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Update On Japan's Nuclear Reactors

IRA FLATOW, host:

This is SCIENCE FRIDAY. I'm Ira Flatow.

Workers in Japan continue their efforts to cool down the spent fuel pools and reactors at Japan's Fukushima Dai-ichi nuclear plant, among reports this morning of steam rising from yet another one of the six reactors at the plant.

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And today Japan's nuclear safety agency raised the severity level for some of the reactors to level five from level four. A level four is for incidents with local consequences; five means there could be consequences beyond a local level. Seven is as high as it gets; Chernobyl was a seven.

And the question on everyone's mind: What happens next? If these reactors and spent fuel pools cannot be cooled down, what's going to happen? We hear the term nuclear meltdown a lot, but what does that mean, and how much radiation could be released into the atmosphere? Who would be at risk?

Also take a look this hour at a new report on U.S. nuclear power plant safety. How safe are the plants here in this country? The report says that there were 14, quote, "near misses" last year, where potentially disastrous events were luckily avoided.

You have a lot of questions too? I know you do out there. We'll try to answer as many of them as we can. Our number is 1-800-989-8255. If you'd like to tweet us, you can tweet us @scifri, @-S-C-I-F-R-I. Or go to our Facebook/scifri, we'll be looking at that also.

Let me introduce my guests: Joe Palca, science correspondent at NPR. He joins us from NPR headquarters in Washington. Thanks for talking with us, Joe.

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JOE PALCA: Hi, Ira.

FLATOW: Good to talk to you.

FLATOW: David Lochbaum is director of the Nuclear Safety Project at the Union of Concerned Scientists. He is a nuclear engineer, and he has worked as a safety trainer for the Nuclear Regulatory Commission. He joins us by phone. Thanks for being with us today.

Mr. DAVID LOCHBAUM (Nuclear Safety Project Union of Concerned Scientists): Good afternoon, Ira, thank you.

FLATOW: You're welcome. David Brenner, professor of radiation and biophysics and director of the Center for Radiological Research at Columbia University Medical Center. He joins us by phone from the U.K. Welcome back to SCIENCE FRIDAY.

Professor DAVID BRENNER (Columbia University): Pleasure to be here again.

FLATOW: You're welcome. Charles D. Ferguson is president of the Federation of American Scientists. He's also trained as a nuclear engineer. He joins us by phone from Washington. Thank you for being with us.

Mr. CHARLES D. FERGUSON (Federation of American Scientists): Hello, Ira.

FLATOW: Hi there. Joe, can you give us an update on what we think we know about what's happening now?

PALCA: Well, I think you characterized it fairly well at the start. There's - it seems as if in the last day or so the concern at the reactors has shifted from the core, which is where the fuel was - well, which had to be - they had to be shut down and cooled, and there was problems getting cooling water to them to begin with.

Those seem to be in pretty stable shape, if I can say that. I wouldn't say it's permanently stable at this point because they had to make some, you know, unusual accommodations like pumping in seawater.

But they seem to be stable, and the concern seems to be turning to these spent fuel pools, which is where you take fuel right after it comes out of the reactor and before you send it off to a more permanent storage place or where you just store it while you're cleaning the reactor or doing whatever you're doing, and then you want to put it back in.

And you know, that seems to be where we are. And oddly, oddly stable there too, even though things are - we've heard that these pools have been drained of water, which is important both for protecting workers from the exposure of radiation and for cooling the spent fuel, or the fuel, as it is.

But nothing - no more terrible bad things have happened, so - at least that we're hearing about.

FLATOW: And that's the thing. I remember when I covered Three Mile Island 30 years ago, you had to rely on just what they were telling you because you could, of course, not get in and see for yourself.

PALCA: Well, you know, Ira, this is the classic. It's just insanely difficult to get any straight information at all. I mean, pictures even can be misleading. People talk about white smoke. Is it steam? Is it smoke? Is it something else? It's very hard.

And frankly, you know, you have to trust when the pictures are taken. So yes, you're right. We're not sitting at the control panels, and we're not getting the most up-to-date information by ourselves. So we're relying on others. And frankly, there's not been the world's greatest history of frank exchange of information in general in this industry.

Now, I'm not saying they're not telling the regulators. I hope that's going on. But certainly the media isn't always informed proactively in this world. So it's been hard to keep track of this.

FLATOW: David Lochbaum, does this jibe with what you believe is happening? Dave, are you there?

Mr. LOCHBAUM: Yes, I am.

FLATOW: The way - the situation that Joe described, is that basically your understanding also of what's happening there?

Mr. LOCHBAUM: It is very much so. I mean, the to elaborate on the point you made also, the problems they're dealing with on the spent fuel pools are complicating the workers' ability to both battle those problems and continue to maintain the reactor cores on, you know, one, two and three in a relatively stable position.

So it's - by putting all the facilities so close together made sense when it was operating for economy of scale, but it's caused problems when these kind of situations developed, and a problem on one unit is complicating the ability of workers to deal with situations on other units.

FLATOW: Would it be safe to say that, like Three Mile Island, like Chernobyl, like other accidents in the past, we won't really know what happened until months later, when people go in and figure it out?

Mr. LOCHBAUM: I think it'll be longer than months because, for example, with Three Mile Island it was pretty evident that there was fuel damage, but it wasn't until almost four years later that a camera was dropped down into the reactor vessel that revealed - we really were able to determine just how bad that damage had been.

FLATOW: And at Three Mile Island, they had talked - I think if I recall they were using robots to try to go where there was too much radiation. Are there other thoughts about here, or is it too early to even think that way?

Mr. LOCHBAUM: Well, I'm sure that the authorities are trying to use all the options they have available, including robots. But I'm not really on the ground. So I don't know what the extent of damage they have and what options they have in their quiver. But I'm sure every conceivable options is being considered as they try to deal with this disaster.

PALCA: Hey, Ira, it's Joe here. I just wanted to - there was one thing you said as we were starting out that kind of I wanted to clarify a bit, and that is this notion that the near-misses didn't result in accidents, and that was a lucky thing.

I think lucky in the generic sense, but I've talked to a lot of plant engineers, and, I mean, they know that accidents or mistakes or unforeseen things will happen, and they feel that it's not luck that takes care of these problems so much as adequate planning.

Now, what we've heard in this particular scenario is that nobody actually - they may have planned for an earthquake, and they may have planned for a tsunami, but it seems as if they may not have planned for an earthquake and tsunami of the magnitude that they were faced with.

And so you would say, well, they were unlucky that their planning wasn't adequate, but I don't think it's always luck that, you know, prevents problems from occurring. These are things that engineers tell you they think about all the time, and when problems occur, and they're solved, they say, well, see, it worked; not, oh my goodness, we were lucky.

FLATOW: David, would you agree with that?

Mr. LOCHBAUM: Well, to some extent. I mean, in 1996 I wrote a book about spent fuel pool issues and where loss of power could cause an overheating problem, which causes the inability of the workers to deal with the situation. That's all described in chapter nine of that book.

No one in the United States or Japan did anything about that problem. So to say that, you know, we didn't anticipate this is not really true. The fact that we didn't react to the known problem is true, and Japan is paying a high price for allowing that known safety hazard to go unresolved.

FLATOW: Charles Ferguson, what's your take on all of this?

Mr. FERGUSON: Well, yeah, I'm agreeing with a lot that Joe and Dave are saying. But I think another issue, and we might get into it a little bit later, I don't want to necessarily preempt, but a question of the plant design itself.

Five of the six reactors at Fukushima Dai-ichi are of this boiling water reactor Mark One-type design, and concerns were raised as far back as 1972, one year after reactor unit one at the plant began operations, that that particular design had some serious design problems. And concerns were yet again raised throughout the 1970s and even into the 1980s.

And I know Dave has done some work directly on that type of model plant, and we have 23 of similar type designs operating right now in the United States, roughly a quarter of our reactor fleet in the United States.

FLATOW: Does anybody think that any - this kind of accident has the potential to happen in this country?

Mr. LOCHBAUM: This is Dave. I would say so. The primary challenge that was faced in Japan was the loss of power that lasted longer than anybody anticipated.

If you look at studies that the Nuclear Regulatory Commission has performed in this country as recently as 2004, our reactors, which have less battery capacity than Japan does, has a very high chance of getting into the same situation.

The River Bend plant outside of Baton Rouge in Louisiana, according to the NRC, has an 87 percent chance of a station blackout. That's when you lose the normal connection to the grid, the connection to the emergency diesel generators, and the batteries are exhausted. There's an 87 percent chance that that scenario will lead to core - reactor core melt at the River Bend plant.

So it is - we are vulnerable. The exact scenario might not be the same, the earthquake and tsunami, but River Bend is vulnerable to hurricanes. We have plants on the West Coast that are vulnerable to earthquakes.

On the East Coast and the northeast you have ice storms and northeasters. In the southeast you have hurricanes that his Florida and the Gulf Coast.

So we might not find it following the exact same script, but we could end up with the exact same ending.

FLATOW: David Brenner, Japanese authorities have told everyone within 12 miles to evacuate, and those between 12 and 19 to take shelter. And the U.S. government has told Americans to get out of there from a 50-mile radius. Are they being overly cautious?

Mr. BRENNER: Well, as of right now, I think they probably are. I think just yesterday we had our first really hard and fast information about what the radiation doses are on the ground to individuals up to somewhere like 100 kilometers away from the incident.

And if things were to stay the way they are, that's probably overly cautious, but of course we can't anticipate what's going to happen in the next days or week even. Nor can we anticipate which way the winds are going to blow, which is such an important component to the whole story.

And we've been saved to a great extent right now by the fact that the winds have basically been offshore, blowing into the sea. Should the winds change, should the amount of radioactive material continue to increase, then they're probably not being overly cautious.

FLATOW: And so really we are at the mercy of the weather at this moment.

Mr. BRENNER: It's certainly ironic. We're talking about an extremely high-tech operation, and we are reduced to hoping that the wind blows in the right direction. It's certainly not an acceptable situation to be in.

FLATOW: All right. We have to take a break. Joe, I want to thank you for taking time to be with us today, as always.

PALCA: You bet. Thanks, Ira.

FLATOW: I know you've got a lot of work to do today on this. We'll let you go. We're going to take a break. We'll be right back and take your questions and talk lots more about the status of what's going on in Japan. So stay with us. We'll be right back.

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FLATOW: We're talking this hour about what's going on at the Japanese nuclear reactors, getting an update, talking about the future with my guests: David Lochbaum, director of the Nuclear Safety Project, Union of Concerned Scientists; David Brenner, professor of radiation biophysics and the director of the Center for Radiological Research at Columbia University Medical Center; Charles D. Ferguson, president of the Federation of American Scientists.

Our number, 1-800-989-8255. And we've got lots of calls and questions coming in. Let's go to a call now that came in verbally.

Unidentified Man (Caller): Hello.

FLATOW: Hi there.

Unidentified Man: If you look up in Wikipedia for Evergreen 747 supertanker, you'll see a description of a firefighting airplane that I think would be the perfect tool for putting water on the nuclear power plants over in Japan. Has there been any discussion at all about using the 747 supertanker to put in water on the nuclear plants? I've heard nothing about this. It seems to me that they could be in and out real fast and get the job done. Thank you.

FLATOW: You're welcome. David Lochbaum, why not get one of these big, you know, tankers? You know, I've seen the kind that put out forest fires. They dip into the ocean. They come back out and dump water. Could we do that instead of the fire hoses they're talking about?

Mr. LOCHBAUM: Well, one of the concerns with doing that is that the water weighs about eight pounds per gallon. The spent pools are on fire, or maybe on fire, and you're trying to get that situation resolved. One of the things you don't want to do is have the cure be worse than the problem originally.

If you put too much weight on top of the spent fuel pool, you could cause the racks that are holding the fuel assemblies to collapse. If the spent fuel reconfigures, you could actually cause a critical mass to be formed and restart a nuclear chain reaction and have a reactor core operating outside of containment.

So you want to do things that make the situation incrementally better with limited downside risk for making the problem worse. So I assume the authorities weighed those kind of considerations and applied the best fix that they could under that situation.

FLATOW: Just as someone who deals with a lot of hot dishes in the kitchen all the time, I know when I pull one out of the oven and I put it on the - if you throw it under the water, it's going to shatter, right? Why is that not going to happen if I dump all this cold water onto this super-hot pile of nuclear material?

Mr. LOCHBAUM: Well, that could also be another consideration. If you slowly add water, you will cool down the metal cladding and not have it shatter. If you completely immerse it in cold water, then you increase the likelihood of having it shatter. So that those are the kind of considerations they want to factor into all this.

FLATOW: Charlie Ferguson, your reaction?

Mr. FERGUSON: Yeah, Ira, I agree with Dave's analysis. I think it's spot-on, especially I don't know if the criticality accident is that likely, but it's something that they surely have to take into account.

We should remind listeners that back in September 1999 there was a criticality accident at Tokaimura nuclear fuel processing facility in Japan, and they've shut down that facility since then. Two workers were killed from radiation-induced sickness. They were mixing in enriched uranium and it caused an increased concentration, uranium, and with the interaction with the water, and caused a criticality accident. So that's a really serious concern they need to take care of.

FLATOW: Here's a question from a tweet that came. It's from Kenny(ph), who says: How come there aren't automatic water systems for these plants, like buildings that have sprinkler systems in them? Why don't they just come on automatically and spray water on everything?

Mr. LOCHBAUM: The facilities are designed with quite a few systems like that. The problem they faced was that the normal source of power, the electrical grid, was taken out of play by the earthquake.

The emergency diesel generators started, and they would have provided power for those kind of pumps in the sprinkler systems, but the tsunami took the emergency diesel generators out.

The backup to all that were batteries that are sized to last eight hours, but the event lasted more than eight hours.

So they - some of those factors were in play, and there were design things to deal with that, but they, you know, the situation just overwhelmed those capacities.

FLATOW: And so there so you would say, you know, in a country where the name tsunami was invented and having a history of tsunamis and nuclear power, why would you why would you have these exposed to those kinds of outdoor conditions or the possibility of those?

Mr. LOCHBAUM: Well, I agree with Joe's remarks earlier. The plant was designed to withstand an earthquake. The plant was also designed to withstand a tsunami. The design wasn't quite robust enough to handle the one-two punch of both occurring in short order.

FLATOW: Let's go to the phones, to Linda(ph) in Princeton. Hi, Linda.

LINDA (Caller): Oh yes, hello. I haven't heard mention or negation of any involvement of plutonium in these reactors in Japan. So I'd like to ask your guest whether that might be a factor. And the other thing is, could he discuss, if he knows anything about it, the plutonium incident in the United States, I think in the Southwest in the late '50s, early '60s, that apparently increased, according to the World Health Organization, the level of lung cancer worldwide. It doubled within a year.

FLATOW: Okay, let's see if we can get an answer to that. Is there any plutonium involved? There is a - there's talk about some of the fuel rods have a mixture of...

Mr. FERGUSON: Right. That's right, Ira. In reactor unit three, that the Japan had started using what's called mixed oxide, or shorthand mox fuel. It's a mixture of plutonium oxide and depleted uranium oxide.

And Japan has moved forward or trying to move forward with so-called recycling of(ph) plutonium at a processing plant in Rokkasho. In fact, I visited Rokkasho back in August of 2007.

They're still struggling to fully commercialize that facility. They've run into some problems. Nonetheless, Japan is committed to plutonium. They may reconsider that in light of this recent event, but they are committed to it because of energy security concerns. They don't want to be overly reliant on external supplies of uranium.

But there are increased health hazards in the use of plutonium-based fuels. If there were a reactor accident that released plutonium into the environment, it could pose greater health threats than fuels that are mainly uranium-based.

FLATOW: So do I understand it correctly that when plutonium is inhaled, it's if not the most toxic substance on earth, it ranks number two?

Mr. FERGUSON: Right, but you know, we've got to be careful and say that - you know, just one atom of plutonium in your lungs and you're a goner, it requires more than that. But it is a significant health concern. You(ph) obviously want to reduce the possibility of inhaling significant amounts of plutonium...

FLATOW: And...

Mr. FERGUSON: ...or ingesting.

FLATOW: And those rods are in which - where are they in this reactor?

Mr. FERGUSON: Reactor number three had been fueled with some of the plutonium mixed oxide fuel.

FLATOW: And so they're not in the cooling pool.

Mr. FERGUSON: I don't know for sure. Maybe Dave Lochbaum has some information on that.

Mr. LOCHBAUM: They were just placed into the unit three core. There's no irradiated mox assemblies in the unit three pools, is our understanding.

FLATOW: What are the likely scenarios? Do you have any idea, given all of your experience and all your years of dealing with nuclear reactors and watching what's progressing here, can you give me what you think is the most likely endgame that's going to happen here? Let me start with you, Dave, and then we'll move through.

Mr. LOCHBAUM: Well, my hope is that they're able to get water back in by either the water cannons, the aerial drops from a helicopter or other means. Yesterday they were able to reestablish an electrical power line to the plant.

So the hope would be that workers are able to get water back into the pools, which would reduce the radiation levels and allow workers to more freely move through the plant to take mitigative measures.

If that fails, then the problems are - the next step is likely to start doing what Chernobyl did, was bring in sand and other materials to try to smother the situation and blanket the radiation so it doesn't go far and wide.

Obviously the hope is for the former, but right now the latter can't be ruled out.

FLATOW: And David?

Prof. BRENNER: Well, in terms of the radiation doses to the population, if things stay roughly the way they are and don't get too much worse, we are looking at something a little worse than Three Mile Island but nothing like the other extreme, as a Chernobyl incident.

And even if things get significantly worse, we are still very much on the scale of Three Mile Island and absolutely nowhere near a Chernobyl-type incident.

So from the population standpoint, I think we will see a small increase in long-term cancer risks, but I stress it's very likely to be very small and maybe even not detectable in any type of studies we might do.

That is different, of course, from the situation of the workers inside the nuclear power plants. There's little doubt that they are getting extremely high radiation doses, and the possibility of fatalities among those brave men is, I think, unfortunately quite high.

FLATOW: Charles Ferguson, the fact that these rods are out in the open, and we've had a history of trying to find storage space, at least the Yucca Mountain, you know, the decades of Yucca Mountain and not going anywhere with them. Does it argue more now for trying to get them out of these pools, into some other drier, more safe place, not exposed to the elements?

Mr. FERGUSON: It does, Ira, and it's kind of ironic. Right after September 11th, I and others who were, you know, worried about the nuclear terrorism threat started to do analysis about nuclear power plant security. And Robert Alvarez and some colleagues did an excellent paper, I think, back around 2002, 2003, and it was peer-reviewed. And it prompted a study by the National Academy of Sciences looking at the vulnerability of the spent-nuclear fuel pools in the United States to terrorist attacks.

So we were so focused on terrorist attack that nature hit us with this double whammy that now has raised new concerns about the vulnerability of spent-fuel pools that if they develop cracks and leaks and they're drained as we're apparently seeing in pool number four and perhaps in pool three that the spent fuel if it's hot enough could catch fire or the zirconium clouding the zircaloy material could catch fire. It burns very, very hot, and that could lead to a release of radioactive materials.

So getting back to your point, I think, we need to do another reevaluation to try to move as soon as possible the oldest spent-fuel material out of those pools in the United States and other locations and store them in dry storage casts.

This is being done in Germany. And the reason why it's not being done so much in the United States - it's being done to an extent in the United States but not to a large extent because of the additional cost.

And the industry has also raised concerns about worker safety, radiation safety in moving the spent fuel out of a pool into a dry storage cast. There is some chance of a worker receiving radiation exposure, but when you balance that against these natural disasters or even possible terrorist attacks and a type of an accident that releases radioactive materials, then it does maybe tilt the balance toward moving this material to dry storage casts as quickly as possible.

FLATOW: David Lochbaum, would you agree?

Mr. LOCHBAUM: Oh, entirely. That's probably the best thing we could do. For the same reason Charles said, it reduces the very profile both for safety events and also for security events. So it's a no-brainer, and we need to make it happen.

FLATOW: Let's go to Sheila(ph) in Pleasant View.

Hi, Sheila.

SHEILA (Caller): Hi. That's really funny that you were talking about Yucca Mountain because that was my question. What about all the waste? You know? I mean, it's never safe. It's never ever safe. And Chernobyl and Three Mile Island and Japan, there are all different reasons for these accidents, and it's never safe. And I just think it's crazy, and that's just about all I got to say.

FLATOW: All right. Thanks for calling, Sheila.

1-800-989-8255 is our number. We're talking about nuclear safety and the incident in Japan this hour on SCIENCE FRIDAY from NPR.

Dr. Lochbaum, I want to go - I want to follow up on something you said earlier. You talked about the River Bend Plant in Louisiana, and you mentioned that it had an 87 percent chance of experiencing a total blackout. Can you clarify that for us? Otherwise, it sounds like it's going to happen tomorrow.

Mr. LOCHBAUM: Yes. I'm glad you asked that question because I want to clarify, or make sure that people understand what that was. That plant owner calculated up all the things that could lead to reactor core meltdown: earthquakes, pipe breaks, station blackout, operator error, you know, all the things that might lead to a reactor core meltdown. Calculated the individual rods and then summed them up.

Station blackout was 87 percent of all the things that could lead to reactor core meltdown. So it's a relatively high risk, a very high risk of core - reactor core meltdown at this plant is represented by a station blackout event.

FLATOW: Charlie Ferguson, you agree?

Mr. FERGUSON: Yes. I haven't studied that plant as intensely as Dave. Dave is the expert in the NGO community when it comes to safety at various nuclear - U.S. nuclear power plants. In fact, I don't think it's been mentioned yet on the show, but I will toot Dave's horn and Union of Concerned Scientists' horn that just yesterday morning they released their latest report on safety issues at U.S. nuclear power plants.

FLATOW: And, Dave, they had - it's a very critical thing to say you did, did you not?

Mr. LOCHBAUM: We did - we tried to - we've been working on this report since November, so it wasn't a post-Japanese reaction. We also, in that report, praised the NRC for doing very good things. They made very great catches of safety problems at Browns Ferry, Oconee and the Kewaunee plant in Wisconsin.

But on the other hand, there were some problems the NRC had at Indian Point, at Peach Bottom and Vermont Yankee. So what we said was that the NRC is a very capable regulator. They just need to be more consistently effective in that regard.

If you look at over the years, the times you heard UCS whine sometimes that are more better voiced, but the times you've heard us whine about stuff it's not that we're arguing that the NRC has set the safety bar at too low a level. We generally think the NRC set the safety bar at the right level, but they're allowing one or more plants to limbo beneath that bar, rather than meet those regulations.

FLATOW: Does it have anything to do with funding levels? I mean, you know, there are all these budgetary cut bills in Congress. Is any money being cut from those safety programs?

Mr. LOCHBAUM: Well, it's related to that. In June of 1998, the Senate threatened to cut the NRC's budget by 40 percent. Five hundred NRC workers would've - had been laid off. What the Senate told the NRC was to stop enforcing its regulations. You're annoying all these plant owners with all these fines and all the requirements to fix safety problems, so just back off.

So the NRC threatened with a huge budget cut like that. They did. They folded their tent and they went away. So, basically, NRC has been allowed to - it's kind of like MMS all over again.

FLATOW: You mean in Louisiana?

Mr. LOCHBAUM: Right. The NRC can do a good job if the Congress won't tie its hands.

FLATOW: And so you - they - you're saying they should reinstate those regulations?

Mr. LOCHBAUM: No. The regulations are there. They should - the Congress should allow the NRC to enforce the regulations. When the NRC was enforcing the regulations, in 1997, nine nuclear power plants were shut down the entire year to fix safety problems. The industry went to the Congress and said, look, you've got these guys off our back. We can't operate if we have to follow all these safety regulations. The Congress told the NRC to stop enforcement of safety regulations or we'll cut your budget by 40 percent. So the NRC played duck and cover.

FLATOW: And that's, you're saying, where we are now.

Mr. LOCHBAUM: That's where we are now. We're fortunate that we haven't had problems like Japan, but if we're hit with something like that or an earthquake in some place then we could - Japan media could be talking about our disaster.

FLATOW: All right. We're going to take a break and come back and wrap up our - the rest of our talk about Japan and the nuclear reactor problems they're having there. Our number 1-800-989-8255. You can tweet us, @scifri, @-S-C-I-F-R-I, or go to our website at sciencefriday.com or our Facebook page. It's /scifri. We're talking with Dave Lochbaum, David Brenner and Charles Ferguson. We'll be right back after this break.

I am Ira Flatow. This is SCIENCE FRIDAY from NPR.

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FLATOW: You're listening to SCIENCE FRIDAY. I'm Ira Flatow. We're talking this hour about nuclear energy, radiation and what's going on in Japan with Dave Lochbaum of Union of Concerned Scientists; David Brenner of Columbia University Medical Center; Charles Ferguson, president of the Federation of American Scientists.

When we last left, we were talking about Congress and the Nuclear Regulatory Commission and money to continue the work that they do and encourage them to do this.

This story is not going away very soon, and we, of course, will invite the Nuclear Regulatory Commission as we keep covering this to come on and talk about it. They're a very big player here. There's just so many people we can get on in one hour, but we do not want to sound like we're not giving everybody a fair chance to chime in, and there will be plenty of time to go on.

Our number, 1-800-989-8255 is our number. Now, let's talk about radiation. And you mentioned, Dave, that if things stay as they are, there should not be much release of radiation. And with things - or comparable to Three Mile Island, does that depend on the weather, or is there just okay what's happening with that amount to be safe?

Prof. BRENNER: If you're talking about the public health consequences...

FLATOW: Yes.

Prof. BRENNER: ...as far as we know, there is no level of radiation which you can characterize as entirely safe. Any increase in radiation exposure to any individual will increase their cancer risk a small amount. But the issue there is (unintelligible) a small amount.

We're all prone to cancer at quite high levels anyway. Forty percent of us are going to get cancer. Twenty-some percent of us are going to die of cancer. So...

FLATOW: But there's been a run on iodine pills. You're saying don't do that, I imagine.

Prof. BRENNER: I don't think there's any harm at all in taking an iodine pill, but there's no real good reason to do it, either; certainly, not in this country.

But even in Japan, the way iodine gets into the human body is actually through dairy products. The radioactive iodine falls to the ground, the cows eat it with the grass. It gets concentrated in the milk. And if you drink the milk, you're going to get exposed.

So the simple solution there is not to drink the milk, and the iodine pills are certainly not harmful in any way. But they shouldn't be considered any sort of panacea against radiation exposure because they're not.

FLATOW: Dave Lochbaum, what - as we watch this develop over the next days and weeks, what would you like to see that's hopeful? What should we - who are - we're watching it with you, what would - what should we hope that we're going to see happen?

Mr. LOCHBAUM: Well, the good news would be for the workers to reestablish water or restore water in all six spent fuel pools, regain control of the cooling of that water and, at the same time or in parallel, reduce the temperature of the water in the three reactor cores - units one, two and three - to less than 212 degrees, less than blowing.

That's not a perfectly safe condition, but that configuration will give workers as much margin as possible should more equipment fail or should aftershocks cause more damage. So that's - if they get to that configuration, I think, that would be a good sign.

FLATOW: Should we expect to see more release of hydrogen? Where is that hydrogen coming from?

Mr. LOCHBAUM: The hydrogen is formed when the - by a chemical reaction between exposed fuel, whether it's in the spent fuel pool or in the reactor core, and the steam that's flowing by it that causes that chemical reaction that produces large amounts of hydrogen.

FLATOW: Which doesn't normally occur.

Mr. LOCHBAUM: Some hydrogen is produced as water flows through the reactor core. The water molecules are disassociated into their oxygen and hydrogen constituents but in relatively small amounts and are handled through normal systems. It's when you get this chemical reaction of exposed fuel that you get tremendously larger quantities of hydrogen being formed.

FLATOW: So if they can keep the fuel rods covered, we should not expect to see much more hydrogen.

Mr. LOCHBAUM: I hope not to see anymore of that. That's - we've seen enough of that.

FLATOW: And that would be a sign that they are uncovered if we continue to see that hydrogen.

Mr. LOCHBAUM: That's a pretty - that plus the high radiation levels are pretty good signs that something is still uncovered that needs to be dealt with.

FLATOW: All right. I want to thank you, gentlemen, all - I know you're busy with this story for taking time to be with us today.

Mr. LOCHBAUM: Thank you, Ira.

Mr. FERGUSON: Thank you, Ira.

FLATOW: Dave Lochbaum, director of the Nuclear Safety Project at the Union of Concerned Scientists; David Brenner, professor of radiation biophysics, director of the Center for Radiological Research at Columbia University Medical Center; Charles Ferguson, president of the Federation of American Scientists. Once again, thanks for joining us today.

Prof. BRENNER: Thank you.

Mr. LOCHBAUM: Thank you. Transcript provided by NPR, Copyright NPR.