Consider a CANDU fuel channel operating in single phase (no boiling; P ~10Mpa).

Consider a CANDU fuel channel operating in single phase (no boiling; P ~10Mpa). The peak linear power, in the outer ring elements, in the channel is 48 kW/m outer ring elements (18 of the 37 elements in a fuel bundle are in the outer ring). Outer ring elements have 13% higher power than the average element power. Ignore extrapolation length, and assume that axial power shape is sinusodial. Assume the coolant flow is well mixed (i.e., resulting in uniform temperature in the radial direction). Fuel dimensions, flow rates and other necessary information are provided below. Assume thermal resistance between the fuel and sheath is negligible because sheath is collapsed on the fuel, and negligible oxide buildup on the clad surface.

Flow rate= 30 kg/s

Inlet temperature= 2500 C

Fuel diameter= 13 mm

Specific heat = 5 kJ/kg K

Average fuel thermal conductivity= 2.25 W/m K

Sheath thickness= 0.4 mm

Sheath thermal conductivity= 15 W/m K

Channel heated length= 6 m

Heat transfer coefficient between sheath and coolant= 35 W/m K

a)Determine the coolant temperature as a function of axial position in a CANDU

b)maximum fuel temperature

c)maximum sheath temperature