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Fukushima Cleanup, 5 Years On (bbc.co.uk)
AmiMoJo writes: Today is five years since the Fukushima Daiichi nuclear plant was damaged by an earthquake and tsunami, leading to a series of meltdowns. Nearly half a million people were evacuated at the time, with 100,000 still unable to return to their homes. The government has set a goal of 20mSv/year before people are allowed to live in affected areas again, and while progress is being made hotspots are still a problem in many areas. Reconstruction has been largely waiting for decontamination to be completed, allowing homes and businesses to fall into ruin. Those who do wish to return find their communities gutted, with essential services and jobs gone. Meanwhile, engineers are still unable to determine exactly what happened at Daiichi, particularly what saved reactor 2's pressure vessel from exploding. The initial reports were scary even before the nuclear plant problems were evident. Engadget notes that even now, the worst part of the cleanup remains a grueling work in progress, tough even for robots. Reader the_newsbeagle writes, too, with a link to the New York Times' take on the 5-year mark, and notes that The state and location of the melted fuel inside the reactors is still a mystery. The meltdown zone is too dangerous for human workers to enter, and robots have had limited success navigating in the wreckage. So Japan is recruiting subatomic particles called muons to map the reactors' insides. These particles, born of cosmic rays, constantly stream down from the atmosphere, passing through most matter unimpeded. But their occasional interactions with the subatomic components of uranium allow physicists to locate the blobs of the deadly stuff.
You do realize this is actually killing off an entire ocean right?
No, I don't realise that. Whatever makes you think that's the case?
You do realize eating ANYTHING from the Pacific Ocean is very very risky... right?
No, I don't realise that because it's not true.
Half of Japan should have been, and still be, evacuated
If that's the case, I'm sure you can tell me what the average excess dose in mSv/yr in the half of Japan that ought to be evacuated? I mean you'd never make such a wild claim without knowing the numbers, right?
Carbon doesn't continue to react outside of the reactor leaking gamma and beta rays
By reaction, you mean decay right? Coal ash has decaying radioactive elements in it too, by the way.
yes, the same ones that made the Hulk
I hate to break it to you, but the Hulk isn't real.
Carbon doesn't cause mutations and cancers,
Certain allotropes of carbon are in fact strongly suspected to be carcinogenic.
SJW n. One who posts facts.
The other reactors were vented. They had a venting system that passed the contaminated air through water before releasing it. The water cleaned it much of the contamination, but not all, and now they have massive amounts of highly contaminated water to deal with.
They had to send people in to connect up emergency battery power to activate the vents. Those are the people who got the biggest dose of radiation, and who saved Eastern Japan.
For some reason the venting system in reactor two didn't work. The water level was low, but due to the severity of losing the containment vessel they decided to vent anyway. That didn't work either. Then at the last moment, with the vessel way beyond design limits, something happened and the pressure dropped.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Indeed. Coal Ash is more radioactive than actual nuclear waste.. In fact, significant amounts of both uranium and thorium are found in coal fly ash, to the point, in some cases, Thorium Reactor advocates have suggested there's more generate-able power if the Thorium was used in a reactor, than was generated by burning the coal. I've seen no numbers to back that up, but it seems plausible, based on back-of-the envelope numbers. . .
Had the reactor containment vessel failed, the worst case was the loss of Eastern Japan. Hopefully one day we can find out what saved the country.
It's not that mysterious. For example, according to this report, the pressure release of Reactor 2 is unexplained, but they weren't close to blowing out the pressure vessel:
The containment pressure rise at first was much slower than should be expected if all the decay heat is delivered to the suppression pool, which is an indication of a leak in the containment boundary. The wetwell venting line configuration had been completed by 11:00 a.m. on March 13, but the containment pressure had not reached the rupture disk setpoint, so no venting occurred. After core damage, the containment pressure increased more rapidly, probably because of hydrogen production. At 6:00 a.m. on March 15, an impulsive sound that was initially attributed to a hydrogen explosion was confirmed near the suppression chamber of the containment. Later reviews suggested that sound was not due to hydrogen burn. In any case the containment pressure did sharply decrease. It is not clear whether the designed vent path was ever in service; however, longer term, the containment pressure has remained low, around the level of atmospheric pressure.
In particular, it's worth noting that there is a rupture disk here precisely to prevent the reactor pressure vessel from experiencing a catastrophic rupture and that the vessel was leaking enough that it might not have even reached a high enough pressure to break the rupture disk.