kritikalitetssäkerhet

Kritikalitetssäkerhet is a Swedish term that translates to criticality safety or critical safety. It refers to the measures and practices implemented to prevent uncontrolled nuclear chain reactions, particularly in nuclear reactors and during the handling of fissile materials. The primary goal of criticality safety is to ensure that nuclear materials remain in a subcritical state, meaning that the rate of neutron production is less than the rate of neutron loss, thereby preventing a self-sustaining chain reaction.

This is achieved through careful control of several factors. The amount and concentration of fissile material are strictly limited within defined areas or containers. The geometry of fissile material is also important, as certain shapes are inherently more prone to becoming critical than others. Furthermore, the presence of neutron moderators, such as water or graphite, can significantly influence criticality. Moderators slow down neutrons, making them more likely to cause further fission events. Therefore, their use and quantity are carefully managed.

Criticality safety protocols involve administrative controls, such as strict procedures for handling, storing, and transporting fissile materials, as well as engineering controls, like shielded enclosures and specific equipment designs. Regular monitoring and assessments are conducted to ensure that these safety measures remain effective and that no conditions arise that could lead to an unintended critical event. The principles of criticality safety are fundamental to the safe operation of nuclear power plants and research facilities.