The main purpose of the Sequoia program is to run complex computer simulations for nuclear weapons research. It will allow nuclear scientists to determine whether weapons are safe and will work as required under the DOE’s National Nuclear Security Administration stockpile stewardship program.

“The problem we have with the nuclear stockpile is similar to one you might have at home with a car you’ve kept in the garage for 20 to 30 years,” Mark Seager, assistant department head for advanced technology at Lawrence Livermore, told PC World.

“How do you carefully maintain the car as it ages so that when you go to start the car, you can be very confident it will start? That the probability that it won’t start is less than 1 in a million? That’s a pretty high level of certitude.”