Land Of The Rising Core Temperature, Part 20

The "concrete box" solution to Fukushima Daiichi is now very much on the table.

Top government spokesman Yukio Edano suggested Wednesday that all of the reactors at the Fukushima Daiichi nuclear plant should be scrapped.


''It is very clear looking at the social circumstances. That is my perception,'' Edano said in a news conference when asked if all six reactors at the troubled nuclear plant should be decommissioned.

And with the damage to Fukushima's containment structures and the surrounding area (after all, you can't just turn off plutonium, folks) it's looking more and more like decommissioning the reactors means building a rather smart tomb around the place, especially since it's looking like the race to stave off nuclear disaster has been lost.

Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian workers at the site appeared to have "lost the race" to save the reactor, but said there was no danger of a Chernobyl-style catastrophe.

Workers have been pumping water into three reactors at the stricken plant in a desperate bid to keep the fuel rods from melting down, but the fuel is at least partially exposed in all the reactors.

At least part of the molten core, which includes melted fuel rods and zirconium alloy cladding, seemed to have sunk through the steel "lower head" of the pressure vessel around reactor two, Lahey said.

"The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the drywell," Lahey said. "I hope I am wrong, but that is certainly what the evidence is pointing towards."

Last of the Fukushima Fifty out the door, turn out the lights.  We're now well beyond a "partial meltdown" scenario and into "what are our emergency containment options at this point".  It's just a matter of how much additional exposure is necessary before the Powers That Be give the order to box the thing in.