Please answer:
Uranium 238 is fissionable only with fast neutrons. It is also found in high abundance as compared to uranium 235. Then why uranium 235 is used in nuclear reactors and it is made to undergo fission with slow neutrons. Is it difficult to obtain fast neutrons?
Answers
Answered by
0
Uranium occurs in several forms as 'isotopes'. ...
U-235 can be readily split, yielding a lot of energy. It is therefore said to be 'fissile' and we use the expression 'nuclear fission'.
Uranium 238 is not fissionable by thermal neutrons, but it undergoes fission from fast or high energy neutrons. Hence it is not fissile, but it is fissionable. ...
In nuclear reactors or reaction even with low energy or thermal neutrons U-235 can be splitted into two light elements with release of energy.
Also in fissile isotopes, like U-235, the critical energy is at or below the excitation of the nucleus when it has absorbed a neutron
Hence U-235 is used instead of U-238.
Similar questions