Extensive faults beneath Nevada nuclear lab raise unanswered earthquake risks

Extensive faults beneath Nevada nuclear lab raise unanswered earthquake risks

Seismological Society of America | April 16, 2026 | phys.org

The underground laboratory in Nevada where the U.S. conducts nuclear subcritical experiments is riddled with faults. Researchers have not confirmed whether any of these faults are active and could rupture during an earthquake, according to a presentation by members of the Defense Nuclear Facilities Safety Board delivered at the 2026 SSA Annual Meeting.

During a 2024 safety review, the Board found documentation detailing extensive faulting and faulting-associated phenomena such as rock displacement within the Principal Underground Laboratory for Subcritical Experimentation or PULSE at the Nevada National Security Site.

Although faults in the facility have been documented since at least 1989, personnel from the National Nuclear Security Administration and the Nevada National Security Site have not studied them to determine whether they are active, the Board noted in a July 2024 letter to U.S. Secretary of Energy Jennifer Granholm that detailed their findings.

Within PULSE's underground drifts, about 1,000 feet below the surface, scientists conduct what are called subcritical experiments, which consist of special nuclear material mated with high explosives. The experiment is designed to prevent a self-sustaining nuclear reaction while providing valuable data on the reliability and viability of stockpiled nuclear weapons...more
https://phys.org/news/2026-04-extensive-faults-beneath-nevada-nuclear.html



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