NE 405/505 Reactor Systems - Nc State Universitydoster/NE405/Notes/Introduction.pdf · NE 405/505 Abbreviations ... ADS Automatic Depressurization System ADV Atmospheric Dump Valve

NE 405/505 Reactor Systems

By

Dr. Paul Turinsky

Amended By Dr. J. Michael Doster

Do not copy or redistribute without permission from Dr. Turinsky or Dr. Doster

Copyright 2007 Paul J. Turinsky, 2016 J. Michael Doster

NE 405/505 Abbreviations List ACRS Advisory Committee on Reactor Safeguards ADS Automatic Depressurization System ADV Atmospheric Dump Valve A/E Architect Engineer AF Availability Factor AFW Auxiliary Feed Water (normally same as EFW) AOV Air Operated Valve ATWS Anticipated Transient Without Scram Aux Bldg Auxiliary Building BIT Boron Injection Tank BOL Beginning of Core Life BOP Balance of Plant BP Burnable Poison BPA Burnable Poison Assembly BTRS Boron Thermal Regenerative System Bus Electric Power Distribution Circuit BWR Boiling Water Reactor BWST Borated Water Storage Tanks (same as RWST) CCW Component Cooling Water CF Capacity Factor CFT Core Flood Tank (same as Accumulator) CHF Critical Heat Flux CHFR Critical Heat Flux Ratio CPR Critical Power Ratio CRA Control Rod Assembly CRD Control Rod Drive CS Core Spray CVCS Chemical & Volume Control system DCBCDO Design Considerations Beyond Common Design Objectives DNB Departure from Nuclear Boiling DNBR Departure from Nuclear Boiling Ratio DP Differential Pressure DTC Doppler Temperature Coefficient EBS Emergency Boron System ECCS Emergency Core Cooling System EFW Emergency Feed Water (normally same as AFW) EOL End of Core Life EPRI Electric Power Research Institute ESF Engineered Safety Features FCC Fuel Cycle Cost FP Fission Products F/W or FW Feed Water GCR Gas Cooled Reactor HEx or H/X Heat Exchanger

HP High Pressure HPCI or HPI High Pressure Core Injection HPCS High Pressure Core Spray HVAC Heating, Ventilation and Air Conditioning IC Ice Condenser I&C Instrumentation & Control ICS Integrated Control System IFBA or IBA Integral Fuel Burnable Absorber INPO Institute of Nuclear Power Operations LBP Lumped Burnable Poison LCO Limiting Condition of Operation LD Letdown Flow LER Licensee Event Report LOCA Loss of Coolant Accident LOFA Loss of Flow Accident LOOP Loss of Offsite Power LP Low Pressure LSSS Limiting Safety System Setting LPCI or LPI Low Pressure Core Injection LWR Light Water Reactor MCC Motor Control Setting MCPR Minimum Critical Power Ratio MDC Moderator Density Coefficient MDNBR Minimum Departure from Nuclear Boiling Ratio MGCR Modular Gas Cooled Reactor MOV Motor Operated Valve MTC Moderator Temperature Coefficient MU Make Up MVC Moderator Void Coefficient ND Nuclear Design NI Nuclear Instrumentation NRC Nuclear Regulatory Commission NSSS Nuclear Steam Supply System O&M Operation & Maintenance OTSG Once Through Steam Generator PCI Pellet Clad Interaction PCT Peak Clad Temperature PID Proportional + Integral + Derivative controller PORV Pilot Operated Relief Valve PPM Parts Per Million by weight of natural boron Pz Pressure Prz Pressurizer PRT Pressurizer Relief Tank PWR Pressurized Water Reactor QA Quality Assurance QC Quality Control

RC Reactor Coolant RCCA Rod Cluster Control Assembly RCIC Reactor Core Isolation Cooling RCS Reactor Coolant System RCP Reactor Coolant Pump REA Rod Ejection Accident RHRS Residual Heat Removal System RPS Reactor Protection System R/V or RV or RPV Reactor Pressure Vessel RWST Refueling Water Storage Tank (same as BWST) SAR Safety Analysis Report SDM Shut Down Margin SFRCS Safety Feed Water Rupture Control System S/G or SG Steam Generator SIS or SI/S Safety Injection System SLBA or SBA Steam Line Break Accident SOV Solenoid Operated Valve SP Suppression Pool SS Stainless Steel TBV Turbine Bypass Valve T/G or TG Turbine-Generator TGV Turbine Governor Valve TTV Turbine Throttle Valve WABA Wet Annular Burnable Absorber W/U Water to Uranium (volume, molecular or weight) ratio Zirc Zirconium

Introduction Design Process Definition of Design: Create a system which meets specified practical goals.

Flow Diagram of a Design Problem

Design Requirements Design Synthesis

Analysis and Evaluation

Comparison

Iter

ate

Tests and ExperimentsCurrent Engineering

Specs

Example: Heat Exchanger Design

Tin

Tin

exT

exT

(1)

(2)

(1)

(2)

m

P

P(1)

(2)m

(1)

(2)

Design Requirements: Specify desired system performance & safety criteria.

1) Transfers Q (BTU/hr) amount of heat

2) Withstand pressure differential (1) (2)P PP , 3) Can mechanically tolerate pressure & temperature cycling, 4) Have materials compatible with fluids being employed, etc…

Design Requirements Design Synthesis

Analysis and Evaluation

Comparison

Iter

ate

Tests and ExperimentsCurrent Engineering

Specs

Design Synthesis: Take all information available to derive estimate of system spec. Info: Tests & Experiments Current engineering: Systems already operational and/or designed. Estimate System Specs: Perform parametric and preliminary design calculations Example: Specs for heat exchanger:

1) Basic Type (once-through/counter-flow/straight tube-shell design). 2) Length, I.D. & O.D of tubes & shell. 3) Material composition of tubes & shell. 4) Etc.

Analysis & Evaluation: From estimated specs, calculate system output characteristics

& design requirement information. Conducted by calculations usually via computer codes & validated against experiments.

Example: Output characteristics of heat exchanger:

1) Energy transfer rate. 2) Temperature distribution of fluids, tubes & shell. 3) Thermal & pressure induced material deformation. 4) Crud deposition on tube walls effect on heat transfer performance. 5) Tube and shell side pressure drop 6) Etc.

Comparison: Contrast design requirements & actual performance & use as further info in Design Synthesis step.

Specs: Once Design Requirements are satisfied, obtain detailed specs of system. Many times

Design Requirements are not specific enough to conclude unique design, so Design Requirements are added during the design process.

Design-Parameter Interplay Many parameters must be set to obtain design specs. Since parameters are highly interrelated, changing one parameter may require several other parameters to be changed to satisfy Design Requirement. Example: Changing tubing material to be more inert to fluid has implications on deformation

and thermal performance. This may require different tube I.D., O.D. & length.

Non-technical Uniqueness of the Nuclear Power Plant Design Process

1) Auditable by customers & NRC. 2) Design organizational structure must conform to NRC requirements. 3) The public’s “right to know” with safety related matters.

Nuclear Power Plant Design Fundamentals Design Requirements: (some of many) (Not Unique to Nuclear Power)

1) Electric Power Output (MWe) 2) Availability Factor (Target of 95% ) 3) Maximum Thermal Efficiency to minimize:

a. Environmental impact b. Power Cost.

4) Low power cost a. Capitol Cost ( 75% of total) b. Fuel cost ( 10% of total) c. Operation & Maintenance cost ( 15% of total)

5) Load follow capability (change power level rapidly) 6) Safety 7) Pollution Control (EPA/State & Local Governments)

(Unique to Nuclear Power)

8) Licensability (ACRS/NRC/EPA/State & Local Governments) 9) Cycle Length (Refuel usually 1 ½ to 2 years)

System Overviews Basic Nuclear Power Plant System Layout: To satisfy the Design Requirements, several different systems have evolved:

Pressurized Water Reactors (PWR) Boiling Water Reactors (BWR) Gas Cooled Reactors (GCR) Sodium Fast Reactors (SFR).

Our attention will be focused principally on the PWR & BWR systems, collectively referred to as Light Water Reactors (LWR). All nuclear reactor plants are designed using the same concepts that fossil fired power plants employ, except that nuclear fission replaces exothermic chemical reactors as the energy source. Typical simplified flow diagrams for a PWR & BWR are shown in the following figures.

Simplified Diagram of a Four-Loop NSSS

Reactor Vessel and Internals

Indirect Cycle PWR

Direct Cycle BWR

Steam and Recirculation Flow Paths of the GE BWR

Typical GE Boiling Water Reactor

Advanced BWR

Industry Subdivisions and Participants Subdivision of Responsibilities in Design Process: Since a nuclear power plant involves many different organizations in the design and construction stages, it was necessary to subdivide the plant in a fashion to allow:

1) Meaningful information flow interfaces to be established 2) Assignment of responsibility

What have evolved are the following two large subdivisions:

1) Nuclear Steam Supply System (NSSS) a. Reactor Vessel & Components:

Pressure Vessel Fuel Assemblies Control Rods & Drives Baffle Thermal Shield Upper & Lower Core Support Plates Steam Separators (BWR), Etc.

b. Reactor Coolant System (RCS) Components:

Coolant Pumps Pressurizer Steam Generators (PWR) Chemical & Volume Control Systems (CVCS) Safety Components Reactor Protection System (RPS) Emergency Core Cooling System (ECCS) Emergency Boration System (EBS) Residual Heat Removal System (RHRS)

2) Balance of Plant (BOP):

a. Containment, Auxiliary Building, Rad Waste Building, etc. b. Steam Components: Piping, Condenser, Turbine/generator c. Feedwater System d. Component Cooling System e. Electrical Systems f. Instrument Air System g. Etc.

Participants:

1) Utilities: Desires: Low Capital investment, short construction time, low energy costs,

reliability, safety, low environmental impact, licensability, and long-term fuel resources.

Role: Defines system gross requirements such as power rating (MWe), load

following capability, availability factor (AF), evaluate bids, project management and license holder, operations and maintenance (O&M)

2) NSSS Vendors: Role: design, fabricate, and warrants NSSS components Examples: GEH, Westinghouse & AREVA

3) Turbo-Generator Vendors: Examples: GE, Siemens

4) Architectural Engineering (A/E): Role: design entire plant, how to assemble components and build structures; also

evaluates bids on NSSS (sometimes) Examples: Bechtel and Shaw

5) Contractors

Role: constructs buildings and assembles equipment Examples: A/E’s, Daniels, etc. and Utilities

Condensation of Responsibility: In some instances, one organization assumes multiple roles, e.g. 1+4+5: Duke and TVA 2+3+4+5: Turn-Key; GE, Westinghouse in the past