[en] The performance and activities during the financial year 1985-86 of the Department of Atomic Energy (DAE), India and its various units are reported. The various units of the DAE can broadly be categorised into groups: research establishments, production units and public sector undertakings. After taking a general survey, the detailed report is presented under the chapters entitled: (1) nuclear power, (2) research and development, (3) Atomic Energy Regulatory Board, (4) public sector undertakings, and (5) other activities. Some of the other activities include international relations in the field of nuclear energy, information services, organization of training courses to meet the requirements of programmes of the DAE, technology transfer, financial support to institutions and universities for research in nucler science, and sponsoring of conferences, symposia etc. in the field of nuclear science and its applications. Major achievements of the DAE during the report period are: (1) attainment of criticality by the indigenously designed and built 100 MWt research reactor DHRUVA at Trombay, Bombay, (2) attainment of criticality by the Fast Breeder Test Reactor at Kalpakkam, (3) commissioning of the second unit of the Madras Atomic Power Station and its subsequent synchronisation with the power grid, (4) commissioning of the vitrification plant for management of high level radioactive wastes at Tarapur, and (5) successful testing of a 5 mwt MHD pilot at Tiruchirapalli. (author)