Kinetics of Aperiodic Cascade Boosters: Speed of Operation and Safety

Abstract

The results of Monte-Carlo calculations of simple spherically symmetric systems, simulating an aperiodic booster, are presented. The purpose of the calculations is to give a clear demonsration of the specific features of the kinetics of cascade reactor systems and the possibilities which the application of the cascade principle in an aperiodic booster adds to increasing safety and improving the time parameters of the pulses. Another goal is to determine the materials for the moderator which are best from the standpoint of optimizing the parameters of the booster. It is shown that for the same total number of fissions the neutron pulses in a cascade booster are generated under conditions of much greater subcriticality and are much shorter in duration than for a single-section booster. The best pulse parameters are obtained in cascade boosters with tungsten, lead, and molybdenum neutron moderators.