Question

A nuclear reactor has a power of 16KW. If the energy per fission is 200MeV, the number of fissions per second is
A. $5\times {{10}^{17}}$
B. $5\times {{10}^{16}}$
C. $5\times {{10}^{14}}$
D. $5\times {{10}^{15}}$

Answer 1

Hint: In this question the total power and energy required per fission is given. Power means the total energy per second. That is, we have total energy and energy per fission. Now it is easy to find the number of fission reactions taking place. We just have to divide the total energy by energy for a single fission.

Complete answer:
Nuclear fission is the splitting of nuclei of heavier atoms into two or more smaller nuclei. Nuclear reactors use controlled fission reactions to produce nuclear energy. Usually, fission of uranium is used to produce nuclear energy. One fission of uranium produces three neutrons which undergoes fission to produce further energy. Nuclear energy is one of the major sources of electricity on a large scale. First nuclear reactor in India is in Tarapur and largest nuclear power plant in India is situated at Kudankulam, Tamil Nadu
Given that
Power of nuclear reactor= 16KW
Energy required per fission= 200MeV

Therefore, number of fissions per second,
$n=\frac{16\times {{10}^{3}}}{200\times {{10}^{6}}\times 1.6\times {{10}^{-19}}}=5\times {{10}^{14}}$

That is, $5\times {{10}^{14}}$ nuclear fission reactions are taking place in that nuclear reactor.

Therefore, the answer is option(C)>

Note: The main sources of nuclear energy are nuclear fission and fusion. Both produce tremendous amounts of energy. Energy in the sun is mainly due to nuclear fusion and nuclear reactors use fission reactions to produce energy. Control rods and moderators like heavy water are used for controlling nuclear reactions inside nuclear reactors. Nuclear fusion is the energy released when two atoms of lower atomic mass combine to form heavier nucleus.