A moderator
Absorbs neutrons
Does not absorb neutrons
Accelerates neutrons
None of these
Correct Answer :
B. Does not absorb neutrons
Related Questions
A moderator, apart from its high neutron slowing power, and low non-productive neutron, should be
Stable under nuclear radiation
Corrosion resistant
Good thermal conductor
All of these
The breeding gain in case of thermal breeder reactor as compared to fast breeder reactor is
Same
Lower
Higher
Unity
For economical operation of a nuclear plant
Used fuel should be reprocessed
Moderator should be used
Coolant should be employed
Control rods should be used
The risk of radioactive hazard is greatest in the turbine with following reactor
Pressurised water
Boiling water
Gas cooled
Liquid metal cooled
Plutonium (Pu239) is produced
Artificially
When U238 is irradiated by neutrons
By fission of Th232
As basic raw material
In order to have constant chain reaction to produce a constant rate of heat output, the value of ratio of the number of neutrons in one generation to the number of neutrons in the immediately preceding generation must be
Greater than 1.0
Less than 1.0
Equal to zero
Equal to 1.0
The size of the reactor is said to be critical when
Chain reaction can be initiated
It becomes uncontrollable
It explodes
It produces no power
Plutonium (Pu₂₃₉) is produced
Artificially
By fission of Th₂₃₂
When U₂₃₈ is irradiated by neutrons
As basic raw material
A power plant giving least running cost of production of electrical power is
Steam power plant
Gas turbine power plant
Hydro electric power plant
Nuclear power plant
In a thermal power plant, coal from the coal handling plant is moved to the boiler bunker through a
Belt conveyor
Bucket conveyor
Fork lift truck
Overhead crane
A fission chain reaction in uranium can be developed
By increasing the contents of U₂₃₅
By slowing down fast neutrons so that U₂₃₅ fission continues by slow neutron
Both (A) and (B)
None of these
The predominant isotope of the naturally occuring element is
U₂₃₅
U₂₃₈
Pu₂₃₃
Pu₂₃₉
Ferrite material is
The most fissionable material
The basic fuel for nuclear paints
Basic raw material for nuclear plants
The material which absorbs neutrons and undergoes spontaneous changes leading to the formation of fissionable material
Pick up the wrong statement fast breeder reactors
Operate at extremely high power densities.
Are liquid metal cooled
Produce more fuel than they consume
Use water as coolant
The main interest of shielding in nuclear reactor is protection against
X-rays
Infrared rays
Neutrons and gamma rays
Electrons
The mass number of a substance represents the sum of total number of
Protons and neutrons in an atom
Protons and electrons in an atom
Neutrons and electrons in an atom
Protons and neutrons in a nucleus
A moderator
Absorbs neutrons
Does not absorb neutrons
Accelerates neutrons
None of these
The nuclear energy is measured as
MeV
Curie
Farads
MW
Boiling water reactor employs
Boiler
Direct cycle of coolant system
Double circuit system of coolant cycle
Multi passes system
The function of control rods in nuclear plants is to
Control temperature
Control radioactive pollution
Control absorption of neutron
Control fuel consumption
Where reactor operation is designed with fast neutrons such as in reactors using highly enriched fuel, the moderator used is
Heavy water
Graphite
Carbon dioxide
No moderator is needed
Reflector in nuclear power plants _________ neutron leakage.
Increases
Decreases
Have no effect on
None of these
A nuclear reactor is said to be critical when the neutron population in the reactor core is
Rapidly increasing leading to the point of explosion
Decreasing from the specified value
Reduced to zero
Constant
Which of the following is the heaviest?
Neutron
Proton
Atom
Electron
In triggering fission, the following types of neutrons are desirable
Fast moving
Slow moving
Critical neutrons
Neutrons at rest
Artificial radioactive isotopes find application in
Power generation
Nucleonic devices
Nuclear fission
Medical field
Superheated steam is generated in following reactor
Boiling water
Gas cooled
Pressurised water
All of the above
In natural uranium, the constituents of three naturally occuring isotopes are
U₂₃₄ = 0.006%, U₂₃₅ = 0.712% and U₂₃₈ = 99.282%
U₂₃₄ = 0.712%, U₂₃₅ = 0.006% and U₂₃₈ = 99.282%
U₂₃₄ = 99.282%, U₂₃₅ = 0.006% and U₂₃₈ = 0.712%
U₂₃₄ = 0.006%, U₂₃₅ = 99.282% and U₂₃₈ = 0.712%
In nuclear fission
The original elements change into completely different elements
The electrons of the element change
The molecules rearrange themselves to form other molecules
None of the above
Reactors for propulsion applications use
Natural uranium
Molten lead
Any form of uranium
Thorium