METHOD AND MANIPULATORS TO LOCATE INNER LEAKS IN WWER-TYPE STEAM-GENERATORS DURING OUTAGE OF THE UNIT

Methods at present laid down to locate leaks in WWER-type steam generator tubes and primary collectors - hydraulic pressure test and luminescence test - proved insufficiently sensitive and little practical. Therefore, the so-called bubble method and specific manipulators have newly been established to locate leaks in WWER-type steam generators during outage of the unit. The present paper gives a brief theoretical consideration of leak problems, the bubble method, and also the design of the manipulators related to their application. Based on practical experience as gained with the use of the manipulators at the Czechoslovak nuclear power plant units, some advantages of the bubble method and practical results of leak location are summarized.