goingcritical:fukushima-daiichi-1Japan · Power reactor

Fukushima Daiichi 1

Status: Shut down reached first criticality October 10, 1970 Reactor status full glossary → Announced Publicly announced — a site and design are proposed, but construction has not begun. Site preparation Early site and civil works are under way; the first safety-related ("nuclear") concrete has not yet been poured. Under construction Formal construction has begun, marked by the first nuclear concrete. Fuel loaded Nuclear fuel has been loaded into the core. The reactor is fuelled but has not yet gone critical. Critical Has reached first criticality — a self-sustaining chain reaction, usually at low power — but is not yet connected to the grid. Grid connected Synchronised to the electrical grid and exporting power for the first time, but still in commissioning and power-ascension testing — not yet in commercial service. Operating In commercial operation — the operator has formally declared the unit in regular commercial service. Shut down Permanently shut down and no longer generating; may be defuelled, undergoing decommissioning, or preserved in place. Canceled Abandoned before completion.

Site: Okuma, Fukushima

North KoreaOsakaTokyoSeoulChangwonDaejeonFukuokaSendai
Okuma, Fukushima37.4214° N, 141.0325° E
Summary:

Oldest Fukushima Daiichi unit and epicenter of the March 2011 triple-meltdown disaster; core melted after the tsunami disabled cooling, and the reactor building was destroyed by a hydrogen explosion on 2011-03-12. Permanently shut down 2011-05-19.

Details

DesignGE BWR-3 (Mark I containment)
Electrical output439 MWe

Milestone history

  1. Announced
  2. Construction start July 25, 1967
  3. Fuel load
  4. First criticality October 10, 1970
  5. Grid connection November 17, 1970
  6. Commercial operation March 26, 1971