NNSA Conducts Nonproliferation Experiment to Strengthen America’s Nuclear Explosion Detection Capabilities

WASHINGTON – The National Nuclear Security Administration (NNSA) today successfully conducted a subsurface, non-nuclear chemical high-explosive experiment at the Nevada National Security Site (NNSS), increasing the United States’ ability to detect low-yield nuclear explosions. 

The experiment reinforces President Trump’s commitment to maintaining American leadership in global nuclear security and ensuring the United States has unmatched capabilities to detect foreign nuclear testing.

“It takes nuclear expertise to detect nuclear activities and experiments like these ensure America remains unmatched in detection,” said Brandon Williams, NNSA Administrator. “The Trump Administration has made it clear that the United States will lead from a position of strength. You cannot evade American innovation. With this experiment, we are sending a clear message: under this administration, America will never be outmatched.” 

The experiment was conducted in the P Tunnel in Area 12 of the NNSS using chemical high-explosives and radiotracers. Data collected from the experiment will be used to validate scientific models and refine algorithms that are critical to U.S. nuclear explosion detection efforts. 

This experiment is especially focused on further enhancing the U.S. capabilities to detect a “decoupled” explosion—the type of test the United States determined that China conducted in June 2020 at its Lop Nur nuclear test site. Just as a stealth aircraft looks smaller on radar, decoupling can greatly muffle the signals detected by nuclear detection sensors, making a large explosion appear smaller. In a conventional, or “coupled,” underground nuclear test, a device is placed deep in a hole in close contact with the rock, allowing much of the explosion’s shockwave to reach sensors. In a decoupled test, by contrast, the device is detonated inside a large underground chamber, substantially reducing the explosion’s seismic signature.

In this experiment, researchers gathered measurements using a broad suite of advanced sensors, including accelerometers, seismometers, infrasound sensors, electromagnetic sensors, chemical and radiotracer samplers, and meteorological sensors. Together, these measurements will improve scientists’ understanding of the signatures produced by underground explosions and strengthen the United States’ ability to detect and characterize nuclear explosive events.