North Korea's 2009 Nuclear Test: Containment, Monitoring, Implications [November 24, 2010] [open pdf - 687KB]
"On May 25, 2009, North Korea announced that it had conducted its second underground nuclear test. Unlike its first test, in 2006, there is no public record that the second one released radioactive materials indicative of a nuclear explosion. How could North Korea have contained these materials from the May 2009 event and what are the implications? As background, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) would ban all nuclear explosions. It was opened for signature in 1996. Entry into force requires ratification by 44 states specified in the treaty, including the United States and North Korea. As of November 2010, 153 states, including 35 of the 44, had ratified. North Korea has not signed the CTBT. President Clinton signed it in 1996; in 1999, the Senate voted not to consent to its ratification. In 2009, President Obama pledged to press for its ratification. [...] Containment could be of value to North Korea. It could keep radioactive fallout from China, Japan, Russia, or South Korea, averting an irritant in relations with them. It could prevent intelligence services from gathering material that could reveal information about the weapon that was tested. It could permit North Korea to host nuclear tests by other nations, such as Iran; while such tests would be detected by seismic means, they could not be attributed to another nation using technical forensic means if effluents, especially particles, were contained. An issue for Congress is how containment could affect CTBT prospects. Supporters might argue that explosion-like seismic signals without detected radioactive material would lead to calls for an onsite inspection. Opponents might claim that only detection of radioactive material proves that a nuclear explosion occurred. Both would note inspections could not be required unless the treaty entered into force, supporters to point to a benefit of the treaty and opponents to note that North Korea could block inspections by not ratifying the treaty. Congress may wish to consider ways to improve monitoring capability, such as supporting further research on test signatures, improving monitoring system capability, and deploying more monitoring equipment. This update reflects developments in the North Korean uranium program and prospects for another nuclear test."
CRS Report for Congress, R41160