The fire protection system of sodium equipment rooms ensures fire safety of fast neutron reactors by localizing and reducing the consequences of leaks and combustion of sodium during depressurization of equipment or pipelines of sodium systems. The present article describes the composition and operation of the fire protection system used at the BN-350 reactor plant. The efficiency of various subsystems and equipment of the fire protection system is considered as applied to the localization of sodium leaks occurred during the operation of the reactor plant. The performed experiments demonstrate the efficiency of drain fire extinguishing as the element of the fire protection system; requirements for drain fire extinguishing subsystems are provided. The article additionally presents data on the most significant sodium coolant leaks during the operation of the BN-350 reactor and considers trends in the development of fire protection systems for sodium equipment rooms of BN reactors. Technical solutions implemented in fire protection systems for the sodium coolant rooms of BN-600 and BN-800 next-generation reactors are examined based on the experience of using fire protection system elements.