Pressurizer (PZR) behavior in typical pressurized water reactor (PWR) nuclear power plants is well understood. Pressure control is relatively straightforward for a typical PWR, since the larger fluid system normally operates in a very steady state condition. However, pressure control is more complicated for a pressurizer in a pulsed cooling system, such as the cooling system for a tokamak fusion reactor. During normal operation the tokamak’s plasma is pulsed, instead of staying at a constant value, which results in temperature swings between the plasma pulses. This design characteristic means that (a) coolant temperatures fluctuate over a larger range during normal operation than typical PWRs experience and (b) fluid volume also varies as the coolant temperature changes, since fluid (water) density is a function of temperature.Pressurizer pressure control is typically accomplished with an on/off and proportional control strategy in PWRs. However, this approach alone may not meet the desired control performance for a pulsed cooling system. Therefore, a dynamic model based control design approach is proposed that permits modification online as the process dynamics change by uniquely combining a hybrid control technique with a method to improve system knowledge. This research includes contributions to PZR control modeling, dynamic simulation inputs, adaptive-optimal and adaptive-dynamic control, and system knowledge. Simulations support that this approach enables greater control of the process during transients than is achievable with a conventional control approach.