Geoff Brumfiel

Terry Quinn oversees high-performance computing at Livermore, and she showed us around. Now, this machine uses advanced processors, similar to those used for generative AI, actually. LCAP can do more than two quintillion calculations per second. Wow. That's two exaflops for those in the supercomputing game. And its only job is to calculate, you know, a nuclear weapon's detonation.

Terry Quinn oversees high-performance computing at Livermore, and she showed us around. Now, this machine uses advanced processors, similar to those used for generative AI, actually. LCAP can do more than two quintillion calculations per second. Wow. That's two exaflops for those in the supercomputing game. And its only job is to calculate, you know, a nuclear weapon's detonation.

It used to be it might take them a week to do a calculation on how a weapon would detonate.

It used to be it might take them a week to do a calculation on how a weapon would detonate.

It used to be it might take them a week to do a calculation on how a weapon would detonate.

As you know, Gina, any good computer model still needs some real world data to make sure it's grounded in reality. Okay. And so, you know, nuclear weapons scientists have continued to collect data. They're doing experiments in the same tunnels underground where they used to set up their nuclear weapons tests.

As you know, Gina, any good computer model still needs some real world data to make sure it's grounded in reality. Okay. And so, you know, nuclear weapons scientists have continued to collect data. They're doing experiments in the same tunnels underground where they used to set up their nuclear weapons tests.

As you know, Gina, any good computer model still needs some real world data to make sure it's grounded in reality. Okay. And so, you know, nuclear weapons scientists have continued to collect data. They're doing experiments in the same tunnels underground where they used to set up their nuclear weapons tests.

Now, this is not a place many journalists get to go. But I asked and asked and asked very nicely— And eventually, I and a few other journalists made it to Nevada, where they do this testing. We stepped onto an old mining elevator. And the elevator just drops into pitch blackness, nearly a thousand feet underground. Here's what it was like at the bottom.

Now, this is not a place many journalists get to go. But I asked and asked and asked very nicely— And eventually, I and a few other journalists made it to Nevada, where they do this testing. We stepped onto an old mining elevator. And the elevator just drops into pitch blackness, nearly a thousand feet underground. Here's what it was like at the bottom.

Now, this is not a place many journalists get to go. But I asked and asked and asked very nicely— And eventually, I and a few other journalists made it to Nevada, where they do this testing. We stepped onto an old mining elevator. And the elevator just drops into pitch blackness, nearly a thousand feet underground. Here's what it was like at the bottom.

There's a long corridor that's been carved out of an ancient lake bed. Pipes along the walls carry air, water, and power. Workers in hard hats are everywhere. David Funk, who oversees work underground, leads us in.

There's a long corridor that's been carved out of an ancient lake bed. Pipes along the walls carry air, water, and power. Workers in hard hats are everywhere. David Funk, who oversees work underground, leads us in.

There's a long corridor that's been carved out of an ancient lake bed. Pipes along the walls carry air, water, and power. Workers in hard hats are everywhere. David Funk, who oversees work underground, leads us in.

So this would have been a test shaft, potentially.

So this would have been a test shaft, potentially.

So this would have been a test shaft, potentially.

Subcritical experiments. That means experiments that simulate conditions inside a nuclear weapon without triggering a nuclear chain reaction. That runaway chain reaction is what gives a nuke its incredible power. These tunnels were originally built to contain nuclear explosions. Then in 1992, the US officially stopped all testing.

Subcritical experiments. That means experiments that simulate conditions inside a nuclear weapon without triggering a nuclear chain reaction. That runaway chain reaction is what gives a nuke its incredible power. These tunnels were originally built to contain nuclear explosions. Then in 1992, the US officially stopped all testing.

Subcritical experiments. That means experiments that simulate conditions inside a nuclear weapon without triggering a nuclear chain reaction. That runaway chain reaction is what gives a nuke its incredible power. These tunnels were originally built to contain nuclear explosions. Then in 1992, the US officially stopped all testing.