c
Power level of reactor, \(P=\frac{E}{\Delta t}=\frac{\Delta m c^{2}}{\Delta t}\)

mass of the fuel consumed per hour in the reactor,

\(\frac{\Delta m}{\Delta t}=\frac{P}{c^{2}}=\frac{10^{9}}{\left(3 \times 10^{8}\right)^{2}}=4 \times 10^{-2} \mathrm{gm}\)