Concerning the transitional system of a reactor as a result of recharging fuel elements

The relationship is discussed between the duration of the transitional state of a reactor (from the point of view of reactivity as well as recharging), the specified irradiation stability of the fuel elements, attainable fuel irradiation and the required rate of recharging of the fuel elements for different cycles, In particular, the advantages and disadvantages are compared of equilibrium transition, transition with delayed recharging at a constant rate, transition with constant reactivity and various combinations of these transitions. The conditions are discussed which (in comparison with equilibrium irradiation) permit saving of excess reactivity because of nonoverirradiation of the fuel elements.Translated from Atomnaya Énergiya, Vol. 16, No. 4, pp. 315–324, April, 1964