A Tramsistorized Reactivity Computer

The usual reactor kinetics equations are shown to consist of three major camponents, a fast term; a product or quotient, and a summation of transient terms. These can be synthesized by using a number of simple R.C. networks having time constants related to the fast time constant and to the decay constants of the various groups of delayed neutron emitters, plus either an analog multiplier or divider. If an input signal proportional to neutron flux or reactor power is applied to this network, the output will be proportional to reactivity. A circuit is shown which incorporates these principles, using a diode divider. Curves are presented of output reading, indicating transient reactivity, for input currents having constant positive period, as obtained from a motor-driven potentiometer. It is shown that these curves are in reasonable agreement with calculated curves of reactivity for such periods.