A passive safety system comprises a heat exchanger, a thermoelectric element, and a fan unit. The heat exchanger is located inside a containment. The heat exchanger allows for temperature of atmosphere in the containment to be reduced. The thermoelectric element is disposed within the heat exchanger. The thermoelectric element is configured to generate electricity due to a temperature difference. The fan unit receives electricity generated by the thermoelectric element. The fan unit is configured to increase flow rate of fluid inside the containment. A nuclear power plant can include the passive safety system.