New Supercomputers Will Improve Nuke Test SimulationsNew Supercomputers Will Improve Nuke Test Simulations

With nuclear weapons testing banned in the United States for the past decade, the only way to understand the effects of aging on the nation's nuclear stockpile has been to run complex computer calculations that simulate the behavior of the radioactive material inside. The Department of Energy on Tuesday revealed that within the next year, it will deploy two new IBM supercomputers at its Lawrence Livermore National Laboratory to more efficiently run these simulations and others related to biotechnology research.

The Energy Department is spending $290 million on the ASCI Purple and Blue Gene/L supercomputers. The ASCI Purple will serve as the primary supercomputer in the department's Advanced Simulation and Computing Initiative (ASCI), using 12,544 IBM Power5 processors and the Unix-based AIX operating system to simulate the aging and operation of U.S. nuclear weapons. The processors will be contained in 196 rack-mounted eight-way servers that will function as the supercomputer's nodes. The nodes will be interconnected at speeds of up to 100 Gbytes per second.

The Linux-based Blue Gene/L will have a peak performance of 360 teraflops with 65,536 computing nodes and will be used by three National Nuclear Security Administration labs--Los Alamos, Sandia, and Lawrence Livermore--as well as ASCI University collaborators and other Energy Department labs in the future. Scientists and researchers will use Blue Gene/L to develop and run apps that simulate the turbulence, biology, and behavior of high explosives.

For its nuclear weapons testing, in particular, the Energy Department needed a faster, more powerful supercomputer than the IBM ASCI White it deployed in August 2001 or the ASCI Blue Pacific in use since October 1998. Lawrence Livermore scientists will run simulations on the ASCI Purple that test the safety, reliability, performance, and effectiveness of each weapon in the U.S. arsenal. To do this on, for example, a Cray supercomputer from 1994, it would take 60,000 years to complete a calculation, an ASCI spokesman says. The ASCI Purple can handle the same set of equations in two months, he says.

With previous supercomputing technology, scientists could only use very basic data that would simulate a piece of a hypothetical nuclear weapon, the spokesman says. With the ASCI Purple, "it's like a Formula One race compared to a Soap Box Derby."