Criteria for determining instability due to temperature changes during transient reactor operation

In this paper we study the kinetics of uranium-graphite reactors of the Calder-Hall type taking into account the temperature coefficient of reactivity and its changes during the burning up of the fuel. We obtain the conditions of instability for the reactor. We show that in reactors of the Calder-Hall type when the fuel is burnt up 3000 Mwatt-day/m the minimum positive period of the reactor must be not less than 170 seconds.Translated from an English paper obtained from India.The author wish to express their deep gratitude to B. M. Udgaonkar for his support and valuable advice and also to A. S. Anikindi for his help in performing the calculations.