Nuclear Energy Revision Sheet
Question I
Identify the NPP parts by writing the number of the correct power plant part
in the blank. Select your answers from the list provided below.
1
Reactor
2 Steam
3
generator
6
Secondary
7 Cooling
water loop
1
1
Condenser
Primary
4
water loop
8
water
Transmission
lines
1 Pressurizer
1
Containment
2
3
building
Control
rods
9
Nuclear
fuel
5
Turbine–
generator
10 Cooling
tower
Question II
1) Fill in the table below with the required information:
Nuclear Reactor
Fuel used
Moderator
Coolant
Boiling water
reactors (BWR)
Pressurized
water reactors
(PWR)
Pressurized
heavy water
reactors
(PHWR)-CANDU
Advanced power
reactors
(APR1400).
Gas-cooled
reactor (GCR)
Enriched UO2
Water
Water
Enriched UO2
Water
Water
Natural UO2
Heavy water
Light or heavy
water
Water
Water
Enriched U-235
Natural U/
Enriched UO2
Graphite
CO2 or Helium
2) What are the three grades of enriched Uranium and where they are used?
1. Slightly enriched uranium: has a U-235 concentration of 0.9% to 2%
Usage: is used in some heavy water reactors.
2. Low enriched uranium: has a lower than 20% concentration of U-235
Usage: For use in commercial light water reactors
3. Highly enriched uranium: has a greater than 20% concentration of U235.
Usage: Weapon grade uranium
3) Match the nuclear reactor or the power plant type in column (A) with the
correct figure in column (B). Write your answer in the answer box provided
No
1
Column A
1
2
3
4
5
6
7
8
Column B
B
C
A
E
G
H
D
F
Column (A)
Boiling water reactors (BWR)
Letter Column ( B )
A
2
B
Pressurized water reactors
(PWR)
3
C
Pressurized heavy water
reactors (PHWR)-CANDU.
4
D
Advanced power reactors
(APR1400).
5
E
Gas-cooled reactor (GCR)
6
F
Advanced Gas-cooled Reactor
(AGR)
7
G
Fast breeder reactor (FBR)
8
H
Steam power plant
Question III
The figure shown below for the pressurized water reactor, name the
indicated parts. Select your answers from the list provided below.
Condenser
Primary loop
Secondary
loop
Tertiary loop
Steam
Generator
Reactor
coolant
pump
Reactor
Pressure
Vessel
Condenser
coolant pump
Turbine
Electricity
Generator
Fill in the indicated parts. Write
your answers in the table below.
Number
Name (select from the list)
1
Reactor Pressure Vessel
2
Steam Generator
3
Primary loop
4
Turbine
5
Electricity Generator
6
Tertiary loop
7
Condenser coolant pump
8
Condenser
9
Primary loop
10
Reactor coolant pump
Question IV
1) Nuclear reactors can be classified according to their types, moderators and use.
Classify the nuclear reactors according to their usage and give examples for each one
as specified below.
Nuclear reactor usage
Electricity production
Examples
I. Boiling water nuclear reactor.
II. Pressurized water nuclear reactor.
Propulsion
I. Nuclear marine propulsion.
II. Various proposed forms of rocket propulsion.
Heat production reactors
Any two of the following:
I. Desalination plants.
II. Heat for domestic use and industrial heating.
III. Hydrogen production for use of hydrogen
economy.
Research Reactors
I. Research and training material testing.
II. Production of radio isotopes for medicine and
industry.
Nuclear Fuel Production
Reactors
I. The breeder reactors
II. Reactors used to produce weapon grade
plutonium
2) Differentiate between the function of the neutron poisons and the function
of neutrons moderators.
Using neutron poisons (neutron absorbers) which absorb
Neutron Poisons
excess neutrons to control the nuclear reaction.
( Absorbers)
Using neutron moderators, which reduce the velocity of
Neutron Moderators
fast neutrons, thereby turning them into thermal neutrons
which are more likely to be absorbed by other nuclei.
3) Referring to the figure shown below, describe how the steam pressure
could be reduced during accidents which cause reactor coolant leakage.
Answer:

During accidents the reactor coolant
converts to steam in the drywell and
pressure builds up quickly.

Vent pipes or tubes from the drywell
Direct the steam below the water level
in the wetwell.

This condenses the steam and reduces
the pressure
Question V
Answer the following questions:
A. For a pressurized water reactor, the containment building encloses
the following components:
marks each)
I.
II.
III.
The steam generator.
The entire reactor building.
The pressurizer.
B. There are three different containment building designs based on their
shapes, these are:
I.
II.
III.
Can design
Spherical Design
Combined design( Can and Spherical)
C. Control rods are used to control the chain reaction in the nuclear
reactor, beside that, the control system includes a number of devices
,these are:
I.
Sensing elements that measure the number of neutrons.
II.
Other devices to regulate the position of the control rods.
Question VI
1) Given the following reaction:
a) State the type of the above reaction.
Nuclear Fusion
Describe the reaction.
Nuclear fusion involves two atomic nuclei (Deuterium and Tritium) joining
To make a large nucleus (Helium).
Energy and fast neutrons are released when this happens.
b) State two disadvantages of utilizing the heat generated by this
reaction in electrical power generation.
Any two of the following:
1. Fusion reactions can produce fast neutrons, a highly energetic and
dangerous form of nuclear reaction.
2. This requires replacing the shielding material periodically which
makes
the operation of the fusion power plant expensive and impractical.
3. Lithium can be used to slowdown these neutrons, but lithium is
chemically reactive and rare so its use is not practical.
2) In many countries, the fuel assemblies, after being in the reactor for 3 to
6 years, are stored underwater for 10 to 20 years. Suggest two reasons for
using water as storage medium for spent fuel.
A. It serves as a shield to reduce the radiation levels that people
working above may be exposed to.
B. It cools the fuel assemblies that continue to produce heat (called
decay heat) for some time after removal.
3) Match the nuclear reactor or the power plant type in column (A) with the
correct figure in column (B). Write your answer in the answer box provided
No
1
Column A
1
2
3
4
5
6
7
8
Column B
B
C
A
E
G
H
D
F
Column (A)
Letter Column ( B )
A
Boiling water reactors (BWR)
2
B
Pressurized water reactors
(PWR)
3
C
Pressurized heavy water
reactors (PHWR)-CANDU.
4
D
Advanced power reactors
(APR1400).
5
E
Gas-cooled reactor (GCR)
6
F
Advanced Gas-cooled Reactor
(AGR)
7
G
Fast breeder reactor (FBR)
8
H
Steam power plant