The figure shows a high temperature nuclear reactor containing a composite cylindrical wall, in which a Thorium fuel element $)$ is encased in graphite $(k=5\frac{W}{mk}.$ It is cooled with 'helium gas at $650K,$ which flows through an annular coolant channel with a convective heat transfer coefficient of $2200\frac{W}{m^2(K)}.$ If the thermal energy is uniformly generated in the Thorium element at a rate of ${10}^8\frac{W}{m^3},$ and if no heat is transferred from the Thorium to the inner core of the reactor, what are the steady state itemperatures at $T_1,T_2,$ and $T_3?$