WASHINGTON, Oct 16: The United States confirmed on Monday that last week’s blast in North Korea was actually an underground nuclear test.
“Analysis of air samples collected on October 11, 2006 detected radioactive debris which confirms that North Korea conducted an underground nuclear explosion,” said a statement issued by the office of US Director of National Intelligence.
The statement identified a place called Punggye as the site of the Oct 9 test and said that the explosion yield was less than a kiloton.
The North Koreans are believed to have conducted the test in a horizontal tunnel in the side of a hill, at Punggye in the northeast of the country.
Experts at Washington-based think tank Global Security said the tunnel was deep enough to avoid sending radioactive debris to the surface. The site with a deep shaft and a nearby horizontal tunnel was constructed last year at Mount Mantap, near Punggye before North Korea declared itself a nuclear power.
Intelligence officials, however, said the nuclear test released significantly less explosive force than North Korea had expected. Officials said intelligence indicated the North Koreans predicted an explosion the equivalent of four kilotons of high explosives - but the test released less than one kiloton.
The statement from John Negroponte’s office provides the first official confirmation from the United States that a nuclear detonation took place, as Pyongyang has claimed.
The US intelligence has been poring over data collected since the explosion, air samples, seismic readings, satellite imagery and communications intercepts, in an effort to reach a conclusion on the nature of the test.
On Friday, a US government intelligence official told reporters in Washington that results from an initial air sampling in the region showed no evidence of radioactive particles which would be expected from a large nuclear detonation. The test results, however, did not necessarily mean the North Korean blast was not a nuclear explosion, the official said.
France, China and South Korea had also expressed similar doubts about the validity of the North Korean nuclear blast, saying that they too found no radiation in the regional environment.
The US confirmation comes at a diplomatically sensitive time. Earlier Monday, US and Japanese officials meeting in Tokyo pledged to move forward with sanctions punishing North Korea.
American and Japanese representatives to the six-party talks said they hope to resume negotiations with Pyongyang on dismantling its nuclear program.
Australia also banned North Korean ships from its ports. Australia’s sanctions go beyond Saturday’s unanimous Security Council resolution that calls for inspections of all cargo into and out of North Korea.
But China said that while it will inspect cargo from North Korea for banned weapons materials, its forces will not stop and board North Korea ships.
