Department of Atomic Energy: set up under the Prime Minister's direct charge by a Presidential Order
Background
The Department of Atomic Energy (DAE) was set up under the direct charge of the Prime Minister through a Presidential Order on August 3, 1954.
By that order, all business of the Government of India related to atomic energy and to the Central Government's functions under the Atomic Energy Act, 1948 (XXIX of 1948) was to be transacted in the Department.
The Atomic Energy Commission, with full executive and financial powers, was set up by a Government resolution dated March 1, 1958, and is responsible for formulating the Department's policy.
The Secretary to the Government of India in the Department of Atomic Energy is ex-officio Chairman of the Commission.
DAE's mandate includes uranium exploration and processing, nuclear fuel fabrication, heavy water production, and the construction and operation of nuclear power plants.
It comprises 6 research centres, including BARC (Mumbai) and IGCAR (Kalpakkam), and 5 public sector undertakings, including NPCIL (Mumbai).
In plain words
AEC Atomic Energy Commission — The body set up in 1958 with full executive and financial powers to formulate DAE policy.
NPCIL Nuclear Power Corporation of India Limited — One of the 5 public sector undertakings of DAE, based at Mumbai.