Which of the following options are correct regarding controlling the rate of nuclear reaction?
Which of the following options are correct regarding controlling the rate of nuclear reaction?
The correct options are
A A smaller size of fuel will have controlled rate of nuclear fission reaction.
B Controlling the energy of neutrons affects the rate of nuclear fission reaction.
D The constituents of the nuclear fuel determine the rate of the chain reaction.
All the emitted neutrons triggering a fission reaction is the main reason for an uncontrolled chain nuclear reaction. So, the Size, Energy of neutron and Constituent of the fuel can control the reaction.
1. Size
If the fission event takes place near the surface of the bulk Uranium material taken, there is a good chance that the neutrons produced will escape from the material without coming in contact with another U-235.
2. Energy of neutrons
The neutrons produced in the fission have kinetic energy ≈2MeV. They are called fast neutrons. The U-235 has a good probability of absorbing a neutron of energy ≈0.04eV which are called slow neutrons. The neutron hence may not get absorbed by a U-235 even if they collide.
3. The constituent of Uranium fuel
U-238 can absorb neutrons of energy 1-100 eV. If the fuel is enriched with this isotope a neutron before being absorbed by U-235 has a good chance to be absorbed by U-238 which then fissions by other means and hence controlling the fission of U-235. All the above three factors are considered in the engineering design of a nuclear reactor.
A
A smaller size of fuel will have controlled rate of nuclear fission reaction.
B
Controlling the energy of neutrons affects the rate of nuclear fission reaction.
D
The constituents of the nuclear fuel determine the rate of the chain reaction.
All the emitted neutrons triggering a fission reaction is the main reason for an uncontrolled chain nuclear reaction. So, the Size, Energy of neutron and Constituent of the fuel can control the reaction.
1. Size
If the fission event takes place near the surface of the bulk Uranium material taken, there is a good chance that the neutrons produced will escape from the material without coming in contact with another U-235.
2. Energy of neutrons
The neutrons produced in the fission have kinetic energy ≈2MeV. They are called fast neutrons. The U-235 has a good probability of absorbing a neutron of energy ≈0.04eV which are called slow neutrons. The neutron hence may not get absorbed by a U-235 even if they collide.
3. The constituent of Uranium fuel
U-238 can absorb neutrons of energy 1-100 eV. If the fuel is enriched with this isotope a neutron before being absorbed by U-235 has a good chance to be absorbed by U-238 which then fissions by other means and hence controlling the fission of U-235. All the above three factors are considered in the engineering design of a nuclear reactor.
