Evaluation of ´period-generated´ control laws for the time-optimal control of reactor power

Time-optimal control of neutronic power has recently been achieved by developing control laws that determine the actuator mechanism velocity necessary to produce a specified reactor period. These laws, designated as the MIT-SNL period-generated minimum-time control laws, function by altering the rate of change of reactivity so that the instantaneous period is stepped from infinity to its minimum allowed value, held at that value until the desired power level is attained, and then stepped back to infinity. The results of a systematic evaluation of these laws are presented. The behavior of each term in the control laws is shown, and the capability of these laws to control properly the reactor is demonstrated. Factors affecting the implementation of these laws are discussed. The results of an experimental study in which these laws were used to adjust the power of the 5 MWt MIT research reactor are shown.