Dynamic period equation: Derivation, relation to inhour equation, and precursor estimation

The dynamic period equation is the basis of several successful techniques f or the closed-loop digital control of nuclear reactors. These include both the reactivity constraint approach and the MIT-SNL period-generated control laws. Information on that equation is documented here including the deriva tion of its standard formulation, its. relation to the Inhour equation, and the method used to estimate precursor concentrations so that closed-loop c ontrol can be achieved in realtime. The dynamic period equation is the pare nt relation to the inhour equation and as such can be used to explain the d ependence of the instantaneous reactor period on both reactivity and its ra te of change. It is argued that the dynamic period equation should be taugh t in its full form as part of nuclear engineering curricula.