Skip to main content

You are here

NNSA Conducts Fifth Experiment aimed to Improve U.S. Ability to Detect Foreign Nuclear Explosions

WASHINGTON, D.C. – On April 26, the Department of Energy’s National Nuclear Security Administration (DOE/NNSA) conducted the fifth experimental conventional explosion as part of its Source Physics Experiment (SPE) series. The SPE series, conducted at the Nevada National Security Site, improves the United States’ capability to detect and characterize underground nuclear explosions.

By conducting the experiments near the location of previous underground nuclear tests, researchers are able to better compare data from conventional and nuclear explosions. This helps to advance the United States’ capability to differentiate low-yield nuclear test explosions from other seismic activity such as mining operations and small earthquakes. Having this advanced capability helps to identify whether state or non-state actors are hiding low-yield nuclear testing to develop or improve nuclear weapons.

“The Source Physics Experiment series and NNSA’s ongoing research and development at our National Laboratories are key to strengthening our national security by advancing technical solutions for treaty monitoring by the United States and its partner nations,” said Anne Harrington, NNSA Deputy Administrator for Nuclear Nonproliferation.

This fifth experiment, known as “SPE-5”, used chemical explosives equivalent to 5,000 kilograms of TNT detonated 76 meters underground. Information is gathered on SPE-5 through a variety of technologies, including high-resolution accelerometer, infrasound, seismic, explosive performance, high-speed video, aerial-based light detection and ranging, drone-based photogrammetry and synthetic aperture radar data. Seismic data from the SPE series are shared on the Incorporated Research Institutions for Seismology website at for researchers around the world to analyze. 

The SPE team is composed of researchers from the Nevada National Security Site, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratories, as well as the University of Nevada-Reno, Weston Geophysical Corp., and the Department of Defense’s Defense Threat Reduction Agency.

# # #

Established by Congress in 2000, NNSA is a semi-autonomous agency within the U.S. Department of Energy responsible for enhancing national security through the military application of nuclear science. NNSA maintains and enhances the safety, security, and effectiveness of the U.S. nuclear weapons stockpile without nuclear explosive testing; works to reduce the global danger from weapons of mass destruction; provides the U.S. Navy with safe and effective nuclear propulsion; and responds to nuclear and radiological emergencies in the U.S. and abroad. Visit for more information