Sketch a single fuel pin including the pellet, gap, clad and coolant. Assuming the reactor is operating at steady state, qualitatively sketch the temperature profile across the fuel pin. Draw a second temperature profile that would be a result of a step increase in fission power. Explain the differences (and similarities) between the two profiles and provide justification for your answer. What neutronic considerations should you consider for this transient in the short time scale (< seconds) and longer time scales