Q2 [70 points] The tristructural-isotropic (TRISO) fuel is designed for high temperature gascooled reactors. The fuel contains a UO2 spherical kernel surrounded by three carbon and SiC shells. In this question, we consider a simplified TRISO fuel: UO2 kernel with a thin polycrystalline SiC shell as shown in the figure below. Assume there is no gap between the UO2 and SiC shell. UO2 kernel radius r=250m SiC shell thickness d=35m Assume the outer surface temperature of the SiC shell is 1000C. Using the dimension information shown in the figure above, calculate the temperature at the center of the fuel kernel (T0) at the steady state. Necessary equations and parameters are provided below. Fourier heat equation at steady state: k2T+Q=0; Heat flux: f=kT Laplace operator 2 in different coordinates Cartesian: 2=x22, Cylindrical: 2=r1r(rr), Spherical: 2=r21r(r2r)