The PJ Tatler

Meltdown at Okuma, Japan nuclear power plant (Update: Explosion)

The nuclear reactor at the Fukushima Daiichi nuclear power plant in Okuma, Japan, damaged by the earthquake, is apparently experiencing a meltdown. According to STRATFOR, the earthquake

appears to have damaged the containment facility, and the explosion almost certainly did. There have been reports of “white smoke,” perhaps burning concrete, coming from the scene of the explosion, indicating a containment breach and the almost certain escape of significant amounts of radiation.

At this point, events in Japan bear many similarities to the 1986 Chernobyl disaster. Reports indicate that up to 1.5 meters (4.9 feet) of the reactor fuel was exposed. The reactor fuel appears to have at least partially melted, and the subsequent explosion has shattered the walls and roof of the containment vessel — and likely the remaining useful parts of the control and coolant systems.

[It] appears to have damaged the containment facility, and the explosion almost certainly did. There have been reports of “white smoke,” perhaps burning concrete, coming from the scene of the explosion, indicating a containment breach and the almost certain escape of significant amounts of radiation.

At this point, events in Japan bear many similarities to the 1986 Chernobyl disaster. Reports indicate that up to 1.5 meters (4.9 feet) of the reactor fuel was exposed. The reactor fuel appears to have at least partially melted, and the subsequent explosion has shattered the walls and roof of the containment vessel — and likely the remaining useful parts of the control and coolant systems.

And so now the question is simple: Did the floor of the containment vessel crack? If not, the situation can still be salvaged by somehow re-containing the nuclear core. But if the floor has cracked, it is highly likely that the melting fuel will burn through the floor of the containment system and enter the ground. This has never happened before but has always been the nightmare scenario for a nuclear power event — in this scenario, containment goes from being merely dangerous, time consuming and expensive to nearly impossible.

Update: The plant has suffered an explosion.

An explosion at a nuclear power station Saturday destroyed a building housing the reactor, but a radiation leak was decreasing despite fears of a meltdown from damage caused by a powerful earthquake and tsunami, officials said.

Government spokesman Yukio Edano said the explosion destroyed the exterior walls of the building where the reactor is placed, but not the actual metal housing enveloping the reactor.

The quake’s magnitude has also been adjusted upward, from 8.9 to 9.1.