Operational Reactor Safety

22.091 /22.903

Professor Andrew C. Kadak Professor of the Practice

Lecture 7 Design Issues

Power Cycles for Nuclear Plants

Topics to be Covered

Design Issues for nuclear plants Kneif (8,9 10)

Rankine Cycle

B a s i c

S uperheat

M ulti-fluid cycles

B rayton cycle

Pressure Ratios

Reactor Design Interactions

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Department of Nuclear Science & Engineering Page 3

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Reactor Core Design

Thermal Analysis

Set inlet and outlet temperature

Assume radial peaking factor to calculate hot channel coolant temperature

Assume axial flux profile and engineering factors to calculate hot channel coolant temperature

Calculate clad surface temperature profile for hot channel assuming a clad surface heat flux and empirical heat transfer coefficient

Design Process (2)

Set clad and gap conductance materials and dimensions

Calculate fuel surface temperature profile

Fuel Pin Composition and diameter selection

For a given fuel material use thermal conductivity and peak temperature to determine limiting heat rate for hot channel

Set pellet diameter based on fuel fabrication cost

Recalculate heat fuel and temperature

Reactor Design (3)

Core sizing

Calculate number of fuel pins from core power and length

Chose geometry and spacing

Calculate physics parameters axial and radial power profiles

Assess safety (reactivity coefficients) and power conversion factor (core lifetime)

Calculate required coolant velocity

Reactor Design (4)

Fuel Cycle Economic Analysis

Fuel Pin Structural Analysis

Hydraulic Analysis

P ressure drops, flow distributions

P umping power requirements

Safety Analysis

R eactivity coefficients for accident analysis

Fuel element reliability analysis fuel stress etc.

Post Irradiation handling considerations cooling needs

Fuel Performance

Prof. Andrew C. Kadak,

& Engi ing

2008

Department of

Fuel Designs for LWRs

BWR Fuel Assembly

PWR Fuel Assembly

Fuel Rod Design Interactions

Typical Protective System

Department o

ak, 2008

Prof. Andrew C. Kad

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Daya Bay PWR French Design

Schematic of Plant Design

Key Reactor Systems

Reactor Coolant System

Heat Removal Systems

Nuclear Support Systems

Plant Service Systems

Nuclear Safety Systems

Balance of Plant

Power Conversion Systems

Temperature Entropy Diagrams

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Department of Nuclear Science & Engineering Page 21

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Basic Rankine Cycle

Steam Generators

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Department of Nuclear Science & Engineering Page 24

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Rankine Cycle with Feedwater Heaters

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Department of Nuclear Science & Engineering Page 25

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Power Cycles

Binary Cycle Plants

Gas Reactor Cycles

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Department of Nuclear Science & Engineering Page 29

Brayton Gas Cycle - O pen

Perfect Gas Relationships

Indirect Brayton Open Cycle

Direct Closed Brayton Cycle

Indirec t Close d Cycl e Ga s t o G as

Indirect Gas to Steam Generator

Specific Heats of Gases

Ideal Brayton Cycle

Non-Ideal Brayton Cycle

Gas-Steam Reactor Power Plant

Departm

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Depart

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Departme

, 2008

Prof. Andrew C. Kadak

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Reading and Homework

Assignmen t

1. Read Knief Chapter 8, 9, 10

2. Outside Reading El-Wakil Chapter 2

3. Problems 2.7, 7.4

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Department of Nuclear Science & Engineering Page 44

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22.091 Nuclear Reactor Safety

Spring 200 8

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