Application of controlled startup to increase the safety of ship pressurized water nuclear reactors

The operating results for antimony-beryllium neutron startup sources in the reactor core of the Vaigach icebreaker are presented. It is shown that such sources used together with pulsed startup apparatus secure controlled startup of ship pressurized water reactors during operation from the initial subcritical state over a period of ≥200 days after shutdown. It is also shown that the neutron-physical state of the reactors can be monitored during loading of the fuel assemblies and physical startup.