From "New Scientist" (Britain):
Quote:
A turning point in the efforts to avert a meltdown at Fukushima Daiichi nuclear power station came in the wake of the blast that destroyed the exterior walls of the crippled reactor.
The Tokyo Electric Power Company, Tepco, had the flexibility to use pressure release valves to vent some steam, even though it was mildly contaminated, because it had taken the precaution of evacuating the local population within a 12 mile radius.
Grimston described this as "extraordinary forward planning".
Although the concrete cladding disintegrated in a spectacular fashion, Grimston said that the fact that the metal frame of the building was left intact suggests that the explosion was not as violent as it looked.
Because the plant went into operation in 1971 and is due for decommissioning, the decision was taken by Tepco to flood it with seawater containing boric acid to kill the nuclear reaction.
This began just after 2pm UK time and would take up to ten hours.
The use of corrosive seawater would render the reactor unusable but would ensure that the risk of a meltdown had been averted, said Grimston.
He said that it was a "textbook example" of how to deal with a nuclear emergency.
Tepco said Fukushima was stable.
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