A reactor cooling system for cooling a nuclear reactor using nitrogen comprising a refrigeration unit for cooling and compressing nitrogen gas into liquid nitrogen, a liquids storage tank to store liquid nitrogen, the tank in fluid communication with the refrigeration unit, a heat exchanger drop system in fluid communication with the liquids storage tank, adjacent to the nuclear reactor, wherein the nitrogen absorbs heat by becoming gaseous, a tank for receiving and holding nitrogen gas in fluid communication with the heat exchanger and in fluid communication with the refrigeration unit, and where the system is a closed-loop drop system.
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