In 1956, after graduating with honors from the Moscow Engineering Physics Institute, began his career at the Institute of Physics and Power Engineering (Obninsk), where for twenty years he rose from senior assistant to the head of the research department.
In January 1976, Armen Abagyan was appointed deputy general director of "Energy" Energy of the USSR, and in 1984, he headed the All-Union Scientific Research Institute for Nuclear stations.
In 1984 he became the general director of "Energy" scientific and industrial state holding and the director of All-Soviet (then Russian) Institute of Atomic Energy Stations (AES). Then he became the deputy director of Rosenergoatom, a member of IAEA Consultative Committee.
In 1986, as an expert of the Government Commission was involved in the accident at the Chernobyl nuclear power plant and research at the scene, which allowed to evaluate the extent and causes of the accident.
In 1995, Armen Abagyan involved in restarting the NPP, was a member of the advisory Security Council on nuclear energy at the President of the Republic of Armenia.