Method and device for controlling the radioactive liquid wastes processing systems

Purpose: To conduct sampling for liquid wastes and processing water with no overlaps in a nuclear power plant by scattering the starting time for the sampling in each of a plurality of pure water cleaning systems by an interval exceeding a predetermined of time in a nuclear power plant. Method: Among output signals from level meters of liquid wastes tanks, the signal selection station of a control unit selectively issues a liquid level signal from a liquid waste tank now in collecting liquid wastes to a precasting station for the start of sampling and a liquid level signal from a liquid waste tank now in conducting water cleaning procession for the liquid wastes to an output station for sampling instruction. The signal from each of the output stations for sampling instruction is issued to the inlet valve of a liquid waste tank to determine if the tank is in collecting the liquid wastes. While on the other hand, the output station for the sampling instruction combines the precast time for the start of water cleaning procession in each of the systems inputted from the precasting station for the start of sampling and each of the signals inputted from a processing amount operating station to conduct logic operation and issues output signal for the sampling operation. (Seki, T.)