Explosive tests validated nukes

ASSOCIATED PRESS

The Central Intelligence Agency has concluded that North Korea has been able to validate its nuclear weapons designs without a nuclear test, the agency disclosed to Congress.

The intelligence service believes that conventional explosives tests, conducted since the 1980s, have allowed the North Koreans to verify their nuclear designs would work. The agency believes North Korea has one or two nuclear weapons similar to what the United States dropped on Hiroshima during World War II; a minority of U.S. analysts believes the communist country may already have made more.

CIA officials do not describe the precise mechanism by which the North Koreans could have verified their designs. The explanation to Congress provides the rationale behind the agency’s conclusion that North Korea already has a nuclear weapon.

The relatively simple fission weapons that North Korea is believed to have produced would presumably detonate a precisely built shell of conventional high explosives around a plutonium core, and the tests may have involved the designs of that shell.

A CIA spokesman declined last week to expand on the agency’s conclusions.

North Korea has suggested it may conduct a nuclear test to demonstrate it is a nuclear power. However, U.S. officials are not sure that the North Koreans would expend a nuclear weapon if they have only a few.

“A North Korean decision to conduct a nuclear test would entail risks for Pyongyang of precipitating an international backlash and further isolation,” the CIA says. “Pyongyang at this point appears to view ambiguity regarding its nuclear capabilities as providing a tactical advantage.”

The CIA’s conclusion was reported in an unclassified letter to the Senate Intelligence Committee in August. That letter, along with similar communications from the Defense Intelligence Agency, the FBI and State Department, was obtained by the Federation of American Scientists, a watchdog group that focuses on security and intelligence matters.

North Korea frequently issues threats but also has taken part in six-country talks regarding its programs. U.S. officials believe North Korea, long in a dire economic state, regards nuclear weapons as a way to exact aid and concessions from the rest of the world.