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Long-Term Impacts of Fukushima Reactor Could Linger For ‘A Generation or More’

March 28, 2011 at 5:11 PM EST
Japanese officials reported that radioactive water has spread beyond a damaged building at the Fukushima nuclear power plant and had contaminated the ground near the site. Jeffrey Brown talks to Columbia University's David Brenner and the Carnegie Endowment for International Peace's James Acton.
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JEFFREY BROWN: Japan’s nuclear troubles grew worse still today, even as confirmed deaths from the earthquake and tsunami topped 11,000. Officials reported radioactive water has spread beyond a damaged reactor building, and radiation has also gotten into the ground.

Smoke rising from parts of the Fukushima Daiichi plant was the most visible sign of ongoing trouble, but the real threat lay beyond public view. At unit two, highly radioactive water, first discovered last week, has now escaped the reactor containment building. It was found today in deep utility trenches used for pipes and wiring with an opening just 180 feet from the sea.

Water has also pooled inside the reactor’s basement, where radiation levels were measured at 100,000 times above normal. The Japanese government acknowledged it’s likely the reactor suffered a partial meltdown.

In fact, on Sunday, the radiation level was initially reported to be even worse.

WOMAN: The water contains 10 million times the usual level of radioactive substances.

JEFFREY BROWN: Hours later, the Tokyo Electric Power Company, TEPCO, said it had miscalculated and apologized.

But the mistake forced employees to flee unit two for hours on Sunday and interrupted their efforts to jump-start cooling systems. Today, the government’s chief Cabinet secretary sharply criticized the utility.

YUKIO EDANO, Japanese chief Cabinet secretary (through translator): The measurement of radiation is necessary to secure various aspects of safety at the plant. So, these kinds of mistakes cannot be forgiven.

JEFFREY BROWN: The problem was not confined to unit two. Workers found reactors one and three also have radioactive water in their utility trenches.

The radiation levels, though, were significantly lower than at unit two. But all told, it left crews with an enormous job, trying to remove the hundreds of tons of contaminated water. Meanwhile, TEPCO officials announced plutonium has been detected in soil outside the Fukushima complex. They insisted the amounts were too small to be a risk to public health.

And contamination in seawater was spreading just offshore. But Japan’s nuclear safety agency said there’s no immediate health risk because a fishing ban is in effect. Amid the rising radiation fears, the government urged people not to return to areas near the plant, though some have gone back to pick up belongings.

And we take a closer look now at the situation at the Japan reactors. James Acton is a physicist in the nuclear policy program at the Carnegie Endowment for International Peace. David Brenner is director of the Center for Radiological Research at Columbia University.

James Acton, I will start with you.

What do we know about this new problem of contaminated water outside the reactor? And how serious is it?

JAMES ACTON, Carnegie Endowment For International Peace: Well, Jeff, this is serious. And it’s serious really for a couple of reasons.

It doesn’t actually surprise me that they’re finding very large quantities of radioactive water, because they have been pumping huge quantities of water into the system. And that water has got to go somewhere.

The radioactive water they have found inside the turbine halls is serious because it’s going to complicate the relief efforts. The radioactive water they have found outside turbine halls, in the trenches, is serious, because if they don’t pump that quickly into a secure storage facility, then there’s the chance that it’s going to leak out and increase the quantity of radiation in the environment.

JEFFREY BROWN: So — so, just to try to make this complicated equation clear, they — they now have a process where they have to pump water in to cool off the fuel rods, but they also have to pump out the contaminated water somewhere, to some safe place.

JAMES ACTON: That’s exactly right.

I mean, if you think back a couple of weeks to where this crisis started, it started with this race to cool down the fuel rods. And they have been doing that by pumping in a lot of seawater and then more recently freshwater. But that water has got to go somewhere.

And, at the moment, it’s just leaking out into side buildings and these trenches. And now they have to pump that back in to an area within the plant that they have identified for storage.

JEFFREY BROWN: And do we know where this contaminated water comes from? You’re saying it might come from the water that is actually being pumped in?

JAMES ACTON: I think — I think — I think that’s where it has to come from. The big question is where is the leak in the system?

Now, on Friday, the Japanese authorities reported they were concerned that there was a leak in the reactor pressure vessel itself. That turns out probably, almost certainly, now to be wrong. And in this very complicated series of piping that comes out from the reactor pressure vessels, somewhere in that complicated series of piping, there appears to be a leak or leaks. But the utility apparently don’t know exactly where that leak is coming from.

JEFFREY BROWN: All right, now, David Brenner, we also, in the meantime, have these — had these conflicting, very confusing reports on the levels of radiation this weekend. What — what do — what do we know right now and where do you see the current danger?

DAVID BRENNER, Columbia University: Well, let’s distinguish between the radiation levels inside the reactor itself and those that the general population outside are being exposed to.

So, if we start with the situation outside the reactor, what we’ve been seeing over the past few days is a steady decrease in radiation exposure levels from a week ago until today. It steadily got smaller and smaller, which is pleasing and really does reflect the way the wind is blowing as much as anything, that the wind is still blowing the radioactivity towards the sea.

The situation for the nuclear workers inside the plant, well, that’s a different story. It’s pretty clear that they are being exposed to high doses of radiation, and we certainly hope not fatal doses. But what they’re doing, it would appear, is actually having more workers now than they did a week ago.

So they’re trying to spread the radiation dose among more people, so that any given person has a lower radiation dose. But I’m still very concerned about the long-term issues for the actual radiation workers. I think we could be looking at some serious injuries.

JEFFREY BROWN: And when — when do we — how long is it before you know, before something like that takes effect?

DAVID BRENNER: Well, in terms of the worst possible scenario, which is mortality, it’s typically 30 to 60 days would be the time scale.

But I think we would know beforehand whether people were exposed to lethal doses.

JEFFREY BROWN: Now…

DAVID BRENNER: But that’s how long it takes to — for it to happen.

JEFFREY BROWN: Now, staying with you, and going now outside the reactor to the new reports of radiation in the ground and spreading at sea, now, you — you started to talk a little bit about the — the impact of that, but flesh that out a little bit for us.

How — how dangerous is it when it goes into the soil and also into the — more into the ocean, spreading in the ocean?

DAVID BRENNER: Well, they are two different situations. And it really depends on what — something that we don’t know quite now is how much radioactivity is being deposited in the sea or in the ground.

I think the short-term issues are actually quite small in terms of public health. But we have much more important long-term issues that we’re going to face. The dominant radioisotopes is going to be radioactive cesium. And that has a half-life of decades.

So we’re really talking about some exposure to the environment for really a generation or more to come. How important that is really depends on how much radioactivity gets into the environment. And that we really don’t know at this point.

But the short-term issues, I think, are not so important for the general population. The exposures that people are getting short term over the next days or even weeks, as it stands at the moment, are relatively small.

JEFFREY BROWN: Well, now, James Acton, just to help us think about where we’re at and what may come about longer — middle or longer term, what does it mean now when the authorities tell us that it’s likely that there has been a partial meltdown? Remind us, what exactly does that mean?

JAMES ACTON: Well, Jeff, when you turn off a nuclear reactor, as it were, the fuel rods still generate heat and remain hot.

And so, you have got to keep those fuel rods cool. Now, if you don’t keep them cool, then they start to melt. And that melting lies along a spectrum, really. You could have a tiny bit of fuel melting all the way through to all of the fuel melting. Now, we know that there has been a partial meltdown. That is to say that some of the fuel within the core has melted but not all of it. And part of the difficulty the operators face is, you know, you can’t just flip the lid on a nuclear reactor and look inside to see what the state of the core is.

We don’t actually know how much of the fuel has melted or indeed many of the other conditions in the core right now.

JEFFREY BROWN: And, David Brenner, I want to ask you about the other new report today, which is the plutonium found in the ground. Now, what does — what does — what does that tell you? What’s the connection here, if any?

DAVID BRENNER: Well, there are there are various sources that the plutonium could have come from. But I think we’re relieved that the levels are actually very low, and actually, typical of plutonium — natural plutonium contamination in this country.

So, right now, we don’t have to worry about any biological consequences of that plutonium. There’s a very small amount of it.

JEFFREY BROWN: So, do we — are we looking — I will start with you on this, David Brenner. Are we looking at days, weeks, months? I mean, you were talking about not knowing about the impact for years. But when you think about the new issues that have been raised, and particularly the water outside the reactor, what are we looking at here?

DAVID BRENNER: Well, in terms of the workers inside the power plant — and I must stress again that these are incredibly brave people, because they are going into a situation where there is a great deal of potential for harm — this is a short-term issue. They are being exposed to either moderate doses or perhaps even high doses of radiation right now. And the issues are short-term.

From the point of view of everybody else outside the plant, there are short-term issues to do with the radiation exposure in the next week or two. But again, as far as we can tell, the extensive measurements that we have would suggest that the risks are not so large.

But we are faced with a lower level, much longer-term issue of exposure to the general population over the next few decades.

JEFFREY BROWN: And let me ask you, James Acton, briefly, again, the same sort of thing. When you are looking at the potential for getting this under control, are we talking days, weeks, months, longer? What — what do you look at?

JAMES ACTON: Well, the longer this crisis has been going on for, the longer — it’s become clear the longer it’s going to take them to get it under control.

What they need to do now is clear out all of the radioactive water from the turbine halls, reconnect the power where it hasn’t yet been reconnected, repair the cooling systems where they have been damaged, and then get those cooling systems operational.

If there’s no major setback, I think, realistically, that process is going to take at least a few weeks. But if they encounter new setbacks and new problems, which, unfortunately, is a distinct possibility, then it could take significantly longer to get this crisis under control.

JEFFREY BROWN: All right.

Well, I want to thank you both very much for the update.

JAMES ACTON: Thank you.

JEFFREY BROWN: James Acton, David Brenner, thanks a lot.

DAVID BRENNER: Thank you.