Japanese atomic program
Encyclopedia
The Japan
ese program to develop nuclear weapon
s was conducted during World War II
. Like the German nuclear weapons program
, it suffered from an array of problems, and was ultimately unable to progress beyond the laboratory stage before the atomic bombings of Hiroshima and Nagasaki
and the Japanese surrender in August 1945.
Today, Japan's nuclear energy infrastructure makes it eminently capable of constructing nuclear weapons at will. The de-militarization of Japan and the protection of the United States
' nuclear umbrella
have led to a strong policy of non-weaponization of nuclear technology, but in the face of nuclear weapons testing by North Korea
, some politicians and former military officials in Japan are calling for a reversal of this policy.
professor Hikosaka Tadayoshi's "atomic physics theory" was released. Hikosaka pointed out the huge energy contained by nuclei and the possibility that both nuclear power generation and weapons could be created.
In December 1938, the German chemists Otto Hahn
and Fritz Strassmann
sent a manuscript to Naturwissenschaften
reporting that they had detected the element barium
after bombarding uranium
with neutrons; simultaneously, they communicated these results to Lise Meitner
. Meitner, and her nephew Otto Robert Frisch
, correctly interpreted these results as being nuclear fission and Frisch confirmed this experimentally on 13 January 1939. Physicists around the world immediately realized that chain reactions could be produced and notified their governments of the possibility of developing nuclear weapons.
, a friend of Niels Bohr
and a close associate of Albert Einstein
. Dr. Nishina was a highly skilled world class physicist with excellent leadership qualities, who co-authored the Klein-Nishina Formula
. Nishina had established his own Nuclear Research Laboratory to study high-energy physics
in 1931 at Riken Institute
(the Institute for Physical and Chemical Research), which had been established in 1917 in Tokyo to promote basic research. Nishina had built his first 26 inch cyclotron
in 1936, and another 60 inch 220 ton cyclotron in 1937. In 1938 Japan also purchased a cyclotron from the University of California, Berkeley
.
In 1939 Nishina recognized the military potential of nuclear fission, and was worried that the Americans were working on a nuclear weapon which might be used against Japan. Indeed, in 1939, President Franklin D. Roosevelt
started the first investigations into fission weapons in the United States
, which eventually evolved into the massive Manhattan Project
, and the laboratory from which Japan purchased its own cyclotron would become one of the major sites for weapons research.
In the early summer of 1940 Nishina met Lieutenant-General Takeo Yasuda
on a train. Yasuda was at the time director of the Army Aeronautical Department's Technical Research Institute. Nishina told Yasuda about the possibility of building nuclear weapons. However, the Japanese fission project did not formally begin until April 1941 when Yasuda acted on Army Minister Hideki Tojo
's order to investigate the possibilities of nuclear weapons. Yasuda passed the order down the chain of command to Okochi Masatoshi, director of the Riken Institute, who in turn passed it to Nishina, whose Nuclear Research Laboratory by 1941 had over 100 researchers.
Meanwhile, the Imperial Japanese Navy's Technology Research Institute had been pursuing its own separate investigations, and had engaged professors from the Imperial University, Tokyo, for advice on nuclear weapons. This resulted in the formation of the Committee on Research in the Application of Nuclear Physics, chaired by Nishina, that met ten times between July 1942 and March 1943. It concluded in a report that while an atomic bomb was, in principle, feasible, "it would probably be difficult even for the United States to realize the application of atomic power during the war". This caused the Navy to lose interest and to concentrate instead on research into radar.
, and centrifugal separation
. By February 1945, a small group of scientists had succeeded in producing a small amount of material in a rudimentary separator in the Riken complex - material which Riken's cyclotron indicated was not Uranium-235. The separator project came to an end two months later when the building housing it was destroyed in a fire caused by an air raid on Tokyo. No attempt was made to build a uranium pile; heavy water
was unavailable, but Takeuchi Masa, who was in charge of Nishina's separator, calculated that light water would suffice if the uranium could be enriched to 5-10% Uranium-235.
While these experiments were in progress, the Army and Navy carried out searches for uranium ore, in locations ranging from Fukushima Prefecture
to Korea, China, and Burma. The Japanese also requested materials from their German allies and 560 kg (1,234.6 lb) of unprocessed uranium oxide was dispatched to Japan in April 1945 aboard the submarine U-234, which however surrendered to US forces in the Atlantic following Germany's surrender. The uranium oxide was reportedly labeled as "U-235", which may have been a mislabeling of the submarine's name and its exact characteristics remain unknown; some sources believe that it was not weapons-grade material and was intended for use as a catalyst in the production of synthetic methanol
to be used for aviation fuel.
, Kyoto. Arakatsu had spent some years studying abroad including at the Cavendish Laboratory
at Cambridge under Ernest Rutherford
and at Berlin University under Einstein. Next to Nishina, Arakatsu was the most notable nuclear physicist in Japan. His team included Hideki Yukawa
, who would become in 1949 the first Japanese physicist to receive a Nobel Prize
.
Early on in the war Commander Kitagawa, head of the Navy Research Institute's Chemical Section, had requested Arakatsu to carry out work on the separation of Uranium-235. The work went slowly, but shortly before the end of the war he had designed an ultracentrifuge
(to spin at 60,000 rpm) which he was hopeful would achieve the required results. Only the design of the machinery was completed before the Japanese surrender.
Shortly after the surrender of Japan, the Manhattan Project's Atomic Bomb Mission, which had deployed to Japan in September, reported that the F-Go Project had obtained 20 grams a month of heavy water from electrolytic ammonia plants in Korea and Kyushu. In fact, the industrialist Jun Noguchi had launched a heavy-water
production program some years previously. In 1926 Noguchi founded the Korean Hydro Electric Company at Hungnam
in north-eastern Korea: this became the site of an industrial complex producing ammonia for fertilizer production. However, despite the availability of a heavy-water production facility whose output could potentially have rivalled that of Norsk Hydro
at Vemork
in Norway, it appears that the Japanese did not carry out neutron-multiplication studies using heavy water as a moderator at Kyoto. A rumor surfaced after the war that Japanese scientists had supposedly planned to conduct a test of a nuclear weapon near Konan on 12 August 1945, but this could not be verified: the Red Army
occupied Konan a few days later, before US occupation authorities could investigate fully.
Finally research of the Japanese atomic bomb was abolished by the command of the Emperor.
s at the Riken Institute for biological and medical research, which was soon granted; however, on 10 November instructions were received from the US Secretary of War in Washington to destroy the cyclotrons at the Riken, Kyoto University, and Osaka University. This was done on 24 November; the Riken's cyclotrons were taken apart and thrown into Tokyo Bay.
In a letter of protest against this destruction Nishina wrote that the cyclotrons at the Riken had had nothing to do with the production of nuclear weapons, however the large cyclotron had officially been a part of the Ni-Go Project. Nishina had placed it within the Project by suggesting that the cyclotron could serve basic research for the use of nuclear power, simply so that he could continue working on the device; the military nature of the Project gave him access to funding and kept his researchers from being drafted into the armed forces. He felt no qualms about this because he saw no possibility of producing nuclear weapons in Japan before the end of the war.
, who had been an investigator with the 24th Criminal Investigation Detachment in Korea after the war, which alleged that the Japanese had successfully tested a nuclear weapon near Konan before being captured by the Russians. He claimed that he had received his information from a Japanese officer who had been in charge of counter-intelligence at Konan. Though no credence was placed in the story by SCAP
officials, it was nonetheless thought necessary to get comments from Japanese scientists who would or should have known about such a project. Bunsaku Arakatsu called the article "false and fantastic" as he was personally acquainted with the few people capable of such a project, and said that Japan's nuclear research had never progressed beyond the laboratory stage, nor had any thought been given to the construction of a pilot plant for the production of nuclear material. Further doubt is cast on Snell's story by the lack of evidence of large numbers of Japanese scientists leaving Japan for Korea and never returning. Snell's claims were repeated by Robert K. Wilcox in his 1985 book Japan's Secret War: Japan's Race Against Time to Build Its Own Atomic Bomb. The book also included what Wilcox stated was new evidence from intelligence material which indicated the Japanese might have had an atomic program at Konan. These specific claims were dismissed in a review of the book by Department of Energy
employee Roger M. Anders which was published in the journal Military Affairs, an article written by two historians of science in the journal Isis and another article in the journal "Intelligence and National Security".
forbids the establishment of offensive military forces, and in 1967 it adopted the Three Non-Nuclear Principles
, ruling out the production, possession, or introduction of nuclear weapons. Despite this, the idea that Japan might become a nuclear power has persisted. After China's first nuclear test
in 1964, Japanese Prime Minister Eisaku Satō
said to President Lyndon Johnson when they met in January 1965, that if the Chinese Communists had nuclear weapons, the Japanese should also have them. This shocked Johnson's administration, especially when Sato added that "Japanese public opinion will not permit this at present, but I believe that the public, especially the younger generation, can be 'educated'."
Throughout Sato's administration Japan continued to discuss the nuclear option. It was suggested that tactical nuclear weapon
s, as opposed to larger strategic weapons, could be defined as defensive, and therefore be allowed by the Japanese Constitution. A White Paper commissioned by future Prime Minister Yasuhiro Nakasone
opined that it would be possible that possessing small-yield, purely defensive nuclear weapons would not violate the Constitution, but that in view of the danger of adverse foreign reaction and possible war, a policy would be followed of not acquiring nuclear weapons "at present".
(NPT) one of its top priorities. In December 1967, to reassure the Japanese public, Sato announced the adoption of the "Three Non-Nuclear Principles". These were that Japan would not manufacture, possess, or permit nuclear weapons on Japanese soil. The principles, which were adopted by the Diet, but are not law, have remained the basis of Japan's nuclear policy ever since.
According to Kei Wakaizumi, one of Sato's policy advisers, Sato realized soon after making the declaration that it might be too constraining. He therefore clarified the principles in a February 1968 address to the Diet by declaring the "Four Nuclear Policies" ("Four-Pillars Nuclear Policy"):
It followed that if American assurance was ever removed or seemed unreliable, Japan might have no choice but to go nuclear. In other words, it kept the nuclear option available.
In 1969 a policy planning study for Japan's Foreign Ministry concluded that Japan should, even if it signed the NPT, maintain the economic and technical ability to develop and produce nuclear weapons in case it should ever become necessary, for example due to the international situation.
Japan finally signed the NPT in 1970 and ratified it in 1976, but only after West Germany
became a signatory and the US promised "not to interfere with Tokyo's pursuit of independent reprocessing capabilities in its civilian nuclear power program".
In 1998 two events strengthened the hand of those in Japan advocating that the nation should at least reconsider if not reverse its non-nuclear policy. Advocates of such policies included conservative academics, some government officials, a few industrialists, and nationalist groups.
The first of these events was India and Pakistan both conducting nuclear tests; the Japanese were troubled by a perceived reluctance on the part of the international community to condemn the two countries' actions, since one of the reasons Japan had opted to join the NPT was that it had anticipated severe penalties for those states who defied the international consensus against further nuclear proliferation. Also, Japan and other nations feared that an Indian nuclear arsenal could cause a localized nuclear arms race with China.
The second event was the August 1998 launch of a North Korean Taepodong-1
missile over Japan which caused a public outcry and led some to call for remilitarization or the development of nuclear weapons. Fukushiro Nukaga
, head of the Japan Defense Agency, said that his government would be justified in mounting pre-emptive strikes against North Korean missile bases. Prime Minister Keizo Obuchi
reiterated Japan's non-nuclear weapon principles and said that Japan would not possess a nuclear arsenal, and that the matter was not even worthy of discussion. However, it is thought that Koizumi implied he agreed that Japan had the right to possess nuclear weapons when he added, "it is significant that although we could have them, we don't".
Earlier, Shinzo Abe
had said that Japan's constitution did not necessarily ban possession of nuclear weapons, so long as they were kept at a minimum and were tactical weapons, and Chief Cabinet Secretary Yasuo Fukuda
had expressed a similar view.
At the present time Japan makes extensive use of nuclear energy from nuclear reactors, which generate a significant percentage of Japan's electricity, the third largest nuclear energy producer after the US and France
, with plans to produce over 40% of its electricity using nuclear power by 2010.
Significant amounts of reactor-grade plutonium are created as a by-product of the nuclear energy industry, and Japan was reported in December 1995 to have 4.7 tons of plutonium, enough for around 700 nuclear warheads. Japan also possesses an indigenous uranium enrichment plant which could hypothetically be used to make highly enriched uranium suitable for weapon use. Japan has also developed the M-V three-stage solid fuel rocket, similar in design to the U.S. LGM-118A Peacekeeper
ICBM, which could serve as a delivery vehicle, and has experience in re-entry vehicle technology (OREX
, HOPE-X
).
It has been pointed out that as long as Japan enjoys the benefits of a "nuclear-ready" status held through surrounding countries, it will see no reason to actually produce nuclear arms, since by remaining below the threshold, albeit with the capability to cross it at short notice, Japan can expect the support of the US while posing as an equal to China and Russia.
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese program to develop nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
s was conducted during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. Like the German nuclear weapons program
German nuclear energy project
The German nuclear energy project, , was an attempted clandestine scientific effort led by Germany to develop and produce the atomic weapons during the events involving the World War II...
, it suffered from an array of problems, and was ultimately unable to progress beyond the laboratory stage before the atomic bombings of Hiroshima and Nagasaki
Atomic bombings of Hiroshima and Nagasaki
During the final stages of World War II in 1945, the United States conducted two atomic bombings against the cities of Hiroshima and Nagasaki in Japan, the first on August 6, 1945, and the second on August 9, 1945. These two events are the only use of nuclear weapons in war to date.For six months...
and the Japanese surrender in August 1945.
Today, Japan's nuclear energy infrastructure makes it eminently capable of constructing nuclear weapons at will. The de-militarization of Japan and the protection of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
' nuclear umbrella
Nuclear umbrella
Nuclear umbrella refers to a guarantee by a nuclear weapons state to defend a non-nuclear allied state.It is usually used for the security alliances of the United States with Japan, South Korea, the North Atlantic Treaty Organization , and Australia, originating with the Cold War with the Soviet...
have led to a strong policy of non-weaponization of nuclear technology, but in the face of nuclear weapons testing by North Korea
North Korea
The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...
, some politicians and former military officials in Japan are calling for a reversal of this policy.
Background
In 1934, Tohoku UniversityTohoku University
, abbreviated to , located in the city of Sendai, Miyagi Prefecture in the Tōhoku Region, Japan, is a Japanese national university. It is the third oldest Imperial University in Japan and is a member of the National Seven Universities...
professor Hikosaka Tadayoshi's "atomic physics theory" was released. Hikosaka pointed out the huge energy contained by nuclei and the possibility that both nuclear power generation and weapons could be created.
In December 1938, the German chemists Otto Hahn
Otto Hahn
Otto Hahn FRS was a German chemist and Nobel laureate, a pioneer in the fields of radioactivity and radiochemistry. He is regarded as "the father of nuclear chemistry". Hahn was a courageous opposer of Jewish persecution by the Nazis and after World War II he became a passionate campaigner...
and Fritz Strassmann
Fritz Strassmann
Friedrich Wilhelm "Fritz" Strassmann was a German chemist who, with Otto Hahn in 1938, identified barium in the residue after bombarding uranium with neutrons, which led to the interpretation of their results as being from nuclear fission...
sent a manuscript to Naturwissenschaften
Die Naturwissenschaften
Naturwissenschaften is a monthly peer-reviewed scientific journal published by Springer on behalf of several learned societies.- History :...
reporting that they had detected the element barium
Barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Barium is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with...
after bombarding uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
with neutrons; simultaneously, they communicated these results to Lise Meitner
Lise Meitner
Lise Meitner FRS was an Austrian-born, later Swedish, physicist who worked on radioactivity and nuclear physics. Meitner was part of the team that discovered nuclear fission, an achievement for which her colleague Otto Hahn was awarded the Nobel Prize...
. Meitner, and her nephew Otto Robert Frisch
Otto Robert Frisch
Otto Robert Frisch , Austrian-British physicist. With his collaborator Rudolf Peierls he designed the first theoretical mechanism for the detonation of an atomic bomb in 1940.- Overview :...
, correctly interpreted these results as being nuclear fission and Frisch confirmed this experimentally on 13 January 1939. Physicists around the world immediately realized that chain reactions could be produced and notified their governments of the possibility of developing nuclear weapons.
World War II
The leading figure in the Japanese atomic program was Dr. Yoshio NishinaYoshio Nishina
was the founding father of modern physics research in Japan. He co-authored the well-known Klein–Nishina formula. He was a principal investigator of RIKEN and mentored generations...
, a friend of Niels Bohr
Niels Bohr
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in...
and a close associate of Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
. Dr. Nishina was a highly skilled world class physicist with excellent leadership qualities, who co-authored the Klein-Nishina Formula
Klein-Nishina formula
The Klein–Nishina formulagives the differential cross section of photons scattered from a single free electron in lowest order ofquantum electrodynamics...
. Nishina had established his own Nuclear Research Laboratory to study high-energy physics
Particle physics
Particle physics is a branch of physics that studies the existence and interactions of particles that are the constituents of what is usually referred to as matter or radiation. In current understanding, particles are excitations of quantum fields and interact following their dynamics...
in 1931 at Riken Institute
RIKEN
is a large natural sciences research institute in Japan. Founded in 1917, it now has approximately 3000 scientists on seven campuses across Japan, the main one in Wako, just outside Tokyo...
(the Institute for Physical and Chemical Research), which had been established in 1917 in Tokyo to promote basic research. Nishina had built his first 26 inch cyclotron
Cyclotron
In technology, a cyclotron is a type of particle accelerator. In physics, the cyclotron frequency or gyrofrequency is the frequency of a charged particle moving perpendicularly to the direction of a uniform magnetic field, i.e. a magnetic field of constant magnitude and direction...
in 1936, and another 60 inch 220 ton cyclotron in 1937. In 1938 Japan also purchased a cyclotron from the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
.
In 1939 Nishina recognized the military potential of nuclear fission, and was worried that the Americans were working on a nuclear weapon which might be used against Japan. Indeed, in 1939, President Franklin D. Roosevelt
Franklin D. Roosevelt
Franklin Delano Roosevelt , also known by his initials, FDR, was the 32nd President of the United States and a central figure in world events during the mid-20th century, leading the United States during a time of worldwide economic crisis and world war...
started the first investigations into fission weapons in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, which eventually evolved into the massive Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...
, and the laboratory from which Japan purchased its own cyclotron would become one of the major sites for weapons research.
In the early summer of 1940 Nishina met Lieutenant-General Takeo Yasuda
Takeo Yasuda
was a general in the Imperial Japanese Army. While serving as director of the Army's Aviation Technology Research Institute during World War II, he was a key figure in scientific and technological development for the Imperial Japanese Army Air Force, most notably his involvement in the early...
on a train. Yasuda was at the time director of the Army Aeronautical Department's Technical Research Institute. Nishina told Yasuda about the possibility of building nuclear weapons. However, the Japanese fission project did not formally begin until April 1941 when Yasuda acted on Army Minister Hideki Tojo
Hideki Tōjō
Hideki Tōjō was a general of the Imperial Japanese Army , the leader of the Taisei Yokusankai, and the 40th Prime Minister of Japan during most of World War II, from 17 October 1941 to 22 July 1944...
's order to investigate the possibilities of nuclear weapons. Yasuda passed the order down the chain of command to Okochi Masatoshi, director of the Riken Institute, who in turn passed it to Nishina, whose Nuclear Research Laboratory by 1941 had over 100 researchers.
Meanwhile, the Imperial Japanese Navy's Technology Research Institute had been pursuing its own separate investigations, and had engaged professors from the Imperial University, Tokyo, for advice on nuclear weapons. This resulted in the formation of the Committee on Research in the Application of Nuclear Physics, chaired by Nishina, that met ten times between July 1942 and March 1943. It concluded in a report that while an atomic bomb was, in principle, feasible, "it would probably be difficult even for the United States to realize the application of atomic power during the war". This caused the Navy to lose interest and to concentrate instead on research into radar.
Ni-Go Project
The Army was not discouraged, and soon after the Committee issued its report it set up an experimental project at Riken, the Ni-Go Project. Its aim was to separate Uranium 235 by thermal diffusion, ignoring alternative methods such as electromagnetic separation, gaseous diffusionGaseous diffusion
Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride through semi-permeable membranes. This produces a slight separation between the molecules containing uranium-235 and uranium-238 . By use of a large cascade of many stages, high separations...
, and centrifugal separation
Gas centrifuge
A gas centrifuge is a device that performs isotope separation of gases. A centrifuge relies on the principles of centripetal force accelerating molecules so that particles of different masses are physically separated in a gradient along the radius of a rotating container.A prominent use of gas...
. By February 1945, a small group of scientists had succeeded in producing a small amount of material in a rudimentary separator in the Riken complex - material which Riken's cyclotron indicated was not Uranium-235. The separator project came to an end two months later when the building housing it was destroyed in a fire caused by an air raid on Tokyo. No attempt was made to build a uranium pile; heavy water
Heavy water
Heavy water is water highly enriched in the hydrogen isotope deuterium; e.g., heavy water used in CANDU reactors is 99.75% enriched by hydrogen atom-fraction...
was unavailable, but Takeuchi Masa, who was in charge of Nishina's separator, calculated that light water would suffice if the uranium could be enriched to 5-10% Uranium-235.
While these experiments were in progress, the Army and Navy carried out searches for uranium ore, in locations ranging from Fukushima Prefecture
Fukushima Prefecture
is a prefecture of Japan located in the Tōhoku region on the island of Honshu. The capital is the city of Fukushima.-History:Until the Meiji Restoration, the area of Fukushima prefecture was known as Mutsu Province....
to Korea, China, and Burma. The Japanese also requested materials from their German allies and 560 kg (1,234.6 lb) of unprocessed uranium oxide was dispatched to Japan in April 1945 aboard the submarine U-234, which however surrendered to US forces in the Atlantic following Germany's surrender. The uranium oxide was reportedly labeled as "U-235", which may have been a mislabeling of the submarine's name and its exact characteristics remain unknown; some sources believe that it was not weapons-grade material and was intended for use as a catalyst in the production of synthetic methanol
Methanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...
to be used for aviation fuel.
F-Go Project
In 1943 a different Japanese Naval command began a nuclear research program, the F-Go Project, under Bunsaku Arakatsu at the Imperial UniversityKyoto University
, or is a national university located in Kyoto, Japan. It is the second oldest Japanese university, and formerly one of Japan's Imperial Universities.- History :...
, Kyoto. Arakatsu had spent some years studying abroad including at the Cavendish Laboratory
Cavendish Laboratory
The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the university's School of Physical Sciences. It was opened in 1874 as a teaching laboratory....
at Cambridge under Ernest Rutherford
Ernest Rutherford
Ernest Rutherford, 1st Baron Rutherford of Nelson OM, FRS was a New Zealand-born British chemist and physicist who became known as the father of nuclear physics...
and at Berlin University under Einstein. Next to Nishina, Arakatsu was the most notable nuclear physicist in Japan. His team included Hideki Yukawa
Hideki Yukawa
né , was a Japanese theoretical physicist and the first Japanese Nobel laureate.-Biography:Yukawa was born in Tokyo and grew up in Kyoto. In 1929, after receiving his degree from Kyoto Imperial University, he stayed on as a lecturer for four years. After graduation, he was interested in...
, who would become in 1949 the first Japanese physicist to receive a Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
.
Early on in the war Commander Kitagawa, head of the Navy Research Institute's Chemical Section, had requested Arakatsu to carry out work on the separation of Uranium-235. The work went slowly, but shortly before the end of the war he had designed an ultracentrifuge
Ultracentrifuge
The ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as 2,000,000 g . There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge...
(to spin at 60,000 rpm) which he was hopeful would achieve the required results. Only the design of the machinery was completed before the Japanese surrender.
Shortly after the surrender of Japan, the Manhattan Project's Atomic Bomb Mission, which had deployed to Japan in September, reported that the F-Go Project had obtained 20 grams a month of heavy water from electrolytic ammonia plants in Korea and Kyushu. In fact, the industrialist Jun Noguchi had launched a heavy-water
Heavy water
Heavy water is water highly enriched in the hydrogen isotope deuterium; e.g., heavy water used in CANDU reactors is 99.75% enriched by hydrogen atom-fraction...
production program some years previously. In 1926 Noguchi founded the Korean Hydro Electric Company at Hungnam
Hungnam
Hŭngnam was the third largest city in North Korea.It is a port city on the eastern coast, in South Hamgyong Province, on the Sea of Japan . The city covers an area of 250 square kilometers...
in north-eastern Korea: this became the site of an industrial complex producing ammonia for fertilizer production. However, despite the availability of a heavy-water production facility whose output could potentially have rivalled that of Norsk Hydro
Norsk Hydro
Norsk Hydro ASA is a Norwegian aluminium and renewable energy company, headquartered in Oslo. Hydro is the fourth largest integrated aluminium company worldwide. It has operations in some 40 countries around the world and is active on all continents. The Norwegian state holds a 43.8 percent...
at Vemork
Vemork
Vemork is the name of a hydroelectric power plant outside Rjukan in Tinn, Norway. The plant was built by Norsk Hydro and opened in 1911, its main purpose being to fix nitrogen for the production of fertilizer. Vemork was later the site of the first plant in the world to mass-produce heavy water...
in Norway, it appears that the Japanese did not carry out neutron-multiplication studies using heavy water as a moderator at Kyoto. A rumor surfaced after the war that Japanese scientists had supposedly planned to conduct a test of a nuclear weapon near Konan on 12 August 1945, but this could not be verified: the Red Army
Red Army
The Workers' and Peasants' Red Army started out as the Soviet Union's revolutionary communist combat groups during the Russian Civil War of 1918-1922. It grew into the national army of the Soviet Union. By the 1930s the Red Army was among the largest armies in history.The "Red Army" name refers to...
occupied Konan a few days later, before US occupation authorities could investigate fully.
Emperor and atomic bomb
Emperor Shōwa was opposed to the atomic bomb plan from the beginning. Emperor thought that use of an atomic bomb would be extermination of mankind.Finally research of the Japanese atomic bomb was abolished by the command of the Emperor.
Postwar aftermath
On 16 October 1945 Nishina sought permission from the American occupation forces to use the two cyclotronCyclotron
In technology, a cyclotron is a type of particle accelerator. In physics, the cyclotron frequency or gyrofrequency is the frequency of a charged particle moving perpendicularly to the direction of a uniform magnetic field, i.e. a magnetic field of constant magnitude and direction...
s at the Riken Institute for biological and medical research, which was soon granted; however, on 10 November instructions were received from the US Secretary of War in Washington to destroy the cyclotrons at the Riken, Kyoto University, and Osaka University. This was done on 24 November; the Riken's cyclotrons were taken apart and thrown into Tokyo Bay.
In a letter of protest against this destruction Nishina wrote that the cyclotrons at the Riken had had nothing to do with the production of nuclear weapons, however the large cyclotron had officially been a part of the Ni-Go Project. Nishina had placed it within the Project by suggesting that the cyclotron could serve basic research for the use of nuclear power, simply so that he could continue working on the device; the military nature of the Project gave him access to funding and kept his researchers from being drafted into the armed forces. He felt no qualms about this because he saw no possibility of producing nuclear weapons in Japan before the end of the war.
Claims of a Japanese weapon test
In 1946 the Atlanta Constitution published a story by reporter David SnellDavid Snell (journalist)
David Snell was a reporter and cartoonist for the defunct Life Magazine and several other publications during his career as a journalist.-Early years, family, education:...
, who had been an investigator with the 24th Criminal Investigation Detachment in Korea after the war, which alleged that the Japanese had successfully tested a nuclear weapon near Konan before being captured by the Russians. He claimed that he had received his information from a Japanese officer who had been in charge of counter-intelligence at Konan. Though no credence was placed in the story by SCAP
Supreme Commander of the Allied Powers
Supreme Commander of the Allied Powers was the title held by General Douglas MacArthur during the Occupation of Japan following World War II...
officials, it was nonetheless thought necessary to get comments from Japanese scientists who would or should have known about such a project. Bunsaku Arakatsu called the article "false and fantastic" as he was personally acquainted with the few people capable of such a project, and said that Japan's nuclear research had never progressed beyond the laboratory stage, nor had any thought been given to the construction of a pilot plant for the production of nuclear material. Further doubt is cast on Snell's story by the lack of evidence of large numbers of Japanese scientists leaving Japan for Korea and never returning. Snell's claims were repeated by Robert K. Wilcox in his 1985 book Japan's Secret War: Japan's Race Against Time to Build Its Own Atomic Bomb. The book also included what Wilcox stated was new evidence from intelligence material which indicated the Japanese might have had an atomic program at Konan. These specific claims were dismissed in a review of the book by Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
employee Roger M. Anders which was published in the journal Military Affairs, an article written by two historians of science in the journal Isis and another article in the journal "Intelligence and National Security".
Postwar
Since the bombing of Hiroshima and Nagasaki, Japan has been a staunch upholder of antinuclear sentiments. Its postwar ConstitutionConstitution of Japan
The is the fundamental law of Japan. It was enacted on 3 May, 1947 as a new constitution for postwar Japan.-Outline:The constitution provides for a parliamentary system of government and guarantees certain fundamental rights...
forbids the establishment of offensive military forces, and in 1967 it adopted the Three Non-Nuclear Principles
Three Non-Nuclear Principles
Japan's are a parliamentary resolution that have guided Japanese nuclear policy since their inception in the late 1960s, and reflect general public sentiment and national policy since the end of World War II. The tenets state that Japan shall neither possess nor manufacture nuclear weapons, nor...
, ruling out the production, possession, or introduction of nuclear weapons. Despite this, the idea that Japan might become a nuclear power has persisted. After China's first nuclear test
596 (nuclear test)
596 is the codename of the People's Republic of China's first nuclear weapons test, detonated on October 16, 1964 at the Lop Nur test site. It was a uranium-235 implosion fission device and had a yield of 22 kilotons...
in 1964, Japanese Prime Minister Eisaku Satō
Eisaku Sato
This article is about the Prime Minister of Japan. For the governor of Fukushima Prefecture of Japan of the same name, see Eisaku Satō ....
said to President Lyndon Johnson when they met in January 1965, that if the Chinese Communists had nuclear weapons, the Japanese should also have them. This shocked Johnson's administration, especially when Sato added that "Japanese public opinion will not permit this at present, but I believe that the public, especially the younger generation, can be 'educated'."
Throughout Sato's administration Japan continued to discuss the nuclear option. It was suggested that tactical nuclear weapon
Tactical nuclear weapon
A tactical nuclear weapon refers to a nuclear weapon which is designed to be used on a battlefield in military situations. This is as opposed to strategic nuclear weapons which are designed to menace large populations, to damage the enemy's ability to wage war, or for general deterrence...
s, as opposed to larger strategic weapons, could be defined as defensive, and therefore be allowed by the Japanese Constitution. A White Paper commissioned by future Prime Minister Yasuhiro Nakasone
Yasuhiro Nakasone
is a Japanese politician who served as Prime Minister of Japan from November 27, 1982 to November 6, 1987. A contemporary of Brian Mulroney, Ronald Reagan, Helmut Kohl, François Mitterrand, Margaret Thatcher, and Mikhail Gorbachev, he is best known for pushing through the privatization of...
opined that it would be possible that possessing small-yield, purely defensive nuclear weapons would not violate the Constitution, but that in view of the danger of adverse foreign reaction and possible war, a policy would be followed of not acquiring nuclear weapons "at present".
Nuclear Non-Proliferation Treaty
The Johnson administration became anxious about Sato's intentions and made securing Japan's signature to the Nuclear Non-Proliferation TreatyNuclear Non-Proliferation Treaty
The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT, is a landmark international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy and to...
(NPT) one of its top priorities. In December 1967, to reassure the Japanese public, Sato announced the adoption of the "Three Non-Nuclear Principles". These were that Japan would not manufacture, possess, or permit nuclear weapons on Japanese soil. The principles, which were adopted by the Diet, but are not law, have remained the basis of Japan's nuclear policy ever since.
According to Kei Wakaizumi, one of Sato's policy advisers, Sato realized soon after making the declaration that it might be too constraining. He therefore clarified the principles in a February 1968 address to the Diet by declaring the "Four Nuclear Policies" ("Four-Pillars Nuclear Policy"):
- Promotion of the peaceful use of nuclear energy
- Efforts towards global nuclear disarmament
- Reliance and dependence on US extended deterrence, based on the 1960 US-Japan Security Treaty
- Support for the "Three Non-Nuclear Principles under the circumstances where Japan's national security is guaranteed by the other three policies."
It followed that if American assurance was ever removed or seemed unreliable, Japan might have no choice but to go nuclear. In other words, it kept the nuclear option available.
In 1969 a policy planning study for Japan's Foreign Ministry concluded that Japan should, even if it signed the NPT, maintain the economic and technical ability to develop and produce nuclear weapons in case it should ever become necessary, for example due to the international situation.
Japan finally signed the NPT in 1970 and ratified it in 1976, but only after West Germany
West Germany
West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....
became a signatory and the US promised "not to interfere with Tokyo's pursuit of independent reprocessing capabilities in its civilian nuclear power program".
Extension of Nuclear Non-Proliferation Treaty
In 1995 the Clinton administration pushed the Japanese government to endorse the indefinite extension of the NPT, but it opted for an ambiguous position on the issue. A former Japanese government official recalled, "We thought it was better for us not to declare that we will give up our nuclear option forever and ever". However, eventually pressure from Washington and other nations led to Japan's supporting the indefinite extension.In 1998 two events strengthened the hand of those in Japan advocating that the nation should at least reconsider if not reverse its non-nuclear policy. Advocates of such policies included conservative academics, some government officials, a few industrialists, and nationalist groups.
The first of these events was India and Pakistan both conducting nuclear tests; the Japanese were troubled by a perceived reluctance on the part of the international community to condemn the two countries' actions, since one of the reasons Japan had opted to join the NPT was that it had anticipated severe penalties for those states who defied the international consensus against further nuclear proliferation. Also, Japan and other nations feared that an Indian nuclear arsenal could cause a localized nuclear arms race with China.
The second event was the August 1998 launch of a North Korean Taepodong-1
Taepodong-1
Taepodong-1 is a two-stage intermediate-range ballistic missile developed in North Korea, and the weapon is currently in use there. The missile was derived originally from the Scud rocket, and can allegedly serve as both a nuclear delivery system and a space launch vehicle...
missile over Japan which caused a public outcry and led some to call for remilitarization or the development of nuclear weapons. Fukushiro Nukaga
Fukushiro Nukaga
is a Japanese politician and a member of the Liberal Democratic Party. He has been a member of the House of Representatives since 1983 and represents Ibaraki's 2nd district. He was Minister of Finance from 2007 to 2008....
, head of the Japan Defense Agency, said that his government would be justified in mounting pre-emptive strikes against North Korean missile bases. Prime Minister Keizo Obuchi
Keizo Obuchi
was a Japanese politician who served in the House of Representatives for twelve terms, and ultimately as the 84th Prime Minister of Japan from July 30, 1998 to April 5, 2000. His political career ended when he suffered a serious and ultimately fatal stroke....
reiterated Japan's non-nuclear weapon principles and said that Japan would not possess a nuclear arsenal, and that the matter was not even worthy of discussion. However, it is thought that Koizumi implied he agreed that Japan had the right to possess nuclear weapons when he added, "it is significant that although we could have them, we don't".
Earlier, Shinzo Abe
Shinzo Abe
was the 90th Prime Minister of Japan, elected by a special session of the National Diet on 26 September 2006. He was Japan's youngest post–World War II prime minister and the first born after the war. Abe served as prime minister for nearly twelve months, before resigning on 12 September 2007...
had said that Japan's constitution did not necessarily ban possession of nuclear weapons, so long as they were kept at a minimum and were tactical weapons, and Chief Cabinet Secretary Yasuo Fukuda
Yasuo Fukuda
was the 91st Prime Minister of Japan, serving from 2007 to 2008. He was previously the longest-serving Chief Cabinet Secretary in Japanese history, serving for three and a half years under Prime Ministers Yoshirō Mori and Junichiro Koizumi....
had expressed a similar view.
At the present time Japan makes extensive use of nuclear energy from nuclear reactors, which generate a significant percentage of Japan's electricity, the third largest nuclear energy producer after the US and France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, with plans to produce over 40% of its electricity using nuclear power by 2010.
De facto nuclear state
While there are currently no known plans in Japan to produce nuclear weapons, it has been argued Japan has the technology, raw materials, and the capital to produce nuclear weapons within one year if necessary, and some analysts consider it a de facto nuclear state for this reason. For this reason Japan is often said to be a "screwdriver's turn" away from possessing nuclear weapons.Significant amounts of reactor-grade plutonium are created as a by-product of the nuclear energy industry, and Japan was reported in December 1995 to have 4.7 tons of plutonium, enough for around 700 nuclear warheads. Japan also possesses an indigenous uranium enrichment plant which could hypothetically be used to make highly enriched uranium suitable for weapon use. Japan has also developed the M-V three-stage solid fuel rocket, similar in design to the U.S. LGM-118A Peacekeeper
LGM-118A Peacekeeper
The LGM-118A Peacekeeper, also known as the MX missile , was a land-based ICBM deployed by the United States starting in 1986. A total of 50 missiles were deployed. They have since been deactivated....
ICBM, which could serve as a delivery vehicle, and has experience in re-entry vehicle technology (OREX
OREX
OREX was a NASDA reentry demonstrator prototype which was launched in 1994 on the H-II launcher. It was a precursor for the Japanese space Shuttle Hope....
, HOPE-X
HOPE-X
HOPE was a Japanese experimental spaceplane project designed by a partnership between NASDA and NAL , started in the 1980s. It was positioned for most of its lifetime as one of the main Japanese contributions to the International Space Station, the other being the Japanese Experiment Module...
).
It has been pointed out that as long as Japan enjoys the benefits of a "nuclear-ready" status held through surrounding countries, it will see no reason to actually produce nuclear arms, since by remaining below the threshold, albeit with the capability to cross it at short notice, Japan can expect the support of the US while posing as an equal to China and Russia.
See also
- History of nuclear weaponsHistory of nuclear weaponsThe history of nuclear weapons chronicles the development of nuclear weapons. Nuclear weapons possess enormous destructive potential derived from nuclear fission or nuclear fusion reactions...
- Japan and weapons of mass destructionJapan and weapons of mass destructionThe nation of Japan conducted numerous experiments in an attempt to acquire weapons of mass destruction before and during World War II, but now has ceased production and abandoned experiments....
- Norwegian heavy water sabotageNorwegian heavy water sabotageThe Norwegian heavy water sabotage was a series of actions undertaken by Norwegian saboteurs during World War II to prevent the German nuclear energy project from acquiring heavy water , which could be used to produce nuclear weapons...
- Nuclear weaponNuclear weaponA nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
External links
- Annotated bibliography of Japanese atomic bomb program from the Alsos Digital Library for Nuclear Issues.
- FAS: Nuclear Weapons Program: Japan - Federation of American Scientists
- Japan's atomic bomb History Channel International documentary