Due to this, the residential complex had a very Indian small-town look, with neat sidewalks, spacious houses, a club with tennis courts, swimming pool, a commissary etc. The residential complex was also constructed by Bechtel to house both Indian and American employees.
The personnel operating the power plant live in a residential complex called T. The facility is operated by the NPCIL ( Nuclear Power Corporation of India).
Unit 3 was brought online for commercial operation on 18 August 2006, and unit 4 on 12 September 2005. More recently, an additional two pressurised heavy water reactor (PHWR) units of 540 MW each were constructed by BHEL, L&T and Gammon India, seven months ahead of schedule and well within the original cost estimates. These were the first of their kind in Asia. Later on this was reduced to 160 MW due to technical difficulties. Units 1 and 2 were brought online for commercial operation on 28 October 1969 with an initial power of 210 MW of electricity. It was built for the Department of Atomic Energy by GE and Bechtel. Tarapur Atomic Power Station was constructed initially with two boiling water reactor (BWR) units under the 1963 123 Agreement between India, the United States, and the International Atomic Energy Agency (IAEA).