ENGINEERING LESSON GUIDE 8

1
INTRODUCTION TO NAVAL ENGINEERING
PRINCIPLES OF NUCLEAR POWER
2
BASIC SYMBOLS AND NOTATIONS
Bohrs Model
EXAMPLE
235
U
92
3
ISOTOPES
TRITIUM
HYDROGEN
DEUTERIUM
4
BASIC FISSION EQUATION
5
ENERGY RELEASED
MASS OF PRODUCTS Zr - 93.90631 amu Ce -
139.90539 amu 2 n - 2(1.00867)
amu ------------------------------ TOT
235.82904 amu
MASS OF REACTANTS U - 235.04390 amu n -
1.00867 amu ------------------------------ TOT
236.95257
mass defect 236.05257 - 235.82904 .22353 amu
Therefore Binding Energy 208.21372 MeV
1 amu 931.48 MeV where 1 Mev 1.52x10-15 Btu
6
TYPES OF NEUTRONS

• Fast neutrons
• Have KE of .1 MeV
• Produced through fission
• Very few will cause fission
• Slow neutrons
• Have KE of 1 eV
• Must be slowed by a MODERATOR
• Main producer of fission

7
THE NEUTRON LIFE CYCLE
8
TERMS RELATED TO REACTIVITY

• REACTIVITY-
• Critical
• Sub-Critical
• Super-Critical

9
UNITED STATES NAVAL REACTORS ARE PRESSURIZED
WATER REACTORS
10
(No Transcript)
11
REACTOR CORE PRESSURE VESSEL
12
NAVAL REACTOR SAFETY

• INHERENT STABILITY
• WATER IS BOTH MODERATOR AND COOLANT
• POWER GOES UP
• TEMP GOES UP
• DENSITY GOES DOWN
• THERMALIZED NEUTRONS GOES DOWN
• POWER GOES DOWN

13
PRESSURIZER
14
RADIATION SHIELDING

• Must protect personnel from the various types of
  radiation
• Alpha particles ( very large, positive)
• Beta particles (tiny, negative)
• Gamma rays (no mass, no charge)
• Neutrons (large, no charge)

15
SHIELDING
16
ADVANTAGES OF NUCLEAR POWER
Allows for truly submersible weapons
platform CVNs can carry twice the JPF and
weapons as a conventional CV Extreme endurance
(only limited by food) ALL AHEAD FLANK FOR A YEAR
17
DISADVANTAGES OF NUCLEAR POWER

• Considerable cost of construction/ decommission
• Great weight of shielding materials
• Environmental concerns
• Public Information

18
FISSION YIELD CURVE

• The probability that a particular pair of
  fission fragments will be produced by fission

19
BINDING ENERGY
MOST STABLE ELEMENT (Fe)
ENERGY
ATOMIC NUMBER