Fukushima Daiichi Water Leak Raised To Level 3 Severity

AmiMoJo writes "Japan's nuclear regulators have raised the level of severity of the radioactive water leak from a tank at the Fukushima Daiichi nuclear plant. It is now a level-3 serious incident. The revision from level 1 is based on estimates of the volume of radioactive substances leaked. The International Atomic Energy Agency supports the revision. They say the tank leak can be assessed separately from the Fukushima Daiichi crisis as a level 3 incident. Japanese experienced a level-3 nuclear event in 1997 with the fire and explosions at a fuel reprocessing plant in Tokai Village, Ibaraki Prefecture. 37 workers there were exposed to the leaked radioactive substances."

Comments

The fate of the 1997 workers

[vivaoporto]

Japanese experienced a level-3 nuclear event in 1997 with the fire and explosions at a fuel reprocessing plant in Tokai Village, Ibaraki Prefecture. 37 workers there were exposed to the leaked radioactive substances.

What was the fate of the 1997 workers exposed like that? That would be a good way to assess what kind of consequences we could expect from the current incident,

Re:The fate of the 1997 workers

[Anonymous Coward]

Five of them became Power Rangers.

Re:The fate of the 1997 workers

[Anonymous Coward]

Nothing happened to those workers.

They had a worse incident where they were carrying uranium in a bucket and it went super-critical in 1999. That was a level 4. 2 people died of multiple organ failure.

http://www.mun.ca/biology/scarr/4241_Tokaimura_Accident.html
http://en.wikipedia.org/wiki/Tokaimura_nuclear_accident

The three operators' doses were far above permissible limits at 3,000, 10,000, and 17,000 mSv; the two receiving the higher doses died several months later.[4] The most severely exposed worker had his body draped over the tank when it went critical. He suffered serious burns to most of his body, experienced severe damage to his internal organs, and had a near-zero white blood cell count.[4]

The cause of the accident was said to be "human error and serious breaches of safety principles", according to the International Atomic Energy Agency.[5]

Re:Capitalism SUCKS!

[fuzzyfuzzyfungus]

Workers must take the power!

Workers at Fukushima appear to be absorbing power, does that count?

Guys, don't worry

[RedHackTea]

I learned about a new keyboard shortcut "Ctrl+Shift+T". It's kind of like the "Ctrl+Z" of radioactive water leak disasters.

The spent fuel pool disaster clock is ticking

[ka9dgx]

The radiation from the corium pockets underground is bad, but it's nothing compared to the mess is still waiting to make a disaster bigger (85 times bigger!) then Chernobyl..

Zirconium

[blindseer]

I learned something very interesting about zirconium. I don't remember when this was but I found the properties of this element very fascinating and it has come back to mind with this article. You see zirconium is a metal that is nearly transparent to neutrons. Because of this property, and other properties that metals have, it is used to make the fuel rods in all fission reactors today.

Using zirconium makes sense. Just like we use glass in light bulbs we use zirconium in nuclear fission reactors. A light bulb is not very useful unless the light can escape from the filament but no barrier exists to protect the filament from damage. We use zirconium to contain the fission fuel and also allow the neutrons that sustain the fission to reach the fuel contained in the other rods.

Zirconium has another very interesting property, it burns when exposed to steam. So, in every fission reactor we have today we place zirconium tubes filled with nuclear fuel in some very hot water. If the ability to cool this water is lost then the water begins to boil. The zirconium ignites. The tubes containing the nuclear fuel burns away. The nuclear fuel falls away from the control mechanisms and piles up at the bottom of the reactor vessel.

Once the nuclear fuel piles up high enough fission will occur. Dumping water on the fuel at this point moderates the fission, that is bounce any escaping neutrons back at the fuel to increase the fission rate, and creates more steam to burn away the zirconium. But not dumping water on the fuel means some very dangerous elements, ones that are solid at any lower temperature, boil away. What needs to be done is to dump enough water on the fire so that the zirconium and other stuff in the pile stops burning. At some point the mess that was once fuel rods melts enough metal and concrete in the reactor floor, and mixes with it, that fission stops.

I don't mention all of this to scare people away from nuclear fission power. I mention this to point out that the technology we use in nuclear fission right now is very stupid. We need nuclear fission power. What we need is nuclear power that does not require zirconium in contact with hot water.

We need molten salt reactors.