Tokai Nuclear Power Plant
Encyclopedia
The was Japan's first nuclear power plant. It was built in the early 1960s to the British Magnox
design, and generated power from 1966 until it was decommissioned in 1998. A second nuclear plant, built at the site in the 1970s, was the first in Japan to produce over 1000 MW of electricity, and still produces power as of 2011. The site is located in Tokai
in the Naka District
in Ibaraki Prefecture
, Japan
and is operated by the Japan Atomic Power Company
. The total site area amounts to 0.76 km2 (188 acres) with 0.33 km2, or 43% of it, being green area that the company is working to preserve.
technology. Unit 1 will be the first nuclear reactor to be decommissioned in Japan. The experience in decommissioning this plant is expected to be of use in the future when more Japanese plants are decommissioned. Below is a brief time-line of the process.
was the first nuclear reactor built in Japan to produce over 1,000 MW of electricity. By some formalities in the paperwork, the unit is technically separate from the rest of the nuclear facilities at Tokai-mura, but it is managed with the rest of them and even shares the same front gate.
On 11 October 2011 Tatsuya Murakami, the mayor of the village Tokai
, said in a meeting with minister Goshi Hosono
, that the Tokai Daini reactor situated at 110 kilometer from Tokio
should be decommissioned, because the reactor was more than 30 years old, and the people had lost confidence in the nuclear safety commission of the government.
the number 2 reactor was one of eleven nuclear reactors nationwide to be shut down automatically
. It was reported on 14 March that a cooling system pump for the number 2 reactor had stopped working. Japan Atomic Power Company stated that there was a second operational pump and cooling was working, but that two of three diesel generators used to power the cooling system were out of order.
After the disaster in Fukushima a stress-test was ordered by the Japanese government, after investigations the electrical installations of the Tokai Daini reactor did not meet the earthquake-resistance standards set by the government.
Although most of the works were completed by September 2010, cable holes in the levee were still not fully covered. This work was scheduled to take place before around May 2011. When the tsunami did hit the Tokai plant in March, the waves were 5.3 to 5.4 meters in height, even higher than earlier estimations but still 30 to 40 centimeters lower than the last assumption. The Tokai plant suffered a loss of external power-supply like it happened in Fukushima. Even the levee was overrun in Tokai, but only one of three seawater pumps did fail, and the reactors could be kept stable and safe in cold shutdown with the emergency diesel generator cooled by the two remaining seawater pumps.
Magnox
Magnox is a now obsolete type of nuclear power reactor which was designed and is still in use in the United Kingdom, and was exported to other countries, both as a power plant, and, when operated accordingly, as a producer of plutonium for nuclear weapons...
design, and generated power from 1966 until it was decommissioned in 1998. A second nuclear plant, built at the site in the 1970s, was the first in Japan to produce over 1000 MW of electricity, and still produces power as of 2011. The site is located in Tokai
Tokai, Ibaraki
is a village located in Naka District, Ibaraki, Japan. It is approximately 120 km north of Tokyo, Japan on the Pacific coast.As of 1 January 2005, the village has an estimated population of 35,467 and a population density of 946.29 persons per km²...
in the Naka District
Naka District, Ibaraki
Naka is a district of Ibaraki, Japan.Following the January 21, 2005 formation of the city of Naka, the district is coextensive with the village of Tōkai. As of January 1, 2005 population data, the district has an estimated population of 35,467 and a density of 946.29 persons per km²...
in 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...
, Japan
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...
and is operated by the Japan Atomic Power Company
Japan Atomic Power Company
The is a company initially formed to jump start the commercial use of nuclear power in Japan, and currently operates two different sites. According to the official web site, JAPC is "the only power company in Japan solely engaged in nuclear energy"....
. The total site area amounts to 0.76 km2 (188 acres) with 0.33 km2, or 43% of it, being green area that the company is working to preserve.
Reactors on site
| Unit | Type | Average electric power | Capacity | Construction started | First criticality | Commercial operation | Closure |
|---|---|---|---|---|---|---|---|
| Tōkai I | Magnox Magnox Magnox is a now obsolete type of nuclear power reactor which was designed and is still in use in the United Kingdom, and was exported to other countries, both as a power plant, and, when operated accordingly, as a producer of plutonium for nuclear weapons... (GCR Gas Cooled Reactor A gas-cooled reactor is a nuclear reactor that uses graphite as a neutron moderator and carbon dioxide as coolant... ) |
159 MW | 166 MW | March 1, 1961 | November 10, 1965 | July 25, 1966 | March 31, 1998 |
| Tōkai II | BWR/5 Boiling water reactor The boiling water reactor is a type of light water nuclear reactor used for the generation of electrical power. It is the second most common type of electricity-generating nuclear reactor after the pressurized water reactor , also a type of light water nuclear reactor... |
1060 MW | 1100 MW | October 3, 1973 | March 13, 1978 | November 28, 1978 |
Unit 1
This reactor was built based on British developed MagnoxMagnox
Magnox is a now obsolete type of nuclear power reactor which was designed and is still in use in the United Kingdom, and was exported to other countries, both as a power plant, and, when operated accordingly, as a producer of plutonium for nuclear weapons...
technology. Unit 1 will be the first nuclear reactor to be decommissioned in Japan. The experience in decommissioning this plant is expected to be of use in the future when more Japanese plants are decommissioned. Below is a brief time-line of the process.
- March 31, 1998: operations cease
- March 2001: last of the nuclear fuel moved off-site
- October 4, 2001: decommissioning plan announced
- December 2001: decommissioning begins, spent fuel pool is cleaned
- 2003: turbine room and electric generator taken down
- Late 2004: fuel moving crane dismantled
- 2011: the reactor itself is dismantled
Unit 2
This Boiling Water ReactorBoiling water reactor
The boiling water reactor is a type of light water nuclear reactor used for the generation of electrical power. It is the second most common type of electricity-generating nuclear reactor after the pressurized water reactor , also a type of light water nuclear reactor...
was the first nuclear reactor built in Japan to produce over 1,000 MW of electricity. By some formalities in the paperwork, the unit is technically separate from the rest of the nuclear facilities at Tokai-mura, but it is managed with the rest of them and even shares the same front gate.
On 11 October 2011 Tatsuya Murakami, the mayor of the village Tokai
Tokai
Tōkai in Japanese may refer to:* Tōkai region, a subregion of Chūbu* Tōkai, Ibaraki, a village, also nown as "Tokaimura" * Tōkai, Aichi, a city* Tōkai University, a private university in Tokyo...
, said in a meeting with minister Goshi Hosono
Goshi Hosono
is a Japanese politician of the Democratic Party of Japan, a member of the House of Representatives in the Diet . A native of Ōmihachiman, Shiga and graduate of Kyoto University, he was elected to the House of Representatives for the first time in 2000. He is the current Nuclear Disaster Minister...
, that the Tokai Daini reactor situated at 110 kilometer from Tokio
Tokio
Tokio is an alternative spelling for Tokyo, the capital of Japan, used primarily in non-english speaking countries.Tokio may also refer to:-Music:*Tokio , a Japanese pop/rock band**Tokio , the debut by Tokio...
should be decommissioned, because the reactor was more than 30 years old, and the people had lost confidence in the nuclear safety commission of the government.
Incidents
Following the 2011 Tōhoku earthquake and tsunami2011 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...
the number 2 reactor was one of eleven nuclear reactors nationwide to be shut down automatically
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...
. It was reported on 14 March that a cooling system pump for the number 2 reactor had stopped working. Japan Atomic Power Company stated that there was a second operational pump and cooling was working, but that two of three diesel generators used to power the cooling system were out of order.
After the disaster in Fukushima a stress-test was ordered by the Japanese government, after investigations the electrical installations of the Tokai Daini reactor did not meet the earthquake-resistance standards set by the government.
Voluntarily measurements by the Japan Atomic Power saved the plant in the 11 March Tsunami
During the earthquake of 11 March 2011, the Tokai-power plant suffered external power-loss, just like it happened in Fukushima. Thanks to extra and voluntarily measurements taken by the Japan Atomic Power, the reactors could still be cooled safely, and another major accident was prevented. In 2002 was concluded, based on an evaluation technology adopted by the Japan Society of Civil Engineers, that at this place tsunami waves could be expected as high as 4.86 meters. After the government of the prefecture Ibaraki in October 2007 their own calculations published, and estimated that these waves could be as high as 6 to 7 meters. Japan Atomic Power changed its wave level assumption to 5.7 meters. The reconstruction works were started in July 2009 to raise the height of the 4.9-meter protection around the plant to 6.1 meters, in order to protect the seawater pumps designed to cool an emergency diesel generator.Although most of the works were completed by September 2010, cable holes in the levee were still not fully covered. This work was scheduled to take place before around May 2011. When the tsunami did hit the Tokai plant in March, the waves were 5.3 to 5.4 meters in height, even higher than earlier estimations but still 30 to 40 centimeters lower than the last assumption. The Tokai plant suffered a loss of external power-supply like it happened in Fukushima. Even the levee was overrun in Tokai, but only one of three seawater pumps did fail, and the reactors could be kept stable and safe in cold shutdown with the emergency diesel generator cooled by the two remaining seawater pumps.
See also
- 2011 Japanese nuclear accidents2011 Japanese nuclear accidentsThis is a list of articles describing aspects of the nuclear shut-downs, failures, and nuclear meltdowns triggered by the 2011 Tōhoku earthquake and tsunami.-Fukushima nuclear power plants:* Fukushima I Nuclear Power Plant...
- List of boiling water reactors
- Lists of nuclear disasters and radioactive incidents
- Tokaimura nuclear accidentTokaimura nuclear accidentThe Tokaimura nuclear accident , which occurred on 30 September 1999, resulted in two deaths. At that time, it was Japan's worst civilian nuclear radiation accident. The criticality accident occurred in a uranium reprocessing facility operated by JCO , a subsidiary of Sumitomo Metal Mining Co...