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Confirming a Nuclear Test


North Korea's nuclear test has not been confirmed. Seismic experts say something happened at the time the test was announced. But the U.S. geological survey could not say whether it was an atomic explosion or a natural earthquake.

So how are nuclear tests confirmed? Here to tell us is Philip Coyle. He's with the Center for Defense Information in Washington. And he joins us today from his home in Sacramento, California. Welcome to the program.


Mr. PHILIP COYLE (Center for Defense Information): Hi. Nice to be with you.

BRAND: Well, this was allegedly an underground test. So how can nuclear monitors confirm it actually took place?

Mr. COYLE: Well, South Korea has a seismic monitoring station close to the border with North Korea. And then there are worldwide seismic monitoring stations that are all now looking at their data to see what happened.

But it looks like it was a small nuclear test, small by nuclear standards, meaning about 1,000 tons of TNT equivalent.

BRAND: And also I understand the U.S. has a sniffer plane in the area that can detect nuclear chemicals?


Mr. COYLE: Yes. Both the United States and Japan have air sampling aircraft, flying vacuum cleaners, that can basically take air samples and look for radioactivity. And if they see any, that will actually help them sleuth out what sort of a nuclear test device this was.

BRAND: When will we know for sure?

Mr. COYLE: I think the Air Force will probably have a pretty good idea in the next 72 hours. It depends a little bit on whether they see anything at all, if the test didn't leak, if there was no radioactivity released, and so far North Korea says there wasn't any released. They may not find anything at all.

BRAND: And just because North Korea conducted this test, it doesn't mean it actually has the ability to put a warhead on top of a missile.

Mr. COYLE: No, it doesn't. North Korea has tried twice now to launch long-range missiles, missiles with enough range that they might reach, say, Hawaii, or perhaps the mainland of the United States.

But both times they failed. In 1998 they failed and then they tried it again recently last July, and again failed. But presumably if they keep trying long enough, they'll figure it out.

BRAND: How far away are they from that?

Mr. COYLE: It's a little hard to say. It appears that their efforts, even with short-range missiles, are pretty primitive still. But they want to get the Bush administration to face-to-face negotiations over the bargaining table. And the administration keeps resisting that.

And so North Korea keeps raising the stakes.

BRAND: There is some speculation that North Korea plans more of these tests. I'm wondering if it's possible for a country to conduct nuclear tests without anyone knowing.

Mr. COYLE: It is possible if it's done underground in a cavity such that the explosion doesn't reach the surrounding rock right away. Imagine blowing off a firecracker in marshmallows. Then the seismic signals are damped out and you might not see it at all.

BRAND: Israel has never confirmed that it has the bomb, yet everyone assumes it does.

Mr. COYLE: That's correct. And if they have ever done a test, there's been great dispute about that. But North Korea's goal is different. North Korea unambiguously wants to be seen as a power that needs to be reckoned with. And in particular they feel threatened by the United States. And so their point of view here is the sword rattle.

BRAND: Phillip Coyle is with the Center for Defense Information in Washington.

Thank you for joining us.

Mr. COYLE: My pleasure. Transcript provided by NPR, Copyright NPR.