Nuclear weapons testing
Milestone nuclear explosions
Table:
Date	Name	Yield ( kt )	Country	Significance

1945-07-16	Trinity	18-20	USA	First fission device test , first plutonium implosion detonation

1945-08-06	Little Boy	12-18	USA	Bombing of Hiroshima , Japan , first detonation of a uranium gun-type device , first use of a nuclear device in combat

1945-08-09	Fat Man	18-23	USA	Bombing of Nagasaki , Japan , second detonation of a plutonium implosion device ( the first being the Trinity Test ) , second and last use of a nuclear device in combat

1949-08-29	RDS-1	22	USSR	First fission weapon test by the USSR

1952-10-03	Hurricane	25	UK	First fission weapon test by the UK

1952-11-01	Ivy Mike	10,400	USA	First cryogenic fusion fuel staged thermonuclear weapon , primarily a test device and not weaponized

1952-11-16	Ivy King	500	USA	Largest pure-fission weapon ever tested

1953-08-12	Joe 4	400	USSR	First fusion weapon test by the USSR ( not staged )

1954-03-01	Castle Bravo	15,000	USA	First dry fusion fuel staged thermonuclear weapon ; a serious nuclear fallout accident occurred ; largest nuclear detonation conducted by United States

1955-11-22	RDS-37	1,600	USSR	First staged thermonuclear weapon test by the USSR ( deployable )

1957-05-31	Orange Herald	720	UK	Largest boosted fission weapon ever tested . Intended as a fallback in megaton range in case British thermonuclear development failed

1957-11-08	Grapple X	1,800	UK	First ( successful ) staged thermonuclear weapon test by the UK

1960-02-13	Gerboise Bleue	70	France	First fission weapon test by France

1961-10-31	Tsar Bomba	50,000	USSR	Largest thermonuclear weapon ever tested - scaled down from its initial 100 Mt design by 50%

1964-10-16	596	22	PR China	First fission weapon test by the People 's Republic of China

1967-06-17	Test No . 6	3,300	PR China	First staged thermonuclear weapon test by the People 's Republic of China

1968-08-24	Canopus	2,600	France	First staged thermonuclear weapon test by France

1974-05-18	Smiling Buddha	12	India	First fission nuclear explosive test by India

1998-05-11	Pokhran-II	45-50	India	First potential fusion/boosted weapon test by India ; first deployable fission weapon test by India

1998-05-28	Chagai-I	40	Pakistan	First fission weapon ( boosted ) test by Pakistan

Consulting the table together with the context snippets below.

Give the answer to the question: On which date did testing occur for the nuclear weapon that was the nuclear bomb used in the Soviet Union 's first nuclear weapon test ? Provide just your answer in a JSON object {"answer": "YOUR ANSWER"}.

The explosive yield of a nuclear weapon is the amount of energy released when that particular nuclear weapon is detonated , usually expressed as a TNT equivalent ( the standardized equivalent mass of trinitrotoluene which , if detonated , would produce the same energy discharge ) , either in kilotons ( kt - thousands of tons of TNT ) , in megatons ( Mt - millions of tons of TNT ) , or sometimes in terajoules ( TJ ) . An explosive yield of one terajoule is equal to 0.239 kilotonnes of TNT . Because the accuracy of any measurement of the energy released by TNT has always been problematic , the conventional definition is that one kiloton of TNT is held simply to be equivalent to 1012 calories . The yield-to-weight ratio is the amount of weapon yield compared to the mass of the weapon . The practical maximum yield-to-weight ratio for fusion weapons ( thermonuclear weapons ) has been estimated to six megatons of TNT per metric ton of bomb mass ( 25 TJ/kg ) . Yields of 5.2 megatons/ton and higher have been reported for large weapons constructed for single-warhead use in the early 1960s . Since then , the smaller warheads needed to achieve the increased net damage efficiency ( bomb damage/bomb mass ) of multiple warhead systems have resulted in decreases in the yield/mass ratio for single modern warheads .
Trinity was the code name of the first detonation of a nuclear device . It was conducted by the United States Army at 5:29 a.m. on July 16 , 1945 , as part of the Manhattan Project . The test was conducted in the Jornada del Muerto desert about 35 miles ( 56 km ) southeast of Socorro , New Mexico , on what was then the USAAF Alamogordo Bombing and Gunnery Range , now part of White Sands Missile Range . The only structures originally in the vicinity were the McDonald Ranch House and its ancillary buildings , which scientists used as a laboratory for testing bomb components . A base camp was constructed , and there were 425 people present on the weekend of the test . The code name Trinity was assigned by J. Robert Oppenheimer , the director of the Los Alamos Laboratory , inspired by the poetry of John Donne . The test was of an implosion-design plutonium device , informally nicknamed The Gadget , of the same design as the Fat Man bomb later detonated over Nagasaki , Japan , on August 9 , 1945 . The complexity of the design required a major effort from the Los Alamos Laboratory , and concerns about whether it would work led to a decision to conduct the first nuclear test . The test was planned and directed by Kenneth Bainbridge . Fears of a fizzle led to the construction of a steel containment vessel called Jumbo that could contain the plutonium , allowing it to be recovered , but Jumbo was not used . A rehearsal was held on May 7 , 1945 , in which 108 short tons ( 96 long tons ; 98 t ) of high explosive spiked with radioactive isotopes were detonated . The Gadget 's detonation released the explosive energy of about 22 kilotons of TNT ( 92 TJ ) .
The United States was the first country to manufacture nuclear weapons and is the only country to have used them in combat , with the separate bombings of Hiroshima and Nagasaki in World War II . Before and during the Cold War , it conducted over a thousand nuclear tests and tested many long-range nuclear weapons delivery systems . [ Note 1 ] Between 1940 and 1996 , the U.S. government spent at least $ 9.49 trillion in present-day terms on nuclear weapons , including platforms development ( aircraft , rockets and facilities ) , command and control , maintenance , waste management and administrative costs . It is estimated that , since 1945 , the United States produced more than 70,000 nuclear warheads , which is more than all other nuclear weapon states combined . The Soviet Union/Russia has produced approximately 55,000 nuclear warheads since 1949 , France built 1,110 warheads since 1960 , the United Kingdom built 835 warheads since 1952 , China built about 600 warheads since 1964 , and other nuclear powers built fewer than 500 warheads all together since they developed their first nuclear weapons . Until November 1962 , the vast majority of U.S. nuclear tests were above ground . After the acceptance of the Partial Nuclear Test Ban Treaty , all testing was relegated underground , in order to prevent the dispersion of nuclear fallout . By 1998 at least $ 759 million had been paid to the Marshall Islanders in compensation for their exposure to U.S. nuclear testing . By February 2006 over $ 1.2 billion in compensation had been paid to U.S. citizens exposed to nuclear hazards as a result of the U.S. nuclear weapons program . [ citation needed ] The U.S. and Russia possess comparable numbers of nuclear warheads ; together , these two nations possess more than 90% of the world 's nuclear warheads . As of 2019 , the U.S. has an inventory of 6,185 nuclear warheads ; of these , 2,385 are retired and awaiting dismantlement and 3,800 are part of the U.S. stockpile . Of the stockpiled warheads , the U.S. stated in its March 2019 New START declaration that 1,365 are deployed on 656 ICBMs , SLBMs , and strategic bombers .
Little Boy was the codename for the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II . It was the first nuclear weapon used in warfare . The bomb was dropped by the Boeing B-29 Superfortress Enola Gay piloted by Colonel Paul W. Tibbets , Jr. , commander of the 509th Composite Group of the United States Army Air Forces and Captain Robert A. Lewis . It exploded with an energy of approximately 15 kilotons of TNT ( 63 TJ ) and caused widespread death and destruction throughout the city . The Hiroshima bombing was the second man-made nuclear explosion in history , after the Trinity test . Little Boy was developed by Lieutenant Commander Francis Birch 's group at the Manhattan Project 's Los Alamos Laboratory during World War II , a development of the unsuccessful Thin Man nuclear bomb . Like Thin Man , it was a gun-type fission weapon , but it derived its explosive power from the nuclear fission of uranium-235 , whereas Thin Man was based on fission of plutonium-239 . Fission was accomplished by shooting a hollow cylinder of enriched uranium ( the bullet ) onto a solid cylinder of the same material ( the target ) by means of a charge of nitrocellulose propellant powder . It contained 64 kg ( 141 lb ) of enriched uranium , although less than a kilogram underwent nuclear fission . Its components were fabricated at three different plants so that no one would have a copy of the complete design . After the war ended , it was not expected that the inefficient Little Boy design would ever again be required , and many plans and diagrams were destroyed . However , by mid-1946 , the Hanford Site reactors began suffering badly from the Wigner effect , the dislocation of atoms in a solid caused by neutron radiation , and plutonium became scarce , so six Little Boy assemblies were produced at Sandia Base .
The United States detonated two nuclear weapons over the Japanese cities of Hiroshima and Nagasaki on August 6 and 9 , 1945 , respectively , with the consent of the United Kingdom , as required by the Quebec Agreement . The two bombings killed between 129,000 and 226,000 people , most of whom were civilians , and remain the only use of nuclear weapons in armed conflict . In the final year of World War II , the Allies prepared for a very costly invasion of the Japanese mainland . This undertaking was preceded by a conventional and firebombing campaign which devastated 67 Japanese cities . The war in Europe had concluded when Germany signed its instrument of surrender on May 8 , 1945 , and the Allies turned their full attention to the Pacific theater . The Allies called for the unconditional surrender of the Imperial Japanese armed forces in the Potsdam Declaration on July 26 , 1945 , the alternative being prompt and utter destruction . Japan ignored the ultimatum and the war continued . By August 1945 , the Allies ' Manhattan Project had produced two types of atomic bombs , and the 509th Composite Group of the United States Army Air Forces ( USAAF ) was equipped with the specialized Silverplate version of the Boeing B-29 Superfortress that could deliver them from Tinian in the Mariana Islands . The Allies issued orders for atomic bombs to be used on four Japanese cities on July 25 . On August 6 , one of the modified B-29s dropped a uranium gun-type bomb ( Little Boy ) on Hiroshima . Another B-29 dropped a plutonium implosion bomb ( Fat Man ) on Nagasaki three days later . The bombs immediately devastated their targets .
Hiroshima ( 広島市 , Hiroshima-shi , /ˌhɪroʊˈʃiːmə/ , also UK : /hɪˈrɒʃɪmə/ , US : /hɪˈroʊʃɪmə/ , Japanese : [ çiɾoɕima ] ) is the capital of Hiroshima Prefecture in Japan . As of June 1 , 2019 [ update ] , the city had an estimated population of 2.089 million . The gross domestic product ( GDP ) in Greater Hiroshima , Hiroshima Urban Employment Area , was US $ 61.3 billion as of 2010 . Kazumi Matsui has been the city 's mayor since April 2011 . Hiroshima was founded in 1589 as a castle town on the Ōta River delta . Following the Meiji Restoration in 1868 , Hiroshima rapidly transformed into a major urban center and industrial hub . In 1889 , Hiroshima officially gained city status . The city was a center of military activities during the imperial era , playing significant roles such as the First Sino-Japanese War , the Russo-Japanese War , and the two world wars . Towards the end of World War II , Hiroshima is best remembered as the first city targeted by a nuclear weapon , when the United States Army Air Forces ( USAAF ) dropped an atomic bomb on the city at 8:15 a.m. on August 6 , 1945 . Most of the city was destroyed , and by the end of the year 90,000-166,000 had died as a result of the blast and its effects . The Hiroshima Peace Memorial ( a UNESCO World Heritage Site ) serves as a memorial of the bombing . Hiroshima was rebuilt after the war .
Japan ( Japanese : 日本 , Nippon [ ɲippoꜜɴ ] ( listen ) or Nihon [ ɲihoꜜɴ ] ( listen ) ) is an island country located in East Asia . It is bordered by the Sea of Japan to the west and the Pacific Ocean to the east , and spans more than 3,000 kilometers ( 1,900 mi ) along the coast of the continent from the Sea of Okhotsk in the north to the East China Sea and Philippine Sea in the south . Part of the Pacific Ring of Fire , Japan encompasses a stratovolcanic archipelago of about 6,852 islands , with five main islands ( Hokkaido , Honshu , Kyushu , Shikoku , and Okinawa ) comprising 97% of the country 's total area of 377,975 square kilometers ( 145,937 sq mi ) . Japan is officially divided into 47 prefectures and traditionally into eight regions . Approximately two-thirds of the country 's terrain is mountainous and heavily forested , and less than one-eighth of land is suitable for agriculture . Consequently , Japan is among the most densely populated and urbanized countries in the world , with over 90% of its population living in urban areas . The largest of these is the metropolitan area centered on the capital city of Tokyo , which is the most populous in the world and home to more than 38 million people . Japan itself is the world 's eleventh most populous country with a population of 126.2 million , of which 97.8% are ethnically Japanese . The kanji ( or Chinese characters ) that make up the name of Japan in the Japanese language mean sun origin ; in the Western world , the country is often known by the sobriquet Land of the Rising Sun . Periods of influence from other regions , primarily China , followed by periods of isolation , particularly from Western Europe , have characterized the history of Japan . While archaeological evidence indicates that Japan was inhabited as early as the Upper Paleolithic period , the first written mention of the archipelago appears in Chinese texts from the first century AD . Between the fourth and ninth centuries , the kingdoms of Japan became gradually unified under an Emperor and imperial court based in Heian-kyō ( modern Kyoto ) .
Fat Man was the codename for the nuclear bomb that was detonated over the Japanese city of Nagasaki by the United States on 9 August 1945 . It was the second of the only two nuclear weapons ever used in warfare , the first being Little Boy , and its detonation marked the third nuclear explosion in history . It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site , and it was dropped from the Boeing B-29 Superfortress Bockscar piloted by Major Charles Sweeney . The name Fat Man refers to the early design of the bomb because it had a wide , round shape ; it was also known as the Mark III . Fat Man was an implosion-type nuclear weapon with a solid plutonium core . The first of that type to be detonated was the Gadget in the Trinity nuclear test less than a month earlier on 16 July at the Alamogordo Bombing and Gunnery Range in New Mexico . Two more were detonated during the Operation Crossroads nuclear tests at Bikini Atoll in 1946 , and some 120 were produced between 1947 and 1949 , when it was superseded by the Mark 4 nuclear bomb . The Fat Man was retired in 1950 .
Nagasaki ( Japanese : 長崎 , Long Cape ) is the capital and the largest city of Nagasaki Prefecture on the island of Kyushu in Japan . It became the sole port used for trade with the Portuguese and Dutch during the 16th through 19th centuries and the Hidden Christian Sites in the Nagasaki Region have been recognized and included in the UNESCO World Heritage List . Part of Nagasaki was home to a major Imperial Japanese Navy base during the First Sino-Japanese War and Russo-Japanese War . During World War II , the American atomic bombings of Hiroshima and Nagasaki made Nagasaki the second and , to date , last city in the world to experience a nuclear attack ( at 11:02 am , August 9 , 1945 'Japan Standard Time ( UTC+9 ) ' ) . As of 1 June 2019 [ update ] , the city has an estimated population of 412,643 and a population density of 1,017 people per km² . The total area is 405.86 km2 ( 156.70 sq mi ) .
The RDS-1 ( Russian : РДС-1 ) , also known as Izdeliye 501 ( device 501 ) and First Lightning ( Russian : Пе́рвая мо́лния , tr . Pérvaya mólniya , IPA : [ pʲˈervəjə mˈolnʲɪjə ] ) , was the nuclear bomb used in the Soviet Union 's first nuclear weapon test . The United States assigned it the code-name Joe-1 , in reference to Joseph Stalin . It was detonated on 29 August 1949 at 7:00 a.m. , at Semipalatinsk , Kazakh SSR , after top-secret research and development as part of the Soviet atomic bomb project .
The Soviet atomic bomb project ( Russian : Советский проект атомной бомбы , Sovetskiy proyekt atomnoy bomby ) was the classified research and development program that was authorized by Joseph Stalin in the Soviet Union to develop nuclear weapons during World War II . Although the Soviet scientific community discussed the possibility of an atomic bomb throughout the 1930s , going as far as making a concrete proposal to develop such a weapon in 1940 , the full-scale program was initiated during World War II . Because of the conspicuous silence of the scientific publications on the subject of nuclear fission by German , American , and British scientists , Russian physicist Georgy Flyorov suspected that the Allied powers had secretly been developing a superweapon since 1939 . Flyorov wrote a letter to Stalin urging him to start this program in 1942.:78-79 Initial efforts were slowed due to the German invasion of the Soviet Union and remained largely composed of the intelligence knowledge gained from the Soviet spy rings working in the U.S. Manhattan Project . After Stalin learned of the atomic bombings of Hiroshima and Nagasaki , the program was pursued aggressively and accelerated through effective intelligence gathering about the German nuclear weapon project and the American Manhattan Project . The Soviet efforts also rounded up captured German scientists to join their program , and relied heavily on knowledge passed by spies to Soviet intelligence agencies . :242-243 On 29 August 1949 , the Soviet Union secretly conducted its first successful weapon test ( First Lightning , based on the American Fat Man design ) at the Semipalatinsk Test Site in Kazakhstan .
Operation Hurricane was the first test of a British atomic device . A plutonium implosion device was detonated on 3 October 1952 in the lagoon in the Monte Bello Islands in Western Australia . With the success of Operation Hurricane , Britain became the third nuclear power after the United States and the Soviet Union . During the Second World War , Britain commenced a nuclear weapons project , known as Tube Alloys , but the 1943 Quebec Agreement merged it with the American Manhattan Project . Several key British scientists worked on the Manhattan Project , but after the war the Americans ended cooperation on nuclear weapons . In January 1947 , a cabinet sub-committee decided , in response to an apprehension of American isolationism and fears of Britain losing its great power status , to resume British efforts to build nuclear weapons . The project was called High Explosive Research , and was directed by Lord Portal , with William Penney in charge of bomb design . Implicit in the decision to develop atomic bombs was the need to test them . The preferred site was the Pacific Proving Grounds in the US-controlled Marshall Islands . As a fallback , sites in Canada and Australia were considered . The Admiralty suggested that the Monte Bello Islands might be suitable , so the Prime Minister of the United Kingdom , Clement Attlee , sent a request to the Prime Minister of Australia , Robert Menzies . The Australian government formally agreed to the islands being used as a nuclear test site in May 1951 .
The United Kingdom was the third country ( after the United States and the Soviet Union ) to develop and test nuclear weapons , and is one of the five nuclear-weapon states under the Treaty on the Non-Proliferation of Nuclear Weapons . The UK initiated a nuclear weapons programme , codenamed Tube Alloys , during the Second World War . At the Quebec Conference in August 1943 , it was merged with the American Manhattan Project . The British contribution to the Manhattan Project saw British scientists participate in most of its work . The British government considered nuclear weapons to be a joint discovery , but the American Atomic Energy Act of 1946 ( McMahon Act ) restricted other countries , including the UK , from access to information about nuclear weapons . Fearing the loss of Britain 's great power status , the UK resumed its own project , now codenamed High Explosive Research . On 3 October 1952 , it detonated an atomic bomb in the Monte Bello Islands of Western Australia in Operation Hurricane . Eleven more British nuclear weapons tests in Australia were carried out over the following decade , including seven British nuclear tests at Maralinga in 1956 and 1957 . The British hydrogen bomb programme demonstrated Britain 's ability to produce thermonuclear weapons in the Operation Grapple nuclear tests in the Pacific , and led to the amendment of the McMahon Act . Since the 1958 US-UK Mutual Defence Agreement , the US and the UK have cooperated extensively on nuclear security matters . The nuclear Special Relationship between the two countries has involved the exchange of classified scientific data and fissile materials such as uranium-235 and plutonium . The UK has not had a programme to develop an independent delivery system since the cancellation of the Blue Streak in 1960 .
Ivy Mike was the codename given to the first full-scale test of a thermonuclear device , in which part of the explosive yield comes from nuclear fusion . Ivy Mike was detonated on November 1 , 1952 , by the United States on the island of Elugelab in Enewetak Atoll , in the now independent island nation of the Marshall Islands , as part of Operation Ivy . It was the first full test of the Teller-Ulam design , a staged fusion device . Due to its physical size and fusion fuel type ( cryogenic liquid deuterium ) , the Mike device was not suitable for use as a deliverable weapon . It was intended as a technically conservative proof of concept experiment to validate the concepts used for multi-megaton detonations . As a result of the collection of samples from the explosion by U.S. Air force pilots ( one of whom died ) , scientists found traces of the isotopes plutonium-246 and plutonium-244 , and confirmed the existence of the predicted but undiscovered elements einsteinium and fermium .
Nuclear weapon designs are physical , chemical , and engineering arrangements that cause the physics package of a nuclear weapon to detonate . There are three existing basic design types :
Ivy King was the largest pure-fission nuclear bomb ever tested by the United States . The bomb was tested during the Truman administration as part of Operation Ivy . This series of tests involved the development of very powerful nuclear weapons in response to the nuclear weapons program of the Soviet Union . The production of Ivy King was hurried to be ready in case its sister project , Ivy Mike , failed in its attempt to achieve a thermonuclear reaction . The Ivy King test actually took place two weeks after Mike . Unlike the Mike bomb , the Ivy King device could theoretically have been added to United States ' nuclear arsenal because it was designed to be air-deliverable .
Joe 4 ( warhead name : RDS-6s ( Reaktivnyi Dvigatel Specialnyi ; Special Jet Engine ) ) was an American nickname for the first Soviet test of a thermonuclear weapon on August 12 , 1953 , that detonated with a force equivalent to 400 kilotons of TNT . Scholars dispute the authenticity of RDS-6 as a thermonuclear device as it did not manage to produce a yield consistent with a true hydrogen bomb . It utilized a scheme in which fission and fusion fuel ( lithium-6 deuteride ) were layered , a design known as the Sloika ( Russian : Слойка , named after a type of layered puff pastry ) model in the Soviet Union . A ten-fold increase in explosive power was achieved by a combination of fusion energy and neutron-initiated ( boosted ) fission . A similar design was earlier theorized by Edward Teller , but never tested in the U.S. , as the Alarm Clock .
Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll , Marshall Islands , as part of Operation Castle . Detonated on March 1 , 1954 , the device was the most powerful nuclear device detonated by the United States and its first lithium deuteride fueled thermonuclear weapon . Castle Bravo 's yield was 15 megatons of TNT , 2.5 times the predicted 6.0 megatons , due to unforeseen additional reactions involving 7Li , which led to the unexpected radioactive contamination of areas to the east of Bikini Atoll . At the time , it was the most powerful artificial explosion in history . Fallout , the most heavy of which in the form of pulverized surface coral from the detonation fell on residents of Rongelap and Utirik atolls , while the more particulate and gaseous fallout spread around the world . The inhabitants of the islands were not evacuated until three days later and suffered radiation sickness . Twenty-three crew members of the Japanese fishing vessel Daigo Fukuryū Maru ( Lucky Dragon No . 5 ) were also contaminated by the heavy fallout , experiencing acute radiation syndrome . The blast incited international reaction over atmospheric thermonuclear testing . The Bravo Crater is located at 11°41′50″N 165°16′19″E / 11.69722°N 165.27194°E / 11.69722 ; 165.27194 . The remains of the Castle Bravo causeway are at 11°42′6″N 165°17′7″E / 11.70167°N 165.28528°E / 11.70167 ; 165.28528 .
Nuclear fallout , or fallout , is the residual radioactive material propelled into the upper atmosphere following a nuclear blast , so called because it falls out of the sky after the explosion and the shock wave have passed . It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes . The amount and spread of fallout is a product of the size of the weapon and the altitude at which it is detonated . Fallout may get entrained with the products of a pyrocumulus cloud and fall as black rain ( rain darkened by soot and other particulates , which fell within 30-40 minutes of the Atomic bombings of Hiroshima and Nagasaki ) . This radioactive dust , usually consisting of fission products mixed with bystanding atoms that are neutron-activated by exposure , is a form of radioactive contamination .
RDS-37 was the Soviet Union 's first two-stage hydrogen bomb , first tested on 22 November 1955 . The weapon had a nominal yield of approximately 3 megatons . It was scaled down to 1.6 megatons for the live test .
Orange Herald was a British nuclear weapon , tested on 31 May 1957 . At the time it was reported as a H-bomb , although in fact it was a large boosted fission weapon .
Operation Grapple was the name of four series of British nuclear weapons tests of early atomic bombs and hydrogen bombs carried out in 1957 and 1958 at Malden Island and Kiritimati ( Christmas Island ) in the Pacific Ocean as part of the British hydrogen bomb programme . Nine nuclear explosions were initiated , culminating in the United Kingdom becoming the third recognised possessor of thermonuclear weapons , and the restoration of the nuclear Special Relationship with the United States with the 1958 US-UK Mutual Defence Agreement . During the Second World War , Britain had a nuclear weapons project , codenamed Tube Alloys , which was merged with the American Manhattan Project in August 1943 . Many of Britain 's top scientists participated in the British contribution to the Manhattan Project . After the war , fearing that Britain would lose its great power status , the British government resumed the atomic bomb development effort , now codenamed High Explosive Research . The successful test of an atomic bomb in Operation Hurricane in October 1952 represented an extraordinary scientific and technological achievement , but Britain was still several years behind the United States in nuclear weapons technology . In July 1954 , the Cabinet decided to develop the hydrogen bomb . The United Kingdom Atomic Energy Authority Atomic Weapons Research Establishment at Aldermaston produced three designs : Orange Herald , a large boosted fission weapon ; Green Bamboo , an interim thermonuclear design ; and Green Granite , a true thermonuclear weapon . The first test series consisted of three tests in May and June 1957 . In the first , Grapple 1 , a version of Green Granite known as Short Granite was dropped from a Vickers Valiant bomber flown by Wing Commander Kenneth Hubbard . The bomb 's yield was estimated at 300 kilotonnes of TNT ( 1,300 TJ ) , far below its designed capability . Despite its failure , the test was hailed as a successful thermonuclear explosion , and the government did not confirm or deny reports that the UK had become a third thermonuclear power .
Gerboise Bleue ( French : [ ʒɛʁbwaz blø ] , blue jerboa ) was the name of the first French nuclear test . It was an atomic bomb detonated near Reggane , in the middle of the Algerian Sahara desert on 13 February 1960 , during the Algerian War ( 1954-62 ) . General Pierre Marie Gallois was instrumental in the endeavour , and earned the nickname of père de la bombe A ( father of the A-bomb ) . Gerboise is the French word for jerboa , a desert rodent found in the Sahara . The following three bombs detonated near Reggane were named respectively white ( Gerboise Blanche ) , red ( Gerboise Rouge ) , and green ( Gerboise Verte ) .
France is one of the five Nuclear Weapons States under the Treaty on the Non-Proliferation of Nuclear Weapons , but is not known to possess or develop any chemical or biological weapons . France was the fourth country to test an independently developed nuclear weapon in 1960 , under the government of Charles de Gaulle . The French military is currently thought to retain a weapons stockpile of around 300 operational ( deployed ) nuclear warheads , making it the third-largest in the world , speaking in terms of warheads , not megatons . The weapons are part of the national Force de frappe , developed in the late 1950s and 1960s to give France the ability to distance itself from NATO while having a means of nuclear deterrence under sovereign control . France did not sign the Partial Nuclear Test Ban Treaty , which gave it the option to conduct further nuclear tests until it signed and ratified the Comprehensive Nuclear-Test-Ban Treaty in 1996 and 1998 respectively . France denies currently having chemical weapons , ratified the Chemical Weapons Convention ( CWC ) in 1995 , and acceded to the Biological Weapons Convention ( BWC ) in 1984 . France had also ratified the Geneva Protocol in 1926 .
Many codenames are attributed to the Tsar Bomba : Project 7000 ; product code 202 ( Izdeliye 202 ) , Product V ( izdeliye V ) ; article designations RDS-220 ( РДС-220 ) , RDS-202 ( РДС-202 ) , RN202 ( PH202 , incorrect codename as the AN602 is a modification of the RN202 ) , AN602 ( AH602 ) ; codename Vanya ; nicknames Big Ivan , Kuzkina mat . The name Tsar Bomba was coined in an analogy with other large Russian objects : the Tsar Bell and Tsar Cannon . The CIA designated the test as JOE 111 . The bomb was also referred to as Kuzma 's mother ( Russian : Ку́зькина ма́ть , tr . Kúz'kina mát ' , IPA : [ ˈkusʲkʲɪnə ˈmatʲ ] ) , possibly referring to First secretary Nikita Khrushchev 's promise to show the United States a Kuzma 's mother ( an idiom roughly translating to We 'll show you ) at a 1960 session of the United Nations General Assembly .
Project 596 , originally named Chic-1 by the US intelligence agencies , was the first nuclear weapons test conducted by the People 's Republic of China , detonated on 16 October 1964 , at the Lop Nur test site . It was a uranium-235 implosion fission device made from weapons-grade uranium ( U-235 ) enriched in a gaseous diffusion plant in Lanzhou . The bomb had a yield of 22 kilotons , comparable to the Soviet Union 's first nuclear bomb RDS-1 in 1949 and the American Fat Man bomb dropped on Nagasaki , Japan in 1945 . With the test , China became the fifth nuclear power . This was the first of 45 successful nuclear tests China conducted between 1964 and 1996 , all of which occurred at the Lop Nur test site .
The People 's Republic of China has developed and possesses weapons of mass destruction , including chemical and nuclear weapons . The first of China 's nuclear weapons tests took place in 1964 , and its first hydrogen bomb test occurred in 1967 . Tests continued until 1996 , when China signed the Comprehensive Test Ban Treaty ( CTBT ) . China has acceded to the Biological and Toxin Weapons Convention ( BWC ) in 1984 and ratified the Chemical Weapons Convention ( CWC ) in 1997 . The number of nuclear warheads in China 's arsenal is a state secret . There are varying estimates of the size of China 's arsenal . China is estimated by the Federation of American Scientists to have an arsenal of about 260 total warheads as of 2015 , which would make it the second smallest nuclear arsenal amongst the five nuclear weapon states acknowledged by the Treaty on the Non-Proliferation of Nuclear Weapons . According to some estimates , the country could more than double the number of warheads on missiles that could threaten the United States by the mid-2020 's . Early in 2011 , China published a defense white paper , which repeated its nuclear policies of maintaining a minimum deterrent with a no-first-use pledge . Yet China has yet to define what it means by a minimum deterrent posture . This , together with the fact that it is deploying four new nuclear-capable ballistic missiles , invites concern as to the scale and intention of Chinas nuclear upgrade .
Test No . 6 is the codename for China 's first test of a three-staged thermonuclear device and , also its sixth nuclear weapons test .
Canopus ( also Opération Canopus in French ) was the code name for France 's first two-stage thermonuclear test , conducted on August 24 , 1968 , at Fangataufa atoll . The test made France the fifth country to test a thermonuclear device after the United States , the Soviet Union , the United Kingdom and China .
Smiling Buddha [ a ] ( MEA designation : Pokhran-I ) was the assigned code name of India 's first successful nuclear bomb test on 18 May 1974 . The bomb was detonated on the army base Pokhran Test Range ( PTR ) , in Rajasthan , by the Indian Army under the supervision of several key Indian generals . Pokhran-I was also the first confirmed nuclear weapons test by a nation outside the five permanent members of the United Nations Security Council . Officially , the Indian Ministry of External Affairs ( MEA ) characterised this test as a peaceful nuclear explosion . A series of nuclear tests was carried out in 1998 under the name Pokhran-II .
India has developed and possesses weapons of mass destruction in the form of nuclear weapons . Although India has not made any official statements about the size of its nuclear arsenal , recent estimates suggest that India has 130-140 nuclear weapons and has produced enough weapons-grade plutonium for up to 150-200 nuclear weapons . In 1999 , India was estimated to have 800 kg of separated reactor-grade plutonium , with a total amount of 8,300 kg of civilian plutonium , enough for approximately 1,000 nuclear weapons . India is a member of three multilateral export control regimes - the Missile Technology Control Regime , Wassenaar Arrangement and Australia Group . It has signed and ratified the Biological Weapons Convention and the Chemical Weapons Convention . India is also a subscribing state to the Hague Code of Conduct . India has signed neither the Comprehensive Nuclear-Test-Ban Treaty nor the Nuclear Non-Proliferation Treaty , considering both to be flawed and discriminatory . India previously possessed chemical weapons , but voluntarily destroyed its entire stockpile in 2009 - one of the seven countries to meet the OPCW extended deadline . India maintains a no first use nuclear policy and has developed a nuclear triad capability as a part of its minimum credible deterrence doctrine .
The Pokhran-II tests were a series of five nuclear bomb test explosions conducted by India at the Indian Army 's Pokhran Test Range in May 1998 . It was the second instance of nuclear testing conducted by India ; the first test , code-named Smiling Buddha , was conducted in May 1974 . The tests achieved their main objective of giving India the capability to build fission and thermonuclear weapons with yields up to 200 Kilotons . The then Chairman of the Indian Atomic Energy Commission described each one of the explosions of Pokhran-II to be equivalent to several tests carried out by other nuclear weapon states over decades . Subsequently , India established computer simulation capability to predict the yields of nuclear explosives whose designs are related to the designs of explosives used in this test . Pokhran-II consisted of five detonations , the first of which was a fusion bomb while the remaining four were fission bombs . The tests were initiated on 11 May 1998 , under the assigned code name Operation Shakti , with the detonation of one fusion and two fission bombs . On 13 May 1998 , two additional fission devices were detonated , and the Indian government led by Prime Minister Atal Bihari Vajpayee shortly convened a press conference to declare India a full-fledged nuclear state . The tests resulted in a variety of sanctions against India by a number of major states , including Japan and the United States . Many names have been assigned to these tests ; originally these were collectively called Operation Shakti-98 , and the five nuclear bombs were designated Shakti-I through to Shakti-V. More recently , the operation as a whole has come to be known as Pokhran II , and the 1974 explosion as Pokhran-I .
Chagai-I is the code name of five simultaneous underground nuclear tests conducted by Pakistan at 15:15 hrs PST on 28 May 1998.:281 The tests were performed at Ras Koh Hills in the Chagai District of Balochistan Province . Chagai-I was Pakistan 's first public test of nuclear weapons . Its timing was a direct response to India 's second nuclear tests , on 11 and 13 May 1998 . These tests by Pakistan and India resulted in United Nations Security Council Resolution 1172 and economic sanctions on both states by a number of major powers , particularly the United States and Japan [ clarification needed ] . By testing nuclear devices , Pakistan became the seventh nation to publicly test nuclear weapons . :14-15 Pakistan 's second nuclear test , Chagai-II , followed on 30 May 1998 .
Pakistan is one of nine states to possess nuclear weapons . Pakistan began development of nuclear weapons in January 1972 under Prime Minister Zulfikar Ali Bhutto , who delegated the program to the Chairman of the Pakistan Atomic Energy Commission ( PAEC ) Munir Ahmad Khan with a commitment to having the bomb ready by the end of 1976 . Since PAEC , consisting of over twenty laboratories and projects under nuclear engineer Munir Ahmad Khan , was falling behind schedule and having considerable difficulty producing fissile material , Abdul Qadeer Khan was brought from Europe by Bhutto at the end of 1974 . As pointed out by Houston Wood , Professor of Mechanical & Aerospace Engineering , University of Virginia , Charlottesville , in his article on gas centrifuges , The most difficult step in building a nuclear weapon is the production of fissile material ; as such , this work in producing fissile material as head of the Kahuta Project was pivotal to Pakistan developing the capability to detonate a nuclear bomb by the end of 1984 . The Kahuta Project started under the supervision of a coordination board that oversaw the activities of KRL and PAEC . The Board consisted of A G N Kazi ( secretary general , finance ) , Ghulam Ishaq Khan ( secretary general , defence ) , and Agha Shahi ( secretary general , foreign affairs ) , and reported directly to Bhutto . Ghulam Ishaq Khan and General Tikka Khan appointed military engineer Major General Ali Nawab to the program . Eventually , the supervision passed to Lt General Zahid Ali Akbar Khan in President General Muhammad Zia-ul-Haq 's Administration . Moderate uranium enrichment for the production of fissile material was achieved at KRL by April 1978 . Pakistan 's nuclear weapons development was in response to the loss of East Pakistan in 1971 's Bangladesh Liberation War . Bhutto called a meeting of senior scientists and engineers on 20 January 1972 , in Multan , which came to known as Multan meeting . Bhutto was the main architect of this programme , and it was here that Bhutto orchestrated the nuclear weapons programme and rallied Pakistan 's academic scientists to build an atomic bomb in three years for national survival .