National Nuclear Security Administration

NNSA scientists find more effective ways to detect nuclear explosions near and far

April 6, 2016

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NNSA activities are vital to detecting nuclear explosions and helping verify compliance with the testing ban worldwide.

Recent developments at NNSA’s Livermore National Laboratory (LLNL) will help NNSA meet this commitment. Using computer-generated models and field experiments, LLNL simulates how gases produced from nuclear tests leak out and mix with the air. Using this method, international inspectors can then locate and identify a clandestine underground explosion site within 1,000 square kilometer search areas.

This detection method is especially useful in cases when the site of the underground nuclear test is unknown, since gases from these tests can be carried by winds far from the point of detonation.

The new simulations take information gathered during field experiments conducted as part of CTBTO’s Integrated Field Exercise 2014 and combine it with new data generated by monitoring gases exiting old nuclear explosive cavities in different parts of the world. In addition to helping develop the computer models, the new tests reveal other potential indicators of hidden underground tests that are otherwise difficult to detect during an on-site inspection.

The new tests were performed as part of the multi-laboratory experimental effort, which is supported by NNSA’s Office of Proliferation Detection. Click to read more about the new LLNL techniques, and more about CTBT.