- Mihama Nuclear Power Plant
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Mihama Nuclear Power Plant 
Mihama Nuclear Power PlantLocation of Mihama Nuclear Power Plant
Country Japan Location Mihama, Fukui Prefecture Coordinates 35°42′12.51″N 135°57′48.88″E / 35.703475°N 135.9635778°ECoordinates: 35°42′12.51″N 135°57′48.88″E / 35.703475°N 135.9635778°E 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 MWAs of 14 March 2011 The Mihama Nuclear Power Plant (美浜発電所 Mihama hatsudensho, Mihama NPP) is operated by The Kansai Electric Power Company, Inc. and is in the town of Mihama, Fukui Prefecture, about 320 km west of Tokyo.[1] It is on a site that is 520,000 m2 of which 60% is green space.[2]
Contents
Reactors on Site
Unit[3] Reactor Type Average Electric Output Electric Power Rating Beginning of Construction First Criticality Commission date Mihama - 1 PWR 320 MW 340 MW 01.02.1967 08.08.1970 28.11.1970 Mihama - 2 PWR 470 MW 500 MW 29.05.1968 21.04.1972 25.07.1972 Mihama - 3 PWR 780 MW 826 MW 07.08.1972 19.02.1976 01.12.1976 Events
Areal view of the plant from 1975. Image: Japan Ministry of Land, Infrastructure and Transport
The Mihama NPP 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.[1] Hot water and steam leaking from a broken pipe killed four workers and resulted in seven others being injured.[1][4][5] The accident had been called Japan's worst nuclear power accident[6][7] before the crisis at Fukushima I Nuclear Power Plant.[8]
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.[9]
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.[9]
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.[10]
The Mihama NPP started back up in January 2007 after making various changes and obtaining permission from Fukui Prefecture and industry regulators.[11]
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.
References
- ^ a b c Four killed in nuclear plant accident
- ^ Kepco (Japanese). Mihama Overview.
- ^ Power Reactor Information System der IAEA: „Japan: Nuclear Power Reactors“
- ^ Press releace from KEPCO (English)
- ^ Mihama Nuclear Power Plant Accident
- ^ Japan's shaky nuclear record
- ^ Japanese utility to shut reactor after admitting accident cover-up
- ^ Japan crisis: third explosion raises spectre of nuclear nightmare
- ^ a b Secondary piping rupture at the Mihama Power Station in Japan
- ^ Tokaimura Criticality Accident at World Nuclear Association
- ^ KEPCO's public announcement on restarting of plant (English)
External links
- Mihama Nuclear Power Plant (Japanese)
- Japanese nuclear operator to shut 11 plants
- Worst Japanese Nuclear Accident Claims Fifth Life
- BBC News Report on the Steam Accident
Nuclear power in Japan Active LWR plants Fukushima Daiichi · Fukushima Daini · Genkai · Hamaoka · Higashidōri · Ikata · Kashiwazaki-Kariwa · Mihama · Ōi · Onagawa · Sendai · Shika · Shimane · Takahama · Tokai · Tomari · TsurugaOther plants Kaminoseki · Maki · Monju · Namie-Odaka · Ōma · Fugen (ATR) (inactive) · Jōyō (FBR) · Rokkasho (reprocessing)Fukushima Daiichi nuclear disaster Cleanup · Timeline · Radiation effects · Japanese reaction · International reaction · Reactor units 4, 5 and 6Companies Chugoku Electric Power Company · Japan Nuclear Fuel Limited · Mitsubishi FBR Systems · Tokyo Electric Power CompanyOrganisations Atomic Energy Commission · Japan Atomic Energy Agency · Japan Electric Association · Nuclear Safety Commission · Nuclear and Industrial Safety AgencyAnti-nuclear movement Anti-nuclear protests · Citizen's Nuclear Information Center · Tetsunari Iida · Haruki Murakami · Kenzaburo Oe · Ryuichi SakamotoMiscellaneous 2011 Japanese nuclear accidents · Iwaishima · Japanese nuclear incidents · Radiation Monitoring · Genpatsu-shinsaiCategories:- Civilian nuclear power accidents
- Fukui Prefecture
- Nuclear power stations in Japan
- 1967 establishments in Japan
- Nuclear power stations using pressurized water reactors
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