World's fastest computer at Energy Dept.

The Energy Department will use IBM's Roadrunner supercomputer -- the first petaflop computer -- the department announced this week, Reuters reports. A petaflop is 1,000 trillion operations per second.

"Roadrunner will be used by the Department of Energy's National Nuclear Security Administration to perform calculations that vastly improve the ability to certify that the U.S. nuclear weapons stockpile is reliable without conducting underground nuclear tests," the department said in a statement.

"Roadrunner will not only play a key role in maintaining the U.S. nuclear deterrent, it will also contribute to solving our global energy challenges, and open new windows of knowledge in the basic scientific research fields," it added. "To put this into perspective, if each of the 6 billion people on earth had a hand calculator and worked together on a calculation 24 hours per day, 365 days a year, it would take 46 years to do what Roadrunner would do in one day," the department said.