WASHINGTON - Scientists introduced the world's fastest supercomputer yesterday, a $100 million machine that for the first time has performed 1,000 trillion calculations per second in a sustained exercise.

The technology breakthrough was accomplished by engineers from the Los Alamos National Laboratory and International Business Machines Corp. on a computer to be used primarily on nuclear-weapons work, including simulating nuclear explosions.

The computer, named Roadrunner, is twice as fast as IBM's Blue Gene system at Lawrence Livermore National Laboratory, which itself is three times faster than any of the world's other supercomputers, according to IBM.

"The computer is a speed demon. It will allow us to solve tremendous problems," said Thomas D'Agostino, head of the National Nuclear Security Administration, which oversees nuclear-weapons research and maintains the warhead stockpile.

But officials said the computer also could have a wide range of other applications in civilian engineering, medicine and science, from developing biofuels and designing more fuel-efficient cars to finding drug therapies and providing services to the financial industry.

To put the computer's speed in perspective, if every one of the six billion people on earth used a handheld computer and worked 24 hours a day it would take them 46 years to do what the Roadrunner computer can do in a single day.

The IBM and Los Alamos engineers worked six years on the computer technology.

Some elements of the Roadrunner can be traced back to popular video games, said David Turek, vice president of IBM's supercomputing programs. In some ways, he said, it is "a very souped-up Sony PlayStation 3."

The interconnecting system occupies 6,000 square feet with 57 miles of fiber optics and weighs 500,000 pounds.