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
Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactiv ...
bomb was detonated in the
Pokhran Test Range of the
Indian Army in
Rajasthan
Rajasthan (; Literal translation, lit. 'Land of Kings') is a States and union territories of India, state in northwestern India. It covers or 10.4 per cent of India's total geographical area. It is the List of states and union territories of ...
. 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) headed by
Raja Ramanna, in assistance with the
Defence Research and Development Organisation (DRDO) headed by
B. D. Nag Chaudhuri under the supervision of the
Atomic Energy Commission headed by
Homi Sethna. A
CIRUS nuclear reactor
A nuclear reactor is a device used to initiate and control a Nuclear fission, fission nuclear chain reaction. They are used for Nuclear power, commercial electricity, nuclear marine propulsion, marine propulsion, Weapons-grade plutonium, weapons ...
given by Canada and
heavy water
Heavy water (deuterium oxide, , ) is a form of water (molecule), water in which hydrogen atoms are all deuterium ( or D, also known as ''heavy hydrogen'') rather than the common hydrogen-1 isotope (, also called ''protium'') that makes up most o ...
(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. It was tightly controlled by
prime minister
A prime minister or chief of cabinet is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. A prime minister is not the head of state, but r ...
Indira Gandhi 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, in diameter, and weighed . 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
kiloton
TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. A ton of TNT equivalent is a unit of energy defined by convention to be (). It is the approximate energy released in the det ...
s.
It was the first confirmed nuclear weapons test by a nation outside the
five permanent members of the
United Nations Security Council
The United Nations Security Council (UNSC) is one of the six principal organs of the United Nations (UN) and is charged with ensuring international peace and security, recommending the admission of new UN members to the General Assembly, an ...
. The test led to the formation of the
Nuclear Suppliers Group (NSG) to control nuclear proliferation. After the test, India carried out one other nuclear test named
Pokhran-II in 1998.
Background
The origins of
India's nuclear programme can be traced back to 1945 when
Homi Bhabha established the
Tata Institute of Fundamental Research with the aid of
Tata Group
The Tata Group () is an Indian multinational conglomerate group of companies headquartered in Mumbai. Established in 1868, it is India's largest business conglomerate, with products and services in over 160 countries, and operations in 100 c ...
. After
Indian independence, the Atomic Energy Act was passed on 15 April 1948, that established the
Indian Atomic Energy Commission (IAEC).
India was involved in the development of the
Nuclear Non-Proliferation Treaty, but ultimately did not sign it. In 1954,
Department of Atomic Energy (DAE) was established which was responsible for the atomic energy development programme and was allocated a significant amount of the defence budget in the subsequent years. In 1956, the first
nuclear reactor
A nuclear reactor is a device used to initiate and control a Nuclear fission, fission nuclear chain reaction. They are used for Nuclear power, commercial electricity, nuclear marine propulsion, marine propulsion, Weapons-grade plutonium, weapons ...
named ''APSARA'' became operational at
Trombay, becoming the first operating reactor in Asia. A
CIRUS reactor was given to India as a part of an understanding with Canada and the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
under the
Atoms for Peace programme. India set up an indigenous programme to manufacture
uranium
Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...
nuclear fuel
Nuclear fuel refers to any substance, typically fissile material, which is used by nuclear power stations or other atomic nucleus, nuclear devices to generate energy.
Oxide fuel
For fission reactors, the fuel (typically based on uranium) is ...
for the reactor, as opposed to importing from other countries.
In July 1958, then
Prime Minister
A prime minister or chief of cabinet is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. A prime minister is not the head of state, but r ...
Jawaharlal Nehru authorized "Project Phoenix" to build a reprocessing plant with a capacity to produce 20 tons of
plutonium fuel a year using the
PUREX process, designed by the
Vitro Corporation of America. The construction of the plutonium plant began in 1961, and it was commissioned in mid-1964.
The civilian nuclear program to produce electricity from nuclear energy was also established during this period with plans to construct new
nuclear power plant
A nuclear power plant (NPP), also known as a nuclear power station (NPS), nuclear generating station (NGS) or atomic power station (APS) is a thermal power station in which the heat source is a nuclear reactor. As is typical of thermal power st ...
s for the purpose. Nehru's discussions with Bhabha and
Kenneth Nichols, a
US Army engineer, showed his approach and intention to create nuclear weapons as a means of
deterrence.
In 1962, India was engaged in a
war with China and with China pursuing its own atomic development programme, it accelerated India's need to develop
nuclear weapons
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either nuclear fission, fission (fission or atomic bomb) or a combination of fission and nuclear fusion, fusion reactions (thermonuclear weap ...
.
During this period, India signed an agreement with
Soviet Union
The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...
to help build nuclear reactors in India.
Development
With two reactors operational in early 1960s, Bhabha was involved in learning and development of know-how to manufacture nuclear weapons. The atomic energy act was amended in 1962 to give far more control to the
central government. Bhabha was also aggressively lobbying for nuclear weapons and made several public speeches on the matter. He also estimated that a nuclear device with a 10
kt yield would cost US$350,000. The reactors were not producing fuel at the expected rate and with Nehru's death in 1964, the programme slowed down.
The incoming prime minister
Lal Bahadur Shastri gave approval for the Subterranean Nuclear Explosion Project in 1964 under Bhabha's insistence. However, Shastri did not want to commit to a weapons test yet, and later appointed physicist
Vikram Sarabhai as the head of the nuclear programme. Because of Sarabhai's non-violent
Gandhian beliefs, he directed the programme towards peaceful purposes rather than military development.
Meanwhile, the design work on the bomb proceeded under physicist
Raja Ramanna, who continued the nuclear weapons technology research after Bhabha's death in 1966.

After Shastri's death in 1966,
Indira Gandhi became the prime minister and work on the nuclear weapons programme resumed.
Homi Sethna, a chemical engineer, was put in charge of plutonium development. The project for the design and manufacturing of the nuclear device employed just 75 scientists because of the secret nature of the project.
Ramanna led the project with
P. K. Iyengar serving as his deputy and the leadership team also included Sethna and Sarabhai. The weapons programme was directed towards the production of plutonium rather than uranium and then in 1969, enough plutonium had been accumulated for the production of a single nuclear bomb.
In 1968–69, Iyengar led a team to the Soviet Union and toured the nuclear research facilities at
Dubna. Upon his return to India, Iyengar set about developing a plutonium fueled
fast breeder reactor named ''Purnima'' under Mahadeva Srinivasan. In 1969,
R. Chidambaram was engaged for researching the use of plutonium.
Simultaneous work on the fabrication of the bomb core and
implosion design was conducted by teams led by physicist
V. S. Ramamurthy. The detonation system development began in April 1970 with
Pranab R. Dastidar collaborating with
W. D. Patwardhan at the
High Energy Materials Research Laboratory (ERDL) of the
Defence Research and Development Organisation (DRDO). In July, physicist
B. D. Nagchaudhuri was appointed as the scientific adviser to the
Defense Minister and as Director of the DRDO.
Nagchaudhuri and Ramanna worked together to recruit the team and set up the requirements necessary for a nuclear weapon test.
Terminal Ballistics Research Laboratory (TBRL) of the DRDO developed the explosive lenses for the implosion system. Srinivasan and K. Subba Rao were tasked with developing fission models and prediction of the test's efficiency. In April 1971, Nagchaudhuri appointed N. S. Venkatesan as the new Director of TBRL to help develop the implosion system.
V.K. Iya was in charge of developing the
neutron
The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...
initiator system. In the same year, Sethna succeeded Sarabhai as the chairman of the Atomic Energy Commission.
In December 1971, during the
Indo-Pakistani War, the U.S. government sent a
carrier battle group led by the into the
Bay of Bengal
The Bay of Bengal is the northeastern part of the Indian Ocean. Geographically it is positioned between the Indian subcontinent and the Mainland Southeast Asia, Indochinese peninsula, located below the Bengal region.
Many South Asian and Southe ...
in an attempt to intimidate India. The Soviet Union responded by sending its own naval force to deter the U.S. from involving militarily. This event is indicated as a reason for India's pursuance of the nuclear programme. After India gained military and political initiative over Pakistan in the
Indo-Pakistani war of 1971, the work on building a nuclear device continued. The hardware began to be built in early 1972 and the Prime Minister authorised the development of a nuclear test device in September 1972.
Nuclear test
The
Indian Army was involved in the test preparations at the
Pokhran Test Range in
Rajasthan
Rajasthan (; Literal translation, lit. 'Land of Kings') is a States and union territories of India, state in northwestern India. It covers or 10.4 per cent of India's total geographical area. It is the List of states and union territories of ...
. The project was code named ''Operation Smiling Buddha'' (
MEA designation: ''Pokhran-I'') while as per the
United States military intelligence, the operation was named as ''Happy Krishna''.
The preparations were carried by civilian scientists assisted by the Indian Army.
Indira Gandhi maintained tight control of all aspects of the preparations of the test, which was conducted in extreme secrecy. Besides Gandhi, only her advisers
Parmeshwar Haksar and
D. P. Dhar were kept informed. Dhar had protested the test, fearing that the sanctions that would follow, would affect the Indian economy.
The Indian Defence Minister
Jagjivan Ram
Jagjivan Ram (5 April 1908 – 6 July 1986), popularly known as Babuji, was an Indian independence activist and politician who served as a minister with various portfolios for over 30 years, making him the List of longest-serving members of the ...
was informed only a few days prior and
Swaran Singh, the
Minister of External Affairs, was given only 48 hours notice.
General
A general officer is an Officer (armed forces), officer of high rank in the army, armies, and in some nations' air force, air and space forces, marines or naval infantry.
In some usages, the term "general officer" refers to a rank above colone ...
G. G. Bewoor,
Indian army chief, and
Lieutenant-General
Lieutenant general (Lt Gen, LTG and similar) is a military rank used in many countries. The rank traces its origins to the Middle Ages, where the title of lieutenant general was held by the second-in-command on the battlefield, who was normall ...
T. N. Raina, the commander of
Indian Western Command were the only military commanders who knew about the test.
The test was called a
Peaceful Nuclear Explosive (PNE). The device was detonated on 18 May 1974 at 8.05
IST with
Dastidar pushing the firing button.
The
nuclear yield of the test has been difficult to determine with unclear data provided by Indian sources. Although politicians had given multiple numbers ranging from 2
kt to 20 kt, the official yield was initially set at 12 kt. Independent seismic data from outside and analysis of the crater features indicated a lower figure. Analysts estimate the yield at 4 to 6 kt, using conventional seismic magnitude-to-yield conversion formulas. Later, both Sethna and Iyengar conceded the official yield to be an exaggeration. Iyengar has stated that the yield was 8–10 kt, that the device was designed to yield 10 kt, and that the yield was 8 kt "exactly as predicted".
Weapon design

The device was of the
implosion-type design with a plutonium core, similar to ''
Fat Man'', the American nuclear bomb
detonated over Nagasaki in 1945. The implosion system was assembled at the TBRL of the DRDO in
Chandigarh
Chandigarh is a city and union territory in northern India, serving as the shared capital of the states of Punjab and Haryana. Situated near the foothills of the Shivalik range of Himalayas, it borders Haryana to the east and Punjab in the ...
. The detonation system was developed at the HEMRL of the DRDO in
Pune
Pune ( ; , ISO 15919, ISO: ), previously spelled in English as Poona (List of renamed Indian cities and states#Maharashtra, the official name until 1978), is a city in the state of Maharashtra in the Deccan Plateau, Deccan plateau in Western ...
.
The 6 kg of plutonium came from the CIRUS reactor at BARC and the neutron initiator was of the
polonium–
beryllium
Beryllium is a chemical element; it has Symbol (chemistry), symbol Be and atomic number 4. It is a steel-gray, hard, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with ...
type, code-named ''Flower''. The entire nuclear bomb was engineered and assembled by Indian engineers at BARC before transportation to the test site. The fully assembled device had a hexagonal cross section, in diameter, and weighed . The device was mounted on a hexagonal metal tripod, and was transported to the shaft on rails which the army kept covered with sand.
Aftermath
Domestic reaction
Indian Prime Minister Indira Gandhi gained much popularity after the test, which had flagged from its heights after the 1971 war with Pakistan. The overall popularity and image of the
Congress Party was enhanced and it was well received in the
Indian Parliament. In 1975, Sethna, Ramanna and Nagchaudhuri were honoured with the ''
Padma Vibhushan'', India's second highest civilian award. Five other project members received the ''
Padma Shri'', India's fourth highest civilian award. India consistently maintained that this was a peaceful nuclear bomb test and that it had no intentions of militarising its nuclear programme, but according to independent monitors, this test was part of an accelerated
Indian nuclear programme. In 1997
Raja Ramanna, speaking to the ''
Press Trust of India
The Press Trust of India Ltd., commonly known as PTI, is the largest news agency in India. It is headquartered in New Delhi and is a nonprofit cooperative among more than 450 Indian newspapers. It has over 500 full-time employees , including abo ...
'', maintained:
International reaction
While India continued to state that the test was for peaceful purposes, it encountered opposition from many quarters. In reaction to the tests, the
Nuclear Suppliers Group (NSG) was established to check international nuclear proliferation.
The NSG decided in 1992 to require full-scope
IAEA safeguards for any new nuclear export deals, which effectively ruled out nuclear exports to India. It was only waived as part of the
Indo-US civilian nuclear agreement in 2008.
The plutonium used in the test had been enriched in the reactor supplied by Canada, using
heavy water
Heavy water (deuterium oxide, , ) is a form of water (molecule), water in which hydrogen atoms are all deuterium ( or D, also known as ''heavy hydrogen'') rather than the common hydrogen-1 isotope (, also called ''protium'') that makes up most o ...
(used as
neutron moderator) supplied by the United States. Both the countries reacted negatively, especially in light of then ongoing negotiations on the
Nuclear Non-Proliferation Treaty and the economic aid both countries had provided to India. Canada concluded that the test violated a 1971 understanding between the two states, and froze nuclear energy assistance for the two heavy water reactors then under construction. However, the United States concluded that the test did not violate any agreement and proceeded with a June 1974 shipment of enriched uranium for the
Tarapur reactor. New Zealand's Prime Minister
Norman Kirk commented that, "The announcement of an underground nuclear explosion by India raises more urgently than ever the need for international agreement to end all nuclear testing."
Pakistan did not view the test as a peaceful nuclear explosion, and cancelled scheduled talks with India. In June 1974,
Prime Minister
A prime minister or chief of cabinet is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. A prime minister is not the head of state, but r ...
Zulfikar Ali Bhutto
Zulfikar Ali Bhutto (5 January 1928 – 4 April 1979) was a Pakistani barrister and politician who served as the fourth president of Pakistan from 1971 to 1973 and later as the ninth Prime Minister of Pakistan, prime minister of Pakistan from 19 ...
said that Pakistan considered this as an intimidation and would not accept India's superiority in the
subcontinent
A continent is any of several large geographical regions. Continents are generally identified by convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as in the case of A ...
. In 2011, Pakistani
nuclear physicist Pervez Hoodbhoy stated that he believed the test pressed Pakistan into developing nuclear weapons of its own.
Other tests
Despite many proposals, India did not carry out further nuclear tests until 1998. Code named as ''Operation Shakti'' (officially known as
Pokhran-II) was carried out at the Pokhran test site, using technology designed and built over the preceding two decades.
See also
*
India and weapons of mass destruction
*
History of nuclear weapons
*
List of countries with nuclear weapons
*
Pokhran-II
References
Bibliography
*
{{India topics
Explosions in 1974
1974 in India
1974 in military history
Indian nuclear weapons testing
Political history of India
Underground nuclear weapons testing
Indira Gandhi administration
Code names
Pokaran
Nuclear history of India
Nuclear proliferation
Military history of India
Politics of India
A. P. J. Abdul Kalam
May 1974 in Asia
History of the Indian Army