Appendix Q.

2. "General Electric Boiling Water Reactor Extended Load Line Limit Analysis for Pilgrim Nuclear Power Station Unit 1 Cycle 6," NEDO-22198, September 1982.

3. "Safety Review of Pilgrim Nuclear Power Station, Unit No. 1 at Core Flow Conditions Above Rated Flow Throughout Cycle 6," NEDO-30242, August 1983.

4. "Safety Review of Pilgrim Nuclear Power Station, Unit No. 1 at Core Flow Conditions Above Rated Flow For End-of-Cycle 6," NEDO-30242, Supplement 1, September 1983.

5. GE-NE-0000-0027-5301-R2-P, April 2006, Pilgrim Nuclear Power Station Single Loop Operation.

6. Maximum Extended Load Line Limit Analyses for Pilgrim Nuclear Power Station Reload 9 Cycle 10, NEDC-32306P, March 1994 (SUDDS/RF94-042).

7. "Density-Wave Instabilities in Boiling Water Reactors,"

NUREG/CR-6003, prepared by J. Marche-Leuba, ORNL, September 1992.

8. NEDO 31960A, BWR Owners Group Long-Term Stability Solutions Licensing Methodology, November 1995.

9. NEDO 31960A, Supplement 1, BWR Owners Group Long-Term Stability Solutions Licensing Methodology, March 1992.

10. NEDO 32465A, Reactor Stability Detect and Suppress Solutions Licensing Basis Methodology for Reload Applications, August 1996.

11. NEDC-33155P, Application of Stability Long-Term Solution Option 1-D to Pilgrim Nuclear Power Station, Revision O, October 2004.

12. General Electric Report GE-NE-GENE-0000-0033-6871-01, Pilgrim Option 1-D APRM Flow Biased Setpoints.

13. Safety Analysis Report for Pilgrim Nuclear Power Station Thermal Power Optimization, NEDC-33050P, GE Nuclear Energy, July 2002.

14. NRC Letter to PNPS dated April 12, 2006 (PNPS Ltr 1.06.042), Issuance of Amendment 219, SER Single Recirculation Loop Operation.

3.7-12 Rev. 30 - Nov. 2015

PNPS-FSAR Figure 3.7-2 has been removed 1 of 1 Rev 25 - Oct 2005

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS Section Title Volume Section 1 Introduction and Summary 1 1.1 Project Identification 1 1.2 Definitions 1 1.3 Methods of Technical Presentation 1 1.4 Classification of BWR Systems, Criteria, 1 and Requirements for Safety Evaluation 1.5 Principal Design Criteria 1 1.6 Station Description 1 1.7 Comparison of Principal Design Characteristics 1 1.8 Summary of Radiation Effects 1 1.9 Station Management 1 1.10 Quality Assurance Program 1 1.11 Station Research, Development, and Further Information Requirements and Resolutions Summary 1 Section 2 Station Site and Environs 1 2.1 Introduction 1 2.2 Site Description 1 2.3 Meteorology 1 2.4 Hydrology 1 2.5 Geology and Seismology 1 2.6 Environs Radiation Surveillance Program 1 Section 3 Reactor 1 3.1 Summary Description 1 3.2 Fuel Mechanical Design 1 3.3 Reactor Vessel Internals Mechanical Design 1 3.4 Reactivity Control Mechanical Design 1 3.5 Control Rod Drive Housing Supports 1 3.6 Nuclear Design 1 3.7 Thermal and Hydraulic Design 1 3.8 Standby Liquid Control System 1 3.9 Recirculation Pump Trip, Alternate Rod Insertion, and Feedwater Pump Trip Systems 1 Section 4 Reactor Coolant System 2 4.1 Summary Description 2 4.2 Reactor Vessel and Appurtenances Mechanical Design 2 4.3 Recirculation System 2 4.4 Nuclear System Pressure Relief System 2 4.5 Main Steam Line Flow Restrictor 2 Summ T of C-i Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 4.6 Main Steam Line Isolation Valves 2 4.7 Reactor Core Isolation Cooling System 2 4.8 Residual Heat Removal System 2 4.9 Reactor Water Cleanup System 2 4.10 Nuclear System Leakage Rate Limits 2 4.11 Main Steam Lines and Feedwater Piping 2 Section 5 Containment 2 5.1 Summary Descriptions 2 5.2 Primary Containment System 2 5.3 Secondary Containment System 2 5.4 Control of Combustible Gas Concentrations in Containment 2 Section 6 Core Standby Cooling Systems 2 6.1 Safety Objective 2 6.2 Safety Design Bases 2 6.3 Summary Description - Core Standby Cooling Systems 2 6.4 Description 2 6.5 Safety Evaluation 2 6.6 Inspection and Testing 2 6.7 The Nuclear Safety Requirements for Plant Operation 2 6.8 Current Technical Specifications 2 Section 7 Control and Instrumentation 3 7.1 Summary Description 3 7.2 Reactor Protection System 3 7.3 Primary Containment and Reactor Vessel Isolation Control System 3 7.4 Core Standby Cooling Systems Control and Instrumentation 3 7.5 Neutron Monitoring System 3 7.6 Refueling Interlocks 3 7.7 Reactor Manual Control System 3 7.8 Reactor Vessel Instrumentation 3 7.9 Recirculation Flow Control System 3 7.10 Feedwater Control System 3 7.11 Turbine Generator Control System 3 7.12 Process Radiation Monitoring 3 7.13 Area Radiation Monitoring System 3 7.14 Environs Radiation Monitors 3 7.15 Health Physics and Laboratory Analysis Radiation Monitors 3 Summ T of C-ii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 7.16 Process Computer System 3 7.17 Nuclear System Stability Analysis for Initial Core 3 7.18 Reactor Building Isolation and Control System 3 7.19 RHR Service Water System (SSW, RBCCW) 3 7.20 Equipment Area Cooling System 3 7.21 Meteorological Instrumentation 3 Section 8 Electrical Power System 4 8.1 Summary Description 4 8.2 Unit and Preferred AC Power Sources 4 8.3 Secondary AC Power Source 4 8.4 Auxiliary Power Distribution System 4 8.5 Standby AC Power Source 4 8.6 125 and 250 Volt DC Power Systems 4 8.7 24 Volt DC Power System 4 8.8 120 Volt AC Power Systems 4 8.9 Cable Installation Criteria 4 8.10 Blackout AC Power Source 4 Section 9 Radioactive Waste Systems 4 9.1 Summary Description 4 9.2 Liquid Radwaste System 4 9.3 Solid Radwaste System 4 9.4 Gaseous Radwaste System 4 9.5 Trash Compaction and Decontamination Facilities 4 Section 10 Auxiliary Systems 4 10.1 Summary Description 4 10.2 New Fuel Storage 4 10.3 Spent Fuel Storage 4 10.4 Fuel Pool Cooling and Cleanup System 4 10.5 Reactor Building Closed Cooling Water System 4 10.6 Turbine Building Closed Cooling Water System 4 10.7 Salt Service Water System 4 10.8 Fire Protection System 4 10.9 HVAC Systems 4 10.10 Makeup Water Treatment System 4 10.11 Instrument and Service Air Systems 4 10.12 Potable and Sanitary Water System 4 10.13 Equipment and Floor Drainage Systems 4 10.14 Process Sampling Systems 4 10.15 Communications Systems 4 10.16 Station Lighting System 4 10.17 Main Control Room Environmental Control System 4 10.18 Equipment Area Cooling System 4 10.19 Post Accident Sampling System 4 Summ T of C-iii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 10.20 Crack Arrest Verification System 4 10.21 Hydrogen Water Chemistry Extended Test System 4 10.22 Electrolytic Hydrogen Water Chemistry System 4 10.23 Mitigation Monitoring System 4 Section 11 Power Conversion Systems 4 11.1 Summary Description 4 11.2 Turbine-Generator 4 11.3 Main Condenser 4 11.4 Main Condenser Gas Removal and Turbine Sealing Systems 4 11.5 Turbine Bypass System 4 11.6 Circulating Water System 4 11.7 Condensate Demineralizer System 4 11.8 Condensate and Feedwater System 4 11.9 Condensate Storage System 4 Section 12 Structures and Shielding 4 12.1 Summary Description 4 12.2 Structural Design 4 12.3 Shielding and Radiation Protection 4 12.4 Radioactive Materials Safety 4 Section 13 Conduct of Operations 5 13.1 Introduction and Summary 5 13.2 Organization and Responsibilities 5 13.3 Training 5 13.4 Preoperational Test Program 5 13.5 Reactor Startup and Power Test Program 5 13.6 Station Procedures 5 13.7 Records 5 13.8 Operational Review and Audits 5 Section 14 Station Safety Analysis 5 14.1 Introduction 5 14.2 Reactor Limits 5 14.3 Method of Approach 5 14.4 Abnormal Operational Transients 5 14.5 Postulated Design Basis Accidents 5 14.6 Special Events 5 14.7 References 5 Summ T of C-iv Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix A Pressure Integrity of Piping and Equipment Pressure Parts 5 A.1 Scope 5 A.2 Classification of Piping and Equipment Pressure Parts 5 A.3 Design Requirements 5 A.4 Materials 5 A.5 Fabrication and Installation Requirements 5 A.6 Testing and Inspection Requirements 5 A.7 Final Cleaning and Protection 5 A.8 F1, F2, F3, and F4 Fabrication and Erection Schedule 5 A.9 M1, M2, and M3 Material Schedules 5 A.10 T1, T2, T3, T4, and T5 Inspection and Testing Schedules 5 Appendix B Technical Specifications 5 B.1 Technical Specifications 5 B.2 Technical Specifications Relocated to the FSAR 5 B.3 Relocated Technical Specifications and Related 5 Bases 5 B.4 References 5 Appendix C Structural Loading Criteria 5 C.1 Scope 5 C.2 Concrete and Steel Structures 5 C.3 Components 5 Appendix D Quality Assurance Program 5 D.1 General 5 D.2 Program Organization and Responsibility 5 D.3 Quality Surveillance and Auditing 5 D.4 Quality Controls and Assurance Measures 5 D.5 QC-QA Documentation and Records 5 D.6 Project Communications 5 Attachment D.I General Electric Quality System for BWR Nuclear Steam Supply Projects 5 Attachment D.II Bechtel Quality Assurance Program, Pilgrim Nuclear Power Station 5 Attachment D.III Site Handling and Storage of Nuclear Steam Supply System Equipment, Pilgrim Nuclear Power Station 5 Summ T of C-v Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix E Stack Release Limit Calculations for Pilgrim Station Site 5 E.1 Analytical Model 5 E.2 Verification of Analytical Model 5 E.3 Stack Release Limit Calculations for Pilgrim Station Site 5 E.4 Building Exhaust Vent Release 5 E.5 Summary 5 E.6 References 5 Appendix F Comparison of Pilgrim Nuclear Power Station with the Proposed General Design Criteria Published by the AEC for Public Comment in The Federal Register July 11, 1967 6 F.1 Summary Description 6 F.2 Criteria Conformance 6 Appendix G Station Nuclear Safety Operation Analysis Supporting Nuclear Safety Requirements for Plant Operation 6 G.1 Analytical Objective 6 G.2 Bases for Selecting Operation Requirements for Plant Operation 6 G.3 Bases for Selecting Surveillance Test Frequencies for Nuclear Safety Systems and Engineered Safeguards for Plant Operation 6 G.4 Method of Analysis 6 G.5 Analysis and Results 6 G.6 Conclusion 6 Appendix H Tornado Criteria for Nuclear Power Plants 6 H.0 Foreword 6 H.1 Introduction 6 H.2 Characteristics of Tornadoes 6 H.3 Tornado Probability 6 H.4 Wind Loading 6 H.5 Pressure Differential 6 H.6 Water Loss 6 H.7 Tornado Missiles 6 H.8 References 6 Summ T of C-vi Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Appendix I Site Investigation of the Seabreezes 6 I.1 Introduction 6 I.2 Results and Conclusions 6 Section Title Volume I.3 Discussion 6 I.4 Data and Calculations 6 I.5 References 6 Appendix J Station Research, Development, and Further Information Requirements and Resolution 6 J.1 Resolution of ACRS Concerns 6 J.2 Areas Specified in the ACRS Construction Permit Letter for Pilgrim Nuclear Power Station 6 J.3 Areas Specified in the AEC Staff Construction Permit - Safety Evaluation Report for Pilgrim Nuclear Power Station 6 J.4 Areas Specified in Recent, Related ACRS Construction and Operating Permit Letters 6 J.5 Summary Conclusions 6 J.6 References 6 Appendix K Inservice Inspection Program 6 K.1 General 6 K.2 Inspection Program Development 6 K.3 Inspection Program Implementation 6 K.4 Reference Base Examinations 6 K.5 Documentation and Records 6 Appendix L Containment Report 7 L.1 Introduction and Summary 7 L.2 Basis for Containment Design 7 L.3 Containment System Design 7 L.4 Initial Overload and Leakage Rate Test 7 L.5 Manufacturer's Data Report for Nuclear Vessels 7 Appendix M Reactor Pressure Vessel Design Report 7 M.1 Introduction to the Report 7 M.2 Summary 7 Appendix N Emergency Plan 7 Summ T of C-vii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix O Analysis of the Consequences of High Energy Piping Failures Outside The Primary Containment 7 O.1 Introduction 7 O.2 Analysis Assumptions 7 O.3 Analysis Approach 7 O.4 Structural Loading Analytical Technique 7 O.5 Jet and Fluid Forces Analytical Techniques 7 O.6 Detailed System Analyses 7 O.7 Environmental Qualification of Electrical Equipment 7 Appendix P Deleted 7 Appendix Q Supplemental Reload Submittal 7 Q.1 Introduction 7 Appendix R Initial Core Station Safety Analysis 7 R.1 Introduction 7 R.2 Analyses of Abnormal Operational Transients (Initial Core) 7 R.3 Analysis of Design Basis Accidents (Initial Core) 7 R.4 Special Events (Initial Core) 7 R.5 Analytical Methods (Initial Core) 7 R.6 Evaluation Using Standard NRC Approach (Initial Core) 7 Appendix S License Renewal Commitments 7 S.1 Supplement for Renewed Operating License 7 S.2 Aging Management programs and Activities 7 Transients (Initial Core) 7 S.3 Evaluation of Time-Limited Aging Analyses 7 S.4 References 7 Summ T of C-viii Rev. 30 - Nov. 2015

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PNPS-FSAR SECTION 4 REACTOR COOLANT SYSTEM TABLE OF CONTENTS Section Title Page 4.1

SUMMARY

DESCRIPTION 4.1-1 4.2 REACTOR VESSEL AND APPURTENANCES MECHANICAL DESIGN 4.2-1 4.2.1 Safety Objective 4.2-1 4.2.2 Safety Design Basis 4.2-1 4.2.3 Power Generation Objective 4.2-1 4.2.4 Power Generation Design Basis 4.2-1 4.2.5 Description 4.2-2 4.2.5.1 Reactor Vessel 4.2-2 4.2.5.2 Shroud Support 4.2-6 4.2.5.3 Reactor Vessel Support Assembly 4.2-7 4.2.5.4 Vessel Stabilizers 4.2-7 4.2.5.5 Refueling Bellows 4.2-8 4.2.5.6 Control Rod Drive Housing 4.2-8 4.2.5.7 Control Rod Drive Housing Supports 4.2-8 4.2.5.8 Incore Flux Monitor Housings 4.2-8 4.2.5.9 Reactor Vessel Insulation 4.2-8 4.2.6 Safety Evaluation 4.2-9 4.2.7 Inspection and Testing 4.2-14 4.2.8 Proposed Nuclear Safety Requirements for Initial Plant Operation 4.2-15 4.2.8.1 General 4.2-15 4.2.8.2 Safety Limit 4.2-15 4.2.8.3 Proposed Limiting Conditions for Initial Plant Operation 4.2-16 4.2.8.4 Proposed Surveillance Requirements for Initial Plant Operation 4.2-20 4.2.9 Current Operational Nuclear Safety Requirements 4.2-22 4.2.10 References 4.2-22 4.3 RECIRCULATION SYSTEM 4.3-1 4.3.1 Power Generation Objective 4.3-1 4.3.2 Power Generation Design Basis 4.3-1 4.3.3 Safety Design Basis 4.3-1 4.3.4 Description 4.3-1 4.3.5 Safety Evaluation 4.3-7 4.3.6 Inspection and Testing 4.3-8 4.3.7 Operational Nuclear Safety Requirements for Plant Operation 4.3-9 4.3.8 Current Technical Specifications 4.3-8 4.3.9 References 4.3-10 4-i Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 4.4 NUCLEAR SYSTEM PRESSURE RELIEF SYSTEM 4.4-1 4.4.1 Safety Objective 4.4-1 4.4.2 Safety Design Basis 4.4-1 4.4.3 Power Generation Objective 4.4-1 4.4.4 Power Generation Design Basis 4.4-2 4.4.5 Description 4.4-2 4.4.6 Safety Evaluation 4.4-7 4.4.7 Power Generation Evaluation 4.4-8 4.4.8 Inspection and Testing 4.4-8 4.4.9 Operational Nuclear Safety Requirements for Plant Operation 4.4-9 4.4.10 Current Technical Specifications 4.4-11 4.4.11 References 4.4-11 4.5 MAIN STEAM LINE FLOW RESTRICTOR 4.5-1 4.5.1 Safety Objective 4.5-1 4.5.2 Safety Design Basis 4.5-1 4.5.3 Description 4.5-1 4.5.4 Safety Evaluation 4.5-2 4.5.5 Inspection and Testing 4.5-2 4.6 MAIN STEAM LINE ISOLATION VALVES 4.6-1 4.6.1 Safety Objectives 4.6-1 4.6.2 Safety Design Basis 4.6-1 4.6.3 Description 4.6-2 4.6.4 Safety Evaluation 4.6-6 4.6.5 Inspection and Testing 4.6-8 4.6.6 Operational Nuclear Safety Requirements 4.6-9 4.7 REACTOR CORE ISOLATION COOLING SYSTEM 4.7-1 4.7.1 Safety Objective 4.7-1 4.7.2 Safety Design Basis 4.7-1 4.7.3 Power Generation Objective 4.7-1 4.7.4 Power Generation Design Basis 4.7-1 4.7.5 Description 4.7-2 4.7.6 Safety Evaluation 4.7-5 4.7.7 Inspection and Testing 4.7-5 4.7.8 Operational Nuclear Safety Requirements for Plant Operation 4.7-6 4.7.9 Current Technical Specifications 4.7-7 4.7.10 References 4.7-7 4.8 RESIDUAL HEAT REMOVAL SYSTEM 4.8-1 4.8.1 Safety Objective 4.8-1 4.8.2 Safety Design Bases 4.8-1 4-ii Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 4.8.3 Power Generation Objective 4.8-1 4.8.4 Power Generation Design Bases 4.8-1 4.8.5 Description 4.8-2 4.8.5.1 General 4.8-2 4.8.5.2 Shutdown Cooling Subsystem 4.8-3 4.8.5.3 Low Pressure Coolant Injection Subsystem 4.8-4 4.8.5.4 Suppression Pool Cooling Subsystem 4.8-5 4.8.5.4.1 LPCI With Heat Rejection 4.8-6 4.8.5.5 Containment Spray Subsystem 4.8-6 4.8.5.6 Augmented Fuel Pool Cooling 4.8-6a 4.8.6 Safety Evaluation 4.8-6b 4.8.7 Inspection and Testing 4.8-6b 4.8.8 Nuclear Safety Requirements for Plant Operation 4.8-7 4.8.9 Current Technical Specifications 4.8-8 4.9 REACTOR WATER CLEANUP SYSTEM 4.9-1 4.9.1 Power Generation Objectives 4.9-1 4.9.2 Power Generation Design Basis 4.9-1 4.9.3 Description 4.9-1 4.9.4 Inspection and Testing 4.9-6 4.10 NUCLEAR SYSTEM LEAKAGE RATE LIMITS 4.10-1 4.10.1 Safety Objective 4.10-1 4.10.2 Safety Design Basis 4.10-1 4.10.3 Description 4.10-1 4.10.3.1 Identified Leakage Rate 4.10-3 4.10.3.2 Unidentified Leakage Rate 4.10-3 4.10.3.3 Reactor Pressure Boundary Leak Detection System 4.10-5 4.10.4 Safety Evaluation 4.10-7 4.10.5 Inspection and Testing 4.10-7 4.10.6 Proposed Nuclear Safety Requirements for Initial Plant Operation 4.10-8 4.10.7 Current Operational Nuclear Safety Requirements 4.10-8 4.11 MAIN STEAM LINES AND FEEDWATER PIPING 4.11-1 4.11.1 Power Generation Objective 4.11-1 4.11.2 Safety Design Basis 4.11-1 4.11.3 Power Generation Design Bases 4.11-1 4.11.4 Description 4.11-1 4.11.5 Safety Evaluation 4.11-3 4.11.6 Testing and Inspections 4.11-3 4-iii Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 4 LIST OF TABLES Table Title 4.2-1 Reactor Pressure Vessel Materials 4.2-2 Reactor Vessel Data 4.2-3 Reactor Vessel Attachments 4.2-4 Summary of Charpy V-Notch and Drop-Weight Tests for Reactor Plates and Forgings 4.3-1 Reactor Recirculation System Design Characteristics 4.4-1 Nuclear System Safety and Relief Valves 4.4-2 Nuclear System Pressure Relief System Requirements for Plant Operation 4.6-1 Main Steam Line Isolation Valve Requirements for Plant Operation 4.7-1 Reactor Core Isolation Cooling System Turbine-Pump Design Data 4.7-2 Reactor Core Isolation Cooling System for Current Plant Safety Analysis Instrument Specifications 4.7-3 Reactor Isolation Cooling System Operational Requirements for Plant Operation 4.8-1 Residual Heat Removal System Equipment Design Data 4.8-2 Residual Heat Removal System (Suppression Pool Cooling Mode) Operational Requirements for Plant Operation 4.9-1 Reactor Water Cleanup System Equipment Design Data 4.9-2 Reactor Water Cleanup System Equipment Materials Specifications 4-iv Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 4.2-1 (Deleted - See Figure 3.3-1 Sheet 1 of 2) 4.2-2 (Deleted - See Figure 3.3-1 Sheet 2 of 2) 4.2-3 Typical Detail for Field Welded Safe End 4.2-4 Reactor Vessel Skirt-Insulation 4.2-5 Change in NDTT vs Neutron Exposure 4.2-6 NDTT versus Neutron Exposure Used in Initial Safety Analysis 4.3-1 Recirculation System Elevation, Isometric 4.3-2 Nuclear Boiler Piping and Instrumentation Diagram, Sheet 1 (Drawing M252) 4.3-3 Recirculation Pump and Instrumentation Diagram (Drawing M251) 4.3-4 Jet Pump Operating Principle 4.3-5 Recirculation System Core Flooding Capability 4.4-1 Nuclear System Relief Valve - Three-Stage - Closed Position 4.4-2 Nuclear System Relief Valve - Three Stage - Open Position 4.4-3 Nuclear System Relief Valve Stage Topworks 4.6-1 Main Steam Line Isolation Valve (Drawing 2518-2-6 Sheets 1 and 2) 4.6-2 Main Steam Line Isolation Valve Schematic Control Diagram 4.7-1 RCIC System P&ID, Sheet 1 (Drawing M245) 4.7-2 RCIC System P&ID, Sheet 2 (Drawing M246) 4.7-3 Reactor Core Isolation Cooling System Process Diagram (Drawing M1G1-2) 4.7-4 Reactor Core Isolation Cooling System Functional Control Diagram, Sheet 1 (Drawing M1G2-5) 4.7-5 Reactor Core Isolation Cooling System Functional Control Diagram, Sheet 2 (Drawing M1G4-5) 4.7-6 Reactor Core Isolation Cooling System Functional Control Diagram, Sheet 3 (Drawing M1G3-4) 4-v Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 4.8-1 Residual Heat Removal System Process Diagram (Drawing M241) 4.8-2 Residual Heat Removal System Process Diagram (Drawing M1H4-4) 4.8-3 Residual Heat Removal System Heat Transfer Capability 4.9-1 Reactor Water Cleanup System Functional Control Diagram (Drawing M1L2-8) 4.9-2 Reactor Water Cleanup System P&ID (Drawing M247) 4.9-3 Cleanup Filter Demineralizer System P&ID (Drawing M248) 4.10-1 (Deleted - See Figure 10.19-1 Drawing M239) 4.10-2 Drywell Sumps Diagram 4-vi Rev. 30 - Nov. 2015

PNPS-FSAR 4.4 NUCLEAR SYSTEM PRESSURE RELIEF SYSTEM 4.4.1 Safety Objective The safety objective of the nuclear system Pressure Relief System is to prevent over pressurization of the nuclear system. In addition, the automatic depressurization feature of the nuclear system Pressure Relief System operates to reduce the nuclear system pressure so that the Low Pressure Core Cooling Systems can reflood the core following certain postulated transients or accidents.

4.4.2 Safety Design Basis

1. The nuclear system Pressure Relief System shall prevent over pressurization of the nuclear system in order to prevent failure of the nuclear system process barrier due to pressure.

2. The nuclear system Pressure Relief System shall provide automatic nuclear system depressurization for small breaks in the nuclear system so that the Low Pressure Coolant Injection (LPCI) and the Core Spray Systems can operate to protect the fuel barrier.

3. The relief valve discharge piping shall be designed to accommodate forces resulting from relief action, and shall be supported for reactions due to flow at maximum relief valve discharge capacity so that system integrity is maintained.

4. The nuclear system Pressure Relief System shall be designed for testing prior to nuclear system operation and for periodic verification of the operability of the nuclear system Pressure Relief System.

5. The capacity of the relief and safety valves shall be sufficient to prevent reactor pressure from exceeding the allowable overpressure of ASME Code,Section III, during a main steam isolation valve closure with indirect scram.

6. The nuclear system Pressure Relief System shall be designed to be capable of providing a manually initiated nuclear system depressurization for postulated transients and accidents in which the main heat sink is unavailable.

4.4.3 Power Generation Objective The power generation objective of the nuclear system Pressure Relief System is to sufficiently relieve normal overpressure transients following load rejections so that safety valve actuation is not required.

4.4-1 Rev. 30 - Nov. 2015

PNPS-FSAR 4.4.4 Power Generation Design Basis

1. The nuclear system relief valves shall be sized to prevent opening of the safety valves during load rejections.

2. The nuclear system relief valves shall discharge to the pressure suppression pool.

3. The relief valves shall properly reclose following a load rejection so that normal operation can be resumed as soon as possible.

4.4.5 Description The nuclear system Pressure Relief System includes two safety and four relief valves, all of which are located on the main steam lines within the drywell between the reactor vessel and the flow restrictor. The safety valves provide protection against overpressure of the nuclear system and discharge directly to the interior space of the drywell.

The relief valves, which discharge to the suppression pool, provide three main protection functions:

1. Overpressure relief operation. The valves are opened (self-actuated) to limit the pressure rise and prevent spring safety valve opening

2. Overpressure safety operation. The valves augment the safety valves by opening in order to prevent nuclear system over pressurization

3. Depressurization operation. The valves are opened automatically or manually by indirectly operated devices, as part of the Core Standby Cooling System (CSCS), for small breaks in the nuclear system process barrier The safety valves are spring loaded valves which are designed, constructed, and marked with data in accordance with the ASME Boiler and Pressure Vessel Code,Section III, Article 9, and in accordance with USAS B31.1.0 and B16.5. Popping point tolerance (pressure at which valve "pops" wide open) is in accordance with ASME Section I, Paragraph PG-72(c). The material on the pressure side of the valve disc, in contact with the steam, is stainless steel. The valves are designed for operation with saturated steam containing less than 1 percent moisture and are designed to have an opening response time equal to or less than 0.3 sec.

4.4-2 Rev. 30 - Nov. 2015

PNPS-FSAR The relief valves are designed, constructed, and marked with data in accordance with the ASME Boiler and Pressure Vessel Code,Section III, Article 9, and in accordance with USAS B31.1.0 and B16.5.

Popping point tolerance (pressure at which valve "pops" wide open) is in accordance with ASME Section I, Paragraph PG-72(c). Each valve is self actuating at the set relieving pressure, but may also be actuated by indirectly operated devices to permit remote manual or automatic opening at lower pressures. For depressurization operation, each relief valve is provided with a power actuated device capable of opening the valve at any steam pressure above 100 psig, and capable of holding the valve open until the steam pressure decreases to about 50 psig. The control system for the actuator is described in Section 7.4, Core Standby Cooling Systems Control and Instrumentation. Pressure containing parts of the valve body are fabricated of ASME SA-105 Carbon Steel and SB-564 Inconel 600. The relief valve is designed for operation with saturated steam containing less than 1 percent moisture. The relieving pressures for overpressure relief and safety modes are adjustable between 1100 and 1200 psig with a maximum back pressure of 40 percent of the set pressure. The delay time (maximum elapsed time between overpressure signal and actual valve motion) and the response time (maximum valve stroke time) are each equal to or less than 0.1 sec. The delay time (maximum elapsed time between overpressure signal and actual valve motion) assumed in the transient analysis for relief valve and safety valves are 0.400 and 0.000 seconds respectively. The opening time (maximum valves stroke time) assumed in the transient analysis for the relief valves and the safety valves are 0.150 and 0.300 seconds respectively.

Temp Mod EC 44839 R1 accommodates the replacement of all four (4)

Safety Relief Valves (SRVs) with 2-stage SRVs.

Each of the three stage SRVs consists of three principal assembly stages: two pilot stages and one main stage. The modular pilot assembly houses the primary pilot controlled by a sensing bellows and is the primary control element for the safety function of the valve. The second stage pilot provides an exhaust path for the pressure above the piston in the main to open the valve. Figures 4.4-1 and 4.4-2 are schematic illustrations of the three stage valve in closed and open positions.

During assembly, the pilot bellows is mechanically extended a slight amount to provide a preload force on the pilot disc which seals the disc tightly and prevents reverse leakage at low system pressures.

In operation, as pressure increases, the bellows preload force is reduced to zero. From this point, the pilot disc is held closed by reactor pressure acting over the pilot valve seat area. This hydraulic seating force increases with increasing system pressure and prevents leakage, or simmering at system pressures near the set pressure. The three-stage pilot disc is submerged in condensate, which provides protection from the corrosive non-condensable that may collect in the valve.

4.4-3 Rev. 30 - Nov. 2015

PNPS-FSAR As system pressure further increases, bellows expansion reduces the abutment gap between the stem and disc yoke. When the stem abuts against the yoke, further pressure increases reduce the net pilot seating force to zero. Once the pilot stage starts to open, the hydraulic seating force is reduced, resulting in a net increase in the force tending to extend the bellows. This increase in net force produces a popping action during the pilot stage opening.

In its normally closed position, the main valve disc is tightly seated by the combined forces exerted by reactor pressure acting over the area of the main valve disc and the main valve preload spring.

When system pressure increases to the pilot stage set pressure, the pilot and second stage of the pilot valve assembly will open, thereby venting the chamber over the main valve piston to the downstream side of the valve. This venting action creates a differential pressure across the main valve piston in a direction tending to open the valve. The main valve piston is sized such that the resultant opening force is greater than the combined spring preload and hydraulic seating force.

As is the case for the pilot stage, once the main valve disc starts to open, the hydraulic seating force is reduced, causing a significant increase in opening force and the characteristic full opening or popping action.

When the reactor pressure has been reduced sufficiently, the pilot stage reseats, the second stage reseats after depressurization of the second stage piston chamber accomplished by leakage past the piston rings and piston orifice. Leakage of system fluid past the main valve piston then repressurizes the chamber over the piston, canceling the hydraulic opening force and permitting the main spring and flow forces to close the main stage. Once closed the additional hydraulic seating force due to system pressure acting on the main valve seats the valve tightly and prevents leakage.

The SRV pilots are fitted with air operators to provide selected remote manual or automatic actuation of the valve at other than set pressure. The air operator is a diaphragm type air operator which is energized to open the valve. It is actuated by means of a solenoid control valve which admits nitrogen to the operator piston chamber and strokes the plunger, in turn stroking the second stage disc. The main valve then opens as described above. De-energizing the solenoid vents the air operator and permits the second stage disc to close. The main valve then reseats as described above.

The 2-stage pilot operated safety relief valve consists of two principle assemblies: a pilot valve section (top works) and the main valve section (Fig. 4.4-3) The pilot valve section (first stage) is the pressure sensing and control element and the main valve (second stage) provides the pressure relief function. The first stage consists of a pilot-stabilizer disc assembly. The pilot is the pressure sensing member to which the stabilizer disc movement is coupled. Though not mechanically connected, a light spring keeps the stabilizer in contact with the pilot. A pilot preload spring permits set point adjustment of the valve and provides pilot seating 4.4-4 Rev. 30 - Nov. 2015

PNPS-FSAR force. The second or main stage consists essentially of a large piston which includes the main valve disc, the main valve chamber, and a preload spring.

A typical sequence of operation for overpressure relief self actuation for the 2-stage SRV can be described as follows. Refer to Figure 4.4-3:

1. When the reactor is at operating pressure, below the set point of the valve, the first stage and main stage chamber are at system pressure with the valve in the closed position (Figure 4.4-3). The preload spring force seats the pilot valve tightly and prevents reverse leakage at low system pressures or high back pressures. The main valve disc is tightly seated by the combined forces exerted by the main valve preload spring and the system internal pressure which acts over the area of the main valve disc. In the closed position, the static pressures will be equal in the valve body and in the chamber over the main valve piston. Leakage through the piston orifice equalizes the pressure.

2. As the system pressure increases to the set point of the valve, the pressure acting on the pilot below the seat produces a force great enough to overcome the preload spring force and lifts the pilot off its seat.

3. As the pilot moves to full open, the stabilizer disc follows the pilot until the stabilizer is seated.

4. With the pilot full open and the stabilizer disc seated, the main piston chamber is vented to the discharge piping. This venting action creates a differential pressure across the main valve piston in a direction tending to open the valve. The main valve piston is sized such that the resultant opening force is greater than the combined spring load and hydraulic seating force. The stabilizer disc is designed to control the valve seating force. The stabilizer disc is designed to control the valve blowdown by holding the pilot open until the proper reclosing pressure is reached. The stabilizer chamber is connected by a passage to the inlet side of the valve.

5. As occurs in the case of the pilot valve, once the main valve disc starts to open, the hydraulic seating force is reduced; this causes a significant increase in opening force and the characteristic full opening or "popping" action.

6. When the pressure has been reduced sufficiently to permit the pilot valve to close, leakage of system fluid past the main valve piston repressurizes the chamber over the piston, eliminates the hydraulic opening force, and permits the preload spring to close the valve. Once the valve is closed, the additional hydraulic seating force due to system pressure acting on the main valve disc seats the main valve tightly and prevents leakage.

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PNPS-FSAR The relief valves are installed so that each valve discharge is piped through its own uniform diameter discharge line to a point below the minimum water level in the primary containment suppression pool to permit the steam to condense in the pool. Water in the line above suppression pool water level would cause excessive pressure at the relief valve discharge when the valve again opened. For this reason, vacuum relief valves are provided on each relief valve discharge line to prevent drawing water up into the line due to steam condensation following termination of relief valve operation.

The relief valves are located on the main steam line piping, rather than on the reactor vessel top head, primarily to simplify the discharge piping to the pool and to avoid the necessity for removing sections of this piping when the reactor head is removed for refueling. In addition, the relief valves, as well as the safety valves, are more accessible during a quick shutdown to correct possible valve malfunctions when located on the steam lines.

Each of the four relief valves is equipped with an air/nitrogen accumulator and check valve arrangement. These accumulators are provided to assure that the valves can be held open following failure of the air or nitrogen supply to the accumulators, and are sized to contain sufficient air for a minimum of 20 valve operations. Bottled gas can be used to manually recharge the accumulators associated with two safety relief valves. This capability was installed to address a potential loss of normal nitrogen supply to the accumulators which was identified during USI-A46 seismic reviews.

The automatic depressurization feature of the nuclear system Pressure Relief System serves as a backup to the High Pressure Coolant Injection (HPCI) System under loss of coolant accident conditions. If the HPCI System does not operate and one of the LPCI or core spray pumps is available, the nuclear system is depressurized sufficiently to permit the LPCI and Core Spray Systems to operate to protect the fuel barrier. Depressurization is accomplished through automatic opening of the relief valves to vent steam to the suppression pool. For small line breaks when the HPCI System fails, the nuclear system is depressurized in sufficient time to allow the Core Spray and LPCI Systems to provide core cooling to prevent any fuel clad melting.

For large breaks, the vessel depressurizes rapidly through the break without assistance. The signal for the relief valves to open and remain open is based upon simultaneous signals from: (1) drywell high pressure unless bypassed by a preset time delay relay, (2) reactor vessel low-low water level, (3) adequate discharge pressure on one of the LPCI or core spray pumps, and (4) 120 sec delay timer completes timing cycle. Further descriptions of the operation of the automatic depressurization feature are found in Section 6, Core Standby Cooling Systems, and Section 7.4, Core Standby Cooling System Control and Instrumentation. The Automatic Depressurization System is designed as Class I equipment in accordance with Appendix C.

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PNPS-FSAR A manual depressurization of the nuclear system can be effected in the event the main condenser is not available as a heat sink after reactor shutdown. The steam generated by nuclear system sensible and core decay heat is discharged to the suppression pool. The core is reflooded by the low pressure CSCS. The relief valves are individually operated by remote manual controls from the main control room to control nuclear system pressure.

Section 7.4.3.3.4 describes instrumentation associated with relief and safety valves that provides leakage monitoring capability and position status.

The number, set pressures, and rated capacities of the relief valves and safety valves are shown on Table 4.4-1.

4.4.6 Safety Evaluation The ASME Boiler and Pressure Vessel Code require that each vessel designed to meet Section III be protected from pressure in excess of the vessel design pressure. A peak allowable pressure for upset conditions of 110 percent of the vessel design pressure is allowed by the code. The code specification for safety valves requires that, (1) the lowest safety valve be set at or below vessel design pressure, and (2) the highest safety valve be set to open at or below 105 percent of vessel design pressure.

The relief valves are set during testing to open by self actuation (overpressure safety mode) at 1155 +/- 1% psig and the safety valves are set to operate at 1280 +/- 1% psig. This satisfies the ASME Code specifications for safety and relief valves since the relief valves open below the 1,250 psig nuclear system design pressure and below 1,313 psig (105 percent of nuclear system design pressure).

Safety and relief valve capacity is determined by analyzing the pressure rise accompanying the main steam flow stoppage resulting from an MSIV closure with the reactor initially operating at 2,028 MWt +2% to account for uncertainty in the initial power level. The analysis hypothetically assumes the reactor is shut down by an indirect flux scram. Reference 1 describes the reasons for choosing this event, the conservatism of applying upset condition limits to the event analysis, and models and methodology used in the evaluation of this event. The sequence of events assumed in this analysis is investigated to meet ASME code requirements and for Pressure Relief System evaluation. Comprehensive supporting analysis for the current relief and safety valve capacities, set pressures, and set pressure tolerance specified in Table 4.4-4 is documented in Reference 2.

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PNPS-FSAR Rated power operation is permitted at PNPS over a core flow range indicated on the power flow map described in FSAR Section 3.7.

Evaluation of maximum vessel pressure resulting from the limiting transients is performed at the core flow included in the PNPS licensed operating domain that results in the highest vessel pressure. This analysis for maximum vessel pressure and verification of the adequacy of overpressure protection is repeated for each reload cycle and the results are provided in the supplemental reload licensing submittal in Appendix Q. The analysis typically indicates that the design capacities of the safety valves and relief valves are capable of maintaining adequate margin, approximately 30 and 35 psi below the peak ASME Code allowable pressure in the nuclear system (1,375 psig).

System malfunctions which pose threats to the radioactive material containment barriers are presented in Section 14, Station Safety Analysis. Evaluation of the most severe abnormal operational transient resulting in a nuclear system pressure rise shows that the relief valves open fully to limit the pressure rise, and that the peak pressure at the vessel dome is much below that given by the hypothetical event of MSIV closure with indirect scram.

Evaluations of the automatic depressurization capability of the nuclear system Pressure Relief System are presented in Section 6, Core Standby Cooling Systems, and Section 7.4, Core Standby Cooling System Controls and Instrumentation.

The piping attached to the relief valve discharges is designed, installed, and tested in accordance with USAS B31.1.0 plus the additional requirements outlined in Appendix A.

It is concluded that the safety design bases are satisfied.

4.4.7 Power Generation Evaluation Although this is not a safety concern, an analysis is performed for each reload to show that the relief valves have the capacity to hold reactor vessel pressure below the safety valve set point of 1280 psig in the event of an abnormal operational transient.

4.4.8 Inspection and Testing The safety and relief valves are tested in accordance with the manufacturer's quality control procedures to detect defects and prove operability prior to installation. The following final tests were performed:

1. Hydrostatic test.

2. Seat leakage test.

3. Steam test: valve pressurized with saturated steam with the pressure rising to the valve set pressure, the specified set point is verified when the valve opens (capacity and blowdown not tested with steam).

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PNPS-FSAR The safety and relief valves are installed as received from the factory. The set points are adjusted, verified, and indicated on the valves by the vendor. Proper manual and automatic actuation of the relief valves is verified during the preoperational test program.

It is recognized that it is not feasible to test the safety and relief valve set points while the valves are in place or during normal station operation. The valves are mounted on 6 in dia, 1,500 lb primary service rating flanges so that they may be removed for maintenance or bench checks, and reinstalled during normal station shutdowns. The internal surface of the relief valves and safety valves are 100 percent visually inspected when the valves are removed for maintenance or bench checks.

Based on a comparison of analyses of safety relief bypass capability made for plants in the GE 1965 Product Line, the original design with three relief valves has been modified to four relief valves to ensure adequate protection.

4.4.9 Operational Nuclear Safety Requirements for Plant Operation Table 4.4-2 represents the nuclear safety requirements for the nuclear system Pressure Relief System for each BWR operating state.

Table 4.4-2 represents an extension of the plant wide BWR systems analysis of Appendix G to the components of the nuclear system Pressure Relief System. The following references provide important information justifying the entries on Table 4.4-2:

Reference Information Provided

1. Earlier parts of Description of the nuclear Section 4.4 system Pressure Relief System hardware; Pressure Relief System relief capacity, and relief set-points.

2. ASME Boiler and Assumptions required for Pressure Vessel Code, the relief and safety valve Section III, Article 9, sizing transients.

Protection Against Overpressure

3. Plant Safety Analysis, Analysis verifying the Section 14 response of the nuclear systems Pressure Relief System to transients and accidents.

4. Plant Nuclear Safety Identifies conditions and Operational Analysis, events for which the nuclear Appendix G system Pressure Relief System is required.

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PNPS-FSAR Each detailed requirement on Table 4.4-2 is referenced to the most significant plant condition originating the need for the requirement by identifying a matrix block on Table G.5-3. The matrix block in the "minimum required for action" columns on Table 4.4-2 and are coded as follows:

Example of Matrix

Reference:

F13 - 64

° ° °

F = BWR operating state F

13 = Event (row #13)

64 = Nuclear System Pressure Relief System (column #64)

All relief valves in the nuclear system Pressure Relief System function as a part of the Automatic Depressurization System. The operational nuclear safety requirements placed on these valves, due to their function in the Automatic Depressurization System, are discussed in Section 6.7.

In the states where the reactor head is on (States C through F), the potential to pressurize exists and overpressure protection is required. The minimum number of relief and safety valves actually required for an abnormal operational transient is variable and dependent on factors such as initial stored energy, initial pressure, energy produced during pressurization, scram setpoint, scram speed, and scram reactivity. Both the closure of all main steam isolation valves and a turbine trip with bypass failure produce severe pressure transients. Evaluation of transient behavior has shown that the most severe pressurization event is the main steam isolation valve closure when credit is taken only for the indirectly derived scrams.

The main steam isolation valve closure with neutron flux scram is utilized for relief and safety valve sizing for the following reasons. The ASME Boiler and Pressure Vessel Code,Section III requires that protection systems directly related to the abnormal operational transient in question cannot be credited with action in determining relief or safety valve capacity. Therefore, the main steam isolation valve closure with neutron flux scram is used in relief and safety valve sizing. Credit for the valve position scram is not taken because it is directly related to the main steam isolation valve closure.

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PNPS-FSAR The main steam isolation valve closure with flux scram is evaluated for each reload and the results are reported in the Supplemental Reload Licensing Report (Appendix Q). The cycle specific analysis of the main steam isolation closure is performed at the core thermal power (including measurement uncertainty) and core flow conditions that result in the highest overpressure condition. This analysis indicates that four relief valves and two safety valves operate.

Analysis is not performed to demonstrate adequate protection from less than four relief and two safety valves. Therefore, the Technical Specifications do not contain any allowance for relief or safety valve inoperability.

The method of testing the operability of a relief or safety valve at rated conditions is to remove it from the reactor and perform a bench test. Thus, when operating, there is little definite knowledge of the actual number of operable relief and safety valves, and adequate redundancy must be assured by providing additional valves. As a result, the limiting condition for operation is more conservatively stated, i.e., the reactor may remain in operation and pressurized only if none of the relief or safety valves are known to be inoperable.

Experience in safety valve operation shows that a testing of 50 percent of the safety and relief valves per cycle is adequate to detect failures or deterioration. The bench tests shall be used to verify that the set points are within the 1 percent tolerance of the design pressure, as specified in Section III of the ASME Boiler and Pressure Vessel Code. An analysis has been performed which shows that with all safety and relief valves set at values given in Table 4.4-1, the reactor vessel code transient overpressure limit of 1,375 psig is not exceeded. The relief valves are exercised once per operating cycle at reduced system pressure to assure that they will open and pass steam.

4.4.10 Current Technical Specifications The current limiting conditions for operation, surveillance requirements, and their bases are contained in the current Station Technical Specifications referenced in Appendix B.

Safety and relief valve leakage monitoring requirements formerly located in the Technical Specifications are located in FSAR Appendix B.

4.4.11 References

1. NEDE-24011-P-A, General Electric Standard Application for Reactor Fuel, applicable revision.

2. NEDC-33532P, Pilgrim Nuclear Power Station Safety Valve Setpoint Increase Revision 2, January 2011 4.4-11 Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 5 CONTAINMENT TABLE OF CONTENTS Section Title Page 5.1

SUMMARY

DESCRIPTIONS 5.1-1 5.1.1 General 5.1-1 5.1.2 Primary Containment System 5.1-1 5.1.3 Secondary Containment System 5.1-1 5.2 PRIMARY CONTAINMENT SYSTEM 5.2-1 5.2.1 Safety Objective 5.2-1 5.2.2 Safety Design Basis 5.2-1 5.2.3 Description 5.2-1 5.2.3.1 General 5.2-1 5.2.3.2 Drywell 5.2-3 5.2.3.3 Pressure Suppression Chamber and Vent System 5.2-5 5.2.3.3.1 General 5.2-5 5.2.3.3.2 Pressure Suppression Chamber 5.2-5 5.2.3.3.3 Vent System 5.2-5 5.2.3.3.4 Pressure Suppression Pool 5.2-6 5.2.3.4 Penetrations 5.2-6 5.2.3.4.1 General 5.2-6 5.2.3.4.2 Pipe Penetrations 5.2-7 5.2.3.4.3 Electrical Penetrations 5.2-7 5.2.3.4.4 TIP Penetrations 5.2-8 5.2.3.4.5 Personnel and Equipment Access Locks 5.2-9 5.2.3.4.6 Access to the Pressure Suppression Chamber 5.2-9 5.2.3.4.7 Access for Refueling Operations 5.2-9 5.2.3.5 Primary Containment Isolation Valves 5.2-9 5.2.3.5.1 General Criteria 5.2-9 5.2.3.5.2 Additional Considerations 5.2-10 5.2.3.5.3 Instrument Piping Connected to the Reactor Primary System 5.2-12 5.2.3.6 Venting and Vacuum Relief System 5.2-15 5.2.3.7 Primary Containment Cooling and Ventilation System 5.2-16 5.2.3.8 Primary Containment Atmospheric Control System 5.2-17 5.2.3.9 Drywell Temperature and Pressure Indication 5.2-18 5.2.3.10 Pressure Suppression Pool Temperature and Level Indication 5.2-18 5.2.3.11 Drywell Level and Torus Pressure 5.2-18 5.2.4 Safety Evaluation 5.2-18 5.2.4.1 General 5.2-18 5.2.4.2 Primary Containment Characteristics Following a Design Basis Accident 5.2-19 5.2.4.3 Primary Containment Capability 5.2-20 5.2.4.4 Primary Containment Leakage Analysis 5.2-20 5-i Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 5 CONTAINMENT TABLE OF CONTENTS Section Title Page 5.2.4.5 Containment Integrity Protection 5.2-20 5.2.4.6 Containment Isolation 5.2-22 5.2.4.7 Containment Flooding 5.2-24 5.2.4.8 Pressure Suppression Pool Water Storage 5.2-24 5.2.4.9 Limitations During Planned Operations 5.2-24 5.2.4.10 Primary Containment Steam Quenching 5.2-25 5.2.4.11 Steam Bypass 5.2-25 5.2.5 Inspection and Testing 5.2-27 5.2.5.1 Primary Containment Integrity and Leaktightness 5.2-27 5.2.5.2 Penetrations 5.2-27 5.2.5.3 Isolation Valves 5.2-28 5.2.6 Nuclear Safety Requirements for Plant Operation 5.2-28 5.2.7 Current Technical Specifications 5.2-31 5.2.8 Pipe Break Transient Analysis 5.2-31 5.2.8.1 Pipe Mechanical Failure and Safety Design 5.2-31 5.2.8.2 Pipe Protection System 5.2-32 5.2.8.3 Design Basis Line Break 5.2-34 5.2.9 References 5.2-35 5.3 SECONDARY CONTAINMENT SYSTEM 5.3-1 5.3.1 Safety Objective 5.3-1 5.3.2 Safety Design Basis 5.3-1 5.3.3 Description 5.3-2 5.3.3.1 General 5.3-2 5.3.3.2 Reactor Building 5.3-2 5.3.3.3 Reactor Building Isolation and Control System 5.3-2 5.3.3.4 Standby Gas Treatment System 5.3-3 5.3.3.5 Main Stack 5.3-5 5.3.4 Safety Evaluation 5.3-5a 5.3.5 Inspection and Testing 5.3-7 5.3.6 Nuclear Safety Requirements for Plant Operation 5.3-8 5.3.7 Current Technical Specifications 5.3-9 5.4 CONTROL OF COMBUSTIBLE GAS CONCENTRATIONS IN CONTAINMENT 5.4-1 5.4.1 Introduction 5.4-1 5.4.2 Source of Hydrogen and Oxygen Accumulation in Containment 5.4-1a 5.4.3 System Description 5.4-2 5.4.4 Containment Mixing 5.4-5 5.4.5 Combustible Gas Monitoring 5.4-6 5.4.6 Radiological Consequences of Containment Venting 5.4-6 5-ii Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 5 CONTAINMENT TABLE OF CONTENTS Section Title Page 5.4.7 Direct Torus Vent 5.4-6 5.4.7.1 Introduction 5.4-6 5.4.7.2 System Description 5.4-6 5.4.7.3 Radiological Consequences of DTVL Use 5.4-7 5.4.8 References 5.4-7 5-iii Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 5 LIST OF TABLES Table Title 5.2-1 Primary Containment System, Principal Design Parameters and Characteristics 5.2-2 Drywell Atmosphere Cooling Data Sheet 5.2-3 (Deleted) Refer to TL.2-1 5.2-4 Containment and Reactor Vessel Isolation Valves 5-iv Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 5 LIST OF FIGURES Figure Title 5.2-1 Reactor Pressure Response for Various Size Steam Leaks 2

5.2-2 Containment Response to 0.02 Ft Steam Leak 2

5.2-3 Containment Response to 0.05 Ft Steam Leak 2

5.2-4 Containment Response to 0.10 Ft Steam Leak 2

5.2-5 Containment Response to 0.35 Ft Steam Leak 2

5.2-6 Containment Response to 0.5 Ft Steam Leak 5.2-7 Time for Containment Wall to Reach 281F for Various Size Steam Leaks 5.2-8 Time to Reach 10 psig in Drywell for Various Size Steam Leaks 5.2-9 Typical Piping Penetration 5.2-10 Typical Piping Penetration 5.2-11 Typical Piping Penetration 5.2-12 Typical Instrument Penetration 5.2-13 Typical Electrical Penetration for Low Voltage Power, Control and Instrumentation Cable 5.2-14 Typical Electrical Penetration for Coaxial Cable 5.2-15 Typical Electrical Penetration for Medium Voltage Power Cable 5.2-16 (Deleted - See Figure 5.4-1 Drawing M227) 5.2-17 (Deleted - See Figure 7.18-2 Drawing M294) 5.2-18 Drywell Atmosphere Cooling Air Flow Diagram (Drawing M291) 5.2-19 (Deleted) 5.2-20 (Deleted) 5.2-21 (Deleted) 5.2-22 Allowable Drywell to Suppression Pool Bypass Capacity vs Primary System Break Area 5.2-23 Drywell Pipe Protection System 5.3-1 Secondary Containment Isolation Control (Drawing M283) 5.4-1 Containment Atmospheric Control System (Drawing M227) 5-v Rev. 30 - Nov. 2015

PNPS-FSAR TABLE 5.2-1 PRIMARY CONTAINMENT SYSTEM PRINCIPAL DESIGN PARAMETERS AND CHARACTERISTICS Pressure suppression chamber:

Internal design pressure ................................. +56 psig External design pressure .................................. +2 psig Drywell:

Internal design pressure ................................. +56 psig External design pressure .................................. +2 psig Drywell free volume ............................... 132,000 to 147,000 ft3 Pressure suppression chamber free volume .......... 115,800 to 124,500 ft3 Pressure suppression pool water volume, maximum ...... (approx) 94,000 ft3 Pressure suppression pool water volume, minimum ...... (approx) 84,000 ft3 Submergence of vent pipe below pressure suppression pool surface ... (approx) 3 ft - 0 in to 3 ft - 5 in Design temperature of drywell ...................................... 281F Design temperature of pressure suppression chamber ................. 281F Downcomer vent pressure loss factor ................................ 6.21 Break area/total vent area ....................................... 0.0194 Drywell free volume/pressure suppression chamber free volume ....... 1.34 Primary system volume/pressure suppression pool volume ............ 0.268 Drywell free volume/primary system volume ........................... 7.4 Calculated maximum pressure during blowdown:

Drywell .................................................... 45 psig Pressure suppression chamber ............................... 27 psig Initial pressure suppression chamber temperature rise .......... 35F 1 of 1 Rev 26 - Oct 2007

PNPS-FSAR TABLE 5.2-2 DRYWELL ATMOSPHERE COOLING DATA SHEET Location Average Maximum*

General 135F 148F Recirculation Pump Motor Area - 128F Entering Air Temperature to Cooling Units 135F 148F Leaving Air Temperature from Cooling Units 85F 95F Cooling Water Supply Temperature 75F 85F Cooling Water Return Temperature 90F 100F Drywell Heat Gain 2.4 X 106 Btu/hr 3.4 X 106 Btu/hr Total Cooling Unit Capacity 3.6 X 106 Btu/hr 5.6 X 106 Btu/hr Total Cooling Unit Fan Capacity 72,000 ft3/min 110,000 ft3/min Total Fan Brake hp 54.8 67.8 Drywell Temperature 10 hr after shutdown 105F 105F NOTE:

As a result of higher cooling water supply temperature and extra heat load from scram of the control rod drives.

1 of 1 Rev 26 - Oct 2007

PNPS-FSAR TABLE 5.2-3, PENETRATION SCHEDULE, HAS BEEN DELETED REFER TO TABLE L.2-1, PENETRATION SCHEDULE 1 of 1 Rev 26 - Oct 2007

PNPS - FSAR TABLE 5 2-4 CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL PENE # & OP TIME TYPE TO OPEN POWER POSITION ISOLATION ISOLATION VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12) GRP POSITION SIGNAL NOTES AO-203-1A Main Steam Line A X-7A,IPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 AO-203-2A Main Steam Line A X-7A,OPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 AO-203-1B Main Steam Line B X-7B,IPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 AO-203-2B Main Steam Line B X-7B,OPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 AO-203-1C Main Steam Line C X-7C,IPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 AO-203-2C Main Steam Line C X-7C,OPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 AO-203-1D Main Steam Line D X-7D,IPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 AO-203-2D Main Steam Line D X-7D,OPC 3 0-5 0 A Globe Air/AC,DC Air & Spring Open 1 Closed B,D,P,Q 1 MO-220-1 Main Steam Drain X-8,IPC 30 0 A Gate AC AC Closed 1 Closed B,D,P,Q 9 MO-220-2 Main Steam Drain X-8,OPC 35 0 A Gate DC DC Closed 1 Closed B,D,P,Q 9 6-58A F W Line A X-9A,IPC -- A-X Check -- process Open -- -- Rev Flow 6-62A F W Line A X-9A,OPC -- A-X Check -- process Open -- -- Rev Flow 1301-50 RCIC Pp Discharge X-9A,OPC -- A-X Check -- process Closed -- -- Rx, Rev Flow MO-1301-49 RCIC Pp Discharge X-9A,OPC -- A-X Gate DC DC Closed -- -- RM MO-1201-80 RWCU Return X-9A,OPC 30 0 A-X Globe AC AC Open 6 Closed A,J,W,Y,RM 29 6-58B F W Line B X-9B,IPC -- A-X Check -- process Open -- -- Rev Flow 6-62B F W Line B X-9B,OPC -- A-X Check -- process Open -- -- Rev Flow 2301-7 HPCI Pp Discharge X-9B,OPC -- A-X Check -- process Closed -- -- Rx Rev Flow MO-2301-8 HPCI Pp Discharge X-9B,OPC -- A-X Gate DC DC Closed -- -- RM MO-1001-47 RHR S/D Cooling X-12,OPC 51 0 A-X Gate DC DC Closed 3 Closed A,F,M,U,RM MO-1001-50 RHR S/D Cooling X-12,IPC 32 0 A-X Gate AC AC Closed 3 Closed A,F,M,U,RM 1 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL PENE # & OP TIME TYPE TO OPEN POWER POSITION ISOLATION ISOLATION VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12) GRP POSITION SIGNAL NOTES MO-1201-2 RWCU Suction X-14;IPC 20 0 A-X Gate AC AC Open 6 Closed A,J,W,Y,RM 29 MO-1201-5 RWCU Suction X-14;OPC 34 0 A-X Gate DC DC Open 6 Closed A,J,W,Y,RM 29 SV-5065-31B H2/02 Analyzer Supply X-15E;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 SV-5065-35B H2/02 Analyzer Supply X-15E;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 1400-9A Core Spray to Rx Loop X-16A/IPC -- A-X Check -- Process Closed -- -- Rx, Rev Flow A /B MO-1400-24A C S to Rx A Loop X-16A;OPC 22 0 A-X Gate AC AC Open -- -- RM 11 MO-1400-25A C S to Rx A Loop X-16A;OPC 22 0 A-X Gate AC AC Closed -- -- RM 11 1400-9B Core Spray to Rx Loop X-16B/IPC -- A-X Check -- Process Closed -- -- Rx, Rev Flow A/B MO-1400-24B C S to Rx B Loop X-16B;OPC 22 0 A-X Gate AC AC Open -- -- RM 11 MO-1400-25B C S to Rx B Loop X-16B;OPC 22 0 A-X Gate AC AC Closed -- -- RM 11 AO-7017A R/W Collection & DW X-18;OPC 20 0 B Plug Air/AC Spring Open 2 Closed A,F, RM Floor Sump AO-7017B R/W Collection and D/W X-18;OPC 20 0 B Plug Air/AC Spring Open 2 Closed A,F, RM Floor Sump AO-7011A R/W Collection and D/W X-19;OPC 20 0 B Plug Air/AC Spring Open 2 Closed A,F, RM Equipment Sump AO-7011B R/W Collection and D/W X-19;OPC 20 0 B Plug Air/AC Spring Open 2 Closed A,F, RM Equipment Sump 31-CK-167 Instrument Air X-22;OPC -- C Check -- Process Open -- -- Rev Flow 30-CK-432 RBCCW Supply X-23;OPC -- C Check -- Process Open -- -- Rev Flow 2 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL PENE # & OP TIME TYPE TO OPEN POWER POSITION ISOLATION ISOLATION VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12) GRP POSITION SIGNAL NOTES MO-4002 RBCCW Return X-24;OPC -- C Gate AC AC Open -- -- RM AO-5043A Drywell 2 Exhaust Bypass X-25;OPC 10 0 B Globe Air/AC Spring Closed 2 Closed A,B,F,Z,RM 9,15,27,30 AO-5043B Drywell 2 Exhaust Bypass X-25;OPC 10 0 B Globe Air/AC Spring Closed 2 Closed A,B,F,Z,RM 9,15,27,30 AO-5044A Drywell Purge Exhaust X-25;OPC 50 B Butterfly Air/AC Spring Closed 2 Closed A,F,Z,RM 27 AO-5044B Drywell Purge Exhaust X-25;OPC 50 B Butterfly Air/AC Spring Closed 2 Closed A,F,Z,RM 27 SV-5081A Post Acc Purge and Vent X-25;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5081B Post Acc Purge and Vent X-25;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5082A Post Acc Purge and Vent X-25;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5082B Post Acc Purge and Vent X-25;OPC -- B Globe AC Spring Closed -- -- RM 19 9-CK-340 Drywell Purge/Makeup X-26;OPC -- B Check -- Process Closed -- -- Rev Flow AO-5033A Drywell Purge/Makeup X-26:OPC 10 0 B Globe Air/AC Spring Closed 2 Closed A,B,F,Z,RM 9,27,30 AO-5033B Drywell/Torus Purge X-26;OPC 10 0 B Gate Air/AC Spring Closed 2 Closed A,F,Z,RM 9,21,27 AO-5035A Drywell Purge/Makeup X-26;OPC 50 B Butterfly Air/AC Spring Closed 2 Closed A,F,Z,RM 27 AO-5035B Drywell Purge/Makeup X-26;OPC 50 B Butterfly Air/AC Spring Closed 2 Closed A,F,Z,RM 27 SV-5085A Post Acc Purge and Vent X-26;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5086A Post Acc Purge and Vent X-26;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5086B Post Acc Purge and Vent X-26;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5065-33A H2/O2 Analyzer & PASS X-29E;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 Supply SV-5065-37A H2/O2 Analyzer & PASS X-29E;OPC 20 B Globe DC Spring Closed 2 Closed A,F,RM 18 Supply 3 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL PENE # & OP TIME TYPE TO OPEN POWER POSITION ISOLATION ISOLATION VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12) GRP POSITION SIGNAL NOTES CV-5065-91 C-19 Return X-32A:OPC 50 B Globe DC Spring Open 2 Closed A,F,RM CV-5065-92 C-19 Return X-32A;OPC 50 B Globe AC Spring Open 2 Closed A,F,RM 45-300A Tip Drive X-35C;OPC 50 A-X Ball Solenoid AC Spring Closed 2 Closed A,F 9,16 45-300B Tip Drive X-35D;OPC 50 A-X Ball Solenoid AC Spring Closed 2 Closed A,F 9,16 45-300C Tip Drive X-35B:OPC 50 A-X Ball Solenoid AC Spring Closed 2 Closed A,F 9,16 45-300D Tip Drive X-35A;OPC 50 A-X Ball Solenoid AC Spring Closed 2 Closed A,F 9,16 Shear Valve A Tip Drive X-35C;OPC -- A-X Explosive Shear DC DC Open -- -- RM 22 Shear Valve B Tip Drive X-35D;OPC -- A-X Explosive Shear DC DC Open -- -- RM 22 Shear Valve C Tip Drive X-35B;OPC -- A-X Explosive Shear DC DC Open -- -- RM 22 Shear Valve D Tip Drive X-35A;OPC -- A-X Explosive Shear DC DC Open -- -- RM 22 9-CK-353 Tip Purge X-35E;OPC -- B-X Check -- Process Open -- -- Rev Flow FCV-302-120 CRD Insert (Typ of 145) X-37;OPC -- A-X FCV Air/AC Spring Closed -- -- RM 4 FCV-302-123 CRD Insert (Typ of 145) X-37;OPC -- A-X FCV Air/AC Spring Closed -- -- RM 4 SV-305-121 CRD Withdraw (Typ of X-38;OPC -- A-X SOV Air/AC Spring Closed -- -- RM 4 145)

SV-305-122 CRD Withdraw (Typ of X-38;OPC -- A-X SOV Air/AC Spring Closed -- -- RM 4 145)

MO-1001-23A RHR Containment Spray X-39A;OPC 45 0 B-X Gate AC AC Closed -- -- G,S,RM 2,24,25 MO-1001-26A RHR Containment Spray X-39A;OPC 45 0 B-X Gate AC AC Closed -- -- G,S,RM 2,24,25 MO-1001-23B RHR Containment Spray X-39B;OPC 45 0 B-X Gate AC AC Closed -- -- G,S,RM 2,24,25 MO-1001-26B RHR Containment Spray X-39B;OPC 45 0 B-X Gate AC AC Closed -- -- G,S,RM 2,24,25 SV-5065-63 PASS Rx Sample X-40Aa;OPC 20 A Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-64 PASS Rx Sample X-40Aa;OPC 20 A Globe AC Spring Closed 2 Closed A,F,RM 18 4 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL ISOLATION ISOLATION PENE # & OP TIME TYPE TO OPEN POWER POSITION GRP POSITION SIGNAL NOTES VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12)

SV-5065-85 PASS Rx Sample X-40Dc;OPC 20 A Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-86 PASS Rx Sample X-40Dc;OPC 20 A Globe AC Spring Closed 2 Closed A,F,RM 18 AO-220-44 Reactor Sample Line X-41A;IPC 10 0 A Gate Air/AC Spring Open 1 or 2 Closed A,B,D,F,P,Q,RM 9,23 AO-220-45 Reactor Sample Line X-41A;OPC 10 0 A Y-Globe Air/AC Spring Open 1 or 2 Closed A,B,D,F,P,Q,RM 9,23 CK-1101-15 SBLC System X-42;IPC -- A-X Check Process Process Closed -- -- Rev Flow CK-1101-16 SBLC System X-42;OPC -- A-X Check Process Process Closed -- -- Rev Flow 45-HO-106 D/W Test Connection X-43;OPC -- B Gate Manual -- Closed -- -- --

262-FO-13A Recirc Pp Seals X-46A;IPC -- C Check -- Process Open -- -- Rev Flow 262-FO-17A Recirc, Pp Seals X-46A;OPC -- C Check -- Process Open -- -- Rev Flow 262-FO-13B Recirc, Pp Seals X-46B;IPC -- C Check -- Process Open -- -- Rev Flow 262-FO-17B Recirc Pp Seals X-46B:OPC -- C Check -- Process Open -- -- Rev Flow 9-HO-378 Backup Nitrogen Supply to X-46E;OPC -- B Gate Manual -- Closed -- --

RV-203-3B and RV-203-3C 9-HO-379 Backup Nitrogen Supply to X-46E;OPC -- B Gate Manual -- Closed -- --

RV-203-3B and RV-203-3C SV-5065-24A H2O2 & PASS Gas Return X-46F;OPC 20 B Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-26A H2O2 & PASS Gas Return X-46F;OPC 20 B Globe AC Spring Closed 2 Closed A,F, RM 18 45-HO-102 D/W Test Connection X-47;OPC -- B-X Globe Manual -- Closed -- -- --

(ILRT Supplemental Test) 45-HO-103 D/W Test Connection X-47;OPC -- B-X Globe Manual -- Closed -- -- --

(ILRT Supplemental Test) 45-HO-104 D/W Test Connection X-47;OPC -- B-X Globe Manual -- Closed -- -- --

(ILRT Supplemental Test) 45-HO-105 D/W Test Connection X-47;OPC -- B-X Globe Manual -- Closed -- -- --

(ILRT Supplemental Test)

SV-5065-13B H2/O2 Analyzer Supply X-50Ad;OPC 20 B Globe AC Spring Open 2 Closed A,F,RM 18 5 of 15 Rev. 30- Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL ISOLATION ISOLATION PENE # & OP TIME TYPE TO OPEN POWER POSITION GRP POSITION SIGNAL NOTES VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12)

SV-5065-20B H2/O2 Analyzer Supply X-50Ad;OPC 20 B Globe DC Spring Open 2 Closed A,F,RM 18 MO-1001-28A RHR Injection A Loop X-51A;OPC 30 0 A-X Globe AC AC Open -- -- E,T,RM MO-1001-29A RHR Injection A Loop X-51A;OPC 30 0 A-X Gate AC AC Closed 3 Closed A,E,F,U,T,RM 11,17 1001-68A RHR Injection A X-51A;IPC -- A-X Check -- Process Closed -- -- Rx, Rev Flow MO-1001-28B RHR Injection B Loop X-51B;OPC 30 0 A-X Globe AC AC Open -- -- E,T,RM MO-1001-29B RHR Injection B Loop X-51B;OPC 30 0 A-X Gate AC AC Closed 3 Closed A,E,F,U,T,RM 11,17 1001-68B RHR Injection B X-51B;IPC -- A-X Check -- Process Closed -- -- Rx, Rev Flow M0-2301-4 HPCI Steam to Turbine X-52;IPC 25 0 A-X Gate AC AC Open 4 Closed L,RM,AA 13 MO-2301-5 HPCI Steam to Turbine X-52;OPC 34 0 A-X Gate DC DC Open 4 Closed L,RM AA 13 MO-1301-16 RCIC Steam to Turbine X-53;IPC 20 0 A-X Gate AC AC Open 5 Closed K,RM,AA 10 MO-1301-17 RCIC Steam to Turbine X-53;OPC 29 0 A-X Gate DC DC Open 5 Closed K,RM,AA 10 SV-5065-14A H2/02 Analyzer Supply X- 20 B Globe AC Spring Open 2 Closed A,F,RM 18 106Ab;OPC SV-5065-21A H2/02 Analyzer Supply X- 20 B Globe DC Spring Open 2 Closed A,F,RM 18 106Ab;OPC 9-CK-341 Torus Makeup X-205;OPC -- B Check -- Process Closed -- -- Rev Flow 9 AO-5033B Drywell/Torus Purge X-205;OPC 10 0 B Gate Air/AC Spring Closed 2 Closed A,F,Z,RM 9,21,27 AO-5033C Torus Makeup X-205;OPC 10 0 B Gate Air/AC Spring Closed 2 Closed A,B,F,Z,RM 9,27 30 AO-5036A Torus Purge Inlet X-205;OPC 50 B Butterfly Air/AC Spring Closed 2 Closed A,F,Z,RM 27,35 AO-5036B Torus Purge Inlet X-205;OPC 50 B Butterfly Air/AC Spring Closed 2 Closed A,F,Z,RM 27,35 SV-5087A Post Accident Purge and X-205;OPC -- B Globe AC Spring Closed -- -- RM 19 Vent SV-5087B Post Accident Purge and X-205;OPC -- B Globe AC Spring Closed -- -- RM 19 Vent 6 of 15 Rev. 30- Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL ISOLATION ISOLATION PENE # & OP TIME TYPE TO OPEN POWER POSITION GRP POSITION SIGNAL NOTES VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12)

SV-5088A Post Acc Purge and Vent X-205;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5088B Post Acc Purge and Vent X-205;OPC -- B Globe AC Spring Closed -- -- RM 19 MO-1001-36A RHR to Torus X-210A;OPC 30 0 B-X Globe AC AC Closed -- -- G,RM 2,9,35 MO-1001-18A RHR Minimum Flow X-210A;OPC 25 0 B-X Gate AC AC Open -- -- RM 9,31 CK-1400-35 Core Spray Recirc X-210A;OPC -- B-X Check -- Process Closed -- -- Rev Flow 28 MO-1001-36B RHR to Torus X-201B;OPC 30 0 B-X Globe AC AC Closed -- -- G,RM 2,9,35 MO-1001-18B RHR Minimum Flow X-210B,OPC 25 0 B-X Gate AC AC Open -- -- RM 9,31 1301-47 RCIC Minimum Flow X-201B;OPC -- B-X Check -- Process Closed -- -- Rev Flow 28 CK-1400-214 Core Spray Recirc X-210B;OPC -- B-X Check -- Process Closed -- -- Rev Flow 28 2301-40 HPCI Minimum Flow X-210B,OPC -- B-X Check -- Process Closed -- -- Rev Flow 28 10-CK-515 Torus Makeup From CST X-210B;OPC -- B-X Check -- Process Closed -- -- Rev Flow 28 MO-1001-34A RHR to Torus A Loop X-211A;OPC 30 0 B-X Gate AC AC Closed -- Closed G,RM 2,9,24 MO-1001-34B RHR to Torus B Loop X-211B;OPC 30 0 B-X Gate AC AC Closed -- Closed G,RM 2,9,24 MO-1001-37A RHR to Torus Spray X-211A;OPC 45 0 B-X Globe AC AC Closed -- Closed G,S,RM 2,24,35 Header A MO-1001-37B RHR to Torus Spray X-211B;OPC 45 0 B-X Globe AC AC Closed -- Closed G,S,RM 2,24,35 Header B MO-2301-33 HPCI Turbine Ex Vac X-219/OPC 30 0 B-X Gate AC AC Open 7 Closed N,RM 36 Brkr MO-2301-34 HPCI Turbine Ex Vac X-219/OPC 30 0 B-X Gate AC AC Open 7 Closed N,RM 36 Brkr 7 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX OP TIME VALVE POWER NORMAL ISOLATION ISOLATION PENE # & (SEC) TYPE TO OPEN POWER POSITION GRP POSITION SIGNAL NOTES VALVE # LINE ISOLATED OPC/IPC CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12)

MO-1301-25 RCIC Pp Suction From X-220;OPC 125 0 B-X Gate DC DC Closed -- -- RM 28 Torus MO-2301-36 HPCI Pp Suction From X-221;OPC 37 0 B-X Gate DC DC Closed 4 Closed L,RM 26,28 Torus MO-1001-7A RHR Pp Suction X-222A;OPC 150 B-X Gate AC AC Open -- -- RM 22,28 MO-1001-7B RHR Pp Suction X-222D;OPC 150 B-X Gate AC AC Open -- -- RM 22,28 MO-1001-7C RHR Pp Suction X-222B;OPC 150 B-X Gate AC AC Open -- -- RM 22,28 MO-1001-7D RHR Pp Suction X-222C;OPC 150 B-X Gate AC AC Open -- -- RM 22,28 2301-45 HPCI Turbine Exhaust X-223; OPC -- B-X Check -- Process Closed -- Closed Rev Flow 2301-74 HPCI Turbine Exhaust X-223;OPC -- B-X Check -- Process Closed -- Closed Rev Flow 2301-218 HPCI Low Point Drain X-223;OPC -- B-X Check -- Process Closed -- Closed Rev Flow CV-9068A HPCI Gland Seal X-223;OPC -- B-X Globe DC Spring Closed 4 Closed L,AA,RM Condenser CV-9068B HPCI Gland Seal X-223;OPC -- B-X Globe DC Spring Closed 4 Closed L,AA,RM Condenser MO-2301-33 HPCI Turbine Ex Vac X-223;OPC 30 0 B-X Gate AC AC Open 7 Closed N,RM 36 Brkr MO-2301-34 HPCI Turbine Ex Vac X-223;OPC 30 0 B-X Gate AC AC Open 7 Closed N,RM 36 Brkr 2301-217 HPCI Exhaust Line Drain X-224;OPC -- B-X Check -- Process Closed -- -- Rev Flow 28 1301-64 RCIC Turbine Exhaust X-225; OPC -- B-X Stop Check -- Process Closed -- -- Rev Flow 28 1301-59 RCIC Vac Pp Discharge X-226; OPC -- B-X Check -- Process Closed -- -- Rev Flow 28 SV-5084A Post Acc Purge and Vent X-227;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5084B Post Acc Purge and Vent X-227;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5083A Post Acc Purge and Vent X-227;OPC -- B Globe AC Spring Closed -- -- RM 19 SV-5083B Post Acc Purge and Vent X-227;OPC -- B Globe AC Spring Closed -- -- RM 19 8 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL ISOLATION ISOLATION PENE # & OP TIME TYPE TO OPEN POWER POSITION GRP POSITION SIGNAL NOTES VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12)

AO-5040A Torus Vacuum Bkrs X-227;OPC 45 0 B Butterfly Spring Air/DC Closed 2 Closed A,F,Z 34,3 AO-5040B Torus Vacuum Bkrs X-227;OPC 45 0 B Butterfly Spring Air/DC Closed 2 Closed A,F,Z 34,3 X-212A Torus Vacuum Bkrs X-227;OPC -- B Check Vacuum Process Closed -- -- Rev Flow 34 X-212B Torus Vacuum Bkrs X-227;OPC -- B Check Vacuum Process Closed -- -- Rev Flow 34 AO-5025 Direct Torus Vent X-227,OPC -- B Butterfly Spring Air/DC Closed -- -- RM 19 AO-5041A Torus Exhaust Bypass X-227;OPC 10 0 B Globe Air/AC Spring Closed 2 Closed A,B,F,Z,RM 9,15,27,30 AO-5041B Torus Exhaust Bypass X-227;OPC 10 0 B Globe Air/AC Spring Closed 2 Closed A,B,F,Z,RM 9,15,27,30 AO-5042A Torus Main Exhaust X-227;OPC 50 B Butterfly Air/AC Spring Closed 2 Closed A,F,Z,RM 27 AO-5042B Torus Main Exhaust X-227;OPC 50 B Butterfly Air/DC Spring Closed 2 Closed A,F,Z,RM 27 SV-5065-22B H2/02 Analyzer Supply X-228C;OPC 20 B Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-15B H2/02 Analyzer Supply X-228C;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 31-CK-434 Air to D/W to Torus X-228E;OPC -- B Check Process Process Closed -- -- Rev Flow Vacuum Breakers CV-5046 Air to D/W to Torus Vac X-228E;OPC -- B Globe Air/AC Spring Closed -- -- RM Breakers SV-5065-77 PASS Liquid Return X-228G;OPC 20 B Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-78 PASS Liquid Return X-228G;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 SV-5065-71 PASS Liquid Return X-228H;OPC 20 B Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-72 PASS Liquid Return X-228H;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 SV-5065-18A H2/02 Analyzer Supply X-228J;OPC 20 B Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-11A H2/02 Analyzer Supply X-228J;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 9 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5 2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES (NOTE 37)

MAX VALVE POWER NORMAL ISOLATION ISOLATION PENE # & OP TIME TYPE TO OPEN POWER POSITION GRP POSITION SIGNAL NOTES VALVE # LINE ISOLATED OPC/IPC (SEC) CLASS (NOTE 6) (NOTES 5 & 6) TO CLOSE (NOTES 9 & 12)

SV-5065-25B H2/O2 Analyzer Supply X-228K;OPC 20 B Globe DC Spring Closed 2 Closed A,F,RM 18 SV-5065-27B H2/02 analyzer Supply X-228K;OPC 20 B Globe AC Spring Closed 2 Closed A,F,RM 18 MO-1400-3A Core Spray Pump Suction X-229A;OPC: -- B-X Gate AC AC Open -- -- RM 28 MO-1400-3B Core Spray Pump Suction X-229B;OPC -- B-X Gate AC AC Open -- -- RM 28 MO-1001-21 RHR Discharge to RW None;OPC 40 0 -- Gate DC DC Closed 2 Closed A,F,RM 8,9 MO-1001-32 RHR Discharge to RW None;OPC 30 0 -- Gate AC AC Closed 2 Closed A,F,RM 8,9 Various Type A Instru Line (typ ) --;OPC -- A-X Hand Globe Manual Manual Open -- -- --

Various Type A Instru Line (typ ) --;OPC -- A-X Flow Spring Process Open -- -- Excess Flow Various Type B Instr Line (typ ) --;OPC -- B-X Hand Globe Manual Manual Open -- -- -- --

10 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5.2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES ISOLATION SIGNAL CODES FOR TABLE 5.2-4 Signal Description A* Reactor vessel low water level - scram and close isolation valves except main steam lines.

B* Reactor vessel low low water level - initiate RCIC, HPCI and close main steam line isolation and drain valves.

C Deleted D* Line break - main steam line (steam line high space temperature or high steam flow).

E Reactor low low level or high drywell pressure - select LPCI and close other loop valves and initiate HPCI..

F* High drywell pressure - close RHR/shutdown cooling and head spray, the RHR to radwaste valves, and Torus Vacuum Breaker.

G Reactor vessel low low water level and low pressurecoincident low reactor pressure; or high drywell pressure - initiate Core Spray and RHR systems.

J* Line break in cleanup system - high space temperature, or high flow.

K* Line break in RCIC system steam line to turbine (high steam line space temperature or high steam flow) or low steam line pressure.

L* Line break in HPCI system steam line to turbine (high steam line space temperature or high steam flow).

M* Line break in RHR shutdown and head cooling (high space temperature; alarm only; no auto closure).

N* High Drywell pressure and Low reactor vessel pressure - close HPCI vacuum breakers.

P* Low main steam line pressure at inlet to main turbine (RUN mode only).

Q* Reactor high water level - isolate main steam line (except in run mode).

RM* Remote manual switch from control room.

Rx This valve is a Reactor Vessel Isolation Valve only (not a Primary Containment Isolation Valve).

S Low drywell pressure - close containment spray valves.

T Low reactor pressure permissive to open core spray and RHR-LPCI valves.

U High reactor vessel pressure - close RHR shutdown cooling valves and head cooling valves.

W High temperature at outlet of cleanup system nonregenerative heat exchanger.

11 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5.2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES ISOLATION SIGNAL CODES FOR TABLE 5.2-4 Y Standby liquid control system actuated.

Z Refuel floor high radiation. This signal is part of the Reactor Building Isolation Control System. See Section 7.18.

AA* Low reactor pressure - closure of HPCI and RCIC steam to turbine isolation valves.

These are the isolation functions of the primary containment and reactor vessel isolation control system; other functions are given for information only.

12 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5.2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES Notes for Table 5.2-4

1. Main steam isolation valves require that both solenoid pilots be deenergized to close valves. Accumulator air pressure plus spring act together to close valves when both pilots are deenergized. Voltage failure at only one pilot does not cause valve closure. The valves are designed to fully close in less than 10 seconds, but in no less than 3 seconds.

2. Containment spray and suppression cooling valves have interlocks that allow them to be manually reopened after automatic closure.

This setup permits containment spray, for high drywell pressure conditions, and/or suppression pool cooling. When automatic signals are not present, valves may be opened for test and operating convenience.

3. On loss of air, this valve fails open.

4. Control rod hydraulic lines can be isolated by the solenoid valves (directional control) outside the primary containment. Lines that extend outside the primary containment are small and terminate in a system that is designed to prevent outleakage. Solenoid valves (directional control) normally are closed, but they open on rod movement.

5. AC motor operated valves are powered from the AC standby power busses. DC isolation valves are powered from the station batteries.

6. All motor operated isolation valves remain in the last position upon failure of valve power. All air operated valves close on motive air failure or power at the solenoid pilots.

7. Not used.

8. MO1001-21 and MO1001-32 are not primary containment isolation valves. They are included for information only since they receive F and A isolation signals.

9. Valves identified by this note can be opened or closed by remote manual switch for operating convenience during any mode of the reactor except when an automatic signal is present. RHR minimum flow valves receive automatic open signal on low flow; they receive no automatic close signal.

10. RCIC Steam supply turbine valves open on Signal B. Line Break signal K overrides to close valves.

11. Coincident signals G and T open core spray and selected LPCI valves. Special interlocks permit testing these valves by manual switch except when automatic signals are present.

12. Normal status position of valve (open or closed) is the position during normal power operation of the reactor (see Normal Position column).

13. HPCI Steam to turbine valves open on Signal GE. Line Break signals L and AA override to close.

14. Not used.

15. Manual switches override all automatic signals on the smaller valves that bypass the suppression chamber and drywell exhaust valves.

13 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5.2-4 CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES Notes for Table 5.2-4

16. Signal A or F causes automatic withdrawal of TIP probe. When probe is withdrawn, the valve automatically closes by mechanical action.

17. MO-1001-29A & B isolate on reactor low water level (signal A) OR high drywell pressure (Signal F) if RHR Shutdown cooling supply valves MO-1001-50 and 47 are NOT fully closed AND reactor pressure (signal U) is below 80 psig. Valve position indicating lights are not required at the isolation valve display panel.

18. Isolation signals are overridden with control switch in the emergency open position.

19. Key locked switch to operate valves administratively control closed.

20. Deleted.

21. These valves are isolation valves for both penetration X-26 and X205. They are shown twice for clarity.

22. Remote manual actuation to close (key locked)

23. Reactor Sample valves isolate on Group 1 signal or Group 2 signal.

24. Isolates on LPCI initiation Signal.

25. May be manually open for high drywell pressure conditions.

26. These valves open on a low CST, or high torus level, if no isolation signal present.

27. In addition to Group 2 isolation, these valves also receive a Refueling Floor High Radiation isolation.

28. Those Class B lines which terminate below the water line of the suppression pool only require one isolation valve. (See Section 7.3.2).

29. High space temperature (Signal J) activates alarm in the control room. Pumps are signaled to stop as a result of valve closure.

30. These valves also receive a reactor low-low water level signal which cannot be bypassed by utilizing the valves emergency open feature.

31. Open on RHR pump low flow. No automatic close signal.

32. Not used.

33. Not used.

34. Valve opens when suppression chamber pressure is 0.5 psi below reactor building pressure.

35. Throttling type valve.

36. These valves are isolation valves for both penetration X-219 and X-223. They are shown twice for clarity.

37. Maximum operating time for AC powered valves are determined assuming AC power is available to the valve. For loss of AC power scenarios, the diesel start and loading time must be added to the maximum operation time.

14 of 15 Rev. 30 - Nov. 2015

PNPS - FSAR TABLE 5.2-4 (CONT)

CONTAINMENT AND REACTOR VESSEL ISOLATION VALVES Group Isolation Signals Group 1: The valves in this group are closed upon any one of the following conditions.

B* Reactor low-low water level D* Main Steam Line high flow D* Main Steam Line tunnel high temperature P* Main Steam Line low pressure (in run mode, only)

Q Reactor high water level (not in run mode, below Main Steam Line Low Pressure MSIV Isolation Setpoint)

Group 2: The valves in this group are closed upon any one of the following conditions.

A* Reactor low water level F* High drywell pressure Group 3: The valves in this group are closed upon any one of the following conditions.

A* Reactor low water level U High reactor pressure F* High drywell pressure Group 4: The valves in this group are closed upon any one of the following conditions.

L* HPCI steam line high flow L* HPCI steam line area high temperature AA* Low Reactor Pressure Group 5: The valves in this group are closed upon any one of the following conditions.

K* RCIC steam line high flow K* RCIC steam line area high temperature K* RCIC steam line low pressure Group 6: The valves in this group are closed upon one of the following conditions.

A* Reactor low water level J* Cleanup area high temperature J* Cleanup inlet high flow Group 7: The valves in this group are closed upon any one of the following conditions.

N* Reactor Low Pressure and High Drywell Pressure 15 of 15 Rev. 30 - Nov. 2015

PNPS-FSAR 5.4 CONTROL OF COMBUSTIBLE GAS CONCENTRATIONS IN CONTAINMENT 5.4.1 Introduction A system for control and monitoring of containment atmosphere is provided as required by 10 CFR 50.44. This system is provided for control of oxygen and hydrogen gases that may be generated following a postulated loss of coolant accident (LOCA) combined with degradation, but not total failure, of core standby cooling systems (CSCS). Degradation, but not total failure of the core standby cooling function means that the performance of the CSCS is postulated, for the purpose of design of the combustible gas control system (CGCS), not to meet the acceptance criteria in 10 CFR 50.46 and that there could be localized clad melting and metal-water reaction. The degree of performance degradation of the CSCS is not postulated to be sufficient to cause core meltdown.

The combustible gas control system was originally designed, built, and maintained as safety-related to control the hydrogen and oxygen that may be generated following a postulated LOCA. However, since the promulgation of Final Rule, 10 CFR 50.44, the regulatory basis of the combustible gas control system has shifted from having to cope with a design basis accident (DBA) LOCA to the mitigation of combustible gas generated by a beyond design basis accident (BDBA).

The Final Rule has down graded the system to non-safety related, Reg. Guide 1.97 Category 3 for Hydrogen and Category 2 for oxygen subsystems. The regulatory commitment made in the Pilgrim License Amendment 206 requires Pilgrim to maintain the system at least to the level of Reg. Guide 1.97 Category 3 for hydrogen and Category 2 for oxygen monitoring. With the elimination of the design-basis LOCA hydrogen release, the hydrogen monitors are no longer required to mitigate design-basis accidents, and therefore, the hydrogen monitors do not meet the definition of safety-related component as defined in 10 CFR 50.2. Likewise, the oxygen monitors are also down graded to Reg. Guide 1.97, Category 2.

The containment atmospheric control system (CACS) is provided to obviate the possibility of an energy release within the primary containment from a hydrogen-oxygen reaction following a postulated LOCA combined with degraded CSCS functioning. This is to be accomplished by maintaining an atmosphere containing less than 4%

oxygen in the drywell and pressure suppression chamber (torus). The system will:

1. Perform initial purging of the primary containment

2. Provide for a supply of nitrogen makeup gas during normal operation or emergency

3. Provide for normal and purge exhaust lines to the standby gas treatment system (SBGT) for normal operating conditions

4. Provide for emergency exhaust from the drywell and torus for release of contaminated drywell and torus gases to the SBGT 5.4-1 Rev. 30 - Nov. 2015

PNPS-FSAR

5. Provide pneumatic supply to instruments inside the drywell An adjunct to the CACS is the direct torus vent line. This line can be used to vent excessive pressure generated inside containment (following a beyond design accident) directly to the main stack, bypassing the SBGT.

5.4.2 Source of Hydrogen and Oxygen Accumulation in Containment Following the postulated design basis LOCA combined with degraded CSCS function, hydrogen may be produced by the postulated metal-water (zirconium-water) reaction. Hydrogen and oxygen may be produced by radiolysis of reactor coolant. Radiolysis of water is the only source of oxygen in the PNPS inerted containment. Under design basis accident conditions, oxygen would be produced in much more limited quantities than hydrogen and is therefore chosen as the parameter to control.

Procedures are in place to control primary containment atmosphere and to maintain the containment inerted during normal operations and transients. The development and implementation of Emergency Operating Procedures (EOPs) industry-wide has fundamentally changed the way in which operators respond to accidents from an event-based approach to a symptom-based approach. The EOPs do not specifically differentiate between symptoms that are within design basis and those that are beyond design basis.

The EOPs and support procedures contain specific instructions for maintaining the concentrations of both hydrogen and oxygen below their respective thresholds for combustibility. The procedures are structured to effect containment purging with nitrogen and/or venting as the control method for reducing combustible gas concentrations inside containment. Containment oxygen concentration in excess of 5% in the presence of detectable hydrogen i.e., 1%,

is not credible for design basis accidents and would be considered beyond PNPS design basis. The EOPs and support procedures contain appropriate instructions for implementing the strategies of BWROG Emergency Procedure Guidelines to control combustible gases for events beyond PNPS design basis for the purpose of preserving primary containment integrity.

5.4-1a Rev. 30 - Nov. 2015

PNPS-FSAR 5.4.3 System Description 10 CFR 50.44(b)(1) requires all containments must have a capability for ensuring a mixed atmosphere.

10 CFR 50.44(b)(2) requires all boiling water reactors with Mark I or Mark II type containments must have an inerted atmosphere. 10 CFR 50.44(b)(4)(i) requires equipment for monitoring oxygen in containments that use an inerted atmosphere for combustible gas control. The equipment for monitoring oxygen must be functional, reliable, and capable of continuously measuring the concentration of oxygen in the containment atmosphere following a significant beyond design-basis accident for combustible gas control and accident management, including emergency planning. 10 CFR 50.44 (b)(4)(ii) requires equipment for monitoring hydrogen in the containment. The equipment for monitoring hydrogen must be functional, reliable, and capable of continuously measuring the concentration of hydrogen in the containment atmosphere following a significant beyond design-basis accident for accident management, including emergency planning.

Pilgrim is a Mark I type containment and is provided with an inerted atmosphere to preclude the possibility of a hydrogen combustion event within the containment. The oxygen deficient atmosphere assures that hydrogen build-up due to metal-water reaction is not a concern for these plants. Combustible gas control for these plants is based on control of oxygen, which is produced in more limited quantities than hydrogen following a LOCA or transient event.

The CACS in conjunction with the SBGT are the systems which Pilgrim Station utilizes for primary containment atmospheric control as required by 10CFR50.44. See Figure 5.4-1 (Drawing M227).

The containment combustible gas control system is used primarily for purging (i.e., inerting) with Nitrogen (N2) or can be used for containment venting. Exhaust from both the torus and drywell can be routed to the main stack via the redundant trains of the SGTS.

Makeup of nitrogen (or air) is supplied via the 1 inch redundant solenoid valve trains. See Figure 5.4-1 (Drawing M227).

The primary method of controlling combustible gas inside the primary containment is by maintaining an oxygen free atmosphere by inerting.

When the containment is deinerted oxygen is present, but containment integrity post-LOCA is ensured by monitoring containment for hydrogen. Should hydrogen levels rise when deinerted, purging with air (dilution) or the CACS can be used to maintain containment atmosphere hydrogen gas accumulation below stoichiometric proportions. This is achieved by inerting the drywell and suppression chamber atmosphere with nitrogen. The inerted atmosphere is maintained by the following controls:

1. Technical Specification 3.7.A.5.a and 3.7.A.5.b require that, when the containment is required to be inerted, the containment atmosphere must be less than four percent oxygen.

2. The pneumatic control systems located inside the primary containment use only nitrogen when the containment is required to be inerted. Additional capability to address USI-A46 is provided and available.

5.4-2 Rev. 30 - Nov. 2015

PNPS-FSAR

3. There are no potential sources of oxygen in containment other than that resulting from radiolysis of reactor coolant when the containment is required to be inerted.

In addition to operating with the primary containment atmosphere inerted with nitrogen, PNPS must maintain a safety grade purge/repressurization system in conformance with the general requirements of Criteria 41, 42, and 43 of Appendix A of 10 CFR 50.

This basis for maintaining the purge/repressurization system is given in the "Safety Evaluation by the Office of Nuclear Reactor Regulation Relating to Generic Letter 84-09 on Hydrogen Recombiner Capability Pilgrim Nuclear Power Station, Unit 1" (April 30, 1986).

It states

"...the "Safety Grade" purge/repressurization system is still necessary to control combustible gas mixtures for a narrow range of accident scenarios which have the potential to generate hydrogen and oxygen at rates that are comparable to the radiolysis rates described in Regulatory Guide 1.7".

The Purge/Repressurization System controls oxygen concentration below flammability limits (5 volume percent) by a feed and bleed method. The time required before initiation of purge (vent) of the primary containment is controlled by repressurization techniques consisting of nitrogen (or air) addition to the primary containment.

Sixteen (16) solenoid valves are arranged to provide redundant paths to and from the drywell and torus for Nitrogen makeup/repressurization and venting. Nitrogen makeup/repressurization is provided by:

1. Connecting, to hose connections outside containment, a portable nitrogen supply via truck with vaporizer or using the existing (non-seismic) nitrogen storage tank with vaporizer (requires opening a manual block valve located outside containment in the yard area Reactor Building north wall) (Primary emergency make-up)

2. Alternatively, provide a compressed air supply from service air connections outside the primary and secondary containment or from portable (gasoline driven) air compressors located on site (secondary emergency make-up)

The solenoid valves are designed to remain closed against maximum containment pressure, to vent containment so that the maximum containment pressure will not be exceeded, and to provide a nitrogen flow sufficient to maintain the oxygen concentration inside containment below the flammability limits.

The valves in redundant paths are powered from independent Class IE distribution systems each of which is powered from an emergency diesel generator after a loss of offsite power or from essential DC supply. The control switches for redundant valves are located in separate Class IE control panels in the main control room. Conduit and permanently installed equipment required for purging and repressurization functions are located in seismically designed, 5.4-3 Rev.30 - Nov. 2015

PNPS-FSAR missile protected buildings, except all the fill connections which are located outside of secondary containment but separated.

Redundant conduit systems are separated commensurate with identified hazards. All conduit and permanently installed equipment required for purging and repressurization functions are supported to meet seismic Category I requirements except for N2 supply equipment described previously.

The solenoid valves are ASME III Class 2 and are qualified environmentally and seismically to the requirements of IEEE 323-1974, IEEE 382-1973, and IEEE 344-1975 for the expected conditions.

The valves are rated at 120V ac and are designed to operate between 80 and 110 percent of rated voltage. This range is compatible with expected bus voltages at Pilgrim Nuclear Power Station. The valves which need to operate the direct torus vent system receive control power from essential 125 volts DC.

The control switches have been qualified to the requirements of IEEE 323-1974 for operation in a control room environment. The switches are mounted on Class IE panels (see Table 7.8-3) and the combination has been qualified to IEEE 344-1975 for the Operating Basis Earthquake. The switch's electrical ratings exceed loading requirements.

The cable and wire used for this modification have been qualified to IEEE 383-1974 for fire and ambient conditions exceeding those required for this installation. The 600 V No. 12 AWG control cable has voltage and current capabilities well above that required.

Control of the solenoid valves is remote manual, there is no automatic isolation capability. Isolation signals have not been provided because:

1. The valves are always keylocked closed during normal operation

2. The valves are required to be operated during a high drywell pressure condition and must be available independent of reactor water level. High drywell pressure and low-low reactor water level are the normal containment isolation signals Nitrogen makeup and ventilation valves are also provided for use under nonaccident conditions. These will automatically close upon receipt of an accident signal. However, these valves may be used after an accident provided the required power supplies are available and a low-low water level signal is not present. Refer to Section 5.2.3.5 and Tables 5.2-4 and 7.3-1.

Indicator lights are provided to continuously monitor valve position. The indicators are driven by reed-type limit switches mounted within the valve electrical housing. Contacts from all control switches are wired to an annunciator window to provide an alarm when a valve is open.

All containment vent and purge valves receive power from either the onsite or offsite emergency power system.

5.4-4 Rev. 30 - Nov. 2015

PNPS-FSAR Hydrogen generation rates and amounts are based upon the guidance of Regulatory Guide 1.7. The amount of hydrogen generated by a fuel cladding and water reaction was obtained by using the larger of:

1. Five times the total amount of hydrogen calculated in a previous Pilgrim reload submittal

2. An average core wide cladding penetration of 0.23 mils In a previous Pilgrim Station reload submittal, GE calculated an average metal water reaction percentage of 0.13 percent (Reference 1). Five times 0.13 is 0.65 percent cladding interaction. A 0.23 mil average cladding penetration is equivalent to 0.68 percent cladding interaction. Hence, the 0.23 mil average cladding penetration was used. All hydrogen generated by the core metal water reaction was assumed to be released to the primary containment immediately. Radiolytic hydrogen generation rates and accumulation curves were calculated by GE (Reference 2). GE used AEC Safety Guide 7 to generate their curves. These assumptions are the same as those used in Regulatory Guide 1.7.

Hydrogen inputs from corrosion for Pilgrim (no chemical spray) are minor (Reference 3). Hence, no other significant source exists from this event.

5.4.4 Containment Mixing Significant combustible gas concentration stratification within the drywell or the torus is not expected. Organizations such as Energy Incorporated and GE have investigated containment mixing. Energy Incorporated has estimated less than 0.1 percent variation in hydrogen concentration in the drywell and expects good mixing will take place in the torus because of thermal gradients (Reference 4).

Energy Incorporated's conclusion are supported by GE's evaluation of mixing in the containment around their BWR 6. GE believes that a very small temperature (T) or concentration (C) difference is sufficient to promote good mixing (T = 2.6 x 10-5 F or C = 4.3 x 10-8 in the containment around a BWR 6).

GE also believes that the analysis used on the containment around a BWR 6 will also apply to a Mark I Containment. Based upon the above analysis, in the open Pilgrim BWR Mark I containment, no significant combustible gas concentration stratification is expected within the drywell or torus.

5.4-5 Rev. 30 - Nov. 2015

PNPS-FSAR 5.4.5 Combustible Gas Monitoring The existing containment combustible gas monitoring system (CCGMS) consists of two redundant, remotely operable, seismically qualified hydrogen analyzers. The hydrogen analyzers are capable of continuously monitoring drywell hydrogen concentration for 30 days following their initiation. They initiate 30 minutes after safety injection begins. They have a remote readout in the main control room. System operation requires manual initiation by control room operators when directed by procedures. Additional information regarding the hydrogen analyzers is contained in Section 10.19, Post-Accident Sampling System.

5.4.6 Radiological Consequences of Containment Venting An evaluation of offsite doses which would be incurred as a result of containment venting to limit containment pressure has been performed in a manner consistent with Regulatory Guides 1.3, 1.7, and 1.45.

The results of this analysis indicate that the doses to receptors at the LPZ would be well within the limits of 10 CFR 100. This analysis assumed that venting at the rate of 50 standard ft3/min through the SGTS would be initiated at 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br /> after the reactor was made subcritical and venting would continue for 30 days.

5.4.7 Direct Torus Vent Line 5.4.7.1 Introduction The consequences of several beyond design basis accident scenarios are more severe than the accidents previously considered herein.

The primary containment pressure during these accidents is estimated to exceed its design capacity. Thus, the primary containment fails, releasing reactor fission products to the secondary containment and potentially to the environment as well. The direct torus vent line (DTVL) provides an emergency primary containment vent path to prevent, or at least slow down, the buildup of potentially damaging pressure within the primary containment.

5.4.7.2 System Description The DTVL is an 8" carbon steel line connecting the 20" torus main exhaust line to the underground 20" main stack exhaust line. The 8" DTVL starts at a branch between the 8" containment isolation valves AO-5042A&B. The DTVL terminates in the 20" main stack exhaust line, several feet downstream of the SBGT outlet valves. The line includes AO-5025, an 8" air-operated, normally-closed butterfly valve which serves as the outboard containment isolation valve for the DTVL rupture disk plate is removed per EC-46822 upstream of the connection to the 20" main stack exhaust line. Both electrical power and valve operator active gas (air or nitrogen) supply are taken from "essential" or reliable sources, or are backed-up to ensure that the system is available during a station blackout or loss of instrument air event. FSAR Figure 5.4-1 (Drawing M227) shows the DTVL arrangement, but the rupture diskc plate is removed per EC-46822 and tie into the 20" main stack exhaust line is shown in FSAR Figure 7.18-2 (Drawing M294).

5.4-6 Rev. 30 - Nov. 2015

PNPS-FSAR The DTVL meets ASME B&PV Code (1980 Edition with Winter 1980 Addenda),Section III, Subsection NC for Nuclear Class 2 requirements up to and including the isolation valve. The new piping downstream of the isolation valve meets ANSI B31.1 (1977 Edition through Winter 1979 Addenda) requirements.

During normal or general transient conditions, the DTVL outboard isolation valve would remain closed. In response to a beyond design basis accident, plant management could direct the control room operators to employ the DTVL to relieve excessive pressure within the containment. In this case, the operator would follow a written procedure to perform the following basic actions:

Close, or confirm closed, the outboard isolation valve for the torus main exhaust line Optimally, turn off the SBGT which likely came on automatically in response to a high drywell pressure signal Close, confirm closed, the SBGT outlet valves to prevent the high containment pressures from back-pressurizing the SBGT filters Open the two DTVL isolation valves Close the two DTVL isolation valves to terminate the release.

5.4.7.3 Radiological Consequences of DTVL Use The exhaust gases released by the DTVL following a beyond design basis accident would have initially been "washed" by the suppression pool water which would reduce the particulates released. These exhaust gases are vented to the highest vent point (main stack),

avoiding the groundlevel release of radioactive material from containment failure due to over-pressurization.

5.4.8 References

1. GE Letter No. SSX:79-64.

2. July 13, 1979 Letter, W. J. Neal (GE) to S. A. Giusti (Bechtel).

3. BLE-459 dated September 25, 1975.

4. Supplement No. 1 to Dresden Station Special Report No. 39 and Quad Cities Special Report No. 14.

5. NRC SER Supporting Amendment 55 to Facility License No. DPR-35, Containment Atmospheric Dilution System.

6. NRC SER Relating to Generic Letter 84-09 on Hydrogen Recombiner Capability, PNPS Unit 1.

7. Pilgrim License Amendment No. 206, dated July 22, 2004.

5.4-7 Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS Section Title Volume Section 1 Introduction and Summary 1 1.1 Project Identification 1 1.2 Definitions 1 1.3 Methods of Technical Presentation 1 1.4 Classification of BWR Systems, Criteria, 1 and Requirements for Safety Evaluation 1.5 Principal Design Criteria 1 1.6 Station Description 1 1.7 Comparison of Principal Design Characteristics 1 1.8 Summary of Radiation Effects 1 1.9 Station Management 1 1.10 Quality Assurance Program 1 1.11 Station Research, Development, and Further Information Requirements and Resolutions Summary 1 Section 2 Station Site and Environs 1 2.1 Introduction 1 2.2 Site Description 1 2.3 Meteorology 1 2.4 Hydrology 1 2.5 Geology and Seismology 1 2.6 Environs Radiation Surveillance Program 1 Section 3 Reactor 1 3.1 Summary Description 1 3.2 Fuel Mechanical Design 1 3.3 Reactor Vessel Internals Mechanical Design 1 3.4 Reactivity Control Mechanical Design 1 3.5 Control Rod Drive Housing Supports 1 3.6 Nuclear Design 1 3.7 Thermal and Hydraulic Design 1 3.8 Standby Liquid Control System 1 3.9 Recirculation Pump Trip, Alternate Rod Insertion, and Feedwater Pump Trip Systems 1 Section 4 Reactor Coolant System 2 4.1 Summary Description 2 4.2 Reactor Vessel and Appurtenances Mechanical Design 2 4.3 Recirculation System 2 4.4 Nuclear System Pressure Relief System 2 4.5 Main Steam Line Flow Restrictor 2 Summ T of C-i Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 4.6 Main Steam Line Isolation Valves 2 4.7 Reactor Core Isolation Cooling System 2 4.8 Residual Heat Removal System 2 4.9 Reactor Water Cleanup System 2 4.10 Nuclear System Leakage Rate Limits 2 4.11 Main Steam Lines and Feedwater Piping 2 Section 5 Containment 2 5.1 Summary Descriptions 2 5.2 Primary Containment System 2 5.3 Secondary Containment System 2 5.4 Control of Combustible Gas Concentrations in Containment 2 Section 6 Core Standby Cooling Systems 2 6.1 Safety Objective 2 6.2 Safety Design Bases 2 6.3 Summary Description - Core Standby Cooling Systems 2 6.4 Description 2 6.5 Safety Evaluation 2 6.6 Inspection and Testing 2 6.7 The Nuclear Safety Requirements for Plant Operation 2 6.8 Current Technical Specifications 2 Section 7 Control and Instrumentation 3 7.1 Summary Description 3 7.2 Reactor Protection System 3 7.3 Primary Containment and Reactor Vessel Isolation Control System 3 7.4 Core Standby Cooling Systems Control and Instrumentation 3 7.5 Neutron Monitoring System 3 7.6 Refueling Interlocks 3 7.7 Reactor Manual Control System 3 7.8 Reactor Vessel Instrumentation 3 7.9 Recirculation Flow Control System 3 7.10 Feedwater Control System 3 7.11 Turbine Generator Control System 3 7.12 Process Radiation Monitoring 3 7.13 Area Radiation Monitoring System 3 7.14 Environs Radiation Monitors 3 7.15 Health Physics and Laboratory Analysis Radiation Monitors 3 Summ T of C-ii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 7.16 Process Computer System 3 7.17 Nuclear System Stability Analysis for Initial Core 3 7.18 Reactor Building Isolation and Control System 3 7.19 RHR Service Water System (SSW, RBCCW) 3 7.20 Equipment Area Cooling System 3 7.21 Meteorological Instrumentation 3 Section 8 Electrical Power System 4 8.1 Summary Description 4 8.2 Unit and Preferred AC Power Sources 4 8.3 Secondary AC Power Source 4 8.4 Auxiliary Power Distribution System 4 8.5 Standby AC Power Source 4 8.6 125 and 250 Volt DC Power Systems 4 8.7 24 Volt DC Power System 4 8.8 120 Volt AC Power Systems 4 8.9 Cable Installation Criteria 4 8.10 Blackout AC Power Source 4 Section 9 Radioactive Waste Systems 4 9.1 Summary Description 4 9.2 Liquid Radwaste System 4 9.3 Solid Radwaste System 4 9.4 Gaseous Radwaste System 4 9.5 Trash Compaction and Decontamination Facilities 4 Section 10 Auxiliary Systems 4 10.1 Summary Description 4 10.2 New Fuel Storage 4 10.3 Spent Fuel Storage 4 10.4 Fuel Pool Cooling and Cleanup System 4 10.5 Reactor Building Closed Cooling Water System 4 10.6 Turbine Building Closed Cooling Water System 4 10.7 Salt Service Water System 4 10.8 Fire Protection System 4 10.9 HVAC Systems 4 10.10 Makeup Water Treatment System 4 10.11 Instrument and Service Air Systems 4 10.12 Potable and Sanitary Water System 4 10.13 Equipment and Floor Drainage Systems 4 10.14 Process Sampling Systems 4 10.15 Communications Systems 4 10.16 Station Lighting System 4 10.17 Main Control Room Environmental Control System 4 10.18 Equipment Area Cooling System 4 10.19 Post Accident Sampling System 4 Summ T of C-iii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume 10.20 Crack Arrest Verification System 4 10.21 Hydrogen Water Chemistry Extended Test System 4 10.22 Electrolytic Hydrogen Water Chemistry System 4 10.23 Mitigation Monitoring System 4 Section 11 Power Conversion Systems 4 11.1 Summary Description 4 11.2 Turbine-Generator 4 11.3 Main Condenser 4 11.4 Main Condenser Gas Removal and Turbine Sealing Systems 4 11.5 Turbine Bypass System 4 11.6 Circulating Water System 4 11.7 Condensate Demineralizer System 4 11.8 Condensate and Feedwater System 4 11.9 Condensate Storage System 4 Section 12 Structures and Shielding 4 12.1 Summary Description 4 12.2 Structural Design 4 12.3 Shielding and Radiation Protection 4 12.4 Radioactive Materials Safety 4 Section 13 Conduct of Operations 5 13.1 Introduction and Summary 5 13.2 Organization and Responsibilities 5 13.3 Training 5 13.4 Preoperational Test Program 5 13.5 Reactor Startup and Power Test Program 5 13.6 Station Procedures 5 13.7 Records 5 13.8 Operational Review and Audits 5 Section 14 Station Safety Analysis 5 14.1 Introduction 5 14.2 Reactor Limits 5 14.3 Method of Approach 5 14.4 Abnormal Operational Transients 5 14.5 Postulated Design Basis Accidents 5 14.6 Special Events 5 14.7 References 5 Summ T of C-iv Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix A Pressure Integrity of Piping and Equipment Pressure Parts 5 A.1 Scope 5 A.2 Classification of Piping and Equipment Pressure Parts 5 A.3 Design Requirements 5 A.4 Materials 5 A.5 Fabrication and Installation Requirements 5 A.6 Testing and Inspection Requirements 5 A.7 Final Cleaning and Protection 5 A.8 F1, F2, F3, and F4 Fabrication and Erection Schedule 5 A.9 M1, M2, and M3 Material Schedules 5 A.10 T1, T2, T3, T4, and T5 Inspection and Testing Schedules 5 Appendix B Technical Specifications 5 B.1 Technical Specifications 5 B.2 Technical Specifications Relocated to the FSAR 5 B.3 Relocated Technical Specifications and Related 5 Bases 5 B.4 References 5 Appendix C Structural Loading Criteria 5 C.1 Scope 5 C.2 Concrete and Steel Structures 5 C.3 Components 5 Appendix D Quality Assurance Program 5 D.1 General 5 D.2 Program Organization and Responsibility 5 D.3 Quality Surveillance and Auditing 5 D.4 Quality Controls and Assurance Measures 5 D.5 QC-QA Documentation and Records 5 D.6 Project Communications 5 Attachment D.I General Electric Quality System for BWR Nuclear Steam Supply Projects 5 Attachment D.II Bechtel Quality Assurance Program, Pilgrim Nuclear Power Station 5 Attachment D.III Site Handling and Storage of Nuclear Steam Supply System Equipment, Pilgrim Nuclear Power Station 5 Summ T of C-v Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix E Stack Release Limit Calculations for Pilgrim Station Site 5 E.1 Analytical Model 5 E.2 Verification of Analytical Model 5 E.3 Stack Release Limit Calculations for Pilgrim Station Site 5 E.4 Building Exhaust Vent Release 5 E.5 Summary 5 E.6 References 5 Appendix F Comparison of Pilgrim Nuclear Power Station with the Proposed General Design Criteria Published by the AEC for Public Comment in The Federal Register July 11, 1967 6 F.1 Summary Description 6 F.2 Criteria Conformance 6 Appendix G Station Nuclear Safety Operation Analysis Supporting Nuclear Safety Requirements for Plant Operation 6 G.1 Analytical Objective 6 G.2 Bases for Selecting Operation Requirements for Plant Operation 6 G.3 Bases for Selecting Surveillance Test Frequencies for Nuclear Safety Systems and Engineered Safeguards for Plant Operation 6 G.4 Method of Analysis 6 G.5 Analysis and Results 6 G.6 Conclusion 6 Appendix H Tornado Criteria for Nuclear Power Plants 6 H.0 Foreword 6 H.1 Introduction 6 H.2 Characteristics of Tornadoes 6 H.3 Tornado Probability 6 H.4 Wind Loading 6 H.5 Pressure Differential 6 H.6 Water Loss 6 H.7 Tornado Missiles 6 H.8 References 6 Summ T of C-vi Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Appendix I Site Investigation of the Seabreezes 6 I.1 Introduction 6 I.2 Results and Conclusions 6 Section Title Volume I.3 Discussion 6 I.4 Data and Calculations 6 I.5 References 6 Appendix J Station Research, Development, and Further Information Requirements and Resolution 6 J.1 Resolution of ACRS Concerns 6 J.2 Areas Specified in the ACRS Construction Permit Letter for Pilgrim Nuclear Power Station 6 J.3 Areas Specified in the AEC Staff Construction Permit - Safety Evaluation Report for Pilgrim Nuclear Power Station 6 J.4 Areas Specified in Recent, Related ACRS Construction and Operating Permit Letters 6 J.5 Summary Conclusions 6 J.6 References 6 Appendix K Inservice Inspection Program 6 K.1 General 6 K.2 Inspection Program Development 6 K.3 Inspection Program Implementation 6 K.4 Reference Base Examinations 6 K.5 Documentation and Records 6 Appendix L Containment Report 7 L.1 Introduction and Summary 7 L.2 Basis for Containment Design 7 L.3 Containment System Design 7 L.4 Initial Overload and Leakage Rate Test 7 L.5 Manufacturer's Data Report for Nuclear Vessels 7 Appendix M Reactor Pressure Vessel Design Report 7 M.1 Introduction to the Report 7 M.2 Summary 7 Appendix N Emergency Plan 7 Summ T of C-vii Rev. 30 - Nov. 2015

PNPS-FSAR

SUMMARY

TABLE OF CONTENTS (Cont)

Section Title Volume Appendix O Analysis of the Consequences of High Energy Piping Failures Outside The Primary Containment 7 O.1 Introduction 7 O.2 Analysis Assumptions 7 O.3 Analysis Approach 7 O.4 Structural Loading Analytical Technique 7 O.5 Jet and Fluid Forces Analytical Techniques 7 O.6 Detailed System Analyses 7 O.7 Environmental Qualification of Electrical Equipment 7 Appendix P Deleted 7 Appendix Q Supplemental Reload Submittal 7 Q.1 Introduction 7 Appendix R Initial Core Station Safety Analysis 7 R.1 Introduction 7 R.2 Analyses of Abnormal Operational Transients (Initial Core) 7 R.3 Analysis of Design Basis Accidents (Initial Core) 7 R.4 Special Events (Initial Core) 7 R.5 Analytical Methods (Initial Core) 7 R.6 Evaluation Using Standard NRC Approach (Initial Core) 7 Appendix S License Renewal Commitments 7 S.1 Supplement for Renewed Operating License 7 S.2 Aging Management programs and Activities 7 Transients (Initial Core) 7 S.3 Evaluation of Time-Limited Aging Analyses 7 S.4 References 7 Summ T of C-viii Rev. 30 - Nov. 2015

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Page, Table (T), or Revision Figure (F) Number F7.12-1 Refer to M1U1-8 ...............................17 F7.12-2 Refer to M1U101-7 .............................17 F7.12-3 (1 of 1).......................................21 7.13-1.................................................11 7.13-2.................................................22 T7.13-1 (1 of 1).......................................11 T7.13-2 (1 of 1).......................................22 F7.13-1 (1 of 1).......................................11 7.14-1.................................................28 7.15-1.................................................23 7.16 Pages 1-12........................................29 T7.16-1 (1 of 8).......................................21 T7.16-1 (2 of 8).......................................21 T7.16-1 (3 of 8).......................................21 T7.16-1 (4 of 8).......................................21 T7.16-1 (5 of 8).......................................21 T7.16-1 (6 of 8).......................................21 T7.16-1 (7 of 8).......................................21 T7.16-1 (8 of 8).......................................21 T7.16-2 (1 of 1).......................................21 F7.16-1 (deleted)......................................21 7.17-1.................................................12 7.17-2.................................................12 7.17-3..................................................0 7.17-4.................................................13 7.17-5..................................................0 7.17-6.................................................12 7.17-7..................................................0 7.17-8..................................................6 T7.17-1 (1 of 1)........................................4 T7.17-2 (1 of 1)........................................0 F7.17-1 (1 of 1)........................................0 F7.17-2 (1 of 1)........................................0 F7.17-3 (1 of 1)........................................0 F7.17-4 (1 of 1)........................................0 F7.17-5 (1 of 1)........................................0 F7.17-6 (1 of 1)........................................0 EP3 - 8 of 9 Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF EFFECTIVE PAGES

- VOLUME 3**VOLUME 3**VOLUME 3**VOLUME 3**VOLUME 3**

Page, Table (T), or Revision Figure (F) Number F7.17-7 (1 of 1)........................0F7.17-8 (1 of 1) 0 F7.17-9 (1 of 1)........................................0 F7.17-10 (1 of 1).......................................0 F7.17-11 (1 of 1).......................................0 F7.17-12 (1 of 1).......................................0 F7.17-13 (1 of 1).......................................0 F7.17-14 (1 of 1).......................................0 F7.17-15 (1 of 1).......................................0 F7.17-16 (1 of 1).......................................0 F7.17-17 (1 of 1).......................................0 7.18 Pages 1-6.........................................26 F7.18-1 (deleted).......................................9 F7.18-2 Refer to M294 .................................26 F7.18-3 Refer to M78 ..................................26 7.19-1.................................................22 7.20-1.................................................22 7.21-1.................................................26 EP3 - 9 of 9 Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 7 CONTROL AND INSTRUMENTATION TABLE OF CONTENTS Section Title Page 7.1

SUMMARY

DESCRIPTION 7.1-1 7.1.1 Safety Systems 7.1-1 7.1.2 Power Generation Systems 7.1-2 7.1.3 Safety Functions 7.1-2 7.1.4 Station Operational Control 7.1-4 7.1.5 Seismic Design Criteria (Reactor Protection and Engineered Safeguards Systems) 7.1-5 7.1.6 Radiation Resistance Design Criteria 7.1-7 7.1.7 Safety Related Components Inside Containment: Environmental Qualification 7.1-9 7.1.8 Effect of Loss of Heating, Ventilation, and Air Conditioning System on Safety Related Equipment 7.1-10 7.1.9 Safety System Periodic Testing Criteria 7.1-11 7.1.10 Definitions 7.1-12 7.2 REACTOR PROTECTION SYSTEM 7.2-1 7.2.1 Safety Objective 7.2-1 7.2.2 Safety Design Bases 7.2-1 7.2.3 Description 7.2-3 7.2.3.1 Identification 7.2-3 7.2.3.2 Power Supply 7.2-3 7.2.3.3 Physical Arrangement 7.2-4 7.2.3.4 Logic 7.2-4 7.2.3.5 Operation 7.2-5 7.2.3.6 Single Failure and Channel Independence Criteria (IEEE-279) 7.2-7a 7.2.3.7 Identification of Protective Actions and Information Readouts (IEEE-279) 7.2-8 7.2.3.8 Scram Functions and Bases for Trip Settings 7.2-9 7.2.3.9 Mode Switch 7.2-13 7.2.3.10 Scram Bypasses 7.2-13 7.2.3.11 Instrumentation 7.2-18 7.2.3.12 Channel Test and Calibration 7.2-21 7.2.3.13 Wiring 7.2-24 7.2.4 Safety Evaluation 7.2-24 7.2.5 System Inspection and Testing 7.2-27 7.2.6 Nuclear Safety Requirements for Plant Operation 7.2-29 7.2.6.1 Surveillance Requirements for Plant Operation 7.2-31 7.2.7 Current Technical Specifications 7.2-33 7.2.8 References 7.2-32 7-i Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.3 PRIMARY CONTAINMENT AND REACTOR VESSEL ISOLATION CONTROL SYSTEM 7.3-1 7.3.1 Safety Objective 7.3-1 7.3.2 Definitions 7.3-1 7.3.3 Safety Design Bases 7.3-1 7.3.4 Description 7.3-4 7.3.4.1 Identification 7.3-4 7.3.4.2 Power Supply 7.3-4 7.3.4.3 Physical Arrangement 7.3-5 7.3.4.4 Logic 7.3-6 7.3.4.5 Operation 7.3-6 7.3.4.6 Isolation Valve Closing Devices and Circuits 7.3-8 7.3.4.7 Isolation Functions and Settings 7.3-10 7.3.4.8 Instrumentation 7.3-18 7.3.4.8.1 High Temperature Sensors 7.3-21 7.3.4.9 Environmental Capabilities 7.3-24 7.3.5 Safety Evaluation 7.3-24 7.3.6 Inspection and Testing 7.3-28 7.3.7 Nuclear Safety Requirements for Plant Operation 7.3-28 7.3.8 Current Technical Specifications 7.3-30 7.3.9 References 7.3-30 7.4 CORE STANDBY COOLING SYSTEMS CONTROL AND INSTRUMENTATION 7.4-1 7.4.1 Safety Objective 7.4-1 7.4.2 Safety Design Bases 7.4-1 7.4.3 Description 7.4-2 7.4.3.1 Identification 7.4-3 7.4.3.2 High Pressure Coolant Injection System Control and Instrumentation 7.4-3 7.4.3.2.1 Identification and Physical Arrangement 7.4-3 7.4.3.2.2 HPCI Initiation Signals and Logic 7.4-4 7.4.3.2.3 HPCI Initiating Instrumentation 7.4-4 7.4.3.2.4 HPCI Turbine and Turbine Auxiliaries Control 7.4-5 7.4.3.2.5 HPCI Valve Control 7.4-8 7.4.3.2.6 HPCI Environmental Considerations 7.4-11 7.4.3.3 Automatic Depressurization System Control and Instrumentation 7.4-11 7.4.3.3.1 Identification and Physical Arrangement 7.4-11 7.4.3.3.2 Automatic Depressurization System Initiating Signals and Logic 7.4-11 7.4.3.3.3 Automatic Depressurization System Initiating Instrumentation 7.4-15 7.4.3.3.4 Automatic Depressurization System Alarms 7.4-15 7.4.3.3.5 Automatic Depressurization System Environmental Considerations 7.4-17 7.4.3.4 Core Spray System Control and Instrumentation 7.4-17 7.4.3.4.1 Identification and Physical Arrangement 7.4-17 7.4.3.4.2 Core Spray System Initiating Signals and Logic 7.4-18 7-ii Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.4.3.4.3 Core Spray System Pump Control 7.4-19 7.4.3.4.4 Core Spray System Valve Control 7.4-20 7.4.3.4.5 Core Spray System Alarms and Indications 7.4-20 7.4.3.4.6 Core Spray System Environmental Considerations 7.4-20 7.4.3.5 Low Pressure Coolant Injection Control and Instrumentation 7.4-21 7.4.3.5.1 Identification and Physical Arrangement 7.4-21 7.4.3.5.2 LPCI Initiating Signals and Logic 7.4-22 7.4.3.5.3 LPCI Pump Control 7.4-23 7.4.3.5.4 LPCI Valve Control 7.4-24 7.4.3.5.5 LPCI Environmental Considerations 7.4-28 7.4.4 Safety Evaluation 7.4-28 7.4.5 Inspection and Testing 7.4-31 7.4.6 Nuclear Safety Requirements for Plant Operation 7.4-31 7.4.7 Current Technical Specifications 7.4-33 7.5 NEUTRON MONITORING SYSTEM 7.5-1 7.5.1 Safety Objective 7.5-1 7.5.2 Power Generation Objective 7.5-1 7.5.3 Identification 7.5-1 7.5.4 Source Range Monitor Subsystem 7.5-1 7.5.4.1 Power Generation Design Bases 7.5-1 7.5.4.2 Description 7.5-2 7.5.4.2.1 Identification 7.5-2 7.5.4.2.2 Power Supply 7.5-2 7.5.4.2.3 Physical Arrangement 7.5-2 7.5.4.2.4 Signal Conditioning 7.5-3 7.5.4.2.5 Trip Functions 7.5-4 7.5.4.3 Power Generation Evaluation 7.5-4 7.5.4.4 Inspection and Testing 7.5-8 7.5.5 Intermediate Range Monitor Subsystem 7.5-8 7.5.5.1 Safety Design Basis 7.5-8 7.5.5.2 Power Generation Design Basis 7.5-8 7.5.5.3 Description 7.5-8 7.5.5.3.1 Identification 7.5-8 7.5.5.3.2 Power Supply 7.5-8 7.5.5.3.3 Physical Arrangement 7.5-9 7.5.5.3.4 Signal Conditioning 7.5-9 7.5.5.3.5 Trip Functions 7.5-10 7.5.5.4 Safety Evaluation 7.5-10 7.5.5.5 Power Generation Evaluation 7.5-12 7.5.5.6 Inspection and Testing 7.5-12 7.5.6 Local Power Range Monitor Subsystem 7.5-12 7.5.6.1 Power Generation Design Basis 7.5-12 7.5.6.2 Description 7.5-13 7.5.6.2.1 Identification 7.5-13 7.5.6.2.2 Power Supply 7.5-13 7.5.6.2.3 Physical Arrangement 7.5-13 7.5.6.2.4 Signal Conditioning 7.5-14 7.5.6.2.5 Trip Functions 7.5-15 7.5.6.3 Power Generation Evaluation 7.5-15 7.5.6.4 Inspection and Testing 7.5-16 7-iii Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.5.7 Average Power Range Monitor Subsystem 7.5-16 7.5.7.1 Safety Design Basis 7.5-16 7.5.7.2 Power Generation Design Basis 7.5-16 7.5.7.3 Description 7.5-16 7.5.7.3.1 Identification 7.5-16 7.5.7.3.2 Power Supply 7.5-16 7.5.7.3.3 Signal Conditioning 7.5-17 7.5.7.3.4 Trip Function 7.5-17 7.5.7.4 Safety Evaluation 7.5-18 7.5.7.5 Power Generation Evaluation 7.5-19 7.5.7.6 Inspection and Testing 7.5-20 7.5.8 Rod Block Monitor Subsystem 7.5-20 7.5.8.1 Power Generation Design Basis 7.5-20 7.5.8.2 Description 7.5-20 7.5.8.2.1 Identification 7.5-20 7.5.8.2.2 Power Supply 7.5-20 7.5.8.2.3 Signal Conditioning 7.5-20 7.5.8.2.4 Trip Functions 7.5-21 7.5.8.3 Power Generation Evaluation 7.5-22 7.5.8.4 Inspection and Testing 7.5-22 7.5.9 Traversing Incore Probe Subsystem 7.5-22 7.5.9.1 Power Generation Design Basis 7.5-22 7.5.9.2 Description 7.5-22 7.5.9.2.1 Identification 7.5-22 7.5.9.2.2 Physical Arrangement 7.5-23 7.5.9.2.3 Signal Conditioning 7.5-25 7.5.9.3 Power Generation Evaluation 7.5-25 7.5.9.4 Inspection and Testing 7.5-25 7.5.10 Period Based Detection Subsystem 7.5-25 7.5.10.1 Functional Design Basis 7.5-25 7.5.10.2 Description 7.5-26 7.5.10.2.1 Identification 7.5-26 7.5.10.2.2 Power Supplies 7.5-26 7.5.10.2.3 Physical Arrangement 7.5-26 7.5.10.2.4 Signal Conditioning 7.5-26 7.5.10.2.5 Operations 7.5-27 7.5.10.2.6 Inspection and Testing 7.5-28 7.5.11 Nuclear Safety Requirements for Plant Operation 7.5-28 7.5.12 Current Technical Specifications 7.5-32 7.5.13 Reference 7.5-28 7.6 REFUELING INTERLOCKS 7.6-1 7.6.1 Safety Objective 7.6-1 7.6.2 Safety Design Basis 7.6-1 7.6.3 Description 7.6-1 7.6.4 Safety Evaluation 7.6-5 7.6.5 Inspection and Testing 7.6-5 7.6.6 Nuclear Safety Requirements for Plant Operation 7.6-5 7.6.7 Current Technical Specifications 7.6-6 7-iv Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.7 REACTOR MANUAL CONTROL SYSTEM 7.7-1 7.7.1 Power Generation Objective 7.7-1 7.7.2 Power Generation Design Basis 7.7-1 7.7.3 Safety Design Basis 7.7-1 7.7.4 Description 7.7-1 7.7.4.1 Identification 7.7-1 7.7.4.2 Operation 7.7-2 7.7.4.2.1 General 7.7-2 7.7.4.2.2 Insert Cycle 7.7-3 7.7.4.2.3 Withdraw Cycle 7.7-4 7.7.4.2.4 Control Rod Drive Hydraulic System Control 7.7-4 7.7.4.3 Rod Block Interlocks 7.7-5 7.7.4.3.1 General 7.7-5 7.7.4.3.2 Rod Block Functions 7.7-6 7.7.4.3.3 Rod Block Bypasses 7.7-8 7.7.4.3.4 Arrangement of Rod Block Trip Channels 7.7-9 7.7.4.4 Instrumentation 7.7-10 7.7.5 Safety Evaluation 7.7-12 7.7.6 Inspection and Testing 7.7-12 7.7.7 Current Operational Nuclear Safety Requirements 7.7-12 7.8 REACTOR VESSEL INSTRUMENTATION 7.8-1 7.8.1 Safety Objective 7.8-1 7.8.2 Power Generation Objective 7.8-1 7.8.3 Safety Design Bases 7.8-1 7.8.4 Power Generation Design Basis 7.8-1 7.8.5 Description 7.8-1 7.8.5.1 Reactor Vessel Surface Temperature 7.8-2 7.8.5.2 Reactor Vessel Water Level 7.8-2 7.8.5.3 Reactor Vessel Coolant Flow Rates and Differential Pressures 7.8-4 7.8.5.4 Reactor Vessel Internal Pressure 7.8-5 7.8.5.5 Reactor Vessel Top Head Flange Leak Detection 7.8-6 7.8.6 Safety Evaluation 7.8-7 7.8.7 Inspection and Testing 7.8-7 7.8.8 Nuclear Safety Requirements for Plant Operation 7.8-8 7.8.9 Current Technical Specifications 7.8-9 7.8.10 Post Accident Monitoring (PAM) 7.8-10 7.9 RECIRCULATION FLOW CONTROL SYSTEM 7.9-1 7.9.1 Power Generation Objective 7.9-1 7.9.2 Power Generation Design Basis 7.9-1 7.9.3 Safety Design Basis 7.9-1 7.9.4 Description 7.9-1 7.9.4.1 General 7.9-1 7.9.4.2 Motor Generator Set 7.9-2 7.9.4.3 Speed Control Components 7.9-3 7-v Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.9.4.4 System Operation 7.9-5 7.9.4.4.1 Recirculation Loop Starting Sequence 7.9-5 7.9.5 Safety Evaluation 7.9-6 7.9.6 Inspection and Testing 7.9-6 7.9.7 Operational Requirements 7.9-6 7.10 FEEDWATER CONTROL SYSTEM 7.10-1 7.10.1 Power Generation Objective 7.10-1 7.10.2 Power Generation Design Bases 7.10-1 7.10.3 Description 7.10-1 7.10.3.1 Reactor Vessel Water Level Measurement 7.10-1 7.10.3.2 Steam Flow Measurement 7.10-2 7.10.3.3 Feedwater Flow Measurement 7.10-2 7.10.3.4 Feedwater Control Signal 7.10-2 7.10.3.4.1 Automatic Operation 7.10-3 7.10.3.4.2 Optional Operating Modes 7.10-4 7.10.3.5 Feedwater Valve Control 7.10-4 7.10.3.6 Feedwater Pump Trip 7.10-5 7.10.4 Inspection and Testing 7.10-5 7.11 TURBINE GENERATOR CONTROL SYSTEM 7.11-1 7.11.1 Power Generation Objective 7.11-1 7.11.2 Power Generation Design Basis 7.11-1 7.11.3 Description 7.11-1 7.11.3.1 General 7.11-1 7.11.3.2 Compound Control Mechanisms 7.11-2 7.11.3.2.1 Pressure Control Unit 7.11-4 7.11.3.2.2 Mechanical Pressure Regulator 7.11-5 7.11.3.2.3 Electrohydraulic Pressure Regulator 7.11-5 7.11.3.2.4 Speed Control Unit 7.11-7 7.11.3.2.5 Speed Governor 7.11-7 7.11.3.2.6 Acceleration Relay 7.11-8 7.11.3.2.7 Main Load Limit Device 7.11-9 7.11.3.2.8 Control Valve Relay Unit 7.11-9 7.11.3.2.9 Bypass Valve Relay Unit 7.11-10 7.11.3.2.10 Intercept Valve Control 7.11-11 7.11.3.2.11 Control Valves 7.11-11 7.11.3.2.12 Combined Intermediate Valves 7.11-12 7.11.3.2.13 Bypass Valves 7.11-13 7.11.3.2.14 Main Stop Valves 7.11-13 7.11.3.3 Emergency Tripping System 7.11-14 7.11.3.3.1 No. 1 Vacuum Trip 7.11-15 7.11.3.3.2 Emergency Overspeed Trip 7.11-15 7.11.3.3.3 Backup Overspeed Trip 7.11-17 7.11.3.3.4 No. 2 Vacuum Trip 7.11-17 7.11.3.3.5 Overspeed Protection Component Tests 7.11-18 7.11.3.3.6 Turbine Shaft High Vibration Trip 7.11-20 7.11.4 Power Generation Evaluation 7.11-20 7.11.5 Inspection and Testing 7.11-21 7.11.5.1 Turbine Generator Supervisory Instruments 7.11-21 7.11.5.2 Testing Provisions 7.11-22 7-vi Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.12 PROCESS RADIATION MONITORING 7.12-1 7.12.1 Main Steam Line Radiation Monitoring System 7.12-3 7.12.1.1 Safety Objective 7.12-3 7.12.1.2 Safety Design Basis 7.12-3 7.12.1.3 Description 7.12-3 7.12.1.4 Safety Evaluation 7.12-4 7.12.1.5 Inspection and Testing 7.12-4 7.12.1.6 Nuclear Safety Requirements for Plant Operation 7.12-5 7.12.1.7 Current Technical Specifications 7.12-6 7.12.2 Air Ejector Offgas Radiation Monitoring System 7.12-6 7.12.2.1 Power Generation Objective 7.12-6 7.12.2.2 Design Basis 7.12-6 7.12.2.3 Description 7.12-7 7.12.2.4 Evaluation 7.12-8 7.12.2.5 Inspection and Testing 7.12-8 7.12.3 Post-Treatment Radiation Monitoring System 7.12-8 7.12.3.1 Objective 7.12-8 7.12.3.2 Design Basis 7.12-9 7.12.3.3 Description 7.12-9 7.12.3.4 Evaluation 7.12-9 7.12.3.5 Inspection and Testing 7.12-10 7.12.4 Main Stack Radiation Monitoring System 7.12-10 7.12.4.1 Objective 7.12-10 7.12.4.2 Design Basis 7.12-10 7.12.4.3 Description 7.12-11 7.12.4.4 Evaluation 7.12-11 7.12.4.5 Inspection and Testing 7.12-12 7.12.4.6 Nuclear Safety Requirements for Plant Operation 7.12-12 7.12.4.7 Current Technical Specifications 7.12-13 7.12.5 Main Stack High Range Radiation Monitoring System 7.12-13 7.12.5.1 Objective 7.12-13 7.12.5.2 Design Basis 7.12-13 7.12.5.3 Description 7.12-13 7.12.5.4 Evaluation 7.12-14 7.12.5.5 Inspection and Testing 7.12-14 7.12.6 Refueling Ventilation Exhaust Radiation Monitoring System 7.12-14 7.12.6.1 Safety Objective 7.12-14 7.12.6.2 Safety Design Basis 7.12-14 7.12.6.3 Description 7.12-15 7.12.6.4 Safety Evaluation 7.12-16 7.12.6.5 Inspection and Testing 7.12-16 7.12.6.6 Nuclear Safety Requirements for Plant Operation 7.12-16 7.12.6.7 Current Technical Specifications 7.12-18 7.12.7 Reactor Building Exhaust Vent Radiation Monitoring System 7.12-18 7.12.7.1 Objective 7.12-18 7.12.7.2 Design Basis 7.12-18 7-vii Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.12.7.3 Description 7.12-18 7.12.7.4 Evaluation 7.12-19 7.12.7.5 Inspection and Testing 7.12-19 7.12.8 Reactor Building Vent High Range Radiation Monitoring System 7.12-19 7.12.8.1 Objective 7.12-19 7.12.8.2 Design Basis 7.12-19 7.12.8.3 Description 7.12-20 7.12.8.4 Evaluation 7.12-20 7.12.8.5 Inspection and Testing 7.12-20 7.12.9 Turbine Building Effluent Radiation Monitoring System 7.12-20 7.12.9.1 Objective 7.12-21 7.12.9.2 Description 7.12-21 7.12.9.3 Inspection and Testing 7.12-21 7.12.10 Turbine Building Roof Exhaust Vent High Range Radiation Monitoring System 7.12-21 7.12.10.1 Objective 7.12-21 7.12.10.2 Design Basis 7.12-21 7.12.10.3 Description 7.12-22 7.12.10.4 Evaluation 7.12-22 7.12.10.5 Inspection and Testing 7.12-22 7.12.11 Standby Gas Treatment Exhaust Radiation Monitoring System 7.12-22 7.12.11.1 Objective 7.12-22 7.12.11.2 Description 7.12-23 7.12.11.3 Inspection and Testing 7.12-23 7.12.12 Control Room Ventilation Intake Radiation Monitoring System 7.12-23 7.12.12.1 Objective 7.12-23 7.12.12.2 Description 7.12-23 7.12.12.3 Inspection and Testing 7.12-24 7.12.13 Torus Atmospheric High Range Radiation Monitoring System 7.12-24 7.12.13.1 Objective 7.12-24 7.12.13.2 Description 7.12-24 7.12.13.3 Evaluation 7.12-24 7.12.13.4 Inspection and Testing 7.12-24 7.12.14 Drywell Atmospheric High Range Radiation Monitoring System 7.12-25 7.12.14.1 Objective 7.12-25 7.12.14.2 Description 7.12-25 7.12.14.3 Evaluation 7.12-25 7.12.14.4 Inspection and Testing 7.12-25 7.12.15 Radwaste Liquid Discharge Radiation Monitoring System 7.12-26 7.12.15.1 Objective 7.12-26 7.12.15.2 Design Basis 7.12-26 7.12.15.3 Description 7.12-26 7.12.15.4 Evaluation 7.12-26 7.12.15.5 Inspection and Testing 7.12-27 7.12.15.6 Nuclear Safety Requirements for Plant Operation 7.12-27 7-viii Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.12.16 Reactor Building Closed Cooling Water 7.12-27 7.12.16.1 Objective 7.12-27 7.12.16.2 Description 7.12-27 7.12.16.3 Evaluation 7.12-28 7.12.16.4 Inspection and Testing 7.12-28 7.13 AREA RADIATION MONITORING SYSTEM 7.13-1 7.13.1 Power Generation Objective 7.13-1 7.13.2 Power Generation Design Bases 7.13-1 7.13.3 Description 7.13-1 7.13.3.1 Monitors 7.13-1 7.13.3.2 Locations 7.13-1 7.13.4 Inspection and Testing 7.13-1 7.13.5 Local Readout Monitors 7.13-2 7.14 ENVIRONS RADIATION MONITORS 7.14-1 7.14.1 General 7.14-1 7.14.2 Air Sampling 7.14-1 7.14.3 External Gamma Radiation 7.14-1 7.15 HEALTH PHYSICS AND LABORATORY ANALYSIS RADIATION MONITORS 7.15-1 7.16 PROCESS COMPUTER SYSTEM 7.16-1 7.16.1 Power Generation Objective 7.16-1 7.16.2 Safety Design Basis 7.16-1 7.16.3 Power Generation Design Basis 7.16-1 7.16.4 EPIC System Description 7.16-1 7.16.4.1 General 7.16-1 7.16.4.1.1 Main Processing Functions 7.16-2 7.16.4.1.2 Man Machine Interface 7.16-2 7.16.4.1.3 Data Acquisition 7.16-2 7.16.4.1.4 Performance Monitoring 7.16-3 7.16.4.1.5 Transient Recording and Analysis 7.16-3 7.16.4.1.6 Real Time Analysis and Display 7.16-3 7.16.4.2 Reactor Core Performance Function 7.16-4 7.16.4.2.1 Power Distribution Evaluation 7.16-4 7.16.4.2.2 LPRM Calibration 7.16-4 7.16.4.2.3 Fuel Exposure 7.16-4 7.16.4.2.4 Control Rod Exposure 7.16-5 7.16.4.2.5 LPRM Exposure 7.16-5 7.16.4.2.6 Isotopic Composition of Exposed Fuel 7.16-5 7.16.4.2.7 PNPS's Core Thermal Power Evaluation 7.16-5 7.16.4.2.8 Feedwater Correction Factors 7.16-5 7.16.4.2.9 SOLOMON 7.16-6 7.16.4.3 Rod Worth Minimizer Function 7.16-6 7.16.4.3.1 Rod Worth Minimizer Inputs 7.16-8 7.16.4.3.2 Rod Worth Minimizer Outputs 7.16-8 7.16.4.3.3 Rod Worth Minimizer Indications 7.16-8 7-ix Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.16.4.4 Monitor Alarm and Logging Functions 7.16-9 7.16.4.4.1 Analog Monitor and Alarm 7.16-9 7.16.4.4.2 Digital Monitor Alarm 7.16-10 7.16.4.4.3 Alarm Logging 7.16-11 7.16.5 Safety Evaluation 7.16-11 7.16.6 Inspection and Testing 7.16-11 7.16.4.3 Rod Worth Minimizer Function 7.16-7 7.16.4.3.1 RWM Inputs 7.16-7 7.16.4.3.2 RWM Outputs 7.16-8 7.16.4.3.3 RWM Indications 7.16-9 7.16.4.4 Monitor Alarm and Logging Functions 7.16-10 7.16.4.4.1 Analog Monitor and Alarm 7.16-10 7.16.4.4.2 Digital Monitor and Alarm 7.16-11 7.16.4.4.3 Alarm Logging 7.16-11 7.16.5 Safety Evaluation 7.16-12 7.16.6 Inspection and Testing 7.16-12 7.17 NUCLEAR SYSTEM STABILITY ANALYSIS FOR INITIAL CORE 7.17-1 7.17.1 Power Generation Objective 7.17-1 7.17.2 Safety Design Basis 7.17-1 7.17.3 Power Generation Design Basis 7.17-1 7.17.4 Initial Core Description and Performance Analysis 7.17-1 7.17.4.1 Introduction 7.17-1 7.17.4.2 Reactor Core and Channel Hydrodynamic Stability Model Description 7.17-3 7.17.4.3 Total System Analytical Stability Model Description 7.17-3 7.17.5 Initial Core Ultimate Performance Limit Criteria and Conformance 7.17-4 7.17.5.1 Criteria Definition 7.17-4 7.17.5.2 Channel Hydrodynamic Conformance to the Ultimate Performance Criteria 7.17-4 7.17.5.3 Reactor Core Conformance to Ultimate Performance Criteria 7.17-5 7.17.5.4 Total System Conformance to the Ultimate Performance Criteria 7.17-5 7.17.6 Initial Operational Design Guide &

Conformance 7.17-5 7.17.6.1 Design Guide Limit Definition 7.17-5 7.17.6.2 Channel Hydrodynamic Conformance to the Operational Design Guide 7.17-6 7.17.6.3 Reactor Core Conformance to the Operation Design Guide 7.17-7 7.17.6.4 Total System Conformance to the Operational Design Guide 7.17-7 7.17.7 Initial Core Summary 7.17-8 7.17.8 Reload Case 7.17-8 7.17.9 References 7.17-8 7-x Rev. 30 - Nov. 2015

PNPS-FSAR TABLE OF CONTENTS (Cont)

Section Title Page 7.18 REACTOR BUILDING ISOLATION & CONTROL SYSTEM 7.18-1 7.18.1 Safety Objective 7.18-1 7.18.2 Safety Design Basis 7.18-1 7.18.3 Description 7.18-1 7.18.3.1 General 7.18-1 7.18.3.2 Power Supply 7.18-4 7.18.3.3 Physical Arrangement 7.18-4 7.18.3.4 Logic 7.18-4 7.18.3.5 Operation 7.18-4 7.18.3.6 Isolation Functions and Settings 7.18-5 7.18.3.7 Instrumentation 7.18-5 7.18.3.8 Environmental Capabilities 7.18-5 7.18.4 Safety Evaluation 7.18-6 7.18.5 Inspection and Testing 7.18-6 7.18.6 Nuclear Safety Requirements for Plant Operation 7.18-6 7.19 RHR SERVICE WATER SYSTEM (SSW, RBCCW) 7.19-1 7.20 EQUIPMENT AREA COOLING 7.20-1 7.21 METEOROLOGY INSTRUMENTATION 7.20-1 7-xi Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 7 LIST OF TABLES Table Title 7.2-1 Reactor Protection System for Current Plant Safety Analysis Instrumentation Specifications 7.2-2 (Deleted) 7.2-3 LRM Control and Indicators 7.2-4 Reactor Protection System Requirements for Plant Operation 7.2-5 Summary of Surveillances for Plant Operation 7.3-1 (Deleted) 7.3-2 Primary Containment and Reactor Vessel Isolation Control System for Current Plant Safety Analysis Instrument Specifications 7.3-3 Steam Leak Temperature Sensors 7.3-4 Primary Containment and Reactor Vessel Isolation Control System Requirements for Plant Operation 7.4-1 High Pressure Coolant Injection System for Current Plant Safety Analysis Instrument Specifications 7.4-2 Automatic Depressurization System for Current Plant Safety Analysis Instrument Specifications 7.4-3 Core Spray System for Current Plant Safety Analysis Instrument Specifications 7.4-4 Low Pressure Coolant Injection System for Current Plant Safety Analysis Instrument Specifications 7.4-5 Core Standby Cooling Systems (Logic) Operational Requirements for Plant Safety Analysis 7.5-1 SRM Trips 7.5-2 IRM Trips 7.5-3 LPRM Trips 7.5-4 APRM Trips 7.5-5 Neutron Monitoring System Operations Requirements for Plant Operation 7.5-6 Period Based Detection Subsystem Trip Functions 7-xii Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF TABLES (Cont)

Table Title 7.5-7 Period Based Detection Subsystem Operability Requirements 7.5-8 Period Based Detection System Surveillance Requirements 7.6-1 Refueling Interlock Effectiveness 7.7-1 Reactor Manual Control System Instrument Specifications 7.8-1 Reactor Vessel Instrumentation Instrument Specifications 7.8-2 Reactor Vessel Instrumentation Requirements for Plant Operation 7.8-3 Post Accident Monitoring Instrument Specifications 7.12-1 Process Radiation Monitoring Systems Characteristics 7.12-2 Main Steam Line Radiation Monitoring System Requirements for Plant Operation 7.12-3 (Deleted) 7.12-4 Process Radiation Monitoring System Environmental and Power Supply Design Conditions 7.12-5 Main Stack Radiation Monitoring System Requirements for Plant Operation 7.12-6 Refueling Ventilation Exhaust Radiation Monitoring System Requirements for Plant Operation 7.13-1 Area Monitoring System Environmental and Power Supply Design Conditions 7.13-2 Locations of Fixed Area Radiation Monitors 7.16-1 Instrumentation Input Summary 7.16-2 Instrumentation Output Summary Signal Output Description 7.17-1 Acceptable Ultimate Performance Limits 7.17-2 Acceptable Operational Design Limits for Initial Core 7-xiii Rev. 30 - Nov. 2015

PNPS-FSAR SECTION 7 LIST OF FIGURES Figure Title 7.1-1 Single-Cycle-BWR Control System (Flow Control Section)

Functional Block Diagram 7.1-2 Use of Protection System Control and Instrumentation Definitions 7.2-1 Reactor Protection System, Block Diagram (Drawing M1P5-5) 7.2-2 Reactor Protection System, Block Diagram (Drawing M1P6-6) 7.2-3 Schematic Diagram of Logic in One Trip System 7.2-4 Schematic Diagram of Actuators and Actuator-Logics 7.2-5 Scram Reset Switch 7.2-6 RPS Reset Switch Channels 7.2-7 Trip Logic A1 for RPS Switch 7.2-8 Reactor Protection System, Scram Functions 7.2-9 Trip Logic A1 for CRD Scram Discharge Volume High Water Level Bypass 7.2-10 Trip Logic for Neutron Monitoring System Trip Bypass 7.2-11 Main Steam Line Isolation Valve Closure Trip Bypass Channels 7.2-12 Trip Logic A1 for Main Steam Line Isolation Valve Closure Bypass 7.2-13 Turbine First Stage Pressure Switches 7.2-14 Trip Bypass Channels for Turbine Stop Valve and Control Valve Fast Closure Trip Bypass 7.2-15 Trip Logic A1 for Turbine Stop Valve and Control Valve Fast Closure Trip Bypass 7.2-16 Reactor Protection System Block Diagram (Drawing M1P7-5) 7.2-17 Relationship Between Neutron Monitoring System and Reactor Protection System 7.2-18 Functional Control Diagram for Neutron Monitoring System Logics 7.2-19 Typical Arrangement of Channels and Logics 7-xiv Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 7.2-20 Typical Configuration for Turbine Stop Valve Closure Scram 7.2-21 Typical Configuration for Main Steamline Isolation Scram 7.2-22 (Deleted) 7.2-23 (Deleted) 7.2-24 (Deleted) 7.2-25 (Deleted) 7.2-26 (Deleted) 7.3-1 (Deleted Refer to Figure 4.3-2) 7.3-2 Typical Isolation Control System Using Motor Operated Valves 7.3-3 Typical Isolation Control System for Main Steamline Isolation Valves 7.3-4 Main Steamline Isolation Valve, Schematic Control Diagram 7.3-5 Nuclear Boiler Miscellaneous System, Functional Control Diagram (Drawing M1A16-5) 7.3-6 Nuclear Boiler Functional Control Diagram (Drawing M1A15-7) 7.3-7 HPCI/RCIC High Temperature Channel 7.3-8 Area and Compartment Leakage Detection by Temperature Measurement 7.3-9 Main Steamline Space High Temperature Channel 7.3-10 Typical Arrangement for Main Steamline Leak Detection by Flow Measurement 7.3-11 Main Steamline High Flow Channels 7.3-12 Typical Elbow Tap Arrangement for Gross Leak Detection 7.3-13 Not used 7.3-14 Primary Containment Isolation System Elementary Diagram (Drawing M1N33-10) 7.3-15 Primary Containment Isolation System Elementary Diagram (Drawing M1N34-9) 7-xv Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 7.3-16 Primary Containment Isolation System Elementary Diagram (Drawing M1N36-7) 7.3-17 Isolation Control System, Typical Controls for Outboard Main Steam Line Isolation Valves 7.3-18 Primary Containment Isolation System Elementary Diagram (Drawing M1N39-13) 7.3-19 Primary Containment Isolation System, Elementary Diagram (2 Sheets) (Drawing M1N60) 7.3-20 Primary Containment Isolation System, Elementary Diagram (Drawing M1N40-12) 7.3-21 Isolation Control System, Typical Controls for RHRS Discharge to Radwaste Valves 7.3-22 Isolation Control System, Typical Controls for Main Steam Line Drain Valves 7.3-23 Isolation Control System, Typical Controls for Recirculation Loop Sample Valves 7.3-24 Isolation Control System, Typical Controls for TIP System 7.4-1 High Pressure Coolant Injection System (Sheet 1) (Drawing M243) 7.4-2 P&ID High Pressure Coolant Injection System (Sheet 2)

(Drawing M244) 7.4-3 High Pressure Coolant Injection System, Functional Control Diagram (Sheet 1) (Drawing M1J22-5) 7.4-4 High Pressure Coolant Injection System, Functional Control Diagram (Sheet 2) (Drawing M1J23-4) 7.4-5 High Pressure Coolant Injection System, Functional Control Diagram (Sheet 3) (Drawing M1J24-4) 7.4-6 Typical Core Standby Cooling Systems Trip System's Actuation Logic 7.4-7 (Deleted - See Figure 7.3-6) 7.4-8 Core Spray System, Piping and Instrumentation Diagram (Drawing M242) 7-xvi Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 7.4-9 Core Spray System, Functional Control Diagram (Drawing M1K1-8) 7.4-10 (Deleted - Refer to Figure 4.8 Drawing M24) 7.4-11 Residual Heat Removal System, Functional Control Diagram (Sheet 1) (Drawing M1H1-7BC) 7.4-12 Residual Heat Removal System, Functional Control Diagram (Sheet 2) (Drawing M1H2-6) 7.4-13 Residual Heat Removal System, Functional Control Diagram (Sheet 3) (Drawing M1H3-6) 7.4-14 (Deleted - See Figures 7.9-2, 7.9-3, and 7.9-4) 7.4-15 LPCI Loop Selection Logic Component Arrangement 7.5-1 SRM/IRM Unit, Neutron Monitoring System (Drawing M1U109-2) 7.5-2 Detector Drive System 7.5-3 SRM/IRM Detector Drive System, Functional Control Diagram (Drawing M1U104-2) 7.5-4 Functional Block Diagram of SRM Channel 7.5-5 Neutron Monitoring System, Functional Control Diagram Drawing M1U104-2) 7.5-6 Source Range Monitoring System Core Locations 7.5-7 Ranges of Neutron Monitoring System 7.5-8 Functional Block Diagram of IRM Channel 7.5-9 IRM Locations 7.5-10 Typical IRM Circuit Arrangement for Reactor Protection System Input 7.5-11 Initial Core Control Rod Withdrawal Error 7.5-12 Initial Core Normalized Flux Distribution for Rod Withdrawal Error 7.5-13 LPRM Locations 7.5-14 Power Range Monitoring Unit, Neutron Monitoring System (Drawing M1U75-4) 7.5-15 LPRM to APRM Assignment Scheme (Trip System A) 7-xvii Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 7.5-16 LPRM to APRM Assignment Scheme (Trip System B) 7.5-17 Typical APRM Circuit Arrangement for Reactor Protection System Input 7.5-18 Initial Core Envelope of Maximum APRM Deviation, Reduction in Power by Flow Control 7.5-19 Initial Core Envelope of Maximum Deviation APRM Tracking with On-Limits Control Rod Withdrawal 7.5-20 Assignment of Power Range Detector Assemblies to RBM's 7.5-21 LPRM Assignment to RBM for Interior Rod Surrounded by Four LPRM Strings 7.5-22 Typical RBM Channel Response (No Failed LPRMs) 7.5-23 Assignment of LPRM Strings to TIP Machines 7.5-24 Traversing Incore Probe Subsystem Block Diagram 7.5-25 Traversing Incore Probe Assembly 7.5-26 Incore Monitor Drywell Equipment Room Arrangement (Drawing M1Q1-5) 7.5-27 Incore Monitor Drywell Equipment Room Arrangement (Drawing M1Q2-6) 7.5-28 Neutron Monitoring System, Functional Control Diagram (Drawing M1V110-1) 7.5-29 Power Dependent RBM Trip Nomenclature 7.6-1 Refueling Interlocks 7.6-2 Control Rod Drive Hydraulic System, Functional Control Diagram (2 Sheets) (Drawings M1D20-2, M1D21-2) 7.7-1 Control Rod Drive Hydraulic System, Functional Control Diagram (4 Sheets) (Drawings M1D16-3, M1D17-3, M1D18-2, and M1D19-2) 7.7-2 Recirculation Flow Rate Circuit, Schematic Diagram 7.7-3 Input Signals to Four Rod Display 7.7-4 Typical Process Computer Printout 7.8-1 (Deleted - Refer to Figure 4.3-2) 7-xviii Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 7.8-2 (Deleted) Refer to M253 7.8-3 (Deleted) Refer to M1A7-4 7.9-1 Recirculation Flow Control, Illustration 7.9-2 Recirculation Flow Control System, Functional Control Diagram (Sheet 1) (Drawing M1E6-6) 7.9-3 Recirculation Flow Control System, Functional Control Diagram(Sheet 2) (Drawing M1E7-5) 7.9-4 Recirculation Flow Control System, Functional Control Diagram (Sheet 3) (Drawing M1E13-3) 7.9-5 Recirculation Flow Control System, Block Diagram (Drawing M1E8-7) 7.9-6 Recirculation Flow Control System, Block Diagram (Drawing M1E14-5) 7.10-1 Reactor Level and Feedwater Control, Block Diagram (Drawing M1P2-7) 7.11-1 Block Diagram for Control System 7.11-2 Simplified Schematic of the Overall System 7.11-3 Simplified Block Diagram 7.11-4 Emergency Trip Circuit Diagram 7.12-1 Process Radiation Monitoring System Block Diagram (Drawing M1U1-8) 7.12-2 Process Radiation Monitoring System (Drawing M1U101-7) 7.12-3 Post-Treatment Radiation Monitoring System 7.13-1 Area Radiation Monitoring System, Functional Block Diagram 7.16-1 Deleted 7.17-1 Damping Coefficient Versus Decay Ratio (Second Order Systems) 7.17-2 Hydrodynamic and Core Stability Model 7.17-3 Comparison of Test Results with Reactor Core Analysis 7-xix Rev. 30 - Nov. 2015

PNPS-FSAR LIST OF FIGURES (Cont)

Figure Title 7.17-4 Total System Stability Model 7.17-5 Initial Core 10-Cent Rod Reactivity Step at Rod Block Power and Natural Circulation 7.17-6 Initial Core 10 psi Pressure Regulator Setpoint Step at Rod-Block Power and Natural Circulation 7.17-7 Initial Core 6-In Water Level Setpoint Step at Rod-Block Power and Natural Circulation 7.17-8 Initial Core Decay Ratio End of Life Power Peaking 7.17-9 Initial Core 10-Cent Rod Reactivity Step at 1998 MWt Conditions 7.17-10 Initial Core 10 psi Pressure Regulator Setpoint Step at 1998 MWt Conditions 7.17-11 Initial Core 6-In Water Level Setpoint Step at 1998 MWt Conditions 7.17-12 Initial Core 10 Percent Load Demand Decrease from 1998 MWt Conditions 7.17-13 Initial Core 10 Percent Load Demand Increase to 1998 MWt 7.17-14 Initial Core 10-Cent Rod Reactivity Step from Analytical Lower Limit of Automatic Flow Control 7.17-15 Initial Core 10 psi Pressure Regulator Setpoint Step at Analytical Lower Limit of Automatic Flow Control 7.17-16 Initial Core 6-In Water Level Setpoint Step at Analytical Lower Limit of Automatic Flow Control 7.17-17 Initial Core 10 Percent Load Demand Increase from Analytical Lower Limit of Automatic Flow Control 7.18-1 (Deleted Refer to Figure 5.3-1) 7.18-2 Heating, Ventilation and Air Conditioning - Standby Gas Treatment System, Control Diagram (Drawing M294) 7.18-3 Reactor Building Isolation and Control System, Logic Diagram (Drawing M278) 7-xx Rev. 30 - Nov. 2015

v t e Letter Sequence Other
CAC:MF7229, Addition of LCO 3.0.8, Inoperability of Snubbers (Open)
Initiation Acceptance... Administration Questions Answers Results Approval... Other: ML16083A448, ML16083A453, ML16083A461, ML16083A464, ML16083A469, ML16083A471
MONTHYEAR2015-11-30 [Table View]

ML16083A448

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