The Shimane Nuclear Power Plant is a nuclear power plant located in the town of Kashima-chou in the city of Matsue in the Shimane Prefecture. It is owned and operated by the Chūgoku Electric Power Company.

This plant was once said to be the closest nuclear power plant to a prefecture capital. However, on March 31, 2005, the area of Kashima-chou merged with Matsue (it was formerly in the Yatsuka District), making it exactly the same city as the prefecture capital.

New Scientist magazine has reported that, in June 2006, a previously unknown geological fault was identified close to the Shimane Nuclear Power Plant, but it is expected to be years before the plant is strengthened.

Shimane Nuclear Power Plant is located on a site that is 1.92 square kilometres (470 acres).

Reactors on site

Name	Reactor Type	Commission date	Power Rating
Shimane - 1	BWR	March 29, 1974	460 MW
Shimane - 2	BWR	February 10, 1989	820 MW
Shimane - 3 (groundwork underway)	ABWR	March 2012	1373 MW

Shimane Nuclear Power Plant
Country	Japan
Construction began	July 2, 1970
Commission date	March 29, 1974
Operator(s)	Chugoku Electric Power Company
Reactor information
Reactors operational	1 x 460 MW 1 x 820 MW
Reactors planned	1 x 1373 MW
Power generation information
Annual generation	7,785 GW·h
Net generation	197,069 GW·h

The Tsuruga Nuclear Power Plant is a nuclear power plant located in the town of Tsuruga, Fukui Prefecture. It is operated by the Japan Atomic Power Company. The total site area amounts to 5.12 km² (1,265 acres) with 4.80 km², or 94% of it, being green area that the company is working to preserve.

The Tsuruga Nuclear Power Plant is a dual site with the decommisioned prototype Fugen Nuclear Power Plant.

The construction of two new nuclear reactors is currently underway.

In March 1981, drainage from unit 1 caused a release of radioactivity. The forty-day cover-up of a spill of 16 tons of radioactive primary cooling water was revealed only in April.

Nuclear Reactors on Site

Unit	Type	Commission date	Electric Power
Tsuruga - 1	BWR	March 14, 1970	357 MW
Tsuruga - 2	PWR	February 17, 1987	1160 MW
Tsuruga - 3 (under construction)	APWR	planned July 2017	1538 MW
Tsuruga - 4 (under construction)	APWR	planned July 2018	1538 MW

Tsuruga Nuclear Power Plant
Country	Japan
Construction began	November 24, 1966
Commission date	March 14, 1970
Operator(s)	Japan Atomic Power Company
Reactor information
Reactors operational	357 MW 1160 MW
Reactors planned	2 x 1538 MW
Power generation information
Annual generation	9,096 GW·h
Net generation	234,086 GW·h

The Mihama Nuclear Power Plant is operated by The Kansai Electric Power Company, Inc. and is in the town of Mihama, Fukui Prefecture, about 320 km west of Tokyo. It is on a site that is 520,000 m² of which 60% is green space.

Reactors on Mihama NPP

Unit	Reactor Type	Average Electric Output	Electric Power Rating	Commission date
Mihama - 1	PWR	320 MW	340 MW	28.11.1970
Mihama - 2	PWR	470 MW	500 MW	25.07.1972
Mihama - 3	PWR	780 MW	826 MW	01.12.1976

Events

The Mihama Nuclear Power Plant has been notable beyond most nuclear plants due to the severity of accidents that have happened there, the 2004 steam explosion in particular.

September 2, 1991

Unit 2 steam generator had one tube fully break. This triggered a SCRAM with full activation of the Emergency Core Cooling System. Eventually, a small amount of radiation was released to the outside.

May 17, 2003

Unit 2 steam generators had two holes open simultaneously. There was no radioactive release to the environment.

August 9, 2004

On 9 August 2004, an accident occurred in a building housing turbines for the Mihama 3 reactor. Hot water and steam leaking from a broken pipe killed four workers and resulted in seven others being injured. The accident had been called Japan's worst nuclear power accident before the crisis at Fukushima I Nuclear Power Plant.

The Mihama 3 is an 826 megawatts electric, 3-loop Westinghouse type pressurized-water reactor (PWR) which has been in service since 1976. The pipe rupture occurred in a 55.9 centimeter (cm) (22 inch) outside diameter pipe in the ‘A’ loop condensate system between the fourth feedwater heater and the deaerator, downstream of an orifice for measuring single-phase water flow. At the time of the secondary piping rupture, 105 workers were preparing for periodic inspections to commence.

A review of plant parameters did not uncover any precursor indicators before the accident nor were there any special operations that could have caused the pipe rupture. An investigation concluded that water quality had been maintained since the commissioning of the plant.

Japan's previous most deadly accident at a nuclear facility took place at a uranium processing plant in Tokaimura, north of Tokyo, on September 30, 1999, when an uncontrolled nuclear chain reaction was triggered after three poorly trained workers mixed Uranium nuclear fuel in a bucket. The resulting release of radiation killed two workers, and exposed one other worker to radiation above legal limits.

The Mihama NPP started back up in January 2007 after making various changes and obtaining permission from Fukui Prefecture and industry regulators.

2006

Another fire occurred in 2006, two workers sustained injuries. There were no fatalities and no release of radioactivity detected, though the ash involved in the fire included some low level radioactive waste.

Mihama Nuclear Power Plant
Country	Japan
Locale	Mihama, Fukui Prefecture
Status	Operational
Construction began	February 1, 1967
Commission date	November 28, 1970
Operator(s)	The Kansai Electric Power Company, Inc.
Reactor information
Reactors operational	1 x 340 MW 1 x 500 MW 1 x 826 MW

The Sendai Nuclear Power Plant is a nuclear power plant located in the city of Satsumasendai in the Kagoshima Prefecture. It is owned and operated by the Kyūshū Electric Power Company.

The plant is on a site of 1.45 km² (358 acres), employs 277 workers, and indirectly employs 790.

The reactors are of the 3-loop M type pressurized water reactor, built by Mitsubishi Heavy Industries.

Reactors on Site

Name	Reactor Type	Commission date	Gross Power Rating	Core Tonnage	Price to build
Sendai-1	PWR	July 4, 1984	890 MW	72 tons/uranium dioxide	278.7 billion Yen
Sendai-2	PWR	November 28, 1985	890 MW	72 tons/uranium dioxide	228.7 billion Yen

Sendai Nuclear Power Plant
Country	Japan
Construction began	December 15, 1979
Commission date	July 4, 1984
Operator(s)	Kyūshū Electric Power Company
Reactor information
Reactors operational	2 x 890 MW {gross) 2 x 846 MW {net)
Power generation information
Annual generation	12,901 GW·h
Net generation	276,655 GW·h

The Shika Nuclear Power Plant 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 (395 acres).

On June 18, 1999 during an inspection, an emergency control rod insertion was to be performed on Unit 1. One rod was to be inserted into the reactor, however, due to improper following of the procedure, instead of one rod inserting, 3 rods withdrew. For the next 15 minutes, the reactor was in a dangerous criticality state. This event was not revealed until March 15, 2007, since it was covered up in the records. The unit has been shut down since that date.

Immediately after the event was revealed, the president of the Hokuriku Electric Power Company was called to the Ministry of Economy, Trade and Industry office and ordered to shut down the unit 1 reactor. Note that this was not the same president as when the event happened in 1999.

On June 5, 2007 the committee chairman of the Japan Nuclear Safety Commission inspected the control rod housing and drive mechanisms and evaluated that the event was due to cutting corners. He also concluded that the reactor operators at the time were under a lot of pressures from above, and simply punishing the operators would not be an effective deterrent for future accidents. One proposed measure was to have alarms automatically record when they go off so that records can not be altered.

A lower court had ordered the entire plant to be shut down, but that decision was later overturned by Nagoya's high court. The utility put in a request to the Ishikawa prefectural government and the town of Shika for the restart of unit 1. The unit returned to power on May 11, 2009 and resumed commercial operation on May 13.

Reactors on Site

Unit	Type	Commission date	Electric Power	Thermal Power	Maker
Shika - 1	BWR	July 30, 1993	540 MW	1,593 MW	Hitachi
Shika - 2	ABWR	March 15, 2006	1,358 MW	3,926 MW	Hitachi

Shika Nuclear Power Plant
Country	Japan
Construction began	July 1, 1989
Commission date	July 30, 1993
Operator(s)	Hokuriku Electric Power Company
Reactor information
Reactors operational	1 x 540 MW 1 x 1358 MW
Power generation information
Annual generation	7,456 GW·h
Net generation	54,864 GW·h

The Ikata Nuclear Power Plant is a nuclear power plant in the town of Ikata in the Nishiuwa District in Ehime Prefecture, Japan. It is the only nuclear plant on the island of Shikoku. It is owned and operated by the Shikoku Electric Power Company.

The plant is on a site with an area of 860,000 m² (212 acres). 47% of the site is green, compared to the other plants Yonden operates which are 13.8, 45.5, 20.1, and 21.2%.

Reactors on site

Unit	Reactor type	Capacity	First criticality	Commissioned	Type
Ikata - 1	PWR	566 MW	February 17, 1977	September 30, 1977	Mitsubishi 2-loop plant
Ikata - 2	PWR	566 MW	August 19, 1981	March 19, 1982	Mitsubishi 2-loop plant
Ikata - 3	PWR	890 MW	March 29, 1994	December 15, 1994	Mitsubishi/Westinghouse 3-loop plant

Accidents

• On March 3, 2004 there was a coolant leak in Unit 3.

Technical achievements

• On August 13, 2003 The maximum burnup for spent fuel was changed from 48,000 MWd/ton to 55,000 MWd/ton.
• Ikata - 1 became the world's first all-in-one extraction of the core internals in a PWR. Mitsubishi Heavy Industries did replacement work of the upper and lower internals in order to accommodate more control rods and allow for higher fuel burnup.
• Ikata - 3 loaded a partial MOX fuel core for the cycle beginning February 24, 2010.

Ikata Nuclear Power Plant
Country	Japan
Construction began	September 1, 1973
Commission date	September 30, 1977
Operator(s)	Shikoku Electric Power Company
Reactor information
Reactors operational	2 x 566 MW 1 x 890 MW
Power generation information
Annual generation	12,925 GW·h
Net generation	281,159 GW·h

The Tomari Nuclear Power Plant is the only nuclear power plant in Hokkaidō, Japan. It is located in the town of Tomari in the Furuu District and managed by the Hokkaido Electric Power Company. All of the reactors are Mitsubishi designs. The Tomari Nuclear Power Plant was originally going to be located on an island and be named the Kyowa-Tomari NPP, but there was a change in plans and the location and name was changed.

Reactors on Tomari Nuclear Power Plant

Unit	Type	Commission date	Electric Power
Tomari - 1	PWR	June 22, 1989	579 MW
Tomari - 2	PWR	April 12, 1991	579 MW
Tomari - 3	PWR	December 22, 2009	912 MW

Events

• In 2000, a worker fell into a sump tank in the chemical control system of the plant. The worker received a high radiation dose and died in the hospital later.
• In September 2003, there was a leak in the steam generator causing about 140 liters of primary coolant to leak.
• In May 2005, there was a trespassing event where someone crossed the fence into the property. Some people had apparently been gathering bamboo sticks as a part of a part time job and when discovered, 24 arrests were made. There were all questioned due to strong concerns about terrorism at the plant.
• Also in 2005, company sensitive information was leaked from a worker's computer by a virus.
• In July 2007, there were three separate fires related to the new unit that was under construction. Electrical wiring had apparently been cut and foul play was expected. Coming just days after a more serious earthquake caused events at the Kashiwazaki-Kariwa plant, it dealt a further blow to Japan's nuclear power industry.
• On September 29, 2007, Kazutoshi Michinaka reported that there was no radiation leakage, and no one was hurt in the small fire at the half-built third reactor at Tomari Nuclear Power Plant, Hokkaidō, Japan At least 7 arson cases have been reported at the construction site this year.

Tomari Nuclear Power Plant
Country	Japan
Construction began	April 18, 1985 (1985-04-18)
Commission date	June 22, 1989 (1989-06-22)
Operator(s)	Hokkaido Electric Power Company
Reactor information
Reactors operational	2 x 579 MW 1 x 912 MW
Power generation information
Annual generation	8,554 GW·h
Net generation	138,706 GW·h

The Tōkai Nuclear Power Plant 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 2009. The site is located in Tokai in the Naka District in Ibaraki Prefecture, Japan and is operated by the Japan Atomic Power Company.

Tokai Nuclear Power Plant Reactors

Unit	Type	Average electric power	Capacity	Construction started	Construction completed	First criticality	Closure
Tōkai I	Magnox (GCR)	159 MW	166 MW	March 1, 1961	November 10, 1965	July 25, 1966	March 31, 1988
Tōkai II	BWR	1060 MW	1100 MW	October 3, 1973	March 13, 1978	November 28, 1978

Unit 1

This reactor was built based on British developed Magnox 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

Tokai Nuclear Power Plant Unit 2

This Boiling Water Reactor was the first nuclear reactor built in Japan to produce over 1000 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. The power produced at the unit is sold by both the Tokyo Electric Company and the Tohoku Electric Company.

Tokai Nuclear Power Plant After 2011 Tohoku Earthquake and Tsunami

The number 2 reactor at Tōkai Nuclear Power Plant was shut down automatically. On 14 March it was reported that a cooling system pump for this reactor had stopped working; however, the Japan Atomic Power Company stated that there was a second operational pump sustaining the cooling system, but that two of three diesel generators used to power the cooling system were out of order.

The Onagawa Nuclear Power Plant is a nuclear power plant in Onagawa in the Oshika District and Ishinomaki city, Miyagi Prefecture, Japan. It is managed by the Tohoku Electric Power Company. It was the most quickly constructed nuclear power plant in the world.

The Onagawa-3 unit is the most modern reactor in all of Japan. It was used as a prototype for the Higashidori Nuclear Power Plant. The plant conforms fully to ISO 14001, a set of international environmental management standards. The plant's waste heat water leaves 7 degrees Celsius higher than it came in and is released 10 meters under the surface of the water, in order to reduce adverse effects on the environment.

All the reactors were constructed by Toshiba.

Onagawa Nuclear Power Plant Reactors

Unit	Type	Start of Operation	Electric Power
Onagawa - 1	BWR	June 1, 1984	524 MW
Onagawa - 2	BWR	July 28, 1995	825 MW
Onagawa - 3	BWR	January 30, 2002	825 MW

Unit 1

Since November 11, 2006 this unit has been shut down due to the result of a test.

Unit 2

• May 2006 it was confirmed that a pipe was leaking due to debris damage.
• June 7, 2006 Difficulties with pressure control prompted further inspections.
• July 7, 2006 METI and the Nuclear and Industrial Safety Agency determined that the plant's performance was not satisfactory.

Unit 3

• July 7, 2006 Due to pipe integrity concerns the reactor was shut down.
• November 25, 2006 Following repairs the reactor was restarted.

Earthquake Events

• The Onagawa Nuclear Power Plant was affected by the 2005 Miyagi earthquake and recorded vibrations above what the plant was designed for. Analysis after the event, however, found no damage to the reactor systems. Some people reported seeing smoke come from the plant after the earthquake and reported it, thinking that it indicated an accident, but the smoke was actually produced by the backup diesel generators. These generators were designed to start up in such an event so that off-site power can still be provided to certain reactor systems. A tank of sulfuric acid on the roof did burst releasing some sulfuric acid into the air, but it was retrieved and processed later.
• A fire at the plant from the turbine section of the plant following the 2011 Sendai earthquake was reported by Kyodo News.
• On 13 March the lowest-level state of emergency was declared regarding the Onagawa plant by TEPCO, as radioactivity readings temporarily exceeded allowed levels in the area of the plant. TEPCO stated this was due to radiation from the Fukushima I nuclear accidents and not from the Onagawa plant itself.

Onagawa Nuclear Power Plant
Country	Japan
Construction began	1970
Commission date	June 1, 1984
Operator(s)	Tohoku Electric Power Company
Reactor information
Reactors operational	1 x 524 MW 2 x 825 MW
Power generation information
Annual generation	5,283 GW·h
Net generation	157,545 GW·h

The Takahama Nuclear Power Plant is a nuclear power plant located in the Ōi District in the Fukui Prefecture. Takahama Nuclear Power Plant is owned and operated by the Kansai Electric Power Company. The plant houses 4 nuclear reactors. Installed capacity on the Takahama Nuclear Power Plant is 3304 MW.

Reactors on Takahama Nuclear Power Plant

Name	Reactor Type	First Criticality	Power Rating
Takahama - 1	PWR	November 14, 1974	826 MW
Takahama - 2	PWR	November 14, 1975	826 MW
Takahama - 3	PWR	January 17, 1985	826 MW
Takahama - 1	PWR	June 5, 1985	826 MW

The Genkai Nuclear Power Plant is a nuclear power plant located in the town of Genkai in the Higashimatsuura District in the Saga Prefecture. It is owned and operated by the Kyūshū Electric Power Company.

Unit 3 has been selected as a special Plutonium fuel test case. The Genkai Nuclear Power Plant is on a site with a total of 0.87 square kilometers.

Reactors on Site

All reactors at the Genkai plant use low enriched (3-4%) Uranium dioxide fuel.

Name	Reactor Type	Power Rating	Thermal Power	Core Tonnage	# of Fuel Assemblies	Capital Costs
Genkai - 1	PWR	559 MW	1650 MW	48 tons	121	54,500,000,000 yen
Genkai - 2	PWR	559 MW	1650 MW	48 tons	121	123,600,000,000 yen
Genkai - 3	PWR	1180 MW	3423 MW	89 tons	193	399,300,000,000 yen
Genkai - 4	PWR	1180 MW	3423 MW	89 tons	193	324,400,000,000 yen

In 2010 there are plans to use plutonium fuel at unit 3.

Genkai Nuclear Power Plant
Country	Japan
Coordinates	33°30′56″N 129°50′14″E / 33.51556°N 129.83722°E / 33.51556; 129.83722Coordinates: 33°30′56″N 129°50′14″E / 33.51556°N 129.83722°E / 33.51556; 129.83722
Construction began	1970
Commission date	October 15, 1975
Owner(s)	Kyūshū Electric Power Company
Operator(s)	Kyushu Electric Power Company
Reactor information
Reactors operational	2 x 559 MW 2 x 1180 MW
Power generation information
Annual generation	25,380 GW·h
Net generation	407,958 GW·h

photo: google.com

The Fukushima II Nuclear Power Plant is a nuclear power plant located in the town of Naraha and Tomioka in the Futaba District of Fukushima Prefecture. Like Fukushima I, it is run by The Tokyo Electric Power Company.

Unit	Type	First Criticality	Electric Power	Installation costs (yen/kW)
Fukushima II - 1	BWR	4/20/1982	1100 MW	25
Fukushima II - 2	BWR	2/3/1984	1100 MW	23
Fukushima II - 3	BWR	6/21/1985	1100 MW	29
Fukushima II - 4	BWR	8/25/1987	1100 MW	25

In January 1989, an impeller blade on one of the reactor coolant pumps in Unit 3 broke at a weld, causing a large amount of metal mass to flow throughout the primary loop. As a result, the reactor was shut down for a considerably long time, making this one of the most serious accidents at the site.

In March 2011, nuclear reactors were automatically shut down at the Fukushima No. 1 and Fukushima No. 2 plants after the biggest-magnitude quake in the country's modern history. Tokyo Electric on March 12 reported that the cooling system for three reactors (nrs 1, 2 and 4) at the plant had topped 100 °C between 5:30 and 6:10 JST, less than one hour after the start of additional cooling with condensate water, and that the "pressure suppression function was lost".













Fukushima 2 after tsunami
photo: google.com

The Fukushima I Nuclear Power Plant is a nuclear power plant located in the town of Okuma in the Futaba District of Fukushima Prefecture. With 8 separate units located on site, Fukushima I is one of the largest nuclear plants in the world. Fukushima I is the first nuclear plant to be constructed and run entirely by the The Tokyo Electric Power Company.

Unit	Type	First Criticality	Electric Power
Fukushima I - 1	BWR	March 26, 1971	460 MW
Fukushima I - 2	BWR	July 18, 1974	784 MW
Fukushima I - 3	BWR	March 27, 1976	784 MW
Fukushima I - 4	BWR	October 12, 1978	784 MW
Fukushima I - 5	BWR	April 18, 1978	784 MW
Fukushima I - 6	BWR	October 24, 1979	1100 MW
Fukushima I - 7 (planned)	ABWR	October, 2013	1380 MW
Fukushima I - 8 (planned)	ABWR	October, 2014	1380 MW

Fukushima I Nuclear Power Plant
The Fukushima 1 NPP
Data
Country	Japan
Operator	Tokyo Electric Power Company
Built	1966
Start of commercial operation	March 26, 1971
Reactors
Reactors active	6 (4,696 MW)
Reactors planned	2 (2,760 MW)
Power
Total power generation in 2006	25,806 GW·h
Average annual generation (last 5 yrs)	21,436 GW·h
Net generation	781,594 GW·h

Fukushima I Nuclear Power Plant after Earthquake 2011

The company also said monitoring data suggested the air pressure level has also soared inside the container of the reactor.

Under Japanese law, a nuclear emergency must be declared if there is a release of radiation, if there is a dangerous level of water in the reactor, or if the cooling mechanisms fail. Japan declared a state of atomic power emergency instructing around 3,000 residents near a reactor in Fukushima Prefecture to evacuate. The evacuation advisory was issued for people living within a 3-kilometer radius of the plant, affecting approximately 5800 residents living near the power plant, while those living within a 10 kilometers radius were requested to stay home.

At 16:30 JST (7:30 GMT) on March 12, there was an explosion at the Fukushima I plant.

Early on March 13, an official of the Japan Nuclear and Industrial Safety Agency told a news conference that the emergency cooling system of Unit 3 had failed, spurring an urgent search for a means to supply cooling water to the reactor vessel in order to prevent a meltdown of its reactor core.

At 7:30 JST, TEPCO prepared to release radioactive steam, indicating that "the amount of radiation to be released would be small and not of a level that would affect human health".

At 12:33 JST on March 13, it was reported that Secretary Edano said "it was 'highly possible' a partial meltdown was underway" in Unit 3. The six other active Fukushima 1 and 2 reactors would be venting radioactive gas to reduce pressure. The Post blamed the hydrogen explosion in Unit 1 on the lack of electrical power to the plant, which disabled a safety device that ignites hydrogen gas before it builds to a dangerous level.

Radiation at the Fukushima No. 1 plant has risen to 882 micro sievert, compared with the legal limit of 500, said Tokyo Electric Power Co.(TEPOC), operator and owner of the Fukushima plants, on Sunday.

At an emergency press conference, Chief Cabinet Secretary Yukio Edano said that the radiation has briefly jumped to 1,204 micro sievert at the plant.

He said that fresh water has been injected into No. 3 reactor of the plant and radiation at the reactor was small and under control.

Earlier in the day, the TEPOC reported the reactor lost its ability to cool the reactor core.

It was the sixth reactor that lost the function after No. 1 and No. 2 reactors at the No. 1 plant and No.1, No.2 and No.4 at the No.2 plant had suffered the same trouble.

Fukushima I Nuclear Reactor Accidents

The Oi Nuclear Power Plant is a nuclear power plant located in the town of Oi in the Fukui Prefecture, managed by the Kansai Electric Power Company.

On December 22, 2005 8:50am there was trouble with a power line due to strong winds and heavy snow, the reactor was shut down as a result.

Unit	Type	First Criticality	Electric Power
Ōi - 1	PWR	March 27, 1979	1175 MW
Ōi - 2	PWR	December 5, 1979	1175 MW
Ōi - 3	PWR	December 19, 1991	1180 MW
Ōi - 4	PWR	February 2, 1993	1180 MW

Ōi Nuclear Power Plant
Data
Country	Japan
Operator	Kansai Electric Power Company
Built	1970
Start of commercial operation	March 27, 1979
Reactors
Reactors active	4 (4,710 MW)
Power
Total power generation in 2006	32,808 GW·h
Average annual generation (last 5 yrs)	32,667 GW·h
Net generation	618,710 GW·h
Other details

The Hamaoka Nuclear Power Plant (Hamaoka Genshiryoku Hatsudensho, Hamaoka NPP) is a nuclear power plant located in Omaezaki city, Shizuoka Prefecture, Japan managed by the Chubu Electric Power Company. There are five units contained at a single site with a net area of 1.6 square kilometers (395 acres, about a fourth of fifth of a typical US plant). A sixth unit began construction on December 22, 2008. On completion, it is expected to replace Hamaoka-1 and Hamaoka-2.

The area is in a possible epicenter of future earthquakes according to predictions. In fact, a fault line runs straight through the site. Earthquake resistance is a very important aspect of this plant, and difficulties have been seen in previous events.

Unit	Reactor Type	Average Power Output	Capacity	Beginning of Construction	Finish of Construction	First Criticality
Hamaoka-1	BWR	515 MW	540 MW	June 10, 1971	August 13, 1974	March 17, 1976
Hamaoka-2	BWR	806 MW	840 MW	June 14, 1974	May 4, 1978	November 29, 1987
Hamaoka-3	BWR	1056 MW	1100 MW	June 18, 1983	January 20, 1987	August 28, 1987
Hamaoka-4	BWR	1092 MW	1137 MW	October 13, 1989	January 27, 1993	September 3, 1993
Hamaoka-5	ABWR	1325 MW	1380 MW	July 12, 2000	June 26, 2004	January 18, 2005

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 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 2 Steam Turbine Problems

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 were placed on Hitachi, the NSSS supplier.

Previous Events

• 1991, April 4 - Unit 3 reactor coolant supply lowered, automatic SCRAM
• 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

Hamaoka Nuclear Power Plant
Image taken from the air (1988). In this image, all units through Hamaoka-3 are operating. Copyright National Land Image Information (Color Aerial Photograph), Ministry of Land, Infrastructure and Transport.
Data
Country	Japan
Operator	Chubu Electric Power Company
Built	1967
Start of commercial operation	March 17, 1976
Reactors
Reactors active	5 (4,997 MWth)
Power
Total power generation in 2006	12,920 GW·h
Average annual generation (last 5 yrs)	17,997 GW·h
Net generation	468,336 GW·h