In Exercise 14.2, it was assumed that the liquid and vapor
phases were moving through a BWR fuel assembly at exactly the same speed. In
reality, the slip ratio in a BWR core is closer to 2.0; that is, the vapor moves
at twice the speed of the liquid. In this case, what is the exit quality at the
top of the core?
In the (see Exercise 14.1), the reader was asked to nd the
void fraction of the coolant of at the top of a BWR fuel assembly (i.e., the
volume of the coolant α that was converted into steam). Now suppose that
we would like to know what percentage of the total mass of the coolant is
converted into steam at this point. What is this percentage called, and what is
its value at the top of the core (z = H)?
Assume that the average density of the coolant exiting a BWR
fuel assembly is 0.155 g/cm3. What fraction of the total volume of the coolant
has been converted into steam at the exit of the fuel assembly in this case?