Tarapur Atomic Power Station Units-1 and 2: Design features, operating experience and license renewal

Tarapur Atomic Power Station (TAPS), a twin-unit BWR station is the oldest NPP in India. These units are operating for the last 30 years with impressive operation performance indicators and in this period their operating license was periodically extended by the Atomic Energy Regulatory Board. Certain modifications and improvements have been made in these units based on operating experiences and to further improve the safety standards. Testing of surveillance samples of the reactor vessel material confirmed that the vessel could operate well beyond 60 Effective Full Power Years (EFPYs), whereas till 2003, these units have completed 18 EFPYs. In order to extend the operating license of these units a fresh comprehensive review involving review of plant operating performance, ageing management and design basis and safety analysis was carried out. These units were reviewed against the current safety practices and based on this review some recommendations are made to bring the safety levels of these vintage units on par with the recently authorized plants. This paper gives a general description and describes the operating experience of TAPS. Also, safety review of TAPS carried out for license renewal is covered.