HIGHLY RELIABLE METHOD TO DETECT LEAKY STEAM GENERATOR AT ATOMIC STATION DEVELOPED

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A highly reliable method of detection of a leaky steam generator at a nuclear power station has been developed. The chemical laboratory at the Kakrapar Atomic Power Station, which has developed this technique can be used at any nuclear power plant unit operating at full power. This original method has been successfully tested for the first time in the history of Nuclear Power Corporation of India Ltd. (NPCIL). This highly sensitive technique can locate a tube leak as low as 50 ml per hour.

Each unit of the Pressurised Heavy Water Reactor at Kakrapar has four mushroom type steam generators with integrated steam drums. Each steam generator consists of 1,830 tubes with 16 mm outside diameter and 1 mm thickness. Heavy Water of the primary heat transport system as coolant, carries the nuclear heat from the fuel to the tube side of the steam generator known as "the primary side" in which the radioactivity is contained.

The new method is based on the measurement of the iodine activity in the secondary side of water. Iodine, a fission product which is present in the primary side water would reflect in the secondary side of water in the event of tube leak in a steam generator. This iodine activity-based measurement method is very innovative and no reference of, use of such a technique elsewhere is available.