A fission chain reaction in uranium can be developed by
Slowing down fast neutrons so that Uz fission continues by slow motion neutrons
Accelerating fast neutrons
Absorbing all neutrons
Using moderator
Correct Answer :
A. Slowing down fast neutrons so that Uz fission continues by slow motion neutrons
Related Questions
In triggering fission, which types of neutrons are more effective?
Fast
Slow
In bulk
Static
Ideally the neutron flux in reactor should be
Maximum in centre and zero at side
Maximum at side and zero in canter
Uniform throughout
Zero throughout
U₂₃₃ is produced
Artificially
As basic raw material
When thorium is irradiated by neutrons
By fission of U₂₃₈
The material most commonly used for shielding is
Carbon
Lead
Concrete
All of these
The process by which a heavy nucleus is spitted into two light nuclei is known as
Splitting
Fission
Fusion
Disintegration
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 presence of reflector in nuclear power plants results in
Increased production of neutrons
Complete absorption of neutrons
Controlled production of neutrons
Decreased leakage of neutrons
Which of the following statement is correct regarding the features of a Breeder reactor?
It produces more fuel than it consumes.
It requires highly enriched fuel.
It requires liquid sodium metal as moderator.
All of the above
When a reactor becomes critical, then the production of neutrons is
Infinite
Zero
Exactly balanced by the loss of neutrons through leakage
Initiated
A fast breeder reactor uses following as fuel
Enriched uranium
Plutonium
Thorium
U₂₃₅
The fast breeder reactor uses the following moderator
Demineralised water
Carbon dioxide
Heavy water
No moderator is used
Hydrogen is preferred as better coolant in comparison to CO₂ because former
Is lighter
Is inert
Has high specific heat
Is a good conductor
In nuclear fission each neutron that causes fission releases
No new neutron
At least one new neutron
One new neutron
More than one new neutron
Plutonium (Pu₂₃₉) is produced
Artificially
By fission of Th₂₃₂
When U₂₃₈ is irradiated by neutrons
As basic raw material
Which of the following particles is the lightest?
Nucleus
Electron
Proton
Meson
Atomic number of an element in the periodic table represents the numbers of
Protons in the nucleus
Electrons in the nucleus
Neutrons in the nucleus
Electrons in the atom
Which of the following nuclear reactor does not need a heat exchanger for generation of steam?
Gas cooled
Liquid metal cooled
Pressurised water
Boiling water
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
Boiling water reactor employs
Boiler
Direct cycle of coolant system
Double circuit system of coolant cycle
Multi passes system
The most practical fuel for a thermonuclear reactor, both from economical and nuclear consideration is
Plutonium
Uranium
Deuterium
Thorium
Reactors for propulsion applications are designed for
Any form of uranium
Natural uranium
Enriched uranium
Plutonium
Reactors designed for propulsion applications are designed for
Natural uranium
Enriched uranium
Pure uranium
Any type of uranium
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
U235 will undergo fission by
High energy (fast) neutrons alone
Low energy (slow) neutrons alone
Either fast or slow neutrons
Medium energy neutrons
Which of the following is more appropriate for a moderator? One which
Does not absorb neutrons
Absorbs neutrons
Accelerates neutrons
Eats up neutrons
The breeding gain in case of thermal breeder reactor as compared to fast breeder reactor is
Same
Lower
Higher
Unity
The efficiency of a nuclear power plant in comparison to conventional and nuclear consideration is
Higher cost of nuclear fuel
High initial cost
High heat rejection in condenser
Lower temperature and pressure conditions
Moderator in nuclear plants is used to
Reduce temperature
Extract heat from nuclear reaction
Control the reaction
Cause collision with the fast moving neutrons to reduce their speed
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
Enriched uranium may contain fissionable contents of the order of
1-99 %
1-25 %
1-50 %
1-75 %