China is expected to dethrone Tennessee as the home of the world's fastest computer by November, a top U.S. Energy Department official said Monday.

That's when China's Nebulae supercomputer in Shenzhen reaches peak performance, said U.S. Energy Undersecretary Steven Koonin. But planned upgrades of the Cray Jaguar computer at the Oak Ridge National Laboratory should help America regain the lead by 2012, he said.

While in Chattanooga Monday, Dr. Koonin told a conference of computer scientists that the United States must stay focused upon computational science and investment to help maintain its lead in innovation.

"High performance computing feeds itself," Dr. Koonin said during the opening session of a weeklong conference in Chattanooga on Scientific Discovery through Advanced Computing Program. "I think it is the only technology that enables the design of the next generation of systems and, once you fall off the exponential curve, it's really hard to get back on."

The supercomputer in Oak Ridge could play a key role in helping to extend the life of the current fleet of U.S. nuclear reactors, including a half dozen nuclear units operated by the Tennessee Valley Authority, Dr. Koonin said.

The DOE announced this spring that Oak Ridge National Laboratory will receive $122 million over the next five years to establish a Nuclear Energy Modeling and Simulation Energy Innovation Hub to test materials, processes and equipment used in the 104 U.S. nuclear reactors.

Dr. Koonin said computer simulations on increasingly faster computers allow for new inventions and product improvements to be more easily modeled and tested without having to build more expensive prototypes or conduct laboratory experiments.

Computer simulations have helped cut product development costs for Boeing, Goodyear and Cummins Engine and also are being developed and used for other companies and government agencies in Chattanooga at the University of Tennessee at Chattanooga SimCenter, which bills itself as the National Center for Computational Engineering.

Oak Ridge will receive about $25 million this year to establish its new nuclear simulation program, where DOE researchers will work with nuclear utilities and industry, including TVA and Westinghouse Electric Co.

The Oak Ridge Hub is the first of at least three such collaborative ventures in which the DOE also plans to tackle new ways to apply basic research to solar energy, building efficiency and battery technologies.

By the numbers

2.3 - Number of petaflops the Oak Ridge Cray Jaguar supercomputer is capable of processing, or a trillion times a trillion operations per second.

2.98 - Theoretical capacity of China's Nebulea supercomputer in Shenzhen

$122 million - Five-year funding for new Nuclear Energy Modeling and Simulation Energy Innovation Hub in Oak Ridge using supercomputers

104 - Number of U.S. nuclear reactors; most either have or are seeking extensions of 40-year licenses.

Source: U.S. Department of Energy

"With the Hubs, we are taking a page from America's great industrial laboratories in their heyday and building creative, highly-integrated research teams that can accomplish more, faster, than researchers working separately," Daniel Poneman, a deputy energy secretary, said in announcing the Oak Ridge hub.

Dr. Koonin said maintaining the lead in computer hardware and software technologies is key to U.S. innovation and he called it "disconcerting" that China may soon gain more computer speed.

"Some who worry about American competitiveness may say, "Well that's OK because they are just building it with U.S. components,'" Dr. Koonin said, noting that the National Supercomputing Center in Shenzhen is supported by Intel and Nvidia chips, both developed in California's Silicon Valley.

"But there is a (nearly as fast) indigenous machine in the works in China and the relative slopes of the pace of innovation in the U.S. and China is somewhat disconcerting," he said.