A passive safety system for removing decay heat from a nuclear power system may comprise a shroud structure and a heat generator that is within the shroud structure. A thermoelectric device may be disposed in thermal contact with the heat generator. The thermoelectric device is configured to generate a voltage based on a temperature difference between opposite parts of the thermoelectric device. A fan arrangement is disposed above the heat generator and in electrical connection with the thermoelectric device. The fan arrangement is configured to increase a coolant flow through the coolant passage to the outlet opening based on the voltage from the thermoelectric device.