The total thermal resistance was imported from the result of a
full-scale single hybrid heat pipe simulation and used to obtain the
amount of heat removed by hybrid heat pipe and calculate the
coolant temperature when all control rods were substituted to the
hybrid heat pipe. The total thermal resistance of hybrid heat pipe
was assumed constant. For calculating the coolant temperature,
energy balance equation was solved numerically for the reactor
coolant volume as net heat from decay heat after shutdown as a
function of time after shutdown and removed heat via hybrid heat
pipe.