IRA FLATOW: This is Science Friday. I’m Ira Flatow. For many folks in the US, the threat of nuclear weapons is out of sight and out of mind. But the nuclear complex is alive and well. And in fact, here, in the US, the state of nuclear weapons is evolving.

The US, among other countries, is giving its nuclear arsenal, which contains about 5,000 weapons, a makeover. This modernization costs around $50 billion a year. With the treaty on the non-proliferation of nuclear weapons in place countries should be stopping the spread of nuclear weapons and technology. That raises the question, if nearly all countries have agreed not to nuke each other, why are nuclear arsenals being updated? And what does that signal to the world?

A new book, called Countdown– The Blinding Future of Nuclear Weapons, analyzes the current nuclear age, what it means to care for thousands of weapons, and why this moment in nuclear history is so important. Joining me is Sarah Scoles, science journalist and author of Countdown. Sarah joins us from Westcliffe, Colorado. Welcome to Science Friday.

SARAH SCOLES: Yeah, thanks so much for having me.

IRA FLATOW: It’s nice to have you. You know, I was one of those children of the ’50s and ’60s, and I recall the duck and cover practices, the fallout shelter plans, the Cuban missile crisis. I know you weren’t around then, but you experienced the nuclear reality in a different way. You live by the nuclear laboratories, right?

SARAH SCOLES: I do, yeah. I live in Southern Colorado, which is not so far from the New Mexican border where a lot of the national laboratories where scientists work on nuclear weapons live and do their work.

IRA FLATOW: And a large part of your book focuses on why the US is modernizing and updating its nuclear arsenal. What does that mean– modernizing, updating? Why do we need to do that? What’s going on there?

SARAH SCOLES: Well, the nuclear weapons that we have now are largely on the scale of decades-old. And the general thinking behind the modernization program is that you wouldn’t buy a car in the ’60s, ’70s, or ’80s, put it in the garage, take it out today and expect it to work exactly as it did when you bought it. You’d probably have to replace some gaskets.

And so that’s part of the idea behind the modernization program is replacing some kind of mundane components of nuclear weapons, like wiring and fuses, and then updating their delivery systems also so that the missiles and things that get them ideally where they never are– ideally they never go anywhere.

IRA FLATOW: Yeah, yeah, and it sounds expensive. When we fix our cars, they’re expensive. I imagine fixing the nukes is a lot more expensive.

SARAH SCOLES: Yeah, the nukes are probably the world’s most expensive car.

[LAUGHTER]

The modernization program will probably cost between $1 and $2 trillion over the course of 30 years. And since government programs are government programs, likely closer to the $2 trillion end.

IRA FLATOW: Yeah, yeah. And why is it so important to do this? I mean, it’s important to have them operating. But as you point out in your book, it’s politically important, too.

SARAH SCOLES: Yes. So the phrase that people within the nuclear complex are very fond of saying is that we need to make sure that the nuclear weapons are “safe, secure, and reliable.” So they’re not going to just have an accident on their own. And also, that if they are ever called upon, which hopefully they never ever are, that they will work exactly as expected, because the nuclear world kind of relies on this idea called deterrence, which is that if I have nuclear weapons and you have nuclear weapons, you won’t attack me because I can retaliate against you.

And that idea, unfortunately, also relies on the idea that I would be willing to launch my nuclear weapon at you and that it would work. And so if other countries don’t have confidence that America’s nuclear weapons will work, then they don’t trust deterrence, and that kind of touchy stability falls apart. So that’s part of the motivation too.

IRA FLATOW: Yeah, yeah. So if I read the arc of your ideas correctly, you seem to be saying that, practically speaking, nukes are not going away, right? So disarmament– total disarmament might be an interesting idea, but it’s not going to be happening. So the deterrent of what we used to call Mutually Assured Destruction– I love the term MAD– for it to work, other countries have to believe that your weapon will work, so that they have to be continually upgraded and tested. And that’s what you write about, right?

SARAH SCOLES: Right. Yeah, that’s correct. And I think at the end of the Cold War, when people stopped doing those duck and cover drills, people within and without the nuclear complex all kind of agreed, like, maybe the world will move toward a place that is more disarmament focused and getting away from reliance on these weapons. But it definitely doesn’t feel like that’s what we’re moving toward right now.

IRA FLATOW: Yeah. Now, weapons used to be tested to make sure they were working. They had to be tested early on in their development. And then years later, when we got H-bombs, they were tested. Some above ground. Some below ground. But now no one’s blowing them up anymore, are they? How do we test a nuclear weapon without firing it off?

SARAH SCOLES: Right. Yeah, we did more than 1,000 nuclear tests, which is pretty wild to think about. But now, yeah, since the ’90s, we haven’t done any of those. And so we have to rely on computer simulations, kind of like digital models of how nuclear weapons work. And then smaller scale experiments that just look at certain components and how they work of nuclear weapons. And putting those two things together to try to get a full picture of what’s going on with the weapon as it is now and as it ages.

And one of the scientists described that to me as when we could test nuclear weapons, if you think of them like a cell phone, you want to know if it works, you turn it on and you find out. But now that we can’t just turn the cell phone on, we have to understand every chip in there, every part of every chip, every circuit, and put those things together to make a very educated guess about exactly what’s going on.

IRA FLATOW: How confident can we be without actually firing off a bomb? Are these computer simulations, are they really, really good enough?

SARAH SCOLES: They are really, really good. When we stopped testing in the 1990s, there was a huge investment within the Department of Energy, which oversees the nuclear weapons, in advancing both supercomputers and the simulations that we run on them. And so in the decades since then, that has largely been the focus of what goes on at the nuclear weapons labs, making those better and better and better.

And so we have a really good understanding of the physics that’s going on inside nuclear weapons. But at the same time, the better and better we get, we actually discover things that we didn’t know we didn’t know. So there are still questions about exactly what’s going on.

IRA FLATOW: How they’re aging, right?

SARAH SCOLES: Right. Yeah, I mean, we only created them 75 years ago. And so there’s never been– there’s not an old nuclear weapon that we can pick apart and say, what happened to this one?

IRA FLATOW: All right, let’s talk about modernization, because you get into that very thoroughly in your book. What does it mean to modernize? What does that entail?

SARAH SCOLES: Nuclear modernization entails putting new parts in, largely, kind of redoing the insides of a nuclear weapon. So some of that is things like upgraded modern electronics. Or the scientists are also placing new kinds of explosives inside nuclear weapons.

So it’s not just the radioactive material. They have, essentially, a fancy version of TNT inside, and we’re replacing that with something that is less sensitive to things like being heated up or dropped or things like that. But one of the biggest things we’re doing right now, at least in my view, is putting new plutonium pits at the centers of nuclear weapons.

IRA FLATOW: Pits? What do you mean pits?

SARAH SCOLES: Plutonium pits are these spheres of plutonium mixed together with gallium. And they’re hollow. They look kind of like a lawn bowling ball– a silver lawn bowling ball. And they are the beginning of a nuclear reaction inside a weapon. So they’re surrounded by this fancy TNT. That goes off. It compresses the plutonium, and then that starts a fission reaction, the splitting of plutonium. And then that goes on, in our modern nuclear weapons, to ignite a fusion reaction. So it’s kind of the starter gun for a nuclear weapon.

IRA FLATOW: Do we have to make new pits? Do we have to create new plutonium for this?

SARAH SCOLES: No, we’re actually using old plutonium that we have sitting around, and kind of purifying it and putting it back into the mix. We do have to make the pits, but we don’t have to make the plutonium for the pits.

IRA FLATOW: Do we have facilities to make those pits like we used to, the same number of facilities?

SARAH SCOLES: Yeah, most of the pits used to be made at a facility in Colorado, actually not too far from me, called Rocky Flats. But that place used to make more than 1,000 pits per year at its height. But unfortunately, things being the way they were decades ago, it got raided by the FBI and the EPA for environmental violations. So that hasn’t been in the mix since the 1980s.

But now we are updating a facility in Los Alamos. It currently works with plutonium, but it doesn’t make pits. And so they’re getting ready for that. And then over in South Carolina at the Savannah River site, they’re doing the same thing.

IRA FLATOW: You know, this idea of deterrence has always been controversial. I’m sure modernization is controversial. On the one hand, people might think more nukes make you safer. That old MAD theory. On the other hand, why would you want to update your nukes unless you have an intention to use them, right?

SARAH SCOLES: That is the way that some of the thinking goes. I think some of the thinking also goes, you update them to keep that idea of MAD going, to match the capabilities of other countries. So yeah, it definitely depends on who you ask. Not everybody is on the same viewpoint with deterrence.

IRA FLATOW: You know, I got the impression, because you mentioned it, that even though we had– and I remember way back in the day we would talk about tens of thousands, between us and the Soviet Union, of nuclear bombs. We have fewer than those, but we have more countries having them. And you seem to be saying we are in greater danger, or at least the same amount of danger, as we were back in the cold war.

SARAH SCOLES: Yeah, unfortunately, that is the view that the experts, who have a better sense of nuclear danger than I do from the outside, that is what they see out there. It’s not just a one on one conflict, which obviously involving nuclear weapons is still complicated. But when you have many on many nuclear deterrence theory going on, it’s much more complicated and there’s more room for misunderstanding or conflict or just a lot more variables going on.

IRA FLATOW: Yeah, there’s recent news that Russia might want to launch nukes to space. I mean, isn’t that the worst kind of idea? I mean, a nuclear bomb is the worst kind of satellite weapon, because wouldn’t it take down everything else?

SARAH SCOLES: [LAUGHS] Yeah, I mean, I think it would be best if no one used any weapons in space probably. But yeah, I mean, a nuclear weapons devastation doesn’t just stay where it explodes. Its point is that it puts out radiation and fallout, and the same thing would be true in space. And so it does have the potential to do more damage, if detonated up there, to the satellites that are there.

IRA FLATOW: Yeah. You spoke with scientists at nuclear weapons labs. I’m sure they were of two minds about what they were working on, right? They couldn’t tell you exactly, of course. There are secrets. But what could they tell you about their research?

SARAH SCOLES: Right. So the scientists who work on nuclear weapons, they do work on the fundamental physics of what is going on inside a weapon. But a lot of times they also go about that by doing basic science in physics and astronomy. So studying how stars work, or how supernovae explode, or what’s going on inside a black hole.

And all of those things, like, physics is physics no matter where in the universe you are. And so they do this kind of astronomy or physics research and then apply it to nuclear weapons more in secret. But they can talk about the basic science that they’re doing. They can publish it in papers. They could get other people’s feedback. And then they can go off in a secret corner and apply it to nuclear weapons.

IRA FLATOW: That’s really– that’s really interesting. In those interviews that you did with them, what did they tell you about how they feel about their work? Now that the films are out about the early days of nuclear bombs, I mean is there some internal conflict with those scientists who are working on modern nuclear weapons?

SARAH SCOLES: I think so. I think the mental philosophical conflict is alive and well with the nuclear scientists of today. I would say that most of the people I spoke to are kind of the mindset, we are not going to disarm tomorrow, so someone has to work on nuclear weapons. And if we don’t have disarmament, deterrence is the best thing we have. So maybe it should be me who keeps these weapons safe, secure and reliable.

But at the same time, they are, in general, people who would like to move toward disarmament, I think, or at least a lot of them are. Some of them are true believers in deterrence and its ability to move forward into the future. But there is always this conflict of, what am I doing? I’m working on these weapons that I don’t actually like.

IRA FLATOW: Yeah. Was there something surprising that you learned in speaking with them?

SARAH SCOLES: I think what was most surprising to me is that the scientists working within the nuclear world are as worried, if not more worried, about our nuclear future than people on the outside. A lot of times as laypeople we get hyped up versions of things we should be afraid of. But when you’re talking to the experts, and they’re maybe more afraid and more aware of the danger than laypeople who don’t work in the field, I don’t know, that was surprising and concerning. I expected a little more comfort from them maybe.

IRA FLATOW: As someone who lived through the ’50s and ’60s, the thing that most surprises me about people today is I don’t think they really understand how terrible a nuclear bomb is.

SARAH SCOLES: Right.

IRA FLATOW: They have no concept of it.

SARAH SCOLES: No, I mean, we don’t– we haven’t, thankfully, used one in a very long time. We don’t test them. So their reality really isn’t a physical part of our world. And they kind of just exist as this abstraction, which, yeah, I think does distance us from how terrible it would be if one ever did go off.

IRA FLATOW: Yeah, we were shown films in schools and on television. Rod Serling used to write Twilight Zones about them. And it was every day we were learning or being fearful of what might happen. And that’s not anywhere evident today, I don’t think.

SARAH SCOLES: No. Maybe Science Friday needs to make a PSA video with a bunch of nuclear explosions.

IRA FLATOW: [LAUGHS] Well, maybe. It’s something to think– not to laugh about. One last thing. What do you want readers to take away from your book?

SARAH SCOLES: Well, I think that nuclear weapons– well, they never went away after the Cold War, even if they kind of receded to the back of our minds. And they are– they’re a big part of our world. They’re a big part of federal funding, international interactions. And they’re not going anywhere, unfortunately.

And so I think nuclear weapons are something that are very secret and hard to talk about. And I hope, mostly, that the people who read the book just get a sense of where things stand now, because we have a lot of information about the past and not a lot of information about the present. So hopefully it’s at least a good overview.

IRA FLATOW: Excellent book, Sarah. Thank you for writing it and thank you for being a guest.

SARAH SCOLES: Thanks for having me.

IRA FLATOW: Sarah Scoles, science journalist and author of Countdown– The Blinding Future of Nuclear Weapons. She is based in Westcliffe, Colorado. To read an excerpt of the book, go to sciencefriday.com/countdown.

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