There's nothing we can do.: ずくなしの冷や水


There's nothing we can do.

Radio Forum 3/7/15

Yuasa (RF): It is going to be four full years since the earthquake and Fukushima Dai-ichi accident, but we still don't even know where the melted nuclear fuel is.

Koide: That's right.

Y: The contaminated water keeps being a difficult problem. TEPCO had said they would complete treating the water within this fiscal year, but it now estimates it requires till May.

I'd like to ask Koide-san about this problem. First of all, what is the current condition of the contaminated water?

K: It's hard to explain in one sentence, but if I try, "It's in the condition where there is nothing we can do about it."

To explain the reason why they produce contaminated water, I have to start with the fact that we don't know where and in what condition the melted fuel rods are now. It's been four years since the accident and we still don't know.

They can't allow the fuel rods to melt more, though, since if that happens a huge amount of radioactive materials will be released in the air. So, TEPCO did what they could do for these four years. They kept pouring water in the RPV [Reactor Pressure Vessel]. This has been the only thing they could do.

Naturally the water they put in will be contaminated with radiation. The more they put in, the more contaminated water they produce. At some point, TEPCO and the government realized that they should circulate the cooling water. However, the big earthquake on March 11, 2011 damaged Fukushima power plant. There are cracks everywhere in buildings, which allows ground water to flow in from outside.

That water, mixed with the contaminated water, increased the amount to 400 tons everyday until recently. TEPCO kept building numerous tanks to keep the contaminated water. It already keeps more than 500,000 tons of contaminated water in the site.

They started to pump up the ground water upstream to reduce the amount, but it only reduced a fraction of the flowing ground water. Everyday we end up with 350 tons of new contaminated water.

Y: They talked about ice wall but it's not materialized yet, right?

K: That's right. I don't think it would work. An ice wall itself is an established, effective technique when you dig a tunnel, for example. When there is a gush of water, an ice wall will stop the water on the spot.

However, in Fukushima's case, they have to build a wall that is 30 meter deep and 1.4 kilometer [0.87 mile] long. This is unprecedented. They have to circulate cooling agent in order to keep the wall frozen. To do that, they have to operate the freezing machine. That means the pump has to work. That means electricity has to work all the time. It can never fail. It's impossible to keep this working for many years. It will not work.

Y: Hmm. So it's like the water keeps running in the sink and we are trying to bail out some water from the bucket underneath, and we now have 500,000 tons of water.

Since the water is highly contaminated they try to somehow take out highly concentrated radioactive materials. ALPS [Advanced Liquid Processing System], is what they came up with. However, ALPS has not been working properly.

K: There is a fundamental reason why it doesn't work. The Fukushima Dai-ichi site is contaminated with radioactive materials all over and you can't avoid exposure to radiation there. When workers try to do their jobs, their exposure amounts rise quickly. It's necessary to build the device properly, but the more they try to do it right, the more they get exposed to radiation.

So they are forced to try to build it quickly, which results in various malfunctions. For example, they use hoses to connect the tanks, not proper plumbing pipes, causing leakages. It's a very difficult job and because it's so difficult, the device doesn't work properly.

Y: And there were fatal accidents last month [there were two fatal accidents in January, one at Fukushima Dai-ichi and another at Fukushima Dai-ni nuclear plant]. They announced they would delay the completion to May, but it seems doubtful.

K: I predict they can't. There was no way they could do it by the end of March. [Prime Minister] Abe said it was under control only to win the bids for Olympic games. TEPCO said [it would be done by] the end of the fiscal year when they were told to do something about it.

They are working on something that is impossible to accomplish. There is no way they can do it by May.

Y: They are trying to control something uncontrollable. Temporary measures have their limits and they have not been able to control the situation.

K: Yes.
posted by ZUKUNASHI at 17:57| Comment(0) | 福島原発事故
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