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TEPCO Confirms Partial Meltdown of No.2 and No.3 Reactors
blau writes with an article in NHK World. From the article "The operator of the crippled Fukushima Daiichi nuclear plant says findings show that fuel meltdowns may have occurred at the No.2 and No.3 reactors within days of the March 11th earthquake. But it says both reactors are now stable at relatively low temperatures."
TEPCO is also now blaming the tsunami for most of the damage rather than the earthquake.
The long term effects of this to the population: Nothing. The levels are so low for the population that they're laughably small.
Don't pretend like 0 is the number of people affected by this meltdown. Nobody has been "laughing" since they got kicked out of homes they lost millions of yen for. It's not like someone's going to give that house back to them, nor their cash. School closings smack in the middle of the Japanese school year also mean lots of disrupted youths.
With Japan's prior issues with unemployment, fukushima was the straw breaking the camel's back for many souls now banned from living somewhere safe and known to them. But nobody is talking about the local lives in the cone of influence of the actual meltdown.
Because, you know, all gunshot wounds only hurt locally and we can just ignore the pain if we concentrate on the body parts not hurting. Right?
If you look at their temp gauges over at the TEPCO website, this is definitely not the case here. Especially at unit 3 there are still temperatures over 200 ÂC and they do not really get them down, even with constantly increasing water injection rates. For some reason, they started borating the water again last week - wonder why that is, if recriticality is not even remotely possible, as by their statements.
Ubi solitudinem faciunt, pacem appellant.
Unit 1 is a 460 MW reactor. Units 2 and 3 are 784 MW reactors. They have totally different ratios of heat generated to cooling capacity. This is why you're seeing reports for unit 1 coming separately, while reports for units 2 and 3 are (generally) coming concurrently. (The rest of your stuff about TEPCO being negligent, I agree with.)
Mod parent up.
Some pumps were still running after the earthquake and tsunami, and they continued to run until the backup batteries ran down. Loss of power was the real cause of the disaster. If they'd some backup power source that worked, the reactors would have reached cold shutdown in a day or two, there would have been no hydrogen explosions, and no core melting.
This is really important. A plant could lose backup power for many other reasons: fire, flood, hurricanes, terrorism, contaminated fuel, tank leakage, transformer damage, maintenance outages, or exhaustion of fuel supplies. Hospitals and data centers with backup power have at times lost power for all those reasons.
Read NUREG/CR-6890, "Reevaluation of Station Blackout Risk at Nuclear Power Plants ", from 2005. Volume 2, page 22, has the line "Risk is evaluated only for critical operation, not for shutdown operation. External events, such as seismic, fire, or flood, are also excluded." That, as we know now, is an overoptimistic assumption. The NRC does a statistical analysis on backup power sources, assuming independent failure of separate units, and computes the odds accordingly.
Nuclear plants that need power to reach shutdown need power sources as tough as the containment vessel. That's now very clear.