According to scientists and officials, the United States’ weapons laboratories, armed with some of the fastest computers on the planet, are peering ever deeper into the mystery of how thermonuclear explosions occur, gaining an understanding that in some ways goes beyond what was learned from explosive tests, which ended in 1992.

A senior U.S. defense official last week voiced confidence in a newly defined "reuse" approach to modernizing nuclear warheads that some scientists have called into doubt.

Russian Prime Minister Vladimir Putin has approved an initiative to improve the testing capacity for the nation's nuclear arsenal.

The Comprehensive Nuclear-Test-Ban Treaty Organization built seismic station PS44 near Ashgabat, Turkmenistan, a “few kilometers” from the Central Asian country’s southern border with Iran. The site adds to the group’s 337 stations worldwide designed to detect seismic activity and atmospheric radiation caused by nuclear explosions.

An update on the international monitoring system, an internationally distributed network of sensors for detecting nuclear explosions, that was created to support the Comprehensive Test Ban Treaty and has currently grown to 340 sensors around the world, even in Iran and Israel.

The Obama administration has informed China, Japan, Russia and other nations of its intent to win Senate approval for U.S. ratification of the Comprehensive Nuclear Test Ban Treaty ahead of the Nuclear Nonproliferation Treaty review conference in May 2010.

North Korea's nuclear test in May indicated that an international network of nuclear detonation sensors is becoming increasingly capable of detecting violations of the Comprehensive Nuclear Test Ban Treaty, said leaders of a study that surveyed more than 200 scientists worldwide on the monitoring project's technical underpinnings.