An explosion at unit 2 of the Fukushima Daiichi plant on Tuesday 15 March may have damaged its containment vessel, risking the release of radioactivity. Seawater with added boron is being pumped into the reactor cores of units 1, 2 and 3 to cool the reactors.
A fire broke out at the shut down unit 4, but has been extinguished; the fire was not caused by burning fuel rods. However the fire has probably raised radioactivity levels in the area, prompting a further extension of the evacuation zone to 20km (9 miles) around the plant; in addition residents less than 30km from the plant were instructed to stay indoors.
In a report about the status of Fukushima Daiichi unit 1, the Japanese prime minister said, "We are trying the best not to release radioactive nuclides further. TEPCO is trying the best to inject water, while braving the risk. I am sorry that I have caused so many worries. I would like all of you to act in a level-headed manner." The comments were translated and published by the Japan Atomic Information Forum.
Fifty TEPCO workers have remained at the station to manage the water injection process.
As a consequence of these developments, JAIF's reactor status diagram has worsened for Fukushima Daiichi 2, but on the positive side core cooling at Fukushima Daini 2 and 4 is now functional.
FilesReactor-by-reactor, system-by-system summary from JAIF on 16 March