Effective moderators are those materials which contain
Light weight atoms
Heavy weight atoms
Critical atoms
Zero weight atoms
Correct Answer :
A. Light weight atoms
Related Questions
The main interest of shielding in nuclear reactor is protection against
X-rays
Infrared rays
Neutrons and gamma rays
Electrons
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
Each fission of U₂₃₅ produces on the average _________ fast neutrons as a product of reaction.
2.46
24.6
246
2460
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 fast breeder reactor uses following as fuel
Enriched uranium
Plutonium
Thorium
U₂₃₅
Each fission of U₂₃₅ produces following number of fast neutrons per fission
1 neutron
3 neutrons
1, 2 neutrons
2 neutrons
In boiling water reactor, moderator is
Coolant itself
Ferrite rod
Graphite rod
Liquid sodium metal
In a fission process, maximum percentage of energy is released as
Kinetic energy of neutrons
Kinetic energy of fission products
Instantaneous release of gamma rays
Gradual radioactive decay of fission products
In triggering fission, the following types of neutrons are desirable
Fast moving
Slow moving
Critical neutrons
Neutrons at rest
The energy produced by a thermal reactor of same size as a breeder reactor is
Almost same
Slightly more
Slightly less
Much less
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
U₂₃₃ is produced
Artificially
As basic raw material
When thorium is irradiated by neutrons
By fission of U₂₃₈
Isotopes of same elements have
Same atomic number and different masses
Same chemical properties but different atomic numbers
Different masses and different atomic numbers
Different chemical properties and same atomic numbers
A fast breeder reactor
Uses graphite rods as moderator
Has powerful moderator
Has no moderator
Uses ferrite material as moderator
The unit of radioactivity is
Electron volt
Electron ampere
Curie
MV
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
In fast breeder reactors
Any type of moderator can be used
Graphite is used as the moderator
Heavy water is used as the moderator
Moderator is dispensed with.
Reactors for propulsion applications are designed for
Any form of uranium
Natural uranium
Enriched uranium
Plutonium
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
Fast breeder reactor uses
Boiler
Direct cycle of coolant system
Double circuit system of coolant cycle
Multi passes system
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
Which of the following is more appropriate for a moderator? One which
Does not absorb neutrons
Absorbs neutrons
Accelerates neutrons
Eats up neutrons
Pick up the wrong statement
In a heterogeneous or solid fuel reactor, the fuel is mixed in a regular pattern within moderator.
Slow or thermal neutrons have energy of the order or 0.025 eV
Fast neutrons have energies above 1000 eV
Fast reactor uses moderator
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
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 nuclear energy is measured as
MeV
Curie
Farads
MW
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
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
The most practical fuel for a thermonuclear reactor, both from economical and nuclear consideration is
Plutonium
Uranium
Deuterium
Thorium
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