DETECTION FOR LEAKAGE OF SODIUM

PURPOSE:To facilitate the discrimination of a leakage with a detector and a trouble of the detector, by arranging resistances between a power source and electrodes so that different values are given in case a voltage leaks between resistances, a wire disconnection occurs or degrading of an insulation resistance takes place between the electrodes. CONSTITUTION:A resistor 22 is connected in series from a power source 3 through a resistor 21 and a detector 1 (comprising electrodes 14 and 15), a resistor 23 is connected in parallel thereto and moreover, a resistor 24 is connected in series. A voltage across terminals of the resistor 24 is connected to voltage detectors 51-55 and an indicator 56 through a buffer amplifier 4. The detector 51 detects a voltage in case of leakage of sodium and an alarm output is generated through an alarm relay 61 when an input voltage attains a set range. The detectors 52-55 detect a voltage in case of a drop in an insulation resistance between electrodes and a disconnection of a wire and a trouble alarm output is generated with an alarm relay 62 when input voltages of in a set range respectively. Thus, with the generation of an alarm, it is discriminated which of the detectors 52-55 is operated by checking a voltage of the indicator 56 thereby enabling analysis on which wire fails.