Smiling Buddha Smiling Buddha , ( MoEA designation as Pokhran - I ) , was an assigned codename of India ' s first nuclear weapon explosion , which took place on 18 May 1974 . The device was detonated by the Indian Army in the long - constructed army base , Pokhran Test Range , at the Pokhran municipality , Rajasthan state , under the aegis of several key Indian army personnel . The " Pokhran - I " was also the first confirmed nuclear test by a nation outside the five permanent members of the United Nations Security Council . Officially , Indian Ministry of External Affairs ( MoEA ) claims this test as peaceful nuclear explosion , but it was actually part of an accelerated nuclear program . The weapon yield remains uncertain , with estimates of up to 8kt . History . Early origins : 1944 – 1960s . India ' s nuclear program began in 1944 when Homi J . Bhabha founded the Tata Institute of Fundamental Research in 1944 . Physicist Raja Ramanna played an integral role in the research of nuclear weapons technology , he expanded and supervised the scientific research on nuclear weapons and was the first directing officer of the small team of scientists that supervised and carried out the test of the nuclear device . < ref name = " http : / / nuclearweaponarchive . org " > < / ref > After Indian independence from United Kingdom , Indian Prime Minister Jawarharalal Nehru authorized the development of a nuclear programme headed by Homi J . Bhabha ; the " Atomic Energy Act " of 1948 focuses on peaceful development . India was heavily involved in the development of the Nuclear Non - Proliferation Treaty , but ultimately opted not to sign . In 1954 , Bhabha moved the nuclear programme in a direction towards weapons design and production . There were two important infrastructure projects were commissioned — first being the Trombay Atomic Energy Establishment at Mumbai while other being the governmental secretariat , the Department of Atomic Energy ( DAE ) of which Bhabha was the first secretary . Between the period of 1954 to 1959 , the nuclear programme grew swiftly and by 1958 the DAE had 1 / 3 of the defence budget for research purposes . In 1954 , India reached a verbal understanding with the United States and Canada , under the Atoms for Peace program ; the United States and Canada ultimately agreed to provide and established the " CIRUS " research reactor , also at Trombay . Acquisition of CIRUS was a watershed event in nuclear proliferation , with understanding between India and the United States that the reactor would be used for peaceful purposes only . CIRUS was an ideal facility to develop the plutonium device , therefore Nehru had refused to accept the nuclear fuel from Canada , and started the programme to develop the indigenous nuclear fuel cycle . In July 1958 , Nehru authorized " " Project Phoenix " " to build a reprocessing plant with a capacity of 20 tonnes of fuel a year - a sized to match the production capacity of CIRUS . The plant used the PUREX process was designed by an American firm , Vitro International . Construction of the plutonium plant began at Trombay on 27 March 1961 and was commissioned in mid - 1964 . The nuclear programme began to be mature in 1960 and Nehru made critical decision to carefully put nuclear programme on military production . During the same time , Nehru held discussions with American firm , the Westinghouse Electric , to construct the country ' s first nuclear power plant in Tarapur , Maharashtra . In a meeting with Nehru , the US Army engineer , Kenneth Nichols , relates that " it was that time when Nehru turned to Bhabha and asked Bhabha for the timeline of the development of nuclear weapon " , which Bhabha estimated that he would need about a year to do it . In 1962 , the nuclear programme continued to develop , but at slow rate . Nehru was distracted by the Sino - Indian War , where India lost territory to China . Nehru turned to the Soviet Union for help but it was facing the missile crisis . The Soviet Politburo turned down Nehru ' s request for weapon supply and continued backing the Chinese . This war left an impression on India that the Soviet Union was an unreliable ally , therefore nuclear deterrence was felt necessary . Design work began in 1965 under Bhabha and proceeded by Raja Ramanna , who took over the programme after former ' s death . Weapons Development : 1967 - 1972 . Bhabha now was aggressively lobbying for the nuclear weapons and made several speeches on Indian radio . In 1964 , Bhabha told the Indian public via India radio that " such nuclear weapons are remarkably cheap " , and supported his arguments by relating the economical cost of American nuclear testing program ( " Plowshare " ) . Bhabha maintained to the politicians that " 10 kt device would cost around $ 350 , 000 and $ 600 , 000 for a 2 Mt " . From this , he estimated that " a stockpile of some 50 atomic bombs would cost under $ 21 million and a stockpile of 50 two - megaton hydrogen bombs something of the order of $ 31 . 5 million . " But , the U . S . " Plowshare " cost figures were based on the incremental cost of producing devices by a vast industrial complex costing tens of billions of dollars , which had already manufactured nuclear weapons numbering in the tens of thousands . The delivery systems for nuclear weapons typically cost several times as much as the weapons themselves . The real cost to India for any nuclear program would be orders of magnitude greater than Bhabha ' s claims , noted by the " " Nuclear Weapon Archive " " . The nuclear programme was partially slowed down when Lal Bahadur Shastri became the prime minister , who had low ambitions regarding the nuclear program . In 1965 , Shastri faced another war , this time with West Pakistan ( now Pakistan ) . Shastri appointed physicist Vikram Sarabhai as the head of nuclear programme , but because of his Gandhian beliefs , Sarabhai focused the programme to be developed into more peaceful purposes rather than the militarization of the program . In 1967 , Indira Gandhi became the prime minister , the work on nuclear programme resumed with a new attitude and goals . Homi Sethna , a chemical engineer , played a significant role in the development of weapon - grade plutonium while Ramanna designed and manufactured the whole nuclear device . Because of the sensitivity , the first nuclear bomb project did not employ more than 75 scientists . The nuclear weapons program was now directed towards plutonium rather than uranium . In 1968 – 69 , P . K . Iyengar visited the Soviet Union with three other colleagues and toured the nuclear research facilities at Dubna , Russia . During his visit , Iyengar was impressed by the plutonium fueled pulsed fast reactor . Upon his return to India , Iyengar set about developing plutonium reactors and the Indian political leadership approved the plan in January 1969 . The secret plutonium plant was known as " Purnima " and construction took place in March 1969 . The plant ' s leadership included the roles of Iyengar , Ramanna , Homi Sethna , and Sarabhai . Sarabhai ' s presence clearly indicates that with or without formal approval , the work on nuclear weapons at Trombay was commenced . Secrecy and test preparations : 1972 - 1974 . India continued to harbour ambivalent feelings about nuclear weapons and accord low priority to their production until the Indo - Pakistani War of 1971 . In the same month of December 1971 , when Richard Nixon sent a carrier battle group led by the into the Bay of Bengal in an attempt to intimidate India , the Soviet Union responded by sending a submarine armed with nuclear missiles from Vladivostok to trail the US task force . The Soviet response demonstrated the deterrent value and significance of nuclear weapons and ballistic missile submarines to Indira Gandhi . India had gained the military and political momentum on Pakistan after acceding the treaty that divided Pakistan into two different political entities in the South Asia . The 1971 war had crushed the Pakistan military which had lost more than half its population , and the Pakistan – China axis was proved to be " paper tiger " after the defeat . On 7 September 1972 , near the peak of her post - war popularity , Indira Gandhi authorized the Bhabha Atomic Research Centre ( BARC ) to manufacture a nuclear device and prepare it for a test . Although , the Indian Army was not fully involved in the nuclear testing , the army ' s highest command was kept fully informed of the test preparations . The preparations were carried out under the watchful eyes of Indian political leadership , with civilian scientists assisted the Indian Army . Throughout its development , the device was formally called the " Peaceful Nuclear Explosive " , but it was usually referred to as the " Smiling Buddha " . Detonation occurred on 18 May 1974 , Buddha Jayanti ( a festival day in India marking the birth of Gautama Buddha ) . Historical accounts found out that Indian political leadership , under Indira Gandhi , remained the tight control of all aspects of the preparations of the " Smiling Buddha " . This test was kept in extreme secrecy , besides Indira Gandhi , only two of her advisers Parmeshwar Haksar and Durga Dhar were kept informed . Scholar Raj Chengappa asserts that Indian Defense Minister Jagjivan Ram was not provided with any kind of knowledge of this test and came to learn of this test after it was conducted . The Minister of External Affairs Swaran Singh was given 48 hour advance notice . The Indira Gandhi administration employed no more than 75 civilian scientists while only General GG Bewoor , Indian army chief and the commander of Indian Western Command were the only military commanders who were kept informed . Development teams and sites . The head of this entire nuclear bomb project was the director of the BARC , Dr . Raja Ramanna . Later in years , his role would be more deeply integrated and headed the nuclear program during most of his life . The designer and the creator of the bomb was Dr . P . K . Iyengar who was put second - in - command of this nuclear bomb project . Iyengar ' s device was further assisted by the chief metallurgist R . Chidambaram and Nagapattinam Sambasiva Venkatesan of the Terminal Ballistics Research Laboratory who developed and manufactured the high explosive implosion system . The explosive materials and the detonation system was developed by Waman Dattatreya Patwardhan of the High Energy Materials Research Laboratory . The overall project was supervised by Homi Sethna , Chairman of the Atomic Energy Commission of India . Chidambaram , who would later coordinate work on the Pokhran - II tests , began work on the equation of state of plutonium in late 1967 or early 1968 . To preserve secrecy , the project employed no more than 75 scientists and engineers from 1967 – 74 . It is also theorised that Abdul Kalam also arrived at the test site as the representative of the DRDO , although he had no role whatsoever in the development of the nuclear bomb or even in the nuclear programme . Roughly , the device was the implosion - type design which had a close resemblance to American nuclear bomb , the " Fat Man " . The implosion system was assembled at the Terminal Ballistics Research Laboratory ( TBRL ) of DRDO in Chandigarh . The detonation system was developed at the High Energy Materials Research Laboratory ( HEMRL ) of DRDO in Pune , Maharashtra State . The 6 kg of plutonium came from the CIRUS reactor at BARC . The neutron initiator was of polonium – beryllium type and code - named " Flower " . The complete nuclear bomb was engineered and finally assembled by Indian engineers in Trombay before transportation to the test site . Nuclear weapon design . Cross - section . The fully assembled device had a hexagonal cross section , 1 . 25 meter in diameter and weighed 1400 kg . The device was mounted on a hexagonal metal tripod , and transported to the shaft on rails which the army kept covered with sand . The device was detonated when Dastidar pushed the firing button at 8 . 05 a . m . in a shaft 107 m under the army Pokhran test range in the Thar Desert ( or Great Indian Desert ) , Rajasthan . Coordinates of the crater are . Controversy regarding the yield . The nuclear yield of this test has yet remained controversial with unclear data provided by Indian sources . Although Indian politicians have given ranges from 20 kt to as low as 2 kt to country ' s occasional press . The official range of the yield was initially set at 12 kt ( post Operation Shakti claims have raised it to 13 kt ) . Outside independent seismic data and analysis of the crater features indicates a lower figure . Analysts usually estimate the yield at 4 to 6 kt using conventional seismic magnitude - to - yield conversion formulas . In recent years , both Homi Sethna and P . K . Iyengar conceded the official yield to be an exaggeration . Iyengar has variously stated that the yield was actually 8 – 10 kt , that the device was designed to yield 10 kt , and that the yield was 8 kt " exactly as predicted " . Although seismic scaling laws lead to an estimated yield range between 3 . 2 kt to 21 kt , an analysis of hard rock cratering effects suggests a tight bound around 8 kt for the yield and is within the uncertainties of the seismic yield estimate . Aftermath . Domestic reaction . Indian Premier Indira Gandhi had already gained much popularity and publicity after her successful military campaign against Pakistan in the 1971 war . The test further caused an immediate revival in Indira Gandhi ' s popularity , which had flagged considerably from its high after the 1971 war . Overall , the popularity and image of Congress Party was heightened and the Congress Party was well received in the Indian Parliament . In 1975 , chemical engineer and the chairman of the Indian Atomic Energy Commission ( AECI ) Homi Sethna , Raja Ramanna of BARC , and Basanti Nagchaudhuri of DRDO , all were conferred and honored with " Padma Vibhushan " — India ' s second highest civilian award . Five other project members received the " Padma Shri " — India ' s fourth highest civilian award . India consistenly maintained that it was a peaceful nuclear bomb test and had no intentions towards the militarization of its nuclear program . But , according to the independent monitors , this test was actually part of an accelerated Indian nuclear program . In 1997 , Raja Ramanna speaking to the " Press Trust of India " maintained to the fact : International reaction . While India continued to state that the test was for peaceful purposes , it was shown opposition from many corners . The Nuclear Suppliers Group ( NSG ) was formed in reaction to the Indian tests 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 , but in 2008 waived this restriction on nuclear trade with India as part of the Indo - US civilian nuclear agreement . Pakistan . Pakistan did not view the test as a " peaceful nuclear explosion " , and canceled talks scheduled for 10 June on normalization of relations . Pakistan ' s Prime minister Zulfikar Ali Bhutto vowed in June 1974 that he would never succumb to " nuclear blackmail " or accept " Indian hegemony or domination over the subcontinent " . The Pakistan Atomic Energy Commission Chairman Munir Ahmed Khan said that the test would force Pakistan to test its own nuclear bomb . Pakistan ' s leading nuclear physicist , Pervez Hoodbhoy , stated in 2011 that he believes the test " pushed [ Pakistan ] further into the nuclear arena " . Canada and United States . The plutonium used in the test was created at the CIRUS reactor supplied by Canada and using heavy water supplied by the United States . Both countries reacted negatively , especially in light of then ongoing negotiations on the Nuclear Non - Proliferation Treaty and the economic aid both countries 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 . 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 . France . France sent a congratulatory telegram to India but later on withdrew it . Subsequent nuclear explosions . After the 1974 test , the Nuclear Suppliers Group placed an embargo on India and Pakistan at once . Indira Gandhi approved the plan to develop Hydrogen bomb s but after her removal in mid 1970s , India ' s nuclear program struggled hard to gain its capabilities . After her return to power in 1980s , India expanded the scope of nuclear program and increased its nuclear power generation capacity all over the country . Despite many proposals , India did not carry out further nuclear tests until 1998 . After 1998 general elections , Operation Shakti ( also known as Pokhran - II ) was carried out at the Pokhran test site , and used devices designed and built over the preceding two decades .