Question

If in a nuclear reactor using U235 as fuel, the power output is 4.8 MW. The number of fissions per second is : [Energy released per fission of $ {{U}^{235}}=200\text{ }MeV,1\text{ }eV $ $ =1.6\times {{10}^{-19}}j $ ]

• A. $ 1.5\times {{10}^{17}} $
• B. $ 3\times {{10}^{19}} $
• C. $ 1.5\times {{10}^{25}} $
• D. $ 3\times {{10}^{25}} $

Answer 1

Answer: (A)

Power output $ P=4.8\,MW $ $ =4.8\times {{10}^{6}}J/s $ $ =\frac{4.8\times {{10}^{6}}}{1.6\times {{10}^{-19}}}=3\times {{10}^{25}}\,eV/s $ $ =\frac{3\times {{10}^{25}}}{{{10}^{6}}}=3\times {{10}^{9}}\,MeV/s $ Energy released per fission of $ {{\text{U}}^{\text{235}}} $ =200 MeV Hence, No. of fissions per second $ =\frac{3\times {{10}^{19}}\,MeV}{200\,MeV} $ $ =1.5\times {{10}^{17}} $