When a reactor becomes critical, then the production of neutrons is
Infinite
Zero
Exactly balanced by the loss of neutrons through leakage
Initiated
Correct Answer :
C. Exactly balanced by the loss of neutrons through leakage
Related Questions
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.
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
In boiling water reactor, moderator is
Coolant itself
Ferrite rod
Graphite rod
Liquid sodium metal
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
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
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 total energy released in fission of U is
5 MeV
10 MeV
199 MeV
168 MeV
U233 is produced
As basic raw material
By neutron irradiation of Uz
By neutron irradiation of thorium
Artificially
The breeding gain in case of thermal breeder reactor as compared to fast breeder reactor is
Same
Lower
Higher
Unity
In triggering fission, the following types of neutrons are desirable
Fast moving
Slow moving
Critical neutrons
Neutrons at rest
U235 will undergo fission by
High energy (fast) neutrons alone
Low energy (slow) neutrons alone
Either fast or slow neutrons
Medium energy neutrons
The following present serious difficulty in designing reactor shield
Alpha particles
Beta particles
Thermal neutrons
Fast neutrons and gamma rays
Amongst the following, the fissionable materials are
U₂₃₃ and Pu₂₂₉
U₂₃₁ and Pu₂₃₃
U₂₃₅ and Pu₂₃₅
U₂₃₈ and Pu₂₃₉
Uranium has isotopes
U₂₃₄
U₂₃₅
U₂₃₈
All of these
A fast breeder reactor uses following as fuel
Enriched uranium
Plutonium
Thorium
U₂₃₅
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
Plutonium (Pu239) is produced
Artificially
When U238 is irradiated by neutrons
By fission of Th232
As basic raw material
Solid fuel for nuclear reactions may be fabricated into various small shapes such as
Plates
Pallets
Pins
Any one of the above
Hydrogen is preferred as better coolant in comparison to CO₂ because former
Is lighter
Is inert
Has high specific heat
Is a good conductor
The function of control rods in nuclear plants is to
Control temperature
Control radioactive pollution
Control absorption of neutron
Control fuel consumption
Natural uranium is made up of
99.282% U₂₃₈, 0.712% U₂₃₅, 0.006% U₂₃₄
99.282% U₂₃₅, 0.712% U₂₃₈, 0.06%' U₂₃₄
99.282% U₂₃₄, 0.712% U₂₃₈, 0.006% U₂₃₅
99.282% U₂₃₅, 0.712% U₂₃₄, 0.006% U₂₃₈
A moderator generally used in nuclear power plants is
Graphite
Heavy water
Concrete
Graphite and concrete
The most practical fuel for a thermonuclear reactor, both from economical and nuclear consideration is
Plutonium
Uranium
Deuterium
Thorium
Boiling water reactor employs
Boiler
Direct cycle of coolant system
Double circuit system of coolant cycle
Multi passes system
The risk of radioactive hazard is greatest in the turbine with following reactor
Pressurised water
Boiling water
Gas cooled
Liquid metal cooled
Which of the following can be used as a coolant in nuclear plant?
Light or heavy water
Molten lead
Carbon dioxide
Freon
The efficiency of a nuclear power plant in comparison to a conventional thermal power plant is
Same
More
Less
May be less or mote depending on size
Reactors for propulsion applications are designed for
Any form of uranium
Natural uranium
Enriched uranium
Plutonium
Which of the following is the heaviest?
Neutron
Proton
Atom
Electron
Artificial radioactive isotopes find application in
Power generation
Nucleonic devices
Nuclear fission
Medical field