Nuclear Weapons: Program Management Improvements Would Benefit U.S. Efforts to Build New Experimental Capabilities

The National Nuclear Security Administration (NNSA) is responsible for ensuring the performance, safety, and reliability of the nation’s nuclear stockpile without nuclear explosive testing. Subcritical experiments are used to support NNSA’s assessments.

NNSA conducts these experiments at the U1a underground facility at the Nevada National Security Site. This allows NNSA to obtain experimental data on plutonium and high explosives together without a nuclear explosion—hence, the experiments remain subcritical.