The Department of Energy’s newest supercomputer will be capable of conducting 1.5 quintillion calculations per second, making it more powerful than the world’s current second most powerful supercomputer.

The department announced Aug. 13 that it had inked a $600 million deal with Cray Inc. to build its third exascale-class supercomputer. Among other responsibilities, the Energy Department is charged with maintaining the United States’ stockpile of nuclear weapons.

Dubbed “El Capitan,” the supercomputer is part of the Exascale Computing Project, a DOE effort to increase computing power so that the department can run highly advanced simulations and modelling of the United States’ nuclear arsenal. These simulations help alleviate the need for underground testing. El Capitan is expected to be used by the department’s National Nuclear Security Administration’s weapons design laboratories to run 3D simulations that are too difficult for today’s state-of-the-art supercomputers.

“NNSA is modernizing the Nuclear Security Enterprise to face 21st century threats,” said Lisa Gordon-Hagerty, the NNSA administrator and the department’s under secretary for nuclear security, said in a release. “El Capitan will allow us to be more responsive, innovative, and forward-thinking when it comes to maintaining a nuclear deterrent that is second to none in a rapidly-evolving threat environment.”

El Capitan will be located at Lawrence Livermore National Laboratory in California. The department’s two other supercomputers, Aurora and Frontier, are located at Argonne National Laboratory and Oak Ridge National Laboratory, respectively. All three supercomputers are being built by Cray.

El Capitan is expected to be delivered in 2022.