Tarapur refuelling outage experience

Seven refuelling outages carried out during 1971-76 at the Tarapur Atomic Power Station - three for the first unit and four for the second unit - are reviewed and time taken for various activities involved in refuelling is compared. In Indian situation, refuelling operation has to be done under many restraints which are pointed out. The first refuelling operation had to start from the very beginning. Special tools e.g. for handling reactor internals had to be fabricated and facilities e.g. rig for operator training set up. Underwater repairs in one region of the core had to be carried out. This resulted in a very long outage of 243 days. With the gain in experience outage duration progressively reduced and for the seventh refuelling it was 82 days only. During the outage of one unit for refuelling, outage of another unit has also to be planned for a few days for maintenance and testing of common facilities such as emergency power supply. It has been pointed out that outage planning depends on resource planning. (M.G.B.)