Japanese nuclear incidents - AbsoluteAstronomy.com

This is a list of Japanese atomic, nuclear and radiological accidents, incidents and disasters.

List

Date		Location	Type
Description				Notes
6 August 1945	Nuclear bombing Nuclear warfare Nuclear warfare, or atomic warfare, is a military conflict or political strategy in which nuclear weaponry is detonated on an opponent. Compared to conventional warfare, nuclear warfare can be vastly more destructive in range and extent of damage...	Hiroshima Hiroshima is the capital of Hiroshima Prefecture, and the largest city in the Chūgoku region of western Honshu, the largest island of Japan. It became best known as the first city in history to be destroyed by a nuclear weapon when the United States Army Air Forces dropped an atomic bomb on it at 8:15 A.M...	13kt explosion

9 August 1945	Nuclear bombing	Nagasaki Nagasaki is the capital and the largest city of Nagasaki Prefecture on the island of Kyushu in Japan. Nagasaki was founded by the Portuguese in the second half of the 16th century on the site of a small fishing village, formerly part of Nishisonogi District...	21kt explosion

5 December 1965	Broken arrow	coast of Japan	Loss of a nuclear bomb
A USN aircraft with one B43 nuclear bomb B43 nuclear bomb The B43 was a United States air-dropped variable yield nuclear weapon used by a wide variety of fighter bomber and bomber aircraft.The B43 was developed from 1956 by Los Alamos National Laboratory, entering production in 1959. It entered service in April 1961. Total production was 2,000 weapons,... fell off the aircraft carrier Aircraft carrier An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations... Ticonderoga into 16200 feet (4,937.8 m) of water while the ship was underway from Vietnam Vietnam Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –... to Yokosuka, Japan. The weapon was never recovered. Navy United States Navy The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S... documents show it happened about 80 miles (128.7 km) from the Ryukyu Islands Ryukyu Islands The , also known as the , is a chain of islands in the western Pacific, on the eastern limit of the East China Sea and to the southwest of the island of Kyushu in Japan. From about 1829 until the mid 20th century, they were alternately called Luchu, Loochoo, or Lewchew, akin to the Mandarin... and 200 miles (321.9 km) from Okinawa.
March 1981	INES International Nuclear Event Scale The International Nuclear and Radiological Event Scale was introduced in 1990 by the International Atomic Energy Agency in order to enable prompt communication of safety significance information in case of nuclear accidents.... Level 2	Tsuruga	Overexposure of workers
More than 100 workers were exposed to doses of up to 155 millirem per day radiation during repairs of a nuclear power plant.
June 1999	INES Level 2	Shika plant Shika Nuclear Power Plant The is a nuclear power plant located in the town of Shika, Ishikawa, Japan. It is owned and operated by the Hokuriku Electric Power Company. It is on a site that is 1.6 km2 .-Reactors on Site:-1999 Criticality Event:... , Ishikawa Prefecture Ishikawa Prefecture is a prefecture of Japan located in the Chūbu region on Honshū island. The capital is Kanazawa.- History :Ishikawa was formed from the merger of Kaga Province and the smaller Noto Province.- Geography :Ishikawa is on the Sea of Japan coast...	Control rod malfunction
Operators attempting to insert one control rod accidentally withdrew three causing a 15 minute uncontrolled sustained reaction at the number 1 reactor of Shika Nuclear Power Plant Shika Nuclear Power Plant The is a nuclear power plant located in the town of Shika, Ishikawa, Japan. It is owned and operated by the Hokuriku Electric Power Company. It is on a site that is 1.6 km2 .-Reactors on Site:-1999 Criticality Event:... .
30 September 1999	INES Level 4	Ibaraki Prefecture Ibaraki Prefecture is a prefecture of Japan, located in the Kantō region on the main island of Honshu. The capital is Mito.-History:Ibaraki Prefecture was previously known as Hitachi Province...	Accidental criticality

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During preparation of a uranyl nitrate

Uranyl nitrate

Uranyl nitrate is a water soluble yellow uranium salt. The yellow-green crystals of uranium nitrate hexahydrate are triboluminescent.Uranyl nitrate can be prepared by reaction of uranium salts with nitric acid...

solution, uranium in solution exceeded the critical mass, at a uranium reprocessing facility in Tokai-mura northeast of Tokyo, Japan. Three workers were exposed to (neutron) radiation doses in excess of allowable limits. Two of these workers died. 116 other workers received lesser doses of 1 mSv or greater though not in excess of the allowable limit.
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| 11–15 March 2011
| INES Level 3
| Fukushima II Nuclear Power Plant

Fukushima II Nuclear Power Plant

The , or Fukushima Dai-ni , is a nuclear power plant located on a site in the town of Naraha and Tomioka in the Futaba District of Fukushima Prefecture, Japan...

, 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....

2011 Tōhoku earthquake and tsunami

The 2011 earthquake off the Pacific coast of Tohoku, also known as the 2011 Tohoku earthquake, or the Great East Japan Earthquake, was a magnitude 9.0 undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST on Friday, 11 March 2011, with the epicenter approximately east...

of March 11, the cooling systems for three reactors (numbers 1, 2 and 4) of the Fukushima II (Fukushima Dai-ni) nuclear power plant were compromised due to damage from the tsunami. Nuclear Engineering International reported that all four units were successfully automatically shut down

Scram

A scram or SCRAM is an emergency shutdown of a nuclear reactor – though the term has been extended to cover shutdowns of other complex operations, such as server farms and even large model railroads...

, but emergency diesel generators at the site were out of order. People were evacuated around 10 kilometres (6.2 mi) from the plant, due to possible radioactive contamination

Radioactive contamination

Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...

Fukushima I Nuclear Power Plant

The , also known as Fukushima Dai-ichi , is a disabled nuclear power plant located on a site in the towns of Okuma and Futaba in the Futaba District of Fukushima Prefecture, Japan. First commissioned in 1971, the plant consists of six boiling water reactors...

, Fukushima Prefecture

Fukushima Prefecture

2011 Tōhoku earthquake and tsunami

of March 11, the cooling systems for multiple reactors (units 1, 2, 3) and spent fuel cooling ponds (all 6 units and central pool) of the Fukushima I (Fukushima Dai-ichi) nuclear power plant were compromised due to damage from the tsunami.
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