A reactor is developing nuclear energy at a rate of 32MW. To run this reactor for 1000hr of continuous operation, the mass of  $U^{235}$ will be required ______gram. (Average energy per fission of $U^{235}$ is 200Mev) (Molar mass of  $U^{235}$ is 235gm) (Avagadro’s number : $6\times {10}^{23}$)