North Korean Nuclear Test Preparations

The Chosun Ilbo reports the US has briefed South Korea that movements of heavy equipment signal an impending nuclear test:

U.S. intelligence authorities have told South Korean intelligence that they have detected suspicious activity indicating possible preparations for an underground nuclear test in Kilju County in North Korea’s North Hamgyeong Province, sources said.

“U.S. spy satellites took in an area of Kilju County, North Hamgyeong Province images of frequent truck movement bringing cranes and other equipment,” a government official said Tuesday. “I understand that U.S. intelligence, putting together the satellite photos with other information, believes it possible that North Korea is preparing for an underground nuclear test in the area, and that they sent the photos and analysis to Korean intelligence authorities.”

Kilju (or Kilchu, depending on your transliteration) is near the East coast of North Korea (see Site 1 on the map). An underground nuclear test would deny US intelligence community debris upon which to perform radiochemistry analysis. Underground testing, however, is much more difficult to instrument. Moreover, even undergound tests may accidentally release debris and gas that can be analyzed.

The Chosun Ilbo story follows reports last week by the Wall Street Journal and Washington Post.

This site is different from the Yongdoktong location that the New York Times reports houses facilities to test conventional explosives for nuclear weapons designs (Site 2 on the map).

That site was featured in a Japanese news weekly that was translated by FBIS (thanks to Alex Montgomery for sending it along).

Analysis of the implosion testing at Site 2 allows the US IC to make predictions about the sophistication of the devices that could end up being tested at Site 1.

The caption reads: “A nuclear detonation testing site discovered this time is located where valleys located at upper stream of the Tongchang River, which flows the northeast part of Kusong, P’yonganpukto, merge (the place was formerly called Yongtok-ri). The Tongchang River flows northeast part of Kusong City, P’yonganpukto located in the northwestern part of North Korea. Traces of explosion can be seen at nine spots, and at least six buildings, which seems to be control facilities, observation facilities, explosives assembly plant, and storage, are located near the testing field.”

“North Korea’s ‘Nukes’ Place World in ‘Crisis’ Again” Tokyo Shukan Posuto (in Japanese), 16 April 1999, FTS-1999-04-10-000079.

Paul Adds: Responding to the Chosun Ilbo story, ROK Defense Minister Yoon Kwang-ung said “We’ve not yet seen any signs” of a nuclear test.