Gas cooled reactor uses following materials as moderator, and coolant
Graphite, CO2
Graphite, air
Heavy water, CO2
Lead, H2
Correct Answer :
A. Graphite, CO2
Related Questions
Plutonium is produced
As basic raw material
By neutron irradiation of Uz
By neutron irradiation of thorium
Artificially
Artificial radioactive isotopes find application in
Power generation
Nucleonic devices
Nuclear fission
Medical field
Each fission of U₂₃₅ produces following number of fast neutrons per fission
1 neutron
3 neutrons
1, 2 neutrons
2 neutrons
The control rods in the control system of nuclear reactors are used to
Absorb excess neutrons
Control fuel consumption
Control temperature
All of these
Enriched uranium may contain fissionable contents of the order of
1-99 %
1-25 %
1-50 %
1-75 %
The unit of radioactivity is
Electron volt
Electron ampere
Curie
MV
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 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
Which of the following is the heaviest?
Neutron
Proton
Atom
Electron
A fast breeder reactor uses following as fuel
Enriched uranium
Plutonium
Thorium
U₂₃₅
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
Amongst the following, the fissionable materials are
U₂₃₃ and Pu₂₂₉
U₂₃₁ and Pu₂₃₃
U₂₃₅ and Pu₂₃₅
U₂₃₈ and Pu₂₃₉
Electron volt is the unit of
Atomic power
Energy
Voltage
Radio activity
Pressurised water reactor is designed
For boiling pi water in the core
To use liquid sodium metal as coolant
To use intermediate coolant
To prevent the water coolant from boiling in the core
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
U238 will undergo fission by
High energy (fast) neutrons alone
Low energy (slow) neutrons alone
Either fast or slow neutrons
Medium energy neutrons
The material most commonly used for shielding is
Carbon
Lead
Concrete
All of these
Enriched uranium is required as a fuel in a nuclear reactor, if light water is used as moderator and coolant, because light water has
High neutron absorption cross-section
Low moderating efficiency
High neutron scatter cross-section
Low neutron absorption cross-section
A moderator, in nuclear power plants, is a medium introduced into the fuel mass in order to
Slow down the speed of fast moving neutrons
Control the reaction
Reduce the temperature
Extracts heat from nuclear reaction
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%
A nuclear unit becoming critical means
It is generating power to rated capacity
It is capable of generating much more than rated capacity
There is danger of nuclear spread
Chain reaction that causes automatic splitting of the fuel nuclei has been established
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
Reflector in nuclear plants is used to
Return the neutrons back into the core
Shield the radioactivity completely
Check pollution
Conserve energy
Effective moderators are those materials which contain
Light weight atoms
Heavy weight atoms
Critical atoms
Zero weight atoms
Uranium has isotopes
U₂₃₄
U₂₃₅
U₂₃₈
All of these
The risk of radioactive hazard is greatest in the turbine with following reactor
Pressurised water
Boiling water
Gas cooled
Liquid metal cooled
The predominant isotope of the naturally occuring element is
U₂₃₅
U₂₃₈
Pu₂₃₃
Pu₂₃₉
The most practical fuel for a thermonuclear reactor, both from economical and nuclear consideration is
Plutonium
Uranium
Deuterium
Thorium
A boiling water reactor uses following as fuel
Enriched uranium
Plutonium
Thorium
U
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