The precursor to the establishment of the Atomic Energy Authority (AEA) is the Sub committee on Atomic Energy established in 1957 under the Planning Council of the Government of Sri Lanka. Sri Lanka became a founder member of the International Atomic Energy Agency (IAEA) of the United Nations during the same year. The Radioisotope Centre of the University of Colombo was established in 1962 on the advice of IAEA experts who visited Sri Lanka in late 1950s.

The Atomic Energy Authority was established in 1969 by the Act. No. 19 of 1969. The first Chairman of the AEAwas late Prof. P.P.G.L.Siriwardena who also functioned as the Vice-Chancellor of the University of Colombo, and as the Director of the Radioisotope Centre. Dr. Granville Dharmawardena functioned as the Chairman of the AEA from 1979 to 1989 and also succeeded Prof. Siriwardena as the Director of the Radioisotope Centre of the University of Colombo. During this twenty year period the AEA developed to an organization of about 35 staff members with a Scientific Staff of about 10 specializing in Radiation Protection, Non-destructive Testing, Nuclear Medicine, XRF Analytical Methods, Food Irradiation, Rubber Vulcanization by Radiation, and Nuclear Electronics.

However, even at this stage the AEA had no laboratory facilities of its own and used the facilities at the Radioisotope Centre on an informal basis. The other main drawback was the number of areas the AEA was involved, when compared to its Scientific Staff strength.

Dr. Douglas Nethsinghe who retired from the IAEA after about 25 years of service was appointed as the Chairman in 1989. He significantly improved the staff/management relationship of the AEA and gave a new direction to the AEA. A firm decision was taken to establish laboratory facilities for AEA and a detailed Corporate Plan was prepared for the future development of the AEA. The income generated by the AEA which was only 4000 Rs in 1989 increased to about Rs. 730,000.00 by 1992, when Dr. Nethsinghe resigned due to personal reasons

Dr. M. Prinath Dias was appointed as the Chairman in 1992 and he continued the work programme for development of the AEA initiated by Dr. Nethsinghe. Funds were obtained from the Government to construct an office and a laboratory building for the AEA, improvements were made to organizational structure of the AEA by creating 5 new divisions, and the Scientific Programmes were significantly improved. By 2001 the income generated by the AEA increased to 6.00 million Rs. and the staff strength to 70 out of which 30 were scientific and technical personnel.

One of the major burdens for the AEA was not having its own premises for its operation. As such several ways and means were deployed to obtain a building for AEA. One of the outstanding member of the employee trade union of AEA, Mr. Nimalsiri Soysa   made a request to make a new office premises for AEA from the Minister of Science and Technology, Hon. Bernard Soysa. This request played a vital role in the allocation of money for the new office and laboratory premises which was built at Orugodawatte in year 2001.

The construction of the new building of the AEA was completed in 2001 and laboratory facilities were established for external monitoring of radiation workers, for calibration and maintenance of nuclear electronic equipment, non-destructive testing, radiation processing, gamma spectroscopic analysis, X-ray fluorescence analysis, radiation processing, and applications of nuclear tracers.

On 26th August 2002 Sir Arthur C Clarke opened the AEA new building officially. In the year 2003 the AEA received a gamma cell from IAEA for research and development purposes.

Prof. M.Prinath Dias was appointed as the Regional coordinator for the East Asia and Pacific Region of the IAEA and he resigned from the chairmanship.
Prof. R.Hewamanna was appointed as the Chairperson of the AEA in May 2003. The gamma cell received from the IAEA was installed and a proposal to establish a Multipurpose Gamma Irradiator was forwarded to the Ministry of Science and Technology in the latter part of the year 2004. The Government allocated 102 million rupees for this purpose.

In November 2004 Prof Hewamanna resigned and Prof.B.M.A.Oswin Perera assumed duties as the new Chairman on 6th March 2006. During his tenure Nuclear Analytical Laboratory of AEA obtained National Accreditation for Gamma Spectroscopy Analysis for food and soil. Prof.B.M.A.Oswin Perera resigned in March 2007.

1956  –  Appointment of a Technical Working Group on Atomic Energy by the National Planning Council

1957 –  Founder membership of the International Atomic Energy Agency of the United Nations (IAEA)

1958 –  IAEA Expert Mission to advise the Government on development of a Nuclear Technology programme.

1961 –  Establishment of the Radioisotope Centre of University of Colombo on the recommendations of the above mission, under the Directorship of Prof. P.P.G.L. Siriwardene and commencement of postgraduate and undergraduate teaching programmes.

1962 –  Commencement of technology transfer to national institutes for utilization of nuclear technology in the medical, agricultural and industrial sectors, with the assistance of the IAEA.

1969  –  Approval of the Atomic Energy Authority Act No. 19 of 1969 by the Parliament for the establishment of an Atomic Energy Authority.

1970  –  Establishment of the Atomic Energy Authority and appointment of Prof. P.P.G.L. Siriwardene as its first Chairman.

1975  –  Promulgation of the Atomic Energy Regulations to regulate the uses of radiation and radioisotopes Sri Lanka received the membership of the Regional Cooperative Agreement of IAEA

1979  –  Appointment of Dr. K.G. Dharmawardena as the Chairman of SLAEB and as the Director of the Radioisotope Centre. 

1983  –  Establishment of a Nuclear Imaging Unit at National Hospital, Colombo to provide medical diagnostic services

1984  –  Commencement of a M.Sc Programme in Nuclear Science at the Radioisotope Centre with the assistance of the IAEA.

1986  –  Establishment of Radioimmunoassay laboratory at National Hospital, Colombo, to provide medical diagnostic services

1989  –  Appointment of Dr. D.A. Nethsinghe as the Chairman of the AEA.

1990  –  Decision to establish laboratory facilities of its own for the AEA and preparation of a Corporate Plan for the AEA.Commencement of a Personal Monitoring Service for the radiation workers. Initiation of action to up-grade the radiation protection programme. Commencement of training programmes on non-destructive testing, radiation protection and electronics by the AEA.

1992  –  Appointment of Dr. M. Prinath Dias as the Chairman of the AEA

1993  –  Approval of a proposal to construct a building to house the laboratories and administrative offices of the AEA by the Committee of Development Secretaries.

1994  –  Commencement of providing Non-destructive Testing Services by the AEA.

1995  –  Establishment of the first Gamma Spectroscopy System with Accuspec-A Card by Mr. Cyril Kasige and Commencement of providing gamma spectroscopic analytical services at the AEA.
Commencement of a service for maintenance and calibration of nuclear electronic equipment at the AEA.
Approval of the AEA building project by the Cabinet. 

1996  –  Creation of new organizational structure at the AEA by establishing four scientific divisions and two administrative divisions. Establishment of a Human Tissue Bank by the Sri Lanka Eye Donation Society, with the assistance of the IAEA 

1997  –  Commencement of the AEA Building project.

2000  –  Promulgation of Radiation Protection Regulations conforming to the Basic Safety Standards of the AEA.

2001  –  Increase of the annual income of the AEA to six million rupees and the staff strength to 70.
Completion of the AEA building project and the establishment of laboratory facilities and administrative complex in the new building.

2003  –  Establishment of a Nuclear Imaging unit at Lady Ridgeway Hospital, Colombo.
Appointment of Prof. M. Prinath Dias as the Regional Co-ordinator of the IAEA and his resignation from the Chairmanship. Appointment of Prof. R. Hewamanna as the Chairman of AEA.
Establishment of a unit at the Faculty of Veterinary Medicine & Animal Science, University of Peradeniya, to identify chemical and drug residues in food products from livestock, poultry and aquatic species, using nuclear technology.
Establishment of a Gamma Cell in the new building.
Establishment of a Business Development Unit at the AEA.

2005  –  Allocation of funds by the Government of Sri Lanka to build up a Multi Purpose Gamma Irradiation Facility (MPGIF).
Resignation of Prof. R. Hewamanna from the Chairmanship.

2006  –  Appointment of Prof. B.M.A. Oswin Perera as the Chairman (March 2006 – March 2007)
Nuclear Analytical Laboratory of AEA obtained National Accreditation for Gamma Spectroscopy Analysis for food and soil

2007  –  Appointment of Dr. W. Abeywickreme as the Chairman of AEA

2009  –  The Atomic energy Authority (AEA) has established an Accredited Secondary Standards Dosimetry Calibration Laboratory
Initiated the project on establishment of laboratory facilities for Biological Dosimetry for those exposed to radiation and detection of cancer prone individuals.
A project on development of national capability to respond to radiological emergencies was started in 2009.
TXRF technique was established.

2010  –  AEA which was functioning under the Ministry of Science and Technology was established under the purview of the Ministry of Power and Energy in May 2010.
Minister of the Ministry: Hon. Patali Champika Ranawaka.
The government arrived at a policy decision to use nuclear power for electricity generation after two decades and manpower training to achieve this goal was initiated.
Cabinet approval was received for the establishment of a National Center for Non-destructive Testing and a block of land was received for this purpose.

2011  –  Appointment of Dr. Ranjith Wijayawardana as the Chairman of AEA

2014- Commencement of operations of Sri Lanka Gamma Centre (SLGC) , the first open access gamma irradiation facility of the country at Biyagama Export Processing Zone

2015  –  The Atomic Energy Authority (AEA) has been repealed and two institutions namely “Sri Lanka Atomic Energy Board(AEB)” and “Sri Lanka Atomic Energy Regulatory Council(AERC)”, which have been established by the Sri Lanka Atomic Energy Act, No. 40 of 2014

2015  –  AEB was established under the purview of the Ministry of Power and Energy in January 2015.
Minister of the Ministry: Hon. Pateli Champika Ranawaka.

2015 – Commencement of operations of National Centre for Non Destructive Testing (NCNDT) , at Kelaniya.

2015  Mar –  Appointment of Mr.Lakshitha Jayawardhana Attorney-at-Law, as the Chairman of AEB

2018 Mar – Late Mr. Yukiyo Amano, Director General of International Atomic Energy Agency (IAEA) declared opened the SLAEB new building as the old building was demolished for the New Kalani Bridge Project.

2018 Dec – Appointment of Mr. Sampath Chandrasena as the Chairman of AEA

2019 Jan – Appointment of Mr. Deepal Guneratne as the Chairman of AEA

2020 Jan – Appointment of Prof. S.R.D. Rosa as the Chairman of AEA