Department of Energy

Why the Nuclear Stockpile Needs Supercomputers

April 28, 2011

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NNSA Supercomputers Part 1: About ASC and Our Supercomputers

NNSA supercomputers are a key part of our ability to keep our nuclear stockpile safe, secure and effective.

Through a scientific mixture of hardware, software, codes and data and using some of the world’s most advanced computer systems, the National Nuclear Security Administration’s (NNSA) Stockpile Stewardship Program performs a critical role in implementing President Obama’s nuclear security agenda.

With the end of underground testing in 1992, supercomputers are a key part of our ability to keep our nuclear stockpile safe, secure and effective. Run by NNSA’s Advanced Simulation and Computing (ASC) program, the supercomputers help us understand everything from weapon design to safety features to overall performance.

NNSA's three national laboratories house some of the world's fastest supercomputers, which are important investments in the future: RoadrunnerBlueGene/L, Redstorm, and Dawn, an early version of a supercomputer named Sequoia, which will eventually reach 20 petaflops.

These supercomputers run large calculations that allow us look inside a weapon in nano-second sized chunks. The systems also help us see data points like temperature and pressure that can’t be found through experimentation. As John Morrison from Los Alamos National Laboratory said, “It’s like trying to take the temperature of the inside of the sun. It’s a hostile environment.” To do that kind of complex work, NNSA relies on really smart people.

“There are actually many elements inside the stockpile stewardship program,” according to Chris Deeney, Assistant Deputy Administrator for Stockpile Stewardship. “You need nuclear physics, indeed, you need people who understand hydrodynamics, you need people who understand high-energy plasma physics, people who understand material under extreme conditions, and then you also need engineers, people who understand radiation damage in silicon, so there’s a wide gamut of scientific and technical disciplines that underpin the stockpile stewardship program.”

Given how critical those scientific and technical disciplines are to the success of the program, NNSA makes a concerted effort to recruit and retain the next generation of nuclear security and supercomputer experts. Just this week, students from across New Mexico participated in the New Mexico Supercomputing Challenge, which was sponsored by Los Alamos National Laboratory and Sandia National Laboratories. Through the Predictive Science Academic Alliance Program, NNSA engages the academic community in making significant advances in predictive modeling and simulation technologies. In addition, NNSA supports an institute at each of its national laboratories to advance basic and applied research initiatives in computational sciences in support of the ASC Program.

While NNSA’s supercomputers exist to safely maintain the nuclear stockpile, there are often important non-nuclear benefits as well. For example, Lawrence Livermore National Laboratory, in conjunction with Los Alamos and Sandia National Laboratories, announced new space debris monitoring capabilities. When the Space Shuttle Columbia broke up re-entering the atmosphere in 2003, scientists used NNSA supercomputing resources to help model the effects of ice hitting the shuttle’s wing. There have also been breakthroughs in HIV research, climate change and research toward understanding an influenza pandemic

To learn more about NNSA’s Advance Science and Computing program, visit: You can also keep up with NNSA on Twitter @NNSANews or on Facebook.