Liquid level reappearance

Once a liquid level reappears in the reflux drum, the condenser capacity has been exceeded. The level in the condenser will continue falling, until the drum empties, and the reflux pump begins to cavitate. 

The decision to stop running the reactor was taken after two successive defects were detected in the primary system containment (double envelope of reactor vessel). The first defect, which appeared in 1978, consisted of a sodium micro leak radioactive sodium aerosols were found in the double wall reactor vessel. Investigations did not find any liquid sodium in the gap nor locate the defect. The reactor was subsequently operated at a reduced power level (-0.6 Pn), which was high enough for irradiation needs but did not cause the leak to reappear. The second defect appeared in 1982 and consisted of a small leak from the nitrogen blanket surrounding the primary system. 

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