Ventilation-air conditioner system in nuclear power plant

This invention concerns a ventilation-air conditioner system which enables, upon occurrence of accidents in a nuclear power plant, continuous operation for other adjacent nuclear power plants with no effect of accidents. Air supply system and exhaust system are operated during usual operaiton. If loss of coolants accidents should occur in an adjacent nuclear power plants, operation is switched from ventilation operaiton to the operation of re-cycling system based on an AND logic of three signals, that is, a pressure HIGH signal for the reactor container, a water level LOW signal for the reactor and a radioactivity signal of the ventilation-air conditioner sytem on the side of air supply in the nuclear power plant. Thus, nuclear reactor buildings of the nuclear power plant are from the external atmosphere. Therefore, the radioactivity HIGH signal for switching to the emergency air conditioner system of the nuclear power plant is not actuated due to the loss of coolant accidents in the adjacent nuclear power plant. In addition, since the atmospheric temperature in the nuclear reactor building can be maintained by a cooling device disposed to the recycling system, reactor shutdown can be prevented. (I.S.)