Nuclear weapons haven’t been tested in the United States since 1992. Find out why, and what could happen if the hiatus ends.

The Department of Energy’s National Nuclear Security Administration recently retracted its intention to publish a draft environmental report for public comment about increasing the amount of fissile ...

A pair of lawmakers exhorted the Energy Department's top official to consider reining in a major nuclear arsenal modernization program amid long-running concerns over its cost and schedule performance ...

LOS ALAMOS — A sphere of plutonium the size of a grapefruit contains enough energy to erase an entire city from existence. That single fact explains why nuclear weapons remain humanity’s most feared ...

Beijing releases 30-page report that includes a call for international community to ‘take concrete and strong measures’ ...

Editor’s Note: An earlier version of this report stated this was the first time a worker who had inhaled plutonium was speaking publicly. Since then, we have learned that the Seattle Times spoke with ...

America’s last nuclear detonation was nothing special. Smaller than the bomb that killed 73,000 people in Nagasaki, it exploded 1,397 feet below the Nevada desert. It shook the ground, created a ...

VIENNA, Sept 2 (Reuters) - There is no sign North Korea reprocessed spent fuel from its main nuclear reactor into plutonium in the past year, but it seems to have continued to enrich uranium, the ...

SEATTLE(AP) — For much of the 20th century, a sprawling complex in the desert of southeastern Washington state turned out most of the plutonium used in the nation’s nuclear arsenal, from the first ...

The lab where Oppenheimer developed the atomic bomb is the linchpin in the United States’ effort to modernize its nuclear weapons. Yet the site has contended with contamination incidents, work ...