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🏛 | Japan-US-Korea, cooperation with North Korea Three-country summit meeting for the first time in about five years

Photo Attending the Japan-US-Korea Summit (from right) Prime Minister Kishida, US President Joe Biden, South Korean President Yoon Seok-you = 29th, Madrid, Spain (Reuters = joint)

Japan-US-Korea, cooperation with North Korea Three-country summit meeting for the first time in about five years

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The prime minister said, "There are serious concerns about the possibility of provocation by North Korea, including a nuclear test.

[Madrid joint] Prime Minister Fumio Kishida attended the Japan-US-Korea summit meeting in Spain on the afternoon of the 29th (the same night of Japan time).Northern Court ... → Continue reading

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Nuclear test

Nuclear testWhat is (Nuclear weapons testing)?Nuclear bombIt refers to the experimental detonation of a nuclear bomb in order to confirm the new development and performance maintenance of the, and to establish the maintenance technology.

Between 1945 and about half a century, 2379 nuclear tests (including 502 in the atmosphere) were conducted in each country.That energy isTNT equivalentAt 530 megatons (440 megatons in the atmosphere), which was dropped on HiroshimaLittle boy(TNT equivalentEquivalent to more than 15 shots of 3kt)[1].

Types of nuclear tests

Nuclear tests are classified into four types according to the location and altitude at which they were conducted.

1. Atmospheric nuclear experiment
Nuclear tests conducted on the ground, at sea, and in the air.The experimental method is on the ridge,balloon, Ships, remote islands, and drops from aircraft are used.Also, although the number is small,High altitude nuclear explosionExperimentrocketIs done by.A nuclear explosion near the ground caused sediment and dustMushroom cloudRolled up by a large amountFalloutWill occur.It is also powerful in a nuclear explosion at high altitude.Electromagnetic pulseCauses serious damage to peripheral electronic devices.

2. Underground nuclear test
It is a nuclear test conducted at various depths below the surface of the earth.The experimental method was established in the United States and the Soviet Union during the Cold War, but methods other than this experiment were concluded in 1963.Partial Nuclear Test Ban Treaty Banned by (PTBT).If the nuclear explosion converges completely underground, little fallout will occur.However, if an explosion causes a hole in the ground, a large amount of fallout will be generated from it.In the underground nuclear test, thatNuclear outputAnd according to the structure of the bombSeismic waveOccurs, but in many cases due to the depression of the crustcraterIs also generated. In 1974, the maximum nuclear output of underground nuclear tests will be 150 kilotons.Underground Nuclear Test Ban Treaty (TTBT) has been signed between the United States and the Soviet Union.

3. Out-of-atmosphere experiment
It is a nuclear test conducted outside the atmosphere, and a rocket is used to carry it out.The purpose of this experiment was mainly fired from enemy nations.ICBMIt is a verification of intercepting the satellite outside the atmosphere and destroying the satellites of the enemy country (mainly spy satellites).However, since there is no atmosphere in space and the target cannot be destroyed by the shock wave of a nuclear explosion, the target can be achieved by physically destroying the target by heat rays and radiation due to a nuclear explosion at a short distance and by electromagnetic pulse. "Electronic" destruction (incapacity) is required.However, the electromagnetic pulse generated by a nuclear explosion affects electronic devices on the ground, and the physical destruction of the target has become a particular problem in recent years.Space debrisThe experiment was banned by PTBT because of the large amount of PTBT.

4. Underwater nuclear experiment
It is a nuclear test conducted under the surface of the water, and it is carried out by ships andbarge(These are destroyed by the explosion during the experiment) is used.The purpose of this experiment is the effect of an underwater nuclear explosion on a ship (Crossroads OperationEtc.) and weapons for ships (Thunder,torpedo) Is to verify the diversion of nuclear weapons.However, a nuclear explosion near sea level diffuses large amounts of radioactive water and steam, contaminating nearby ships and buildings.

Historically important nuclear test

The following is a list of historically important nuclear tests.In addition to the atomic bomb drops in Hiroshima and Nagasaki, it includes the country's first nuclear test of a given weapon, or a prominent one, for example, the largest nuclear test to date.AllNuclear output(Explosive power) is equivalent to estimated energyTNTGiven by the mass (kt) of.

"Practical / non-practical weapons" in the table means whether the tested device could be used as a hypothesis in actual combat (as opposed to a theoretical demonstration device).

Early experimental nuclear bombs, such as those surrounded by large-scale equipment to cause a nuclear explosion, are not practical weapons. "Multi-stage / non-multi-stage" means whether it was a true hydrogen bomb of the so-called Teller-Ulam composition, or simply in the form of an amplified fission weapon.

Incidentally,Tsar Bomba1998Accurate estimates of nuclear power in some nuclear tests, such as those in India and Pakistan, have been controversial with experts.

Nuclear tests are not limited to military and scientific tests, and often play a role in political propaganda.

Nuclear explosions and tests of high historical importance
dateName (experimental name)Nuclear output (kt)Country of implementationImportance
19457/16Gadget(Trinity experiment19United States flag The United States of AmericaFirst in human historyAtomic bombExperiment
19458/6Little boy15United States flag The United States of AmericaFirst practical use in human history (Atomic bomb dropped on Hiroshima city
19458/9Fat man21United States flag The United States of AmericaMost recent actual battle use (Atomic bomb dropped on Nagasaki city
19498/29RDS-1(Joe 1)22Soviet Union flag Soviet UnionFirst by the Soviet UnionAtomic bomb
195210/3Hurricane25British flag United KingdomFirst by the UKAtomic bomb
195211/1Ivy Mike10,400United States flag The United States of AmericaFirst multi-stage thermonuclear reaction weapon experiment in human history (impractical weapon)
19538/12RDS-6(Joe 4)400Soviet Union flag Soviet UnionFirst by the Soviet UnionHydrogen bomb(Non-multistage, practical weapon)
19543/1Castle Bravo15,000United States flag The United States of AmericaHydrogen bomb(First multi-stage, practical weapon in human history),Falloutaccident(Daifuku RyumaruIs exposed to radiation)
195511/22RDS-371,600Soviet Union flag Soviet UnionHydrogen bomb(First multi-stage, practical weapon by the Soviet Union)
195711/8Grapple X1,800British flag United KingdomHydrogen bomb(First successful multi-stage by the UK)
19602/13Gerboise Bleue70French flag FranceFirst by FranceAtomic bomb
196110/31Tsar Bomba50,000Soviet Union flag Soviet UnionThe largest in human historyHydrogen bombExperiment (Originally limited to 100 megatons to 50 megatons)
196410/1659622Flag of the People's Republic of China ChugokuFirst by ChinaAtomic bombExperiment
19676/17Experiment No. 63,300Flag of the People's Republic of China ChugokuFirst by ChinaHydrogen bombExperiment
19688/24Canopus2,600French flag FranceFirst by FranceHydrogen bombExperiment
19745/18Smile Buddha12Indian flag IndiaFirst fission explosion experiment by India
19985/11Shakti I43Indian flag IndiaFirst experiment by India (exact nuclear output is discussed between 25 kt-45 kt)
19985/11Shakti II12Indian flag IndiaFirst by IndiaAtomic bombExperiment
19985/28Chagai-I9-12?Pakistan flag PakistanFirst by PakistanAtomic bombExperiment
200610/9North Korea nuclear test (2006)1.5-15?Democratic People's Republic of Korea flag north koreaFirst by North KoreaAtomic bombExperiment
201011/18?United States flag The United States of America"By the United States"Z machineThe first subcritical nuclear test using a device called "", 2014 experiments have been repeated for this Z machine until November 11.
20132/12North Korea nuclear test (2013)10-45?Democratic People's Republic of Korea flag north koreaFirst by North KoreaBoosted Atomic Bombexperiment?
20161/6North Korea nuclear test (September 2016)10?Democratic People's Republic of Korea flag north koreaFirst by North KoreaHydrogen bombExperiment (some are skeptical)

Nuclear tests in each country

Number of nuclear tests around the world 1945-2014

The United States of America

Nuclear test in New Mexico

19457/16ToThe United States of America Manhattan planThe first nuclear test in human history (Trinity experiment) Then dropped on NagasakiFat manThe same type of plutonium implosion type atomic bomb (Gadget)New mexicoAlamogordoIt exploded at the experimental site in.

  • A vitreous green ore (a vitreous green ore that melts and becomes liquid and accumulates in the desert sand that was blown up into the fireball by the explosion.Trinitite) Was generated and still carries a medium level of radioactivity.Mostly1952It has been reclaimed in Japan and is prohibited from being taken out.
  • Even now, more than 50 years after the experiment, residual radiation about 10 times that of the normal environment is detected at the site of the experimental site.

Nuclear test in Marshall Islands

19467/1Japan under US military occupationMandateIsマ ー ャ ル ル OfBikini atollConducted a nuclear test at, and continued the nuclear test even after becoming an American territory in 1947.Enewetak Atoll67 nuclear tests were conducted in total.[2][3].

1946January,Atomic bombExperimentCrossroads OperationThen,Japan OfBattleship NagatoApproximately 70 ships were gathered as targets, and the effects were measured by attacking them with an atomic bomb. The first time7/1Experimented (Able), and the second time (Baker)7/25Was done in.

after that,Pacific Proving GroundsDesignated as19543/1At Bikini AtollHydrogen bombExperiment (Castle operationIn), the experimental plan estimated that the explosive power was several Mt class, but in reality it had an explosive power of 15 Mt, so it was wider than expected.FalloutSpread and caused a large number of exposed people.

  • Bikini atollIslanders are forcedRongerik AtollI was relocated to the island and have not been able to return to the island until now.
  • JapanTuna fishing boatDaifuku RyumaruHundreds to thousands of fishing vessels were exposed to fallout.
  • 240km awayRongelap AtollFallout also fell, and all residents were evacuated three days after the experiment.
  • Although 80% of the area of ​​Bikini Atoll has been restored, 28 species of coral have been extinct in the atomic bomb test.

Nuclear test in Nevada

Experiments in the South Pacific are expensive, soTrumanAt the president's suggestion1951Toネ バ ダ 州In the desertNevada National Security Site (NTS, Nevada Test Site) was set up.After that, 928 experiments were conducted to measure fallout (radioactive fallout) and to investigate the effects on buildings and animals, including above and below ground.

The vibration of the nuclear testLas VegasBecause it affected the buildingNuclear outputAs a preliminary step to the 5Mt explosion experiment19681/19130km north of Las VegasTonopahA 1Mt underground experiment "FAULTLESS" was conducted in the suburbs.This isMainland usaIt was the largest nuclear explosion that took place in.As a result, it is big on the ground due to impactFaultBecause of the completion of the experiment, we decided not to conduct the experiment on the mainland, and the 5Mt experiment was conducted.Alaska OfAmchitka IslandIt was decided to do it at.

19977/2 First in the underground laboratorySubcritical nuclear testWas done.

  • There is a documentary that many people are dying from cancer due to the radiation of 928 repeated nuclear tests.[4].

Nuclear test in New Mexico

2010/11/18 Z machine(Sandia National Laboratories) CalledNuclear fusionExperimental device/X-rayUsing a generator, we have succeeded in a "new nuclear test" that does not involve a nuclear explosion (this test is called a new nuclear test in the mass media to distinguish it from the subcritical nuclear test).This is an experiment in which intense X-rays are generated, a situation similar to an ultra-high temperature and ultra-high voltage nuclear explosion is reproduced, and the reaction of plutonium is observed.This experiment has continued until November 2014 and has been conducted 11 times in total.[5][6].

Nuclear test on Amchitka Island

Other nuclear tests

19555/14 Operation Wigwam CaliforniaSan Diego500 miles southwest,Nuclear lightningAn experiment aimed at verifying. 1961から1973Up to shock wave measurementNatural gasSmall-scale (less than 150kt) atomic bomb tests were conducted in various parts of the United States for peaceful use experiments such as mining (Plowshare Project,Operation Plowshare).


SemipalatinskNuclear test at
  • 19498/29 The first atomic bomb test (Nagasaki type). 22kt.Codename"RDS-1". American codename" Joe (=Stalin) -1 ".
  • 19538/12 The "first" hydrogen bomb experiment. 400kt.Codename "RDS-6". American codename" Joe 4 ".
It is said that it was not fusion from the analysis of radioactive fallout.
  • 195511/22 Hydrogen bomb experiment. 1.6Mt.Codename "RDS-37". American codename" Joe 19 ".
The first successful hydrogen bomb experiment in the Soviet Union.
Nuclear test at Novaya Zemlya

United Kingdom

Montebello IslandsBetween Western Australia and Western Australiacoral reef(Australia) Nuclear test.
  • October 1952, 10 The first atomic bomb test.Code nameHurricane.
Nuclear test in (Australia)

Conducted in 1953

MaralingaNuclear test in (Australia)

1957ToOperation AntlerHas been conducted, and three experiments have been conducted.

Christmas IslandNuclear test at

19575/15 The first hydrogen bomb experiment.


SaharaNuclear test at

19602/13 First atomic bomb test (Gerboise Bleue).IsraelScientist is present.Virtually a joint experiment with Israel.

19688/24 The first hydrogen bomb experiment.

French polynesiaNuclear test at.

1966から1996Conducted about 1 times by January.

People's Republic of China



  • 19985/28-30 days The first atomic bomb test in Japan. The May 5 atomic bomb test was found to be plutonium-type, and is likely to be a North Korean surrogate nuclear test.[7].

DPR Korea

  • 1986In March, an American reconnaissance satellite has a North Korean nuclear facilityNyongbyonI found some cylindrical craters showing traces of high-performance explosion experiments.
  • 200610/9 Hamambuk ExpresswayKichishuToyokeriThe first nuclear test in.
  • 20095/25 The second nuclear test at Punggye-ri, Kilju-gun, North Hamgyong Province.
  • 20132/12 Third nuclear test at Punggye-ri, Kilju-gun, North Hamgyong Province[8].
  • 20161/6 The first hydrogen bomb experiment in Punggye-ri, Kilju-gun, North Hamgyong Province.However, there are many suspicious views about the hydrogen bomb in this experiment.
  • 20169/9 5th nuclear test.
  • 20179/3 Sixth nuclear test.North Korea claims "hydrogen bomb test"[9][10].

Detection of nuclear tests

East and westCold WarInside,The United States of AmericaAround the world for the purpose of detecting underground nuclear testsSeismographWas installed.MainlySoviet UnionCaused by the underground nuclear test conducted bySeismic waveI caught.On the other hand, the countries conducting nuclear tests also conducted clever nuclear tests to make them look like natural earthquakes.For example, arrange bombs and explode them in order in a short time.FaultThey pretended to be destroyed, or exploded two bombs in quick succession to generate waves similar to the pP waves peculiar to natural earthquakes.

Seismometers installed in this way are now being used extensively in the field of pure seismology (for example).Seismic tomography).

The details of nuclear test detection by seismographs are described in Bruce A. Bolt's "Underground Nuclear Test Detection".

Prohibition of nuclear test

Nuclear tests conducted in the atmosphere are conducted in the atmosphereRadioactive materialWill be scattered, and an international treaty will be signed to ban this.1963To limit nuclear tests to undergroundTreaty banning nuclear weapons tests in the atmosphere, outer space and underwaterThe Partial Test Ban Treaty (PTBT) was signed and came into effect during the same year.The treaty has been signed by more than 100 countries and has been ratified by the United States and the Soviet Union.France and the People's Republic of China have not signed, but later canceled the atmospheric nuclear test. The PTBT itself does not limit the scale or number of experiments.The United States and the Soviet Union in 1974Underground Nuclear Test Ban Treaty(TTBT) was signed, and in 1976, the Peace Purpose Underground Nuclear Explosion Restriction Treaty was signed, and it was agreed to limit the nuclear output in underground nuclear tests to 150 kt and mutually verify, but these treaties came into effect during the Cold War. It was delayed until 1990 after the end.

Underground nuclear tests are also prohibitedComprehensive Nuclear Test Ban Treaty (CTBT) was proposed and signed in 1996.The treaty has not been ratified in all 44 specific countries that are conditions for entry into force, and is not a valid treaty as of 2011.Also, subcritical nuclear tests are not prohibited by his CTBT.

Effect of radioactivity

A large amount by nuclear testRadioactive materialBut,Fallout(So-called "fallout" / "black Rain”), It causes air pollution, soil pollution, marine pollution, and biological pollution by spreading over a wide area.Therefore, there are various short-term and long-term effects.

  • Northern part since nuclear tests began大西洋Even in the middle layerRadioisotopeThe ratio is rising.This is because the radioactive elements scattered on the surface of the oceanOcean general circulationThis is because it sank.
  • In a nuclear testRadioisotope OfCarbon-14Was sprayed into the atmosphereRadiocarbon datingDating by law can no longer be used with conventional procedures as dating to identify after around 1950.


[How to use footnotes]
  1. ^ United Nations Scientific CommitteeUNSCEAR Annex BView page 255 2011-7-17
  2. ^ Country name: Republic of the Marshall Islands Ministry of Foreign Affairs
  3. ^ Islanders Want The Truth About Bikini Nuclear Test International Herald Tribune / Asahi Shimbun, March 2, 2004. Posted at Japan Focus on March 3, 2004
  4. ^ Hirose Takashi"Why John Wayne Died" Bungei Shunju, Revised Edition (1988January),ISBN-978 4163424903
  5. ^ Z-Machine Nuclear Tests and Subcritical Tests Conducted by the United States-Nagasaki University Research Center for Nuclear Weapons Abolition (RECNA)
  6. ^ US, new nuclear test plutonium small amount used "complementing subcritical",Chinese newspaper,20115/24,20129/20Browse
  7. ^ Pakistan May Have Aided North Korea A-Test New York TIMES 2004-2-27
  8. ^ North Korea Forces Nuclear Test Announced through Korean Central News Agency Sankei Shimbun Read April 2013, 2
  9. ^ North reports "complete success" in hydrogen bomb experiment "total war to complete nuclear force" Sankei Shimbun Read April 2017, 9
  10. ^ Completely successful in an intercontinental ballistic rocket mounting hydrogen bomb experiment Korean Central News Agency, viewed September 2017, 9

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