An electrical power system for a nuclear power facility includes an active alternating current (AC) power bus configured to be electrically coupled to a plurality of engineered safety feature (ESF) loads of a plurality of nuclear power systems, each of the ESF loads configured to fail to a safe position upon loss of primary AC power; a critical battery system electrically coupled to the active AC bus, the critical battery system comprising a plurality of valve regulated lead acid (VRLA) batteries; and a primary AC power source electrically coupled to the active AC bus.