This book is an introductory text bringing out the principles and concepts in nuclear reactor engineering. It is based on the syllabus followed in Indian universities. After discussing the rationale for nuclear power plants, the book introduces the basic concepts of reactor physics, power plant engineering (including heat transfer and fluid flow principles) and different facets of nuclear power plants.
Salient Features
• Explains the nuclear reactor fuel cycle from mining to waste disposal.
• Describes the different types of reactors and their components which include
pressurised water reactor, boiling water reactor, pressurised heavy water reactor,
gas cooled reactor, sodium cooled fast reactor, and molten salt reactor.
• Brings out in brief India’s nuclear power programme based on the three stages
envisaged by Dr. Homi Bhabha.
• Deals with safety features and approaches in reactor design.
• Discusses direct energy conversion including radionuclide thermoelectric
generator, thermionic generators and other radionuclide power sources for
space applications.
• Highlights the upcoming technology of fusion reactors and its advantages.

Dedication v
Foreword xxii
Preface xxiv
CHAPTER 1 MOTIVATION FOR NUCLEAR ENERGY
1.1 Introduction 1.1
1.2 The Role of Electricity 1.2
1.3 Disparities Among Countries 1.3
1.4 Sources of Energy 1.3
1.5 Present Sources of Electricity 1.4
1.5.1 Issues Regarding Coal 1.4
1.5.2 Issues with Natural Gas 1.6
1.5.3 Issues of Energy from Water 1.7
1.5.4 Issues with Wind Power 1.8
1.5.5 Issues with Solar Photovoltaic 1.8
1.5.6 Issues with Concentrated Solar Thermal Plants 1.9
1.5.7 Issues with Nuclear 1.9
1.5.8 Environmental Impact of Energy Sources 1.11
1.6 Comparison of Energy Sources 1.14
1.7 Alternatives to Fossil Fuels 1.16
1.7.1 The Potential Role of Nuclear Energy 1.17
1.7.2 The Example of France 1.19
1.8 The Status of Nuclear Energy 1.19
1.9 Types of Nuclear Reactors 1.21
1.9.1 Pressurised Water Reactor (PWR) 1.21
1.9.2 Boiling Water Reactor (BWR) 1.22
1.9.3 Pressurised Heavy Water Reactor (PHWRs) 1.23
1.9.4 Sodium Cooled Fast Reactor (SFR) 1.24
1.9.5 Gas Cooled Reactors GCRs 1.24

Contents vii
1.10 India’s Energy Resources and Nuclear Power 1.25
Closure 1.27
References 1.28
Bibliography 1.29
Assignments 1.30
CHAPTER 2 BASIC PHYSICS OF NUCLEAR REACTORS
2.1 Introduction 2.1
2.2 Isotopes 2.2
2.3 Binding Energy 2.2
2.4 Nuclear Stability 2.4
2.5 Neutron Reactions 2.6
2.6 Radioactive Decay 2.7
2.7 Units of Radioactivity 2.9
2.8 Fission 2.9
2.8.1 Fission Energy 2.9
2.8.2 Critical Mass 2.10
2.8.3 GABON- Natural Fission Reactor 2.10
2.8.4 Liquid Drop Model of Fission 2.11
2.9 Cross Section 2.12
2.10 Prompt and Delayed Neutrons 2.14
2.11 Neutron Life Cycle 2.14
2.12 Infinite Multiplication Factor (K∞) 2.15
2.12.1 Four Factor Formula 2.16
2.13 Effective Multiplication Factor (keff) 2.18
2.13.1 Fast Neutron Non-Leakage Probability (Lf

) 2.19
2.13.2 Thermal Neutron Non-Leakage Probability (Lt
) 2.19
2.13.3 Six Factor Formula 2.20
2.14 Actinides and Related Isotopes 2.21
2.15 Neutron Moderation 2.24
2.16 Neutron Slowing Down 2.24
2.17 Neutron Moderators 2.25
2.18 Criticality and Reactor Power 2.27

viii Nuclear Reactor Engineering
2.19 Burners, Converters, and Breeders 2.27
2.20 Decay/Residual Heat 2.30
2.21 Reactivity 2.31
2.21.1 Feedback Reactivity 2.31
2.22 Heat Generation 2.37
2.22.1 Heat Generation in Nuclear Fuel 2.37
2.22.2 Heat Generation in Moderator 2.39
2.22.3 Heat Generation in Reflector & Shields 2.39
2.22.4 Heat Generation in Structures 2.39
2.23 Reactor Kinetics 2.40
2.23.1 Effective Delayed Neutron Fraction 2.41
2.24 Reactor Control 2.43
2.25 Radiation Shielding 2.44
Closure 2.45
References 2.45
Bibliography 2.47
Assignments 2.47
CHAPTER 3 BASICS OF POWER PLANT THERMODYNAMICS
3.1 Introduction 3.1
3.2 Laws of Thermodynamics (Nag, 2002) 3.2
3.3 Carnot Cycle 3.3
3.4 Rankine Cycle 3.4
3.5 Reheat Cycle 3.7
3.6 Regenerative Cycle (Feed Water Heating) 3.10
3.7 Brayton Cycle 3.11
Closure 3.14
References 3.14
Bibliography 3.15
Assignments 3.15
CHAPTER 4 NUCLEAR FUEL CYCLE
4.1 Introduction 4.1

Contents ix
4.2 Material Balance in the Nuclear Fuel Cycle 4.3
4.3 Uranium Mining 4.3
4.4 Uranium Milling 4.4
4.5 Conversion to Uranium Hexafluoride 4.5
4.6 Enrichment 4.6
4.6.1 Gaseous Diffusion 4.6
4.6.2 Gas Centrifuge 4.7
4.7 Fuel Fabrication 4.8
4.8 Fuel in Power Generation 4.9
4.8.1 Accident Tolerant Fuel 4.10
4.9 Transport of Radioactive Materials 4.11
4.10 Spent Fuel Storage 4.12
4.11 Reprocessing 4.13
4.11.1 Solvent Extraction 4.14
4.11.2 Pyro-processing 4.16
4.12 Waste Management 4.18
4.12.1 Types of Radioactive Wastes 4.18
4.12.2 Treatment and Conditioning of Nuclear Wastes 4.20
4.13 Waste Disposal Methods 4.24
4.13.1 Near-surface Disposal 4.24
4.13.2 Deep Geological Disposal 4.25
4.13.3 Disposal in Outer Space 4.27
4.13.4 Deep Boreholes 4.27
4.13.5 Disposal at Sea 4.28
Closure 4.28
References 4.28
Bibliography 4.29
Assignments 4.30
CHAPTER 5 COMPONENTS OF A NUCLEAR REACTOR
5.1 Introduction 5.1
5.2 Fermi Pile 5.1
5.2.1 Control 5.2

x Nuclear Reactor Engineering
5.2.2 Safety 5.3
5.2.3 Radiation Monitoring 5.3
5.3 Reactor Core 5.3
5.4 Coolant 5.5
5.5 Control Rods 5.5
5.6 Moderator 5.6
5.7 Other Core Components 5.6
5.8 Containment 5.7
5.9 Core Catcher 5.7
5.10 Steam Generator 5.7
5.11 Turbine Generator 5.7
5.12 Steam/Water System 5.7
5.13 Fuel Handling 5.8
5.14 Spent Fuel Cooling 5.8
5.15 Emergency Core Cooling 5.8
5.16 Types of Nuclear Reactors 5.8
5.17 Nuclear Instrumentation 5.9
5.17.1 Source Range Detectors 5.11
5.17.2 Intermediate-Range Detectors 5.12
5.17.3 Power Range Detector 5.14
5.17.4 Signals and Safety Logic 5.15
Closure 5.16
References 5.17
Bibliography 5.17
Assignments 5.18
CHAPTER 6 FUEL ELEMENT HEAT TRANSFER
6.1 Introduction 6.1
6.2 Factors Influencing Fuel Performance 6.1
6.3 Principal Fuel and Clad Materials 6.3
6.3.1 Fuel Material 6.3
6.3.2 Cladding Materials 6.4
6.4 Heat Conduction in Fuel Elements 6.6

Contents xi
6.5 Thermal Properties of Fuel 6.9
6.5.1 Thermal Conductivity 6.9
6.5.2 Melting Point 6.12
6.5.3 Fission Gas Release 6.13
6.5.4 Specific Heat 6.13
6.6 Steady State Temperature Distribution in
Plate Type Fuel Elements 6.13
6.7 Steady State Temperature Distribution in
Cylindrical Fuel Pins 6.18
6.8 Temperature Distribution in Restructured Fuel Elements 6.22
6.8.1 Zone-3 6.25
6.8.2 Zone-2 6.26
6.8.3 Zone-1 6.27
6.8.4 Implications of Fuel Restructuring in Core Design 6.29
6.9 Pellet-Clad Gap Conductance 6.30
6.10 Overall Resistance 6.34
Closure 6.36
Reference 6.36
Bibliography 6.38
Assignments 6.38
CHAPTER 7 HEAT AND FLUID FLOW IN REACTOR COMPONENTS
7.1 Introduction 7.1
7.2 Dimensionless Quantities 7.1
7.3 Characteristics of a Reactor Coolant 7.5
7.4 Boiling Heat Transfer 7.9
7.4.1 Pool Boiling 7.9
7.4.2 Flow Boiling 7.11
7.5 Heat Transfer Correlations 7.13
7.5.1 Heat Transfer Correlation for
Single Phase (Water, Steam) 7.13
7.5.2 Heat Transfer Correlation for Nucleate Boiling 7.14
7.5.3 Correlation for CHF 7.16
7.6 Condensation Heat Transfer 7.17

xii Nuclear Reactor Engineering
7.7 Pressure drop 7.17
7.7.1 Evaluation of Frictional Pressure Drop 7.18
7.7.2 Elevation Pressure Drop 7.20
7.7.3 Acceleration Pressure Drop 7.20
7.7.4 Local Pressure Drop 7.22
7.7.5 Pressure Drop in Fuel Rod Bundle 7.23
7.7.6 Two Phase Pressure Drop 7.26
7.8 Critical/Choked Flow 7.27
7.9 Natural Convection and Thermo Syphon 7.28
7.10 Flow Instabilities (Nayak, 2008) 7.31
7.10.1 Static/Ledinegg Instability 7.33
7.10.2 Dynamic Instability 7.35
7.10.3 Coupled Neutronic Thermal-Hydraulic Instabilities 7.36
7.10.4 Natural Boiling Oscillations 7.37
7.11 Orificing Requirement 7.38
7.12 Hot Spot Factors in Nuclear Reactor Design 7.38
7.12.1 Nuclear Factors 7.40
7.12.2 Engineering Factors 7.40
7.12.3 Combination of Sub-factors 7.41
7.13 Loss of Flow and Pump Coast Down 7.41
Closure 7.42
References 7.42
Bibliography 7.44
Assignments 7.44
CHAPTER 8 PRESSURIZED WATER REACTORS
8.1 Introduction 8.1
8.2 Reactor Configurations 8.2
8.2.1 Overall System 8.2
8.2.2 Coolant 8.3
8.2.3 Moderator 8.4
8.2.4 Core Configuration 8.5
8.2.5 Reactor Vessel 8.8

Contents xiii
8.3 Reactor Control 8.9
8.4 Steam Generation 8.11
8.5 Other Primary System Components 8.14
8.5.1 Primary Coolant Pumps 8.14
8.5.2 Pressurizer 8.16
8.6 Auxiliary Systems 8.17
8.7 Steam Turbine Cycle 8.18
8.8 Chemical Volume Control System 8.19
8.9 Residual (Shutdown) Heat Removal Circuit 8.20
8.10 Emergency Core Cooling Circuit 8.22
8.11 Containment Systems 8.24
8.11.1 Containment Spray System 8.24
8.11.2 Hydrogen Control in Containment 8.25
8.12 Advantages over BWR 8.25
8.13 PWR Typical Issues 8.26
Closure 8.27
References 8.27
Bibliography 8.28
Assignments 8.28
CHAPTER 9 BOILING WATER REACTOR
9.1 Introduction 9.1
9.2 BWR Reactor Vessel Assembly 9.3
9.3 Fuel and Control Assemblies 9.5
9.4 Reactor Water Cleanup System 9.6
9.5 Shutdown/ Decay Heat Removal 9.7
9.6 Reactor Core Isolation Cooling 9.8
9.7 Standby Liquid Control System 9.9
9.8 Emergency Core Cooling Systems 9.9
9.9 Boiling Water Reactor Containments 9.11
Closure 9.13
References 9.13
Bibliography 9.14
Assignments 9.14

xiv Nuclear Reactor Engineering
CHAPTER 10 PRESSURISED HEAVY WATER REACTOR
10.1 Introduction 10.1
10.2 Genesis of CANDU HWR 10.3
10.3 Reactor 10.4
10.4 Moderator Systems 10.5
10.5 Heat Transport Systems 10.6
10.6 Feed and Bleed Circuit 10.8
10.7 Fuel 10.8
10.8 Fuel Handling 10.10
10.9 Reactor Power Control 10.11
10.10 Reactor Safety 10.11
10.10.1 Shutdown Systems 10.12
10.10.2 Shutdown Cooling System 10.13
10.10.3 Emergency Core Cooling System 10.14
10.11 Containment System 10.17
10.12 Main Steam and Feedwater Systems 10.19
10.12.1 Steam Generator Pressure Control 10.20
10.12.2 Steam Generator Level Control 10.21
Closure 10.21
References 10.21
Bibliography 10.22
Assignments 10.23
CHAPTER 11 GAS COOLED REACTOR
11.1 Introduction 11.1
11.2 Magnox-General Description(Jensen, 1999) 11.2
11.3 Magnox Reactors in Other Countries 11.5
11.4 UNGG (Uranium Naturel Graphite Gaz) Reactors 11.5
11.5 Advanced Gas Cooled Reactor (AGR) 11.6
11.6 High Temperature Gas Cooled Reactor (HTGR) 11.9
11.6.1 Dragon Reactor Experiment (Brey 2001) 11.10
11.6.2 The AVR (Brey, 2001) 11.11

Contents xv
11.6.3 Peach Bottom (No. 1) (Brey, 2001) 11.12
11.6.4 HTGR Demonstration Plants and
Large Plant Designs 11.14
Closure 11.19
References 11.19
Bibliography 11.20
Assignments 11.21
CHAPTER 12 SODIUM COOLED FAST REACTORS
12.1 Introduction 12.1
12.2 Flexible Use of Actinides 12.4
12.3 Waste Minimization 12.6
12.4 Overview of Sodium-Cooled Fast Reactor (SFR) 12.7
12.5 Layout of SFR Components 12.8
12.5.1 Pool Concept 12.11
12.5.2 Loop Concept 12.12
12.6 Fuel Design 12.12
12.6.1 Fuel Element 12.12
12.6.2 Fuel Subassembly 12.14
12.7 Intermediate Circuits 12.16
12.7.1 Intermediate Heat Exchanger (IHX) 12.17
12.7.2 Steam Generators 12.19
12.8 Sodium Pumps 12.24
12.8.1 Electromagnetic Pump 12.24
12.8.2 Centrifugal Pumps 12.25
12.9 Auxiliary Circuits 12.27
12.9.1 Inert Gas System 12.27
12.9.2 Trace Heating 12.27
12.9.3 Sodium Purification System 12.28
12.10 Decay Heat removal Systems 12.29
12.10.1 DHR in Primary Sodium 12.29
12.10.2 DHR in Secondary Sodium 12.30
12.10.3 Steam Generator Auxiliary Cooling System 12.30

xvi Nuclear Reactor Engineering
12.10.4 DHR through Steam Water System 12.31
12.10.5 Reactor Vessel Auxiliary Cooling System 12.31
12.11 Shut-Down Systems 12.32
Closure 12.34
References 12.34
Bibliography 12.35
Assignments 12.36
CHAPTER 13 MOLTEN-SALT REACTORS
13.1 Introduction 13.1
13.2 ORNL Developmental Work 13.1
13.3 Molten-Salt Reactor Experiment (MSRE) 13.3
13.4 Problems of MSR 13.6
13.5 Impact of SFR Programme on MSR 13.6
13.6 Recent Developments 13.7
Closure 13.10
References 13.10
Bibliography 13.11
Assignments 13.11
CHAPTER 14 INDIA’S NUCLEAR POWER PROGRAMME
14.1 Introduction 14.1
14.2 Setting Up of Nuclear Establishment 14.2
14.3 Research Reactor APSARA (BARC, 2024) 14.3
14.4 Canada India Research Reactor (CIRUS) 14.4
14.5 DHRUVA (Agarwal, 2006) 14.5
14.6 Spent Fuel Reprocessing (Dey, 2006) 14.5
14.7 India’s Nuclear Facilities 14.5
14.7.1 Power Reactors 14.5
14.7.2 Fast Breeder Test Reactor
(Suresh Kumar, 2011) 14.7
14.7.3 KAMINI Research Reactor (Manoharan, 2024) 14.8
14.7.4 Uranium Enrichment Facilities 14.8

Contents xvii
14.7.5 Heavy Water Production 14.8
14.7.6 Fuel Fabrication 14.9
14.7.7 Reprocessing Facilities 14.9
14.7.8 Uranium Mining 14.9
14.8 Future Indian Stage 3 Programme 14.10
14.8.1 Advanced Heavy Water Reactor (AHWR)
(Sinha, 2006) 14.11
14.8.2 Accelerator Driven Subcritical Systems
(ADS) (Dulera, 2021) 14.14
14.8.3 Indian High Temperature Reactor Development
Programme (Dulera, 2021) 14.15
14.8.4 Indian Molten Salt Breeder Reactor
(Dulera, 2021) 14.17
Closure 14.18
References 14.18
Bibliography 14.11
Assignments 14.11
CHAPTER 15 ADVANCES IN PASSIVE SAFETY OF NUCLEAR REACTORS
15.1 Introduction 15.1
15.2 Some Safety Terminologies 15.2
15.3 Categorization of Passive Systems 15.4
15.4 Passive Reactor Shutdown Systems 15.6
15.4.1 PHWR/CANDU Reactor (Cutler, 1991) 15.6
15.4.2 Sodium Fast Reactor 15.7
15.5 Passive Decay Heat Removal in LWR/PHWR Reactors 15.9
15.5.1 Pre-pressurized Core Flooding Tanks 15.10
15.5.2 Elevated Tank Natural Circulation Loops 15.11
15.5.3 Elevated Gravity Drain Tanks 15.11
15.5.4 Passively Cooled Steam Generator
Natural Circulation 15.12
15.6 Passive Safety Systems for Containment Cooling and
Pressure Suppression 15.12

xviii Nuclear Reactor Engineering
15.6.1 Containment Pressure Suppression Pools 15.13
15.6.2 Containment Passive Heat Removal/Pressure
Suppression Systems 15.13
15.6.3 Passive Containment Spray Systems 15.15
15.7 Hydrogen Removal 15.16
15.8 Reactor Evolution 15.17
15.8.1 ABWR (The Advanced Boiling Water Reactor) 15.19
15.8.2 The EPR (European Pressurised Reactor or
Evolutionary Power Reactor) 15.19
15.9 AP600 and AP1000 (IAEA, 2011) 15.20
15.9.1 AP600/AP1000 Passive Safety Systems 15.22
15.9.2 Passive Residual Heat Removal (PRHR) System 15.23
15.9.3 Core Make-up Tank (CMT) 15.24
15.9.4 Automatic Depressurization System (ADS) 15.24
15.9.5 Accumulators (ACC) 15.24
15.9.6 In-containment Refueling Water
Storage Tank (IRWST) 15.25
15.9.7 Containment Sump Recirculation 15.25
15.9.8 Containment and Passive Containment Cooling
System (PCCS) 15.26
15.9.9 Integrated Passive Safety System Response
During a SBLOCA 15.27
15.9.10 Description of Main Control Room Habitability
System (VES) 15.28
15.9.11 AP Reactors Status 15.28
15.10 Small Modular Reactors (SMR) 15.29
Closure 15.31
References 15.31
Bibliography 15.32
Assignments 15.32
CHAPTER 16 REACTOR SAFETY AND REGULATION
16.1 Introduction 16.1
16.2 Environmental Impact Assessment 16.2

Contents xix
16.3 Comprehensive Safety Analysis (Jaharlal koley, 2006) 16.3
16.3.1 Defence in Depth 16.3
16.3.2 The Fundamental Safety Functions (IAEA, 2006) 16.5
16.4 Current Safety Approach 16.6
16.4.1 Facilities to Control & Shutdown Reactor 16.8
16.4.2 Facilities to Cool the Reactor 16.8
16.4.3 Containment 16.8
16.4.4 Redundancy, Diversity and Independence 16.10
16.5 Safety Analysis 16.12
16.5.1 Deterministic Safety Analysis (IAEA, 2009) 16.13
16.5.2 Risk and Probabilistic Safety Analysis (PSA) 16.15
16.5.3 Design Basis Events (DBE) 16.17
16.6 Regulatory Process in India (Jaharlal koley, 2006) 16.21
16.6.1 Site Approval 16.23
16.6.2 Construction Approval 16.23
16.6.3 Operating License 16.24
16.6.4 Regulatory Inspection 16.24
16.7 Radiation Dose Limits and actual dose 16.25
16.7.1 Occupational Radiation in Various Reactor Designs 16.26
Closure 16.27
References 16.28
Bibliography 16.28
Assignments 16.29
CHAPTER 17 DIRECT ENERGY CONVERSION
17.1 Introduction 17.1
17.2 Thermoelectric Generators 17.2
17.2.1 Radionuclide Thermoelectric Generators 17.3
17.2.2 Reactor Thermoelectric Generators 17.6
17.3 Thermionic Electrical Generators (Shultis, 2002) 17.6
17.3.1 Radionuclide Thermionic Generators 17.8
17.4 AMTEC Conversion 17.10

xx Nuclear Reactor Engineering
17.5 Beta-voltaic Batteries 17.11
17.6 Radioisotopes for Thermal Power Sources 17.12
Closure 17.14
References 17.14
Bibliography 17.15
Assignments 17.15
CHAPTER 18 FUSION ENERGY
18.1 Introduction 18.1
18.2 Binding Energy 18.2
18.3 Fusion Reactions 18.3
18.4 Fusion Fuel Availability 18.5
18.5 Issues in Fusion 18.5
18.6 Thermonuclear Reaction in Plasma 18.7
18.6.1 Inertial Confinement Fusion (ICF) 18.8
18.6.2 Magnetic Confinement 18.9
18.7 Lawson’s Criteria 18.9
18.8 Fusion Power Plants 18.10
18.9 Safety and Environmental Considerations 18.11
18.10 The “Cold Fusion” Confusion 18.12
18.11 Fusion Research in India 18.12
18.11.1 Aditya and SST-1 (Saurav Jha, 2022) 18.13
18.11.2 ITER-India (ITER India, 2024) 18.16
18.11.3 India’s plans for SST-2 and then DEMO
(Saurav Jha, 2022) 18.17
18.12 ITER (ITER, 2024) 18.17
18.13 Advantages of Fusion Energy (Ragheb, 2018) 18.20
Closure 18.21
References 18.21
Bibliography 18.22
Assignments 18.22

Contents xxi
Annexure A A.1
Annexure B B.1
Annexure C C.1
Annexure D D.1
List of Tables xxvii
List of Figures xxix
Index IND-1

Dr. G. Vaidyanathan, BE, MBA, PhD, served in the Department of Atomic Energy,
India, for 38 years, retiring in 2010 as Director of the Fast Reactor Technology Group
at IGCAR, Kalpakkam. A specialist in thermal hydraulics and safety analysis, he
played a pivotal role in India’s Fast Reactor Programme. Post-retirement, he has been
actively teaching nuclear energy and alternative systems at several Indian universities.
He has authored four books on nuclear energy and created a 30-lecture video module for NPTEL. Dr. Vaidyanathan is a lifetime fellow of the Institution of Engineers
(India) and a life member of the Indian Nuclear Society. He has published 40 journal
papers and continues to contribute to nuclear safety as a committee member.