The development would be officially announced today at the White House. The new supercomputer, dubbed ``Pacific Blue'' and built for the department of energy, will enable scientists to maintain the reliability of atomic weapons stockpiles without having to conduct nuclear tests, the officials said, speaking on condition of anonymity.

The new computer runs 15,000 times faster and has 80,000 times more memory than the average desktop personal computer, the officials said. Complex calculations that would normally consume months of time even on other advanced computers can be completed in just days with the new high-speed machine, they said.

The primary mission of the supercomputer is to ensure the safety, security and reliability of the nuclear weapons stockpile using simulations and faster calculations rather thantests, the officials said.

But it also might be used in other areas, such as helping predict climate changes and designing airplanes.

Many of the major recent drug advances in health care have been driven by high performance computers. The new IBM model could play a role there, the officials said, helping identify compounds that are likely to succeed in clinical tests and freeing scientists from having to try unnecessary combinations in the lab.