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Tomari nuclear power plant

Tomari nuclear power plant is a nuclear site in Japan with 3 units on record. None is currently operating.

Mothballed1circle 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
0
Operating capacity
not disclosed
Country

Units

UnitStatusTypeModelGross MWOnline
Unit 1 Mothballed PWR M (2-loop) 579 1989
Unit 2 Mothballed PWR M (2-loop) 579 1991
Unit 3 Mothballed PWR M (3-loop) 912 2009

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.

Tomari nuclear power plant 1 Mothballed

Reactor typePressurised water reactor (PWR)
ModelMitsubishi 2-loop
Size classLarge
Gross capacity579MW
Net capacity550MW
Thermal output1,650MWt
Enrichment3–5% U-235
NSSS vendorMitsubishi Heavy Industries
OwnerHokkaido Electric Power Co Inc100%
OperatorHokkaido Electric Power
Construction start18 Apr 1985
First criticality16 Nov 1988
Grid connection6 Dec 1988
Commercial operation22 Jun 1989

Tomari nuclear power plant 2 Mothballed

Reactor typePressurised water reactor (PWR)
ModelMitsubishi 2-loop
Size classLarge
Gross capacity579MW
Net capacity550MW
Thermal output1,650MWt
Enrichment3–5% U-235
NSSS vendorMitsubishi Heavy Industries
OwnerHokkaido Electric Power Co Inc100%
OperatorHokkaido Electric Power
Construction start13 Jun 1985
First criticality25 Jul 1990
Grid connection27 Aug 1990
Commercial operation12 Apr 1991

Tomari nuclear power plant 3 Mothballed

Corrected against a later source

GNPT records the unit as under construction, with a commercial operation date in the future. The Japan Atomic Industrial Forum's table of the status of Japan's nuclear power plants, as of 7 August 2026, lists Tomari-3 (PWR, 912 MWe) among the operable units, commercial operation 2009, in outage since 2012.05.05. Only Ohma, Higashidori-1 and Shimane-3 are in its under-construction table. The unit is complete and idle, like its sister units already recorded as mothballed, so it is not under construction. The commercial operation year is the JAIF's; the exact day is not given there, so only the year is recorded.

status: construction → mothballed · Japan Atomic Industrial Forum, Current Status of Nuclear Power Plants in Japan (as of 7 August 2026) · verified 2026-10-22

GNPT records the unit as under construction, with a commercial operation date in the future. The Japan Atomic Industrial Forum's table of the status of Japan's nuclear power plants, as of 7 August 2026, lists Tomari-3 (PWR, 912 MWe) among the operable units, commercial operation 2009, in outage since 2012.05.05. Only Ohma, Higashidori-1 and Shimane-3 are in its under-construction table. The unit is complete and idle, like its sister units already recorded as mothballed, so it is not under construction. The commercial operation year is the JAIF's; the exact day is not given there, so only the year is recorded.

commercial_operation: 2027-01-01 → 2009 · Japan Atomic Industrial Forum, Current Status of Nuclear Power Plants in Japan (as of 7 August 2026) · verified 2026-10-22

GNPT records the unit as under construction, with a commercial operation date in the future. The Japan Atomic Industrial Forum's table of the status of Japan's nuclear power plants, as of 7 August 2026, lists Tomari-3 (PWR, 912 MWe) among the operable units, commercial operation 2009, in outage since 2012.05.05. Only Ohma, Higashidori-1 and Shimane-3 are in its under-construction table. The unit is complete and idle, like its sister units already recorded as mothballed, so it is not under construction. The commercial operation year is the JAIF's; the exact day is not given there, so only the year is recorded.

start_year: 2027 → 2009 · Japan Atomic Industrial Forum, Current Status of Nuclear Power Plants in Japan (as of 7 August 2026) · verified 2026-10-22

Reactor typePressurised water reactor (PWR)
ModelMitsubishi 3-loop
Size classLarge
Gross capacity912MW
Net capacity866MW
Thermal output2,660MWt
Enrichment3–5% U-235
NSSS vendorMitsubishi Heavy Industries
OwnerHokkaido Electric Power Co Inc100%
OperatorHokkaido Electric Power
Construction start18 Nov 2004
First criticality3 Mar 2009
Grid connection20 Mar 2009
Commercial operation2009

Tomari nuclear power plant in context

The nearest other tracked nuclear sites are Ohma nuclear power plant (173 km).

Nearest tracked nuclear sites

SiteCountryDistanceOperating GW gross
Ohma nuclear power plantJapan173 km-

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
LocationHokkaido, Japan
Coordinates43.0367, 140.5125
Elevationabout 20 mabove sea level
SettingOn the sea coast, 0.1 km from the water
RegionEastern Asia
Units by status
Mothballed: 3

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
Hokkaido Electric Power Co Inc
Operators
Hokkaido Electric Power

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Sources

How these sources are used, including the corrections applied on top of them and what is deliberately left blank · download the underlying data

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