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 $U^{235}=200MeV,1eV$ $=1.6\times {10}^{-19}j$ ]

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