Re-evaluating The Fukushima Nuclear Situation
IRA FLATOW, host:
This is SCIENCE FRIDAY. I'm Ira Flatow. It's been a little over two months since the devastating earthquake and tsunami in Japan wrecked the Fukushima nuclear power station, releasing enough radiation to have analysts comparing it to Chernobyl.
Only very recently have workers been able to get in-person views of some parts of the damaged reactors there. What are they seeing inside? And how is that new information changing the plan for how to respond to the unprecedented situation?
Joining me now is Ed Lyman. He's been tracking developments at the power plant. He's a senior scientist with the Global Security Program of the Union of Concerned Scientists in Washington. Welcome to SCIENCE FRIDAY.
Mr. ED LYMAN (Union of Concerned Scientists): Thank you.
FLATOW: You know, it's almost as if this story has dropped off the radar screen here in the States.
Mr. LYMAN: Yes, well, that is the trend. You know, if things aren't blowing up every day, then people tend to forget. But the situation is still pretty serious.
FLATOW: How serious is it? Give us an update on where we stand now with it.
Mr. LYMAN: Well, the update is that the authorities have learned what a lot of people pretty much have figured all along, that in three reactors the nuclear fuel has completely melted and is now sitting at the bottom of the steel reactor vessels, and that is actually probably going to complicate the ability to stabilize the situation further.
FLATOW: Well, what about the cooling situation? Are they able to keep it cool?
Mr. LYMAN: They are providing cooling, but they haven't yet brought these cores to what they call cold shutdown, which is bringing them below the boiling point of water. And as a result, they're cooling by continuing to dump water into the reactor vessels.
That's boiling off the steam. It's condensing as contaminated water, and it's ending up in the basements of these buildings and still leaking, probably, into the groundwater and into the sea. So they don't have a stable closed(ph) circuit to maintain cooling at this point.
FLATOW: Does that mean that the melted core is stable itself, it's not melting through, the China syndrome, as we used to call it?
Mr. LYMAN: Well, it does appear that way. It looks like they were able to stabilize the situation before these cores actually melted through completely the steel vessel. In that case it would have dropped down to the floor of the containment building and potentially eaten through the containment.
So the situation isn't as bad as it could have been, but the vessels are believed to be leaking. There are holes in them, and there are also holes in the containment building. So anything you put in is still finding its way out.
FLATOW: So you're basically, by pouring water in and it flushing out, you're just basically flushing radioactive material to the outside.
Mr. LYMAN: That does seem to be the consequence there. They're washing huge quantities of radioactive water into the basements of the buildings, and that's causing an enormous cleanup problem they're going to have to face for a long time to come.
FLATOW: And so is there a plan, or is it is it what?
Mr. LYMAN: Well, the original plan would be to flood the containment buildings with water. They knew that the vessels weren't completely full. That's the steel vessel within the containment. But they didn't realize they were completely empty, which means that there are holes probably at the bottom.
So the original plan was to flood the containment buildings and try to cover the cores that way, but since the containment buildings also all seem to be leaking, their new plan is to build a system which would extract the water that's leaking out of the containment buildings, run it through filters, clean it up and put it back in the reactor. So they're going to have to siphon off all the contaminated water it's collecting in the basements.
FLATOW: Is that sort of like building a moat around it and pumping out the water as it leaks out or how?
Mr. LYMAN: They'll have to build a new piping system with pumps that will, you know, draw the water out of these buildings.
FLATOW: So we're talking about something that's going to take many months, and in all that time the radioactivity will continue to leak out.
Mr. LYMAN: Yes, unfortunately, that seems to be the situation. Their estimate is to have the reactors in cold shutdown within six to nine months. That's probably an optimistic assessment, but to deal with all the radioactivity that's already gotten into the environment and to actually stabilize the cores, package the materials safely and eventually decontaminate the site, that's -you're talking about decades.
FLATOW: And as far as those holding pots, are they in a different situation or basically in the same situation?
Mr. LYMAN: Well, they've managed to stabilize the leaks that they know about. They've used a mineral called zeolite, which absorbs certain radioactive isotopes to try to soak up some of the radiation and keep it from spilling into the environment.
But there's already been a lot that's been released, both in the water and also in the air. So there's also contamination of ground farmland, tens of miles downwind from the site.
FLATOW: Would it be fair, then, at this point - I know when the accident first happened, people were comparing it to Three Mile Island. Have we moved over to a Chernobyl comparison?
Mr. LYMAN: Yeah, I mean, I don't think the comparison's that useful. This is definitely a very, very severe event. It's led to a massive amount of radiation released into the environment and a cleanup problem that's going to take decades.
I think it's, you know, qualititatively speaking, as bad as Chernobyl.
FLATOW: And how are the Japanese taking this?
Mr. LYMAN: The Japanese are reacting with a lot of concern. Japan - nuclear power was a big part of Japan's energy strategy for hundreds of years. They wanted to build a new fleet of reactors called fast breeder reactors, use plutonium fuel. It was really part of their self-identity, is having a big nuclear power program.
And this has caused a shock to the system that's really turned public opinion around. It's led the government to require the shutdown of other plants that are in seismically active areas. And I think it's causing a real reconsideration of nuclear power in Japan.
FLATOW: So things will just stay at the status quo until they're able to change that, whenever that may be?
Mr. LYMAN: Yes, I mean, they've identified eight areas that they need to address, not only cooling the reactors and the spent fuel pools but stabilizing the site in the event of further seismic events or tsunamis.
They need to improve the situation of the workers at the site. That's very important because the working conditions have been terrible, not just because of the radiation levels but also basic human needs.
And they also need to build covers around the reactors and to deal with contaminated topsoil. You know, it's just a whole laundry list of chores there, and making slow progress. But it's - there was no playbook for how to deal with this type of situation. So they're making things up as they go along.
FLATOW: All right, Ed, thanks for checking in with us.
Mr. LYMAN: Thank you.
FLATOW: Ed Lyman, he's been tracking the developments at the Fukushima nuclear reactor. He is a senior scientist with the Global Security Program of the Union of Concerned Scientists in Washington.
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