The volumetric heat generation rate in a cylindrical nuclear reactor fuel rod of 5 cm diameter is 5 $\times$107 W/m3. Under steady state operating condition, the temperature distribution in the rod is t = 800 – 4.167 $\times$105 r2. Density, specific heat and thermal conductivity of rod material are 1100 kg/m3, 800 J/kg-K and 30 W/m-K respectively.
- What are the rates of heat transfer per unit length of the rod at the centre line (axis) and at the rod surface?
ii If the reactor power level is suddenly increased to 108 W/m3, what are the initial time rate of change of temperature at the centre line and at the surface?