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Mihama nuclear power plant

Mihama nuclear power plant is a nuclear power station in Japan with 1 operating unit totalling 826 MW gross. The site has 3 units on record in total.

Operating4Mothballed2Retired2circle area ∝ site capacity Coastlines, borders and lakes: Natural Earth (1:10 million, public domain), which is generalised, so a coastal plant can sit a couple of kilometres off its true shoreline. Site positions: Global Nuclear Power Tracker.
Units on record
3
Operating
1
Operating capacity
826MW
Country

Units

UnitStatusTypeModelGross MWOnline
Unit 3 Operating PWR M (3-loop) 826 1976
Unit 1 Retired PWR WH 2LP 340 1970
Unit 2 Retired PWR M (2-loop) 500 1972

Unit by unit

Each unit's rating, type and milestone dates as recorded by the Global Nuclear Power Tracker, with any correction we made to it. A dash or "not disclosed" means the source does not give the value.

Mihama nuclear power plant 3 Operating

Reactor typePressurised water reactor (PWR)
ModelMitsubishi 3-loop
Size classLarge
Gross capacity826MW
Net capacity780MW
Thermal output2,440MWt
Enrichment3–5% U-235
NSSS vendorMitsubishi Heavy Industries
Planned retirement2036planned, not actual
OwnerKansai Electric Power Co100%
OperatorKansai Electric Power
Construction start7 Aug 1972
First criticality28 Jan 1976
Grid connection19 Feb 1976
Commercial operation1 Dec 1976

Mihama nuclear power plant 1 Retired

Reactor typePressurised water reactor (PWR)
ModelWestinghouse 2-loop
Size classLarge
Gross capacity340MW
Net capacity320MW
Thermal output1,031MWt
Enrichment3–5% U-235
NSSS vendorWestinghouse Electric Company
OwnerKansai Electric Power Co100%
OperatorKansai Electric Power
Construction start1 Feb 1967
First criticality29 Jul 1970
Grid connection8 Aug 1970
Commercial operation28 Nov 1970
Permanent shutdown27 Apr 2015

Mihama nuclear power plant 2 Retired

Reactor typePressurised water reactor (PWR)
ModelMitsubishi 2-loop
Size classLarge
Gross capacity500MW
Net capacity470MW
Thermal output1,456MWt
Enrichment3–5% U-235
NSSS vendorMitsubishi Heavy Industries
OwnerKansai Electric Power Co100%
OperatorKansai Electric Power
Construction start29 May 1968
First criticality10 Apr 1972
Grid connection21 Apr 1972
Commercial operation25 Jul 1972
Permanent shutdown27 Apr 2015

Mihama nuclear power plant in context

By gross operating capacity Mihama nuclear power plant is the 7th largest of 9 operating nuclear sites in Japan, holding 6% of the country's operating capacity, and ranks 156th of 172 worldwide.

Its operating unit started up in 1976; the unit is 50.0 years old, older than the median of 35.0 in Japan.

The 3 units with both construction and grid dates on record took 3.5 to 3.9 years (median 3.5) from construction start to grid connection; the median across all reactors connected in the 1970s is 5.4 years.

The nearest other tracked nuclear sites are Ohi nuclear power plant (33 km), Takahama nuclear power plant (46 km) and Shimane nuclear power plant (269 km).

The tracker lists a planned retirement year, a forecast and not a decision on record, for 1 operating unit: Unit 3 (2036).

Build time by unit

UnitConstruction startGrid connectionYearsFleet median, same decade
Unit 1196719703.55.4 (1970s)
Unit 2196819723.95.4 (1970s)
Unit 3197219763.55.4 (1970s)

Nearest tracked nuclear sites

SiteCountryDistanceOperating GW gross
Ohi nuclear power plantJapan33 km2.4
Takahama nuclear power plantJapan46 km3.4
Shimane nuclear power plantJapan269 km0.8

How these are worked out: ranks use gross operating capacity; ages count from the start-up year on record, as on the age page; build times run from construction start to grid connection, as on the build-times page; ratings are the tracker's net and design net capacity, as on the uprates page. Distances are straight-line between exact positions, so a site with only an approximate position gets none. A unit missing a date or a rating is left out of the figure that needs it.

Site detail
LocationFukui, Japan
Coordinates35.7024, 135.9634
Elevationabout 15 mabove sea level
SettingOn the sea coast, 0.1 km from the water
RegionEastern Asia
Units by status
Operating: 1
Retired: 2

Elevation is read at the listed coordinates from a 30 m terrain model (SRTM 30 m). Two independent models differ by a median of 6 m across our plants and by up to about 40 m on steep or coastal ground, and a point on a shoreline can read as sea level. Distance to the water is measured to a generalised 1:10 million coastline, so a few kilometres or less is not resolved. This is context, not a design-basis or flood-risk figure.

Owners & operators
Owners
Kansai Electric Power Co
Operators
Kansai Electric Power

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Sources

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