Smiling Buddha

Smiling Buddha (MEA designation: Pokhran-I) was the code name of India's first successful nuclear weapon test on 18 May 1974. The nuclear fission type bomb was detonated in the Pokhran Test Range of the Indian Army in Rajasthan. As per the United States military intelligence, the operation was named as Happy Krishna.

The Indian Ministry of External Affairs (MEA) described the test as a peaceful nuclear explosion. The bomb was built by scientists at the Bhabha Atomic Research Centre (BARC) in assistance with the Defence Research and Development Organisation (DRDO). A CIRUS nuclear reactor given by Canada and heavy water (used as a neutron moderator) supplied by the United States were used in the production of nuclear material for the bomb. The preparations for the test and the detonation was conducted in extreme secrecy with very few people outside the team of scientists being aware of the test.

The device was of the implosion-type design with a plutonium core. It had a hexagonal cross section, 1.25 m (4 ft 1 in) in diameter, and weighed 1,400 kg (3,100 lb). It was assembled, mounted on a hexagonal metal tripod, and was transported to the test site on rails. The test was conducted at 8.05 IST on 18 May 1974. The data on the exact nuclear yield of the test has been varied and scarce, and sources indicate that the bomb might have yielded between six and ten kilotons.

It was the first confirmed nuclear weapons test by a nation outside the five permanent members of the United Nations Security Council. The test led to the formation of the Nuclear Suppliers Group (NSG) to control nuclear proliferation. After the test, India carried out one other subsequent nuclear test named Pokhran-II in 1998.