METHOD AND DEVICE FOR DETECTING LEAKS THROUGH THE BUSHINGS OF THE COVER OF A NUCLEAR REACTOR VESSEL

摘要

The method and device are applicable to the bushings (2) of the cover (1) of a pressure water nuclear reactor vessel in operation. The device comprises a double circuit for taking two gas samples (100, 16, 17; 12, 13, 14, 15) and a measuring unit (18) comparing regularly the content particularly of water vapour in both samples. The first sample is taken from the volume of the chamber (7) into which the leak (10) leads and the second sample is taken at the vicinity of the cover (1) outside the area of immediate influence of the leak. The unit or assembly (18) generates (19) an arlarm in the case of a leak and discriminates such an alarm from operation alarms. Techniques and means are also provided to determine the scavenging flow rate in the volume of the chamber (7) and to monitor the sample taking and detection systems.