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Bigger supercomputers
to help safeguard nation
Posted May 5, 2011

Part of a series.
When someone mentions national security and computation, the phrase “war games” probably pops into many heads. Indeed, the U.S. government uses powerful computers to run such strategic simulations.
But war strategy is not the first thing that comes to mind for many security experts (see sidebar, "National security workshop sets ambitious agenda"), including Robert Rosner, senior fellow at the University of Chicago’s Computation Institute and professor of physics and astronomy and astrophysics.
When Rosner considers the potential contribution from extreme-scale computing for national security, his mind “is on certification of the stockpile. That is a very important issue.”
The new Strategic Arms Reduction Treaty with the Russian Federation, signed earlier this year, reduces the strategic stockpile to 1,550 deployed nuclear warheads. Since the United States stopped testing nuclear weapons in 1992, simulation is the only way to reduce the stockpile while guaranteeing weapons’ safety and reliability. But ensuring reliability is a complex proposition – especially given the stockpile’s age.
Simulating the nuclear stockpile involves calculating multiple, concurrent physical processes. Computing power “beyond petascale will enable yet more fidelity in the calculations” and the inclusion of even more complicated physics, Rosner says.
Complexity is key
Fred Streitz, director of Lawrence Livermore National Laboratory’s (LLNL) Institute for Scientific Computing Research, says that many “people think that with the ridiculously large computers that we have we should be able to simulate anything. But our problems are fantastically complicated.”
Take, for instance, the challenge of keeping the nuclear stockpile in working order. Suppose, Streitz says, that you are in your garage, and your job is to certify that your car will start if you put the key in the ignition and turn it. Moreover, your car must not start without your key, and it must not start if someone else uses your key. In addition, your car is aging, because it’s been sitting idle in your garage since 1950. Yet, even after 60 years, you need to guarantee that your car will start but only when it is supposed to.
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