Apsara was Asia’s first research reactor, and it went critical on 4 August 1956 at the Bhabha Atomic Research Centre (BARC), Bombay (now Mumbai), Maharashtra.

Commissioned: 4 August 1956

Designed by: Indian nuclear scientists under the leadership of Dr. Homi Bhabha

Type: Swimming pool-type reactor

Fuel: Initially highly enriched uranium (HEU) supplied by the United Kingdom

Power Output: 1 MW (megawatt)

First research reactor in Asia, making India a leader in nuclear science at that time.

Used for neutron activation analysis, materials testing, and isotope production for medical and industrial applications.

Helped train Indian nuclear scientists and engineers, boosting India’s self-reliance in atomic energy.

Paved the way for India’s nuclear program, leading to the development of more advanced reactors.

In September 2018, Apsara was upgraded to Apsara-U, a more advanced version using low-enriched uranium (LEU), making it safer and more efficient.

The new reactor produces radioisotopes for medical, industrial, and agricultural applications while maintaining a low environmental impact.