5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM
One to six delayed neutron groups. Five temperatures - fuel, canning, coolant, surface of moderator and bulk moderator. A maximum of 20 x 30 mesh points can be accommodated. Radial and axial reflectors are simulated by extrapolation conditions. The thermal characteristics are assumed uniform with the exception of the coolant for which the radial distribution is estimated, assuming that the exit temperature is constant, and taking proper account of the thermal capacity of the moderator.
Overall control is a function of the temperature variation of the coolant at exit. The axial control is a function of the variation of the relation between the heating of the canning and the heating of the coolant.