Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

"A ban on all nuclear tests is the oldest item on the nuclear arms control agenda. Three treaties that entered into force between 1963 and 1990 limit, but do not ban, such tests. In 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which would ban all nuclear explosions. In 1997, President Clinton sent the CTBT to the Senate, which rejected it in October 1999. In a speech in Prague in April 2009, President Obama said, “My administration will immediately and aggressively pursue U.S. ratification of the Comprehensive Test Ban Treaty.” However, while the Administration has indicated it wants to begin a CTBT “education” campaign with a goal of securing Senate advice and consent to ratification, it has not pressed for a vote on the treaty and there were no hearings on it in the 111th, 112th, or 113th Congresses. There will be at least one hearing in the 114th Congress—a Senate Foreign Relations Committee hearing on the CTBT planned for September 7, 2016..."
Nuclear test-ban treaty

North Korea’s 2009 Nuclear Test: Containment, Monitoring, Implication
"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..."

North Korea’s 2009 Nuclear Test: Containment, Monitoring, Implications
"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 April 2010, 151 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.

The treaty establishes a verification mechanism, including an International Monitoring System
(IMS) to detect nuclear tests. Three IMS technologies detect waves that pass through the oceans
(hydroacoustic), Earth (seismic), or atmosphere (infrasound); a fourth detects radioactive material from a nuclear test. Scientists concur that only the latter proves that an explosion was nuclear.Some believe that deep burial and other means can contain radioactive effluents. Another view is that containment is an art as much as a science. The United States learned to improve containment over several decades. Yet by one estimate, North Korea contained over 99.9% of the radioactive effluents from its 2009 test. It might have done so by application of lessons learned from its 2006 test or the U.S. nuclear test experience, use of a higher-yield device, release of material below the detection threshold, good luck, or some combination. Alternatively, the 2009 event may have been a nonnuclear explosion designed to simulate a nuclear test