Feature Article

Fukiushima Daiichi: 10 years on

The Fukushima Daiichi site before the accident. All images are provided courtesy of TEPCO unless noted otherwise.

It was a rather normal day back on March 11, 2011, at the Fukushima Daiichi nuclear plant before 2:45 p.m. That was the time when the Great Tohoku Earthquake struck, followed by a massive tsunami that caused three reactor meltdowns and forever changed the nuclear power industry in Japan and worldwide. Now, 10 years later, much has been learned and done to improve nuclear safety, and despite many challenges, significant progress is being made to decontaminate and defuel the extensively damaged Fukushima Daiichi reactor site. This is a summary of what happened, progress to date, current situation, and the outlook for the future there.

Earthquake has impact on Fukushima Daiichi plant

The black star represents the epicenter of the February 13 earthquake. Image: USGS

There has been no off-site impact from the February 13 earthquake that struck off the east coast of Japan near the Fukushima Daiichi nuclear power plant, Tokyo Electric Power Company (TEPCO) reported on February 19. The earthquake, however, has caused a water leakage from two of the site's primary containment vessels (PCVs).

A nuclear alert order was issued by the plant about 20 minutes after the earthquake, and the water treatment and transfer facilities were shut down. Inspections after the event revealed no anomalies and the nuclear alert order was rescinded on February 14.

The nuclear plant in Fukushima Prefecture in northeastern Japan is now undergoing decommissioning.

Anniversary Observations

The seismic event was huge and was felt all over the world.  With a moment magnitude of over 9.0, the earthquake and was the fourth largest ever in the more than 100 years of recorded history.  Huge land masses shifted as much as 2.4 meters, and the rotation of the earth was changed so that days were suddenly just a little (but measurable) bit shorter.  It had sped up the world.