Question

Find the number of neutrons generated per unit time in uranium reactor, whose thermal power is $100$ MW. The average number of neutrons liberated per fission is $2.5$ and each fission releases an energy of $200$ MeV.

• A. $7.8\times$${10}^{18}$
• B. $7.8\times$${10}^5$
• C. $7.8\times$${10}^{10}$
• D. $7.8\times$${10}^{12}$

Answer 1

The correct option is A $7.8\times$${10}^{18}$

Power of reactor = 100 MW = ${10}^8$ watts
=${10}^8$ joule/sec
Energy released in each fission= $200\times 1.6\times {10}^{-19}\times {10}^6$ joules
=$3.2\times {10}^{-11}$ joules
So,
Number of fission taking place in second =$\frac{{10}^8}{3.2\times {10}^{-11}}$ fission
=$3.125\times {10}^{18}$
So,
Neutrons released in each fission =2.5
Neutrons released in total =$2.5\times 3.125\times {10}^{18}$ neutrons
=$7.8\times {10}^{18}$ neutrons