Negative air sample queries North Korean test

Results from an initial air sampling after North Korea’s announced nuclear test showed no evidence of radioactive particles that would be expected from a successful nuclear detonation, a US government intelligence official said today.

The test results do not necessarily mean the North Korean blast was not a nuclear explosion, the official said.

The US government remains uncertain of the nature of the underground explosion, officials said, although the result from air sampling tends to reinforce the indication that the test blast was not entirely successful.

Earlier, South Korea said it had detected no abnormal levels of radioactivity in rainwater collected throughout the country since North Korea announced its first-ever nuclear test earlier this week.

The Ministry of Science and Technology said it had been studying rainwater collected since Monday’s apparent test, but found no artificial radiation in any sample.

Ministry official Yoo Bong-jin cautioned, however, the finding did not indicate the North didn’t conduct a nuclear test or that it may have failed.

The North announced on Monday that it had conducted an underground nuclear test, but said there had been no radioactivity leaks from the site.