New supercomputer will test aging nukes

By Rick Nathanson / Journal Staff Writer PUBLISHED: Friday, July 11, 2014 at 12:05 am

A new supercomputer to test nuclear weapons that could perform up to 50 million billion calculations per second will be built and installed at the Metropolis Computing Center at Los Alamos National Laboratory.

The National Nuclear Security Administration and Cray Inc. announced Thursday an agreement to build the next generation of supercomputer. Trinity, as it is called, will replace Los Alamos’ current supercomputer, Cielo, which can perform from 1 million billion to 2 million billion calculations per second.

Like Cielo, Trinity will be used as part of the Stockpile Stewardship Program, which requires advanced calculations and simulations necessary to determine the viability, safety and security of the nation’s aging nuclear weapons inventory.

Trinity is a joint effort of the New Mexico Alliance for Computing at Extreme Scale, or ACES, between Los Alamos and Sandia national labs, and is part of the NNSA’s Advanced Simulation and Computing Program.

Trinity will cost about $174 million to build and install. That does not count the roughly $20 million annually for electricity to power it and water to cool it, nor does it count the cost of manpower and expertise to run and maintain the supercomputer, said Gary Grider, the High Performance Computing Division leader at Los Alamos.

“The way we do science-based stewardship of the weapons is we spend time tearing them apart, and we have to certify that they are useful and safe and will provide a deterrent,” without testing them via a nuclear blast, Grider said.

The age of the nuclear weapons, some of them more than 40 years old, requires ever more complicated calculations, which cannot be performed on either Cielo or the Sequoia supercomputer at Lawrence Livermore in California.

Trinity, which is expected to come on line in phases in 2015 and 2016, will also be the first supercomputer to be cooled by an evaporative water system that uses recycled county sewer water, Grider said. The water will be cycled through the system three times before being treated and sent to a wetlands area. It will eventually work its way back to the Rio Grande.

Also a first, Grider said, is Trinity will have a “burst buffer” of three levels of memory and storage.

Not everyone is excited about this latest generation of supercomputers. Greg Mello, executive director of the Los Alamos Study Group, a nuclear policy think tank and nuclear weapons disarmament lobbying group, said the Stockpile Stewardship Program is nearly two decades old.

“We’ve not really changed the design of nuclear weapons, so we don’t really need the extra computing power and speed, or the extra taxpayer expense,” he said.

Mello said the supercomputer race is in part about “bragging rights” to see who can make the biggest and fastest computer. “More centrally, we just don’t need an endless succession of supercomputers at multiple laboratories doing the exact same thing and at great expense.”

Kevin Alvin, a senior manager for Advanced Simulation and Computing at Sandia, said Sandia is working on the architecture of the supercomputer.

“The science becomes extremely complex as the weapons get older,” he said. “Sandia’s role is to ensure the safety and reliability of the whole weapons system, and use simulations to understand all the potential safety and accident scenarios” as well as the different environments in which the weapons are stored, carried or may be used.

The primary focus for scientists at Los Alamos is understanding the nuclear performance of the weapons, Alvin said.