Radiation Spews From Crippled Nuclear Power Plant
RENEE MONTAGNE, host:
This is MORNING EDITION from NPR News. Steve Inskeep is on assignment in Cairo. I'm Renee Montagne.
LINDA WERTHEIMER, host:
And I'm Linda Wertheimer.
We're getting still more bad news, this morning, from the crippled Japanese nuclear reactors. They've emitted a substantial amount of radiation over the last 12 hours. That apparently came from both an explosion in one unit and a fire in another. In all, four of the six reactors at the power plant have now had major problems, including one that wasn't even in operation at the time of last week's earthquake and tsunami.
Joining us now with the latest from Tokyo is NPR's Richard Harris. Richard.
RICHARD HARRIS: Hi, Linda.
WERTHEIMER: Let's start with the explosion. Is there some reason to believe it was not a hydrogen explosion like the others we've seen?
HARRIS: It's unclear what caused the explosion. And let me back up for a second and remind you that there are six reactors at this Fukushima Daiichi power plant. We've already heard problems at Reactors Number One and Number Three; those were hydrogen explosions. And engineers had been struggling to cool Unit Number Two for several days, doing what they did before - pumping in seawater and so on. But they were losing that battle.
This morning we learned that about nine feet of reactor fuel was actually sticking out of the cooling water; was not being cooled at all, was exposed to air and that left it at very high risk of melting - both the fuel in there and the metal that surrounds it, which can also generate hydrogen. So there are suspicions that hydrogen might be involved in this.
But early this morning Japan time, workers at the plant heard an explosion. It wasn't there, though. It was down below. It was in a part of the plant that's designed to carry heat away from the reactor core, called the suppression pool. And so, we don't know what caused the explosion there, but it's possible the suppression pool may have cracked or otherwise been damaged.
Soon thereafter radiation readings started to climb around the plant. And the worst-case scenario in this case is that the reactor vessel, which is sort of the final line of defense to keep all that nuclear fuel in place, could've been broken; which, if that's true, that could leave a passageway for radiation to get into the environment.
I spoke to a government spokesman a little while ago and he says he does not know if, in fact, that has happened.
WERTHEIMER: Is there anything more known about the fire that happened?
HARRIS: Yeah. The fire, it broke out in a reactor that people actually hadn't been so concerned about. It had been shut down for maintenance during the tsunami, so it was actually cold. Engineers didn't think it was that big a deal. But this morning, a fire broke out there. Apparently the fire took place in the place where they'd been storing fuel that they'd already taken out of the reactor. And it was a sort of a cooling pond where it sits for a couple of years and cools down before they ship it off for storage.
It took firemen a couple of hours to put out that fire. The government spokesman says it was apparently also triggered by a hydrogen explosion of some sort. But the picture on that is still a bit fuzzy, for sure.
WERTHEIMER: What about radiation? How much radiation are we talking about?
HARRIS: A lot more than we have been hearing up to this point; enough for the prime minister of Japan to come out on television and urge everyone to remain calm, and to admit that it was a significant amount of radiation.
Exact numbers are spotty but the highest reading mentioned was 400 milli-sieverts per hour, which over a number of hours that could give you enough radiation to give you radiation sickness. And over a day, it could even be a lethal dose. So if you're exposed for a short period of time, it's not that big a deal. But if you're exposed for hours or days, it's really - you do not want to be in an area like that.
The utility evacuated most of its workers at one of the reactors to get them out of that harm's way. But they did leave 50 people behind to tend to the emergency. It is unclear what radiation doses they might have received and what kind of injuries they may have experienced.
Most other readings, though, reported by the utility, except for this one really huge number - they're much, much lower - but again, not the kinds of exposure you want to hang around with for a long, long time.
And, as a matter of fact, as the day progressed progress here in Tokyo, we even got a little elevated reading of radiation here. But again, that was way down in the noise. Not something to be of concern.
WERTHEIMER: So what happens next? Are we looking at major radiation exposures down the line?
HARRIS: It can get worse. It still remains to be seen, exactly how bad. The main challenge here, really, is to cool off these overheated reactors. If they can accomplish that by getting water into them finally, and they stop generating the steam that's helping to spread this radiation, then they've really got the situation pretty well under control.
But they keep thinking, we're just at ready to turn that corner, they've been thinking that day, after day, after day and it hasn't been true. They still can't get enough water to pump in there. So that's the major concern. And if they can't get it under control, yes, it could certainly be worse than it is.
At this point, probably not as bad as Chernobyl, which was an enormous fire that essentially burned up all the reactor and fuel that was inside. But it could see - be a very significant exposure.
WERTHEIMER: Thank you.
We've been speaking with NPR science correspondent with very frightening news from Tokyo.
Thank you, Richard Harris.
HARRIS: Okay, Linda.
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