94. Review of the status, objectives and requirements in the USSR for future fast reactor safety

FBRs with sodium coolant possess some advantages in comparison with reactors based on other design and principal conceptions, due to the low pressure in the coolant circuits and large heat capacity of the sodium, which makes it possible to secure decay heat removal in the case of accidents.

High levels of safety of FBRs should be provided by the operational reliability of the shut-down systems and by guaranteed reactor subcritical conditions after defined initial events leading to disturbances of coolant flow rate and reactor power. The inherent safety characteristics of FBR, such as the high thermal capacity of the coolant, negative reactivity feedback, the possibility of decay heat removal by means of natural convection, should be utilised to a maximum extent in FBR designs to provide reactor safety.