Japan's Nightmare Fight Against Radiation in
the Wake of the 3.11 Meltdown Apr. 01, 2012
Koide Hiroaki, a researcher at Kyoto
University's Nuclear Reactor Experiment Research Center, speaks with Watanabe
Taeko,Translated by Kyoko Selden
It is now the second year in the fight
against radiation. What should be done in a situation where we can't see what
lies ahead of us at all, and what is the situation inside the Fukushima atomic
power plant meltdown? We asked Koide Hideaki.
―The fight against radiation and
contamination has entered a second year and new issues are emerging. First I
would like to ask about plans to widely disperse contaminated rubble, which are
troubling the nation.
As far as radioactivity is concerned, the
fundamental rule is to make it compact and seal it off, not dilute and spread
it. Scattering rubble all over the country violates the rule. National policy
at present consists of two pillars. One is for local governments throughout the
country to burn contaminated rubble in incinerators. The other is for each
local government to dispose of the ashes as it wishes. Both are wrong.
-Although it is not good to
scatter the rubble . . .
Radiation should not be handled except at
facilities designed for that purpose. It should not be burned in an ordinary
incinerator. If you do that, radioactive matter will disperse. If radioactive
contaminated rubble has to be burnt throughout the country, then the first
thing that has to be done is to check whether the facilities have the capacity
to prevent radiation from scattering. If it seems that radiation may scatter,
then equipment must be added to prevent it. Unless that is done, burning should
not take place.
―Do you mean adding a filter?
Yes. Most incinerators are equipped with a
bag filter. If that is correctly used, then I think that cesium can be
processed. However, it is necessary to check whether radiation can, in fact, be
captured by a filter. If a bagged filter doesn't work, then it is necessary to
add a ceramic or high performance filter to contain radiation.
Next, one should never allow each local
government to bury the ashes. My proposal is to return the ashes to the
Fukushima Daiichi Nuclear Power Plant. In the past, ashes following a meltdown
have been used as material for making concrete. At Fukushima Daiichi, a
concrete sarcophagus may be constructed over the power plants. Also, it will be
necessary to build dams underground to prevent contaminated water from leaking
out. For that, massive amounts of concrete will be necessary. So, my idea is to
use the ashes to make concrete.
Ideally, incinerators should be used
exclusively to handle the rubble at the actual site. But the country has not
created appropriate incinerators. Even now the rubble is exposed to the air. If
this situation continues unchecked, children in the contaminated areas will
continue to be exposed to radiation.
I want to protect children from exposure to
radiation. Children here includes those in Tokyo, Osaka, Fukushima, Miyagi,
Iwate and all other areas. I think that the main issue is how we can best
reduce children's exposure to radiation. We cannot wait until an incinerating
facility for exclusive handling of radiation-contaminated rubble is available.
But if it can't be helped that the entire country accepts the rubble, the two
conditions that I posited must be fulfilled.
About half a month ago, thirty some members
of Osaka's Ishin no Kai (Mayor Hashimoto's group) asked me about disposal of
contaminated waste. My proposal was that it should not be done unless the two
conditions have been met. But they ignored this. It seems they are claiming
that, "Koide says that the rubble must be accepted." People at large,
too, are angry, saying that Koide is saying something preposterous. But I am
saying no such thing.
If Reactor #4 Crumbles,
That's the End
―It was pointed out in the October 21 2011
issue that Reactor #4 is in danger. Recently, an aerial video was broadcast
showing workers at #4.
I saw that video, too. The environment is one
of intense exposure to radiation. How many minutes can one stay in that place?
It's work that requires a stopwatch held in one's hand. But the work has to be
done because, if the pool for spent fuel rods at # 4 crumbles, that's the end.
So, the spent fuel at the bottom of the pool has to be taken out before the
pool crumbles. At any rate, it has to be removed as soon as possible, before an
after shock occurs. For that purpose, some radiation exposure is inescapable.
The reactor core contains approximately 100
tons of uranium. The pool for spent fuel at reactor #4 contains approximately
2.5 times that amount of spent fuel . . . approximately 250 tons. And besides
that, there is fuel that has not yet been spent. So, in all, the amount of fuel
must be around 300 tons. That is 4,000 times the size of the Hiroshima atomic
bomb. Spent fuel is a huge mass of nuclear reaction product. Keeping it at the
bottom of the pool allows it to be cooled. At the same time, radiation is
blocked.
It cannot be released into the air, so the
only way to handle it is to sink a special container exclusively for removal of
the spent fuel. The only way is to put the spent fuel into the container within
the pool, put a lid over the container and pull it out. But the floor of the
reactor building where the spent fuel pool is buried is crumbling, so a crane
cannot be used. Therefore, it is necessary to suspend a long armed crane from
outside the building, which means that you have to make a colossal container
that exceeds the weight of 100 tons. You have to sink the crane to the bottom
of the pool and move the spent fuel into it. This is an enormous operation.
―What about re-criticality and explosion?
I think that the possibility of
re-criticality is low, and I don't think that there will be an explosion. When
the fuel melted and the zirconium reacted with water to produce hydrogen, the
hydrogen leaked into the closed space in the reactor building and an explosion
occurred. The spent fuel pool is now exposed, but even if the fuel melts and
produces hydrogen, it is not accumulating within a closed space. It becomes
diluted and escapes. So I don't think that there will be a hydrogen explosion.
However, spent fuel is heat generating. If water evaporates and cooling becomes
impossible, then the temperature rises and the fuel melts. It melts at 2800
degrees (C.) At that temperature, what can become a gas will all come out.
Iodine, cesium, all kinds of radiation, will suddenly jump out into the air.
We Want to Take it Out,
But We Can't Take it Out
As mentioned, the basic principle for
handling radiation is to not spread but seal it in as compactly as possible. So
if it is there, then take it out and compact it.
TEPCO and the government imagine that
Reactors No. 1-3 had a meltdown of the fuel and the bottom of the pressure
containment vessel dropped, so the fuel is at the bottom of the container. But
even that is not clear. It is possible that the bottom of the containment
vessel is also broken, so the fuel may have sunk even lower. If that is the
case, it can no longer be taken out and the only thing to do is to seal it in
place.
The Chernobyl Nuclear Reactor was sealed with
a sarcophagus without taking out the fuel. Now that coffin is crumbling, so
they have to make a second coffin. That too will crumble, so eventually they
will have to make a third . . . to be repeated eternally. I think that this
will be the case at Fukushima, too. You make a huge concrete coffin; when it
crumbles, you cover it with a larger coffin . . . then an even bigger coffin.
It is an overwhelming operation. So if possible it would be good to take the
fuel out, including the fuel that has already melted. TEPCO also says so. But I
think that will take more than ten years to accomplish.
―Concerning the report that the thermometer
broke at No. 2, should this claim be taken at face value?
Yes, I think it is broken. Radiation
generates heat, so if it accumulates where the thermometer is, the temperature
rises. However, the thermometer indicated 400 degrees C. It is impossible that
a temperature of 400 degrees C. could be generated in the pressure containment
vessel. So after all my guess is that the thermometer is broken. TEPCO's
conjecture seems to be the same.
That thermometer uses the principle of
thermocoupling. It is a very simple principle and it rarely breaks down. So
what does it mean that the thermometer broke?
Some time ago, TEPCO put an industrial TV set
inside the containment vessel of No. 2. Water was not visible. In short, water
has not accumulated there. Moreover, inside the containment vessel, water is
dropping like a waterfall, radiation rays are flying wildly and the image on TV
is scarred. It was realized afresh that this was a terrible environment. In
that environment, a cable runs which pulls the signal of the thermocouple
outside. What I think is that the cable was hit.
This means that from now on, thermometer
after thermometer will break. When they break, we have no clue to detect what
is going on and we will less and less understand the present situation.
What Does it Mean to
Decommission a Nuclear Reactor?
―We often hear of decommissioning, but what
precisely is meant?
When a nuclear plant operates and stops
without any big accident, that is, when it runs its course, the reactor is then
decommissioned and the spent fuel is removed, but the pressure vessel and other
things remain a radioactive mass. So, how is decommissioning accomplished? To
oversimplify, there are two approaches.
One is to bury it on the spot. You seal the
door so that people cannot approach. In this method, you don't have to do too
much and there is little exposure to radiation. However, this means that the
power plant itself becomes garbage. So it's thought that this is not a very
good plan for a country like Japan where land is scarce. So Japan proposes
another method.
That method is to take apart the plant and
sort out things ranging from badly contaminated parts like the pressure vessel
to things that are not so badly contaminated. Something like a pressure vessel
can't be handled, so it is necessary to make a deep hole and bury it. As for
things that are not badly contaminated with radiation, because it is too much
work to baby-sit them given the radiation, they can be handled as general
waste.
Handling these parts as general waste is
called clearance. But when you chop up a nuclear plant, you get 600,000
cubic meters. When you sort that garbage by degree of radiation, more than 90%
is barely contaminated, so it can be handled as general waste.
For example, iron. It may be viewed as
general waste. Then scrap iron dealers buy it and recycle it, making for
example, tables or desks or frying pans for home use. If you cook with such a
frying pan, you will eat radiation with the food. If you eat something cooked
in that pan, and if the amount of radiation does not exceed 10 mSv, then it's
ok. This was the law up to now. This is what decommissioning a nuclear reactor
means.
But the case this time is completely
different. First, it's not clear if the spent fuel can be removed and it's
hardly possible to dismantle the reactor. So whatever we choose, there has to
be a sarcophagus. But it is said that to decommission a normal atomic power
plant without problems takes 30, 40, or 50 years. So, it will take far longer
to decommission Fukushima Daiichi, which has melted down.
To Mothers of Fukushima
―I hear that in Koriyama, people who call
themselves advisors have been instructing groups of ten or more people saying,
"We radiation specialists are here, so you need not worry." When
people are totally exhausted, many feel "that's enough". Fukushima
mothers say that they are utterly exhausted. May I have your message for them?
I'm not qualified. I'm at one end of the
spectrum of the group of criminals. I'm among the criminals who made them
shoulder a heavy weight. I can only say that I'm very sorry. It's impossible to
keep facing fear forever. That is exhausting and people want to forget if
possible.
How are we to handle such a heavy burden? If you speak of monetary
calculation, individual suffering and sorrow can't be translated into money and
there is already a huge amount of sorrow. It's hard to know what to do. As long
as one lives, there is no choice but to live with this reality. I'm very sorry.
I don't know how to apologize.
But apology doesn't allow one to take
responsibility. I have long been thinking about what I can do to reduce
radiation exposure in children, if only a little. And I would like to continue
to do so.
***
Interviewer: Watanabe Taeko (editorial board,
Shukan Kinyobi.)
Koide Hiroaki, b. 1949, assistant professor,
Kyoto University, Nuclear Reactor Experiment Research Center.
Main writings: Genpatsu no uso (The Lie of
Nuclear Power) (Fusosha); Genpatsu wa iranai (We don't need Genpatsu)
(Gentosha); Genpatsu. hoshano -- kodomo ga abunai (Nuclear Power Generation:
Radiation. Children are in Danger (co-authored, Bunshun Shinsho).
***
Kyoko Selden is an Asia-Pacific Journal
associate. With Noriko Mizuta she edited and translated Japanese Women
Writers and More Stories
by Japanese Women Writers. She is the coeditor and translator of The
Atomic Bomb: Voices From Hiroshima and Nagasaki.
This interview appeared in the March 16, 2012
Shukan Kinyobi. http://japanfocus.org/events/view/136
***
