Anuclear fuel rod of diameter 30 mm generates heat uniformly at a rate of 7 × 108 w/m3 and is cooled by a circulating coolant at 20°c. the convection heat transfer coefficient at the surface is h = 7000 w/m2 .k and the thermal conductivity of the fuel rod material is 52 w/m. k. in case of coolant pumping system failure, the surface temperature of the fuel rod could be estimated as the average of the steady state surface and the center temperatures of the rod. nuclear fuel rods are typically clad to prevent the leakage of radioactive material into the coolant. if you were given a choice to clad the fuel rod with either aluminum, stainless steel or zirconium, what material would you use ?