After North Korea announced that it had conducted its third nuclear test in February, few doubted the regime had pulled it off: Seismic signals registered around the world clearly showed that a massive explosion had occurred. In the hours after the blast, the U.S. military and others scrambled to catch whiffs of radioxenon leaking from the test site that might indicate whether North Korea had detonated a plutonium bomb or a uranium bomb. Identifying the fissile material would help intelligence agencies size up North Korea’s nuclear arsenal. To the frustration of the United States and its allies, however, too few radioxenon atoms were detected to make that determination.
Next time may be a different story. Yesterday, the world’s main nuclear weapons monitoring organization announced that China has agreed to begin sharing data from 10 stations on its territory. Seven stations register seismic waves and infrasound waves; three stations in Beijing, Lanzhou, and Guangzhou detect radionuclides. Data from the stations would be fed into the International Data Centre (IDC) maintained by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) in Vienna. The additional information “will help us further refine our analysis” of events around the world, says CTBTO spokesperson Thomas Mützelburg. China’s radionuclide data, he says, will be especially valuable and “most welcome.” To date, 85% of CTBTO’s 337 planned monitoring stations around the world are operational.
The breakthrough came during a visit to Beijing this week by Lassina Zerbo, the new executive secretary of CTBTO’s preparatory commission. China is one of eight CTBT signatories whose ratification would bring the treaty into force; other holdouts include the United States and North Korea. (So far, 159 countries have ratified the treaty.) Analysts don’t expect China to ratify before the United States, and few are optimistic that the United States will move on the treaty any time soon, despite President Barack Obama’s pledge to do so in 2009.
Observers applaud China for opening the spigot on data that would stream into the IDC. Because the CTBT has not entered into force, China, like other signatories, “has no legal obligation to provide data to anybody,” says one analyst who formerly worked in CTBTO and asked to remain anonymous. Over the past decade, as China built up its monitoring stations, it was especially leery of providing radionuclide data. “They’ve come around,” says the analyst. CTBTO now must certify the Chinese stations. “Their data would be the first step in the necessary testing and evaluation,” says Mützelburg, a process that he expects will begin “in the next couple weeks.”