National Security

Workmen at Sandia National Laboratories' Z machine test for any energy irregularities at the huge machine’s core prior to setting up for another experiment. Photo by Randy Montoya. Read

Safe. Secure. Reliable.

Z is crucial to Sandia’s mission to assure the reliability and safety of our nuclear stockpile as it ages – it allows scientists to study materials under conditions similar to those produced by the detonation of a nuclear weapon, and it produces key data used to validate physics models in computer simulations.

The detonation of nuclear weapons may affect equipment even at great distances from the explosion, which means electronic weapons systems and related equipment could malfunction when exposed to radiation from an opponent’s weapons. Since a wide variety of materials are used to build weapons and military equipment, researchers must study the effects of nuclear radiation on a variety of materials and under varying conditions in order to understand the vulnerability of U.S. weapons.

Alternatives to live tests

Simulations were an attractive alternative to live tests because live tests were more expensive and produced more explosive power and radiation than laboratory tests. Since 1992 the U.S. has had a moratorium on nuclear testing, so in 1994 the Department of Energy established the Stockpile Stewardship Program to allow for continuing study of the stockpile in the absence of live tests.

Today, simulations based on supercomputer models and laboratory experiments remain the only available method to assess the reliability and safety of our nuclear stockpile as it ages. Simulation work involves testing of existing systems to assess their vulnerabilities to radiation, predicting problems as the stockpile ages, developing ways to harden future systems, and remanufacturing weapons and components as necessary.