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Things Get Worse at Fukushima
An anonymous reader writes "Radiation levels are skyrocketing around Japan's Fukushima nuclear plant as reports indicate that a radioactive core has overheated and melted through its containment vessel and onto a concrete floor. Radiation levels inside reactor two were recently gauged at 1,000 millisieverts per hour — a level so high that workers could only remain in the area for 15 minutes under current exposure guidelines."
Reactors 1-4 will never be used again. But burying them in concrete is absolutely the wrong thing to do. Right now, the cores are still hot enough to melt through the reactor vessel if not constantly cooled by constant pumping of (now) fresh water through the coolant system.
Worst case scenario (though not hugely likely) - water stops getting in, or stops cooling the fuel rods, they melt down through the reactor into the outer containment vessel, and there's not enough left of the control rods mixed in to prevent the molten fuel reaching criticality again, and it then gets hot enough to melt through the containment itself, then either contaminate groudwater, or even worse, hit enough water to cause a steam explosion, spreading radioactive elements for miles around.
It's going to take *years* to decommission these plants after the damage they've suffered from the quake and tsunami. No doubt some sort of concrete shroud will be part of the final solution, but right now, keeping control of the coolant flow in both the reactors and the used fuel ponds is the top priority, closely followed by patching any leaks from the containment vessels caused by the multiple hydrogen fires/explosions.
Remember kids, it's all fun and games until someone commits wholesale galactic genocide.
Each reactor was written off the moment they pumped seawater into it. The corrosive nature of salt means the steel containment vessels will never pass inspection to allow them be used again to house an active reactor. Reactors #1, #2, and #3 will never be used again. TEPCO deserves criticism for waiting too long to pump in seawater (long enough to allow the rods to become exposed and melt), but refusing to use concrete has nothing to do with it.
They aren't encasing it in concrete because doing so would compromise their ability to continue cooling, and thus practically guarantee the core melting through the steel containment vessel.. TFA is speculation that this has already happened based on one industry expert's interpretation of the reports he has seen. He's apparently forgotten that reactor #2 suffered a hydrogen explosion inside containment early on (near or in the suppression pool, or "torus"). They've been suspecting for a while that they have a containment breech there, allowing water from the core to leak out. The high radiation readings from the water near that area are consistent with that scenario.
Our sun, a nuclear fusion source which is already working reliably for more than 5 billion years, produces an extreme amount of energy. Within 6 hours, deserts on Earth receive more solar energy than we use in a whole year globally. Why do we keep ignore this most power full energy source? For the world energy demand (18.000 TWh) we need only a surface area of 188 x 188 square miles with Concentrated Solar Plants. This is a small thumbnail on the map of Africa. Germany has seen the light and is investing 500 billion euro's in Desertec. A CSP plant runs 24 x 7 hours on full power (even when the sun is away because it can store sun heat in molten salt). These CSP plants can easily replace nuclear and coal power plants.
“The power of accurate observation is commonly called cynicism by those who haven't got it.” -- Bernard Shaw
The clearly the /. editors or the dimwit who submitted this story are not cynics, because they certainly lack the power of accurate observation. This report speculates that the reactor pressure vessel may have melted, but for some unaccountable reason the summary suggests that the containment may have been breached.
There are probably better discussions out there, but here's my take on the reactor design, which includes a pretty picture from Wikipedia that gives an idea of the difference between the pressure vessel and the containment.
This story is pure sensationalism by abstraction and amplification. The mental health effects of fear due to misinformation, sensationalism and lies surrounding nuclear accidents of this type are far greater than the physical health effects, and I dearly hope one day the ignorant assholes who promulgate these kinds of sensationalistic accounts get their propper cumuppance: a massive class-action suit brought by the victims of their voyeuristic fearmongering.
Blasphemy is a human right. Blasphemophobia kills.