DAVID GREENE, HOST:
Here's an unsettling image: for the last few days, steam has been rising from one of the reactors at the crippled nuclear power plant in Japan. As you might remember, that facility, the Fukushima Daiichi plant, was all but destroyed by an earthquake and tsunami. Two years later, the company that owns the plant is still struggling to control the damage. And to understand what's happening there, we're joined by NPR's science correspondent Geoff Brumfiel. Geoff, thanks for coming in.
GEOFF BRUMFIEL, BYLINE: Thank you.
GREENE: So, this steam, where is it coming from?
BRUMFIEL: Well, it's coming from the Unit 3 reactor, which is one of the three reactors that melted down at the plant. But nobody knows exactly where in Unit 3 it's coming from, because the reactor is just too radioactive to get near. Now, there's a fear that it could come be coming from inside the reactor vessel itself, where the melted down fuel is, and that some of that fuel is heating up again. Maybe there's a hotspot. There's a small chance that the nuclear reactions could have restarted.
GREENE: Likely that might be happening?
BRUMFIEL: No, no. It's very unlikely. Fortunately, TEPCO, the company that owns the plant, has been monitoring the reactor very closely. And all the indications are that this is not a result of any new nuclear reactions inside the reactor vessel. Their best guess is it's been rainy and humid in Fukushima, and they think that rain is falling onto the outside of the vessel that holds all this nuclear fuel. That outside is still hot. It's still 104 degrees Fahrenheit. And so that could be causing the rain to come up as steam.
GREENE: OK. So, it sounds like the steam may be not that dangerous a situation. But one concern has also been just the groundwater possibly being contaminated around the plant. And the company comes out and says now, for the first time, yes, that's happening.
BRUMFIEL: Right. For a long time now, it's been clear that there's been radiation still coming out of the plant into the Pacific Ocean. This plant is right on the coast, which is how it struck by a tsunami. Until now, TEPCO has claimed that this is a result of some residual radiation from the initial accident. But they drilled some test wells, and they're now admitting that the groundwater around the plant is contaminated with radioactivity. And this is a big admission for the company.
GREENE: OK. And how much of a risk does that pose to the public?
BRUMFIEL: I've been speaking to some experts in Japan. It's a little unclear at this point, because the problem is that we don't know exactly how much there is and we don't know exactly where it's going. It's difficult to say. It's just soaked into the ground. What we do know is that it probably is being dispersed out into the ocean. And while it's creating a local problem around the plant - and there's already a lot of radioactivity out in the seabed there - it's unlikely to pose any sort of a major risk at this stage.
GREENE: And I guess one question is: What is the company going to do about this groundwater problem?
BRUMFIEL: Well, I mean, there's a limited number of things it can do, because, obviously, it can't, you know, there are broken pipes in the plant. The plant itself is damaged, and water is flowing into the plant all the time, partially to keep it cool, partially just brown water flowing into the basement. So they can't really stop the water. What they could do is try and stop it from going in the ocean. So they're putting in some chemicals into the soil to try to harden it, make it less permeable to water. They're going to asphalt over the top of it to try and keep rainwater from getting in. Eventually, they're hoping to put a huge, 30-foot-deep steel wall into the ground that will literally serve as sort of a barrier for that water from getting into the sea. But that's going to take a year.
GREENE: That sounds like an elaborate process. And I guess, in a way, all this is a reminder that two years is not that long when it comes to recovering from a nuclear disaster like this.
BRUMFIEL: That's right. And, I mean, these are issues that TEPCO's going to be wrestling with for decades. And Chernobyl - in many ways, a much more dangerous accident back in the '80s - they're still working out how to deal with the nuclear remnants of that accident, which are still radioactive.
GREENE: Geoff Brumfiel, thanks for coming in.
BRUMFIEL: Thank you very much.
GREENE: He's NPR's science correspondent.
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