US official describes underground experiment to detect concealed nuclear tests

A conventional explosive was detonated underground in Nevada to improve detection of concealed nuclear tests, National Nuclear Security Administration Deputy Administrator Matthew Napoli said during an appearance at the Carnegie Endowment.

Napoli said the charge was placed in an artificial underground chamber 300 meters deep. The experiment yielded seismic and geophysical data.

Such a chamber reduces the transfer of energy into surrounding rock, weakening the signal picked up by sensors. Napoli said researchers had modeled that method of concealing a test.

He said the data would be used to improve the accuracy of detecting and classifying underground nuclear explosions.