The most commonly used moderator in nuclear plants is
Heavy water
Concrete and bricks
Graphite and concrete
Graphite
Correct Answer :
D. Graphite
Related Questions
A nuclear fission is initiated when the critical energy as compared to neutron binding energy of the atoms is
Same
More
Less
There is no such criterion
Hydrogen is preferred as better coolant in comparison to CO₂ because former
Is lighter
Is inert
Has high specific heat
Is a good conductor
Which of the following is the primary fuel?
U₂₃₃
U
U₂₃₈
Pu
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
U₂₃₃ is produced
Artificially
As basic raw material
When thorium is irradiated by neutrons
By fission of U₂₃₈
Solid fuel for nuclear reactions may be fabricated into various small shapes such as
Plates
Pallets
Pins
Any one of the above
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
Which of the following type of pump is used in liquid metal cooled reactor for circulation of liquid metal
Centrifugal
Axial
Reciprocation
Electromagnetic
The predominant isotope of the naturally occuring element is
U₂₃₅
U₂₃₈
Pu₂₃₃
Pu₂₃₉
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
A moderator
Absorbs neutrons
Does not absorb neutrons
Accelerates neutrons
None of these
In the breeder reactors the generation of new fissionable atom is
At the lower rate than the consumption
At a higher rate than the consumption
At an equal rate of the consumption
Depends on other considerations
One gram of uranium will produce energy equivalent to approximately
1 tonne of high grade coal
4.5 tonnes of high grade coal
10 tonnes of high grade coal
100 tonnes of high grade coal
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
The primary fuel used in nuclear power plants is
U₂₃₅
U₂₃₈
Pu₂₃₉
Pu₂₃₃
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
Which is not identical for an atom and an isotope?
Mass number
Atomic number
Chemical properties
Position in periodic table
Plutonium (Pu₂₃₉) is produced
Artificially
By fission of Th₂₃₂
When U₂₃₈ is irradiated by neutrons
As basic raw material
Enriched uranium is one in which
Percentage of U₂₃₅ has been artificially increased
Percentage of U has been artificially increased
Percentage of U₂₃₄ has been artificially increased
Extra energy is pumped from outside
Each fission of U₂₃₅ produces following number of fast neutrons per fission
1 neutron
3 neutrons
1, 2 neutrons
2 neutrons
The material most commonly used for shielding is
Carbon
Lead
Concrete
All of these
The main interest of shielding in nuclear reactor is protection against
X-rays
Infrared rays
Neutrons and gamma rays
Electrons
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
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
Which of the following are ferrite materials?
U₂₃₃ and Pu₂₃₉
U
U₂₃₈ and Pu₂₃₉
U₂₃₈ and Th₂₃₉
U238 will undergo fission by
High energy (fast) neutrons alone
Low energy (slow) neutrons alone
Either fast or slow neutrons
Medium energy neutrons
The most commonly used moderator in nuclear plants is
Heavy water
Concrete and bricks
Graphite and concrete
Graphite
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
Reactors for propulsion applications use
Natural uranium
Molten lead
Any form of uranium
Thorium
Electron volt is the unit of
Atomic power
Energy
Voltage
Radio activity