Calculate power output of \({ }_{92}^{235} \mathrm{U}\) reactor, if it takes 30 days to use up \(2…

Calculate power output of \({ }_{92}^{235} \mathrm{U}\) reactor, if it takes 30 days to use up \(2 \mathrm{~kg}\) of fuel, and if each fission gives \(185 \mathrm{~MeV}\) of useable energy. Avogadro's number \(=6 \times 10^{23} / \mathrm{mol}\) ?
  1. \(56.3 \mathrm{~MW}\)
  2. \(60.3 \mathrm{~MW}\)
  3. \(58.3 \mathrm{~MW}\)
  4. \(54.3 \mathrm{~MW}\)

Solution

Mass of \({ }_{92}^{235} \mathrm{U}\) per second in the reactor is \(m=\frac{2 \times 10^3}{30 \times 24 \times 60 \times 60}=7.72 \times 10^{-4} \mathrm{~g} / \mathrm{sec}\) \(\therefore\) Number of fissions reaction per second \(\begin{aligned} & =\frac{6 \times 10^{23}}{235} \times m=\frac{6 \times 10^{23} \times 7.72 \times 10^{-4}}{235} \\ & =1.97 \times 10^{18} / \mathrm{sec} \end{aligned}\) Power of nuclear reactor \(=1.97 \times 10^{18} \times 185 \mathrm{MeV} / \mathrm{s}\) \(=1.97 \times 10^{18} \times 185 \times 10^6 \times 1.6 \times 10^{-19} \mathrm{~J} / \mathrm{s}\). \(=58.3 \mathrm{~MW}\).

Asked in: NEET 2002

Practice more Nuclear Physics questions on Aicharya