Hamaoka Nuclear Power Plant
Encyclopedia
Nuclear power plant
A nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.Nuclear power plants are usually...
located in Omaezaki city
Omaezaki, Shizuoka
is a city in Shizuoka Prefecture, Japan. Omaezaki is located at the tip of a peninsula on Japan's Pacific coast. As of 2010, the city had an estimated population of 34,614 and the density of 530 persons per km². The total area was 65.86 km².- Geography :...
, Shizuoka Prefecture
Shizuoka Prefecture
is a prefecture of Japan located in the Chūbu region on Honshu island. The capital is the city of Shizuoka.- History :Shizuoka prefecture was formed from the former Tōtōmi, Suruga and Izu provinces.The area was the home of the first Tokugawa Shogun...
, on 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...
's east coast, 200 km south-west of Tokyo
Tokyo
, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...
. It is managed by the Chubu Electric Power Company
Chubu Electric Power Company
, abbreviated as Chuden in Japanese, is the electric provider for the middle Chūbu region of the Honshū island of Japan. It provides electricity at 60 Hz, though an area of Nagano Prefecture uses 50 Hz. Chubu Electric Power ranks third among Japan’s largest electric utilities in terms of power...
. There are five units contained at a single site with a net area of 1.6 km2 (395 acres). A sixth unit began construction on December 22, 2008. On January 30, 2009, Hamaoka-1 and Hamaoka-2 were permanently shut down.
On 6 May, 2011, Prime Minister Naoto Kan
Naoto Kan
is a Japanese politician, and former Prime Minister of Japan. In June 2010, then-Finance Minister Kan was elected as the leader of the Democratic Party of Japan and designated Prime Minister by the Diet to succeed Yukio Hatoyama. On 26 August 2011, Kan announced his resignation...
requested the plant be shut down as an earthquake of magnitude 8.0 or higher is estimated 87% likely to hit the area within the next 30 years. Kan wanted to avoid a possible repeat of the Fukushima nuclear disaster. On 9 May 2011, Chubu Electric decided to comply with the government request. In July 2011, a mayor in Shizuoka Prefecture and a group of residents filed a lawsuit seeking the decommissioning of the reactors at the Hamaoka nuclear power plant permanently.
Earthquake susceptibility
Hamaoka is built directly over the subduction zoneSubduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...
near the junction of two tectonic plates
Tectonic Plates
Tectonic Plates is a 1992 independent Canadian film directed by Peter Mettler. Mettler also wrote the screenplay based on the play by Robert Lepage. The film stars Marie Gignac, Céline Bonnier and Robert Lepage.-Plot summary:...
, and a major Tokai earthquake
Tokai earthquakes
The Tōkai earthquakes are major earthquakes that have occurred regularly with an interval of 100 to 150 years in the Tōkai region of Japan. The Tokai segment has been struck by earthquakes in 1498, 1605, 1707 and 1854...
is said to be overdue. The possibility of such a shallow magnitude
Moment magnitude scale
The moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The magnitude is based on the seismic moment of the earthquake, which is equal to the rigidity of the Earth multiplied by the average amount of slip on the fault and the size of...
8.0 earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
in the Tokai region
Tokai region
The is a sub-region of the Chūbu region in Japan that runs along the Pacific Ocean. The name means "East sea" and comes from the Tōkaidō, one of the Edo Five Routes...
was pointed out by Kiyoo Mogi
Kiyoo Mogi
Dr is a prominent seismologist. He is regarded as Japan's foremost authority on earthquake prediction and is a former chair of the Japanese Coordinating Committee for Earthquake Prediction . Mogi is also a former Director of the University of Tokyo's Earthquake Research Institute, was a professor...
in 1969, 7 months before permission to construct the Hamaoka plant was sought, and by the Coordinating Committee for Earthquake Prediction
Coordinating Committee for Earthquake Prediction
The Coordinating Committee for Earthquake Prediction in Japan was founded in April 1969, as part of the Geodesy Council's Second Earthquake Prediction Plan, in order to carry out a comprehensive evaluation of earthquake data in Japan. The committee consists of 30 members and meets four times each...
(CCEP) in 1970, prior to the permission being granted on December 10, 1970. As a consequence, Professor Katsuhiko Ishibashi
Katsuhiko Ishibashi
is a professor in the Research Center for Urban Safety and Security in the Graduate School of Science at Kobe University, Japan and a seismologist who has written extensively in the areas of seismicity and seismotectonics in and around the Japanese Islands...
, a former member of a government panel on nuclear reactor safety, claimed in 2004 that Hamaoka was 'considered to be the most dangerous nuclear power plant in Japan' with the potential to create a genpatsu-shinsai
Genpatsu-shinsai
, meaning nuclear power plant earthquake disaster is a term which was coined by Japanese seismologist Professor Katsuhiko Ishibashi in 1997...
(domino-effect nuclear power plant earthquake disaster). In 2007, following the 2007 Chūetsu offshore earthquake
2007 Chuetsu offshore earthquake
The Chūetsu Offshore Earthquake was a powerful magnitude 6.6 earthquake that occurred 10:13 a.m. local time on July 16, 2007, in the northwest Niigata region of Japan. The earthquake shook Niigata and neighbouring prefectures...
, Dr Mogi, by then chair of Japan's Coordinating Committee for Earthquake Prediction
Coordinating Committee for Earthquake Prediction
The Coordinating Committee for Earthquake Prediction in Japan was founded in April 1969, as part of the Geodesy Council's Second Earthquake Prediction Plan, in order to carry out a comprehensive evaluation of earthquake data in Japan. The committee consists of 30 members and meets four times each...
, called for the immediate closure of the plant.
On 6 May 2011, Japanese prime minister Naoto Kan
Naoto Kan
is a Japanese politician, and former Prime Minister of Japan. In June 2010, then-Finance Minister Kan was elected as the leader of the Democratic Party of Japan and designated Prime Minister by the Diet to succeed Yukio Hatoyama. On 26 August 2011, Kan announced his resignation...
asked Chubu Electric Power Company
Chubu Electric Power Company
, abbreviated as Chuden in Japanese, is the electric provider for the middle Chūbu region of the Honshū island of Japan. It provides electricity at 60 Hz, though an area of Nagano Prefecture uses 50 Hz. Chubu Electric Power ranks third among Japan’s largest electric utilities in terms of power...
, which operates the Hamaoka plant, to halt reactors No. 4 and No. 5, and not to restart reactor No. 3 which was then offline for regular inspection. Kan said that a science ministry panel on earthquake research has projected an 87% possibility of a magnitude-8-class earthquake hitting the region within 30 years. He said that considering the unique location of the Hamaoka plant, the operator must draw up and implement mid-to-long-term plans to ensure the reactors can withstand the projected Tokai Earthquake and any triggered tsunami. Kan also said that until such plans are implemented, all the reactors should remain out of operation. Chubu Electric has decided to comply with the government request on 9 May 2011. Yomiuri Shinbun, one of Japan's largest newspapers, criticized Kan and his request, calling it "abrupt" and noting the difficulty towards Chubu Electric's shareholders and further stated Kan "should seriously reflect on the way he made his request." Yomiuri followed up with an article that wondered how dangerous Hamaoka really was and claimed the request was "a political judgment that went beyond technological worthiness." The next day damage to the pipes inside the condenser were discovered following a leak of seawater into the reactor.
The plant has been designed to withstand an earthquake of magnitude 8.5. Sand hills of up to 15 metres (49.2 ft) height provide defence against a tsunami of up to 8 metres (26.2 ft) high, but Hamaoka currently lacks a concrete sea barrier.
On 22 July 2011 plans were unfolded to build an 18-meter-high embankment by December 2012 to prevent tsunami damage to the facility. This would protect the reactors against waves higher than the waves that occurred in the Fukushima Daiichi nuclear power plant on March 11, 2011. The barrier would also be 10 meters taller than the highest waves expected in the area in the event of 3 major earthquakes occurring at the same time. Plans were studied to build a new embankment 1.5 kilometers along the coast by the plant. Next to this a waterproof building was planned to house a backup-pump and also the wall around the reactors was extended. Overall costs of the plans: 1.3 billion dollars.
Reactor data
| Unit | Reactor Type | Net Capacity | Gross Capacity | Construction Start | Grid Connection | Commercial Operation | Status |
|---|---|---|---|---|---|---|---|
| Hamaoka-1 | BWR 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... |
515 MW | 540 MW | June 10, 1971 | August 13, 1974 | March 17, 1976 | Shutdown January 30, 2009 |
| Hamaoka-2 | BWR 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... |
806 MW | 840 MW | June 14, 1974 | May 4, 1978 | November 29, 1978 | Shutdown January 30, 2009 |
| Hamaoka-3 | 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... |
1056 MW | 1100 MW | April 18, 1983 | January 20, 1987 | August 28, 1987 | Shutdown May, 2011 |
| Hamaoka-4 | 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... |
1092 MW | 1137 MW | October 13, 1989 | January 27, 1993 | September 3, 1993 | Shutdown May, 2011 |
| Hamaoka-5 | ABWR Advanced Boiling Water Reactor The Advanced Boiling Water Reactor is a Generation III boiling water reactor. The ABWR is currently offered by GE Hitachi Nuclear Energy and Toshiba... |
1212 MW | 1267 MW | July 12, 2000 | April 26, 2004 | January 18, 2005 | Shutdown May, 2011 |
Performance
The plant showed stellar performance through the 1990s, however, problems that caused Unit 1 to be shut down from 2001 to present, and Unit 2 from 2005 to present significantly hurt the capacity factor figures in the recent history of the plant.
Unit 1 HPCI Rupture
On November 7, 2001, a valve in the HPCI system of Unit 1 ruptured during a Periodical-manual-startup-test. Since this is considered a part of the ECCS, the implications reach further than the event itself, and drew into question the reliability of the emergency safety system. Unit 2 was also shut down for the purpose of investigating similar structures.Unit 5 Steam Turbine Problems
Too recent to cover the entire relevant time frame in the data above, on June 15, 2006 Unit 5 was shut down due to excessive turbine vibrations. It was discovered that a number of turbine vanes had actually completely broken off. In the turbine that failed, nearly all vanes showed fractures or cracking while the majority of the vanes of the other two low pressure turbines also showed problems. Fault for the problems was placed on HitachiHitachi
Hitachi is a multinational corporation specializing in high-technology.Hitachi may also refer to:*Hitachi, Ibaraki, Japan*Hitachi province, former province of Japan*Prince Hitachi and Princess Hitachi, members of the Japanese imperial family...
, the NSSS supplier.
Previous events
- 1991, April 4 - Unit 3 reactor coolant supply lowered, automatic SCRAMScramA 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...
- 2001, November 7 - Unit 1 pipe burst accident
- 2001, November 9 - Unit 1 coolant leak accident
- 2002 - In an independent inspection, it was discovered that 16 unique signs of cracks in steam pipes were known by the utility but failed to report to the prefecture level authorities.
- 2002, May 24 - Unit 2 water leak
- 2004, February 21 - Unit 2 outbreak of fire in room above turbine room.
- 2004, August - Unit 4 problem with fabrication of data by utility.
- 2005, November 4 - Unit 1 pipe leak incident
- 2005, November 16 - Unit 3 outside pipe leak due to corrosion
- 2005, November 16 - Unit 1 spent fuel pool had foreign matter detected in it
- 2006, June - Unit 5 damage to turbine blades
- 2007, March - Utility admitted to 14 cases of unfair business practices
- 2009, August 11 - Units 4 and 5 (the only ones operating) automatically shut down due to an earthquake
- 2011, May 6 - Prime minister Naoto KanNaoto Kanis a Japanese politician, and former Prime Minister of Japan. In June 2010, then-Finance Minister Kan was elected as the leader of the Democratic Party of Japan and designated Prime Minister by the Diet to succeed Yukio Hatoyama. On 26 August 2011, Kan announced his resignation...
orders Units 4 and 5 to be shut down and Unit 3 not to be restarted - 2011, May 15 - 400 tons of seawater were found to have leaked into the Unit 5 turbine steam condenser
- 2011, May 20 - Damaged pipes were located in the Unit 5 condenser and the operator estimated that about 5 tons of seawater may have entered the reactor itself.