Science Vs - Nuclear Power - what are the Risks?

Episode Date: June 1, 2017

Fukushima. Chernobyl. Three Mile Island. There’s been some big nuclear accidents over the past few decades, but how dangerous is nuclear power really? We take you inside the core of America’s biggest nuclear power plant and trace what went wrong at Fukushima to try to figure out: when will the next meltdown happen? And what our chances are of getting cancer from it? This week we talk to Dr. Spencer Wheatley, Dr. Jonathan Samet, and Jack Cadogan, an executive at the Palo Verde Nuclear Generating Station. UPDATE! We’ve made a couple of small changes to this episode, thank you to all the listeners who picked up on them. 1. We called the energy that comes from nuclear power a chemical reaction… it’s not. It’s a nuclear reaction. Chemical reactions involve the electrons in an atom. Nuclear reactions involve the nucleus. 2. We said that the Joker became The Joker After falling into a vat of radioactive waste. This is disputed. It seems it was a vat chemicals.. But what those chemicals were , that’s unclear. 3. A clarification: We said that the waste that nuclear power produces in the US… 2200 metric tons per year… was like 323 male African Elephants. That was a weight comparison. They weigh roughly the same… It wasn’t a three dimensional size comparison. Nuclear waste is much denser than an elephant, and so it takes up much less room. And if you want to read the most amazing calculation from an academic of how much bigger 323 African Elephants are in 3D space you’ve got to sign up to our brand spanking new newsletter! To do that head to https://gimletmedia.com/newsletter/ And FINALLY! We got a lot of feedback from that episode that listeners really wanted to hear how nuclear power compares to other energy sources: like coal, solar and wind! Now we decided that to do a fair comparison that really needs it’s own episode - it wasn’t as simple as just throwing out some numbers. So we’re working on that episode for next season. Our Sponsors: Cloudflare - To learn more visit cloudflare.com/sciencevs Credits: This episode has been produced by Heather Rogers, Ben Kuebrich, Shruti Ravindran and Wendy Zukerman.Kaitlyn Sawrey is our senior producer. We’re edited by Annie-Rose Strasser. Fact checking by Ben Kuebrich and Heather Rogers. Original music and mixing by Bobby Lord. Extra thanks to Leo Rogers, Joseph Lavelle Wilson as well as Prof. Steven Biegalski, Prof. Mark Jacobson, Jussi Heinonen, and Dr. Eric Grant. Selected References:Radiation Basics Primer from the U.S. Nuclear Regulatory CommissionDr. Spencer Wheatley’s paper ‘Reassessing the safety of nuclear power’National Research Council Report on Health Risks from Low Levels of Ionizing Radiation Learn more about your ad choices. Visit podcastchoices.com/adchoices

Hi, I'm Wendy Zuckerman and you're listening to Science Versus from Gimlet Media. A quick note before we start, this is Wendy from the future. We've made a couple of small changes to this episode. For details, have a look at the show notes. Okay, let's begin. On today's show, we're pitting facts against fallout as we ask, how dangerous is nuclear power? An accident at the Three Mile Island nuclear power plant. There's a hell of a lot of radiation in the reactor building.

There has been a nuclear accident in the Soviet Union. A third explosion at the Fukushima nuclear plant causes a reactor to leak. Over the last four decades, there have been three major nuclear power plant accidents. Three Mile Island, Chernobyl and most recently, Fukushima. These disasters are frightening and their consequences play out for years. And the fear of nuclear power has had a special place in our cultural imagination for decades.

James Bond fights baddies in nuclear reactors. Stay from the radiation! a special place in our cultural imagination for decades. James Bond fights baddies in nuclear reactors. We're safe from the radiation. James! And the nuclear plant in The Simpsons is constantly having troubles. Oh, meltdown. It's one of those annoying buzzwords. 15 seconds to core meltdown. But nuclear power also has some big upsides, because when you use it to create electricity, it releases practically no greenhouse gases into the atmosphere.

And that's why the Intergovernmental Panel on Climate Change says that nuclear power could be an important part of the low-carbon energy mix. But still, in the US, a majority of people oppose nuclear power, and they don't want any more plants built in America. So today we're going to dig into the fears around nuclear power and we're not going to be comparing nuclear power to other energy sources like coal or wind or solar. It's a really important part of this discussion but it's also a really complicated one. So we're saving that comparison for its own episode. In this episode, we're going to look at,

one, what is the likelihood of another plant melting down in the future? And two, what are the real health risks if you're trapped in the fallout zone? Plus, we're going to explain to you exactly how nuclear power works by going inside a nuclear power plant right to the reactor core. When it comes to nuclear power, there are lots of calm fembots counting down. But then there's science. Crisis has been averted. Everything is super.

Science vs Nuclear Power is coming up right after the break. There's science. Crisis has been averted. Everything is super. Science versus nuclear power is coming up right after the break. Science versus. So what's it like to buy your first cryptocurrency on Kraken? Well, let's say I'm at a food truck I've never tried before. Am I going to go all in on the loaded taco? No, sir. I'm keeping it simple. Starting small. Crypto trading involves risk of loss. See Kraken.com slash legal slash ca dash pru dash disclaimer for info on Kraken's undertaking to register in Canada. After decades of shaky hands caused by debilitating tremors, Sunnybrook was the only hospital in Canada who could provide Andy with something special.

Three neurosurgeons. Two scientists. One movement disorders coordinator. 58 answered questions. Two focused ultrasound procedures. One specially developed helmet. Thousands of high-intensity focused ultrasound procedures, 1 specially developed helmet, thousands of high-intensity focused ultrasound waves, 0 incisions. And that very same day, 2 steady hands.

From innovation to action, Sunnybrook is special. Learn more at sunnybrook.ca. Chiara, it means smart in Italian. Too bad your barista can't spell it right. So you just give a fake name, your cafe name, Julia. But the more you use it, the more it feels like you're in witness protection. Wait a minute. What kind of espresso drinks does Julia like anyway?

Is it too late to change your latte order? But with an espresso machine by KitchenAid, you wouldn't be thinking any of this because you could have just made your espresso at home. Shop now at KitchenAid.ca. Wendy, this is it. This is it? I'm at the Palo Verde Nuclear Power Station in Arizona. It's the largest nuclear power plant in the United States.

And I'm here to see exactly what nuclear power is. My senior producer, Caitlin Sorey, is here with me. I could practically imagine the Simpsons lady being like, we will melt down in five, four, three, two... We're standing inside one of the buildings where nuclear power gets made. It's a massive concrete dome and there's lots of big pipes and nuclear power gets made. It's a massive concrete dome and there's

lots of big pipes and weird submarine echo noises. It's all very steampunk. Dude, it looks like the future in the 80s. Looks like the future in the 80s. So we're getting a tour of the facility and our guide is Paul Burry and we're in this big room and at the centre of the room is a pool, and it's glowing an eerie blue. Now, at the bottom of the pool, that's where all the action happens. So what you're looking at right here, straight down, is the actual reactor vessel itself. So in this pool sits the nuclear reactor vessel. It's basically a metal container.

But inside the container is what makes nuclear power so special. It's uranium and it's been stuffed into metal tubes. This is what makes up the nuclear reactor core. So what is going on when nuclear power is being created? Well, some of the uranium in the core at the bottom of this pool breaks apart. And that means uranium atoms split into two. It's a process called nuclear fission. And when it happens, it releases heat.

Right now, is that splitting atoms and creating heat? Absolutely. You are watching the effect of fission. So that's exactly what you're seeing. That's amazing. Now, when one uranium atom splits apart, it creates a little bit of heat. But to get the amount of heat that this plant is looking for, you want to split a tonne of uranium atoms,

which is why there's that big bundle of uranium in the core. You see, every time a uranium atom splits, it doesn't just release heat, it also releases neutrons. And when these little guys are set free, they can go hurtling into other uranium atoms that are hanging out nearby. And that can then split those atoms, releasing more and more neutrons, splitting more and more atoms

and releasing more and more heat. Now, we wouldn't normally be allowed to get inside of the building where all of this is going on, but the reactor core is temporarily shut down for maintenance. Still, even when the reactor is turned off, like today, some atoms are still splitting. So why bother with this big, complicated reaction? Well, it's the heat that we're interested in, because that heat will be used to turn water into steam.

In the plant, our guide Paul pointed at two big steam generators. They're massive, right? That's what generates all the steam. That one and an identical one on the other side. Now, all that steam is then used to spin turbines, which, voila, gives you electricity. And this is actually the same way that a coal or a gas power plant works. And here's what you need to know. Nuclear power plants have to make sure

that their cores are constantly surrounded by water because without that water the whole system would overheat. Conclusion. Nuclear power works by splitting uranium atoms which creates a lot of heat and that heat is used to turn water into steam and that steam spins turbines to ultimately create electricity. So if you've ever driven past a nuclear power plant, now you know that those plumes that look like a smokestack coming from the plant, they're not smoke, they're steam. So far, so good.

But nuclear power isn't just creating steam. It also has a dangerous by-product. As Caitlin and I were standing over the core, we were quickly shuffled away. That's amazing. And so how did they do that? How are they... Let's head out that way and I'll talk about it out there.

Again, I just want to... We're not getting a whole lot of dose here, but I really want no dose. It's a bit hard to hear, but our guide is saying that he wants no dose. Of radiation, that is. And that's because when the uranium atoms split, giving us heat, the elements that are left behind are radioactive,

which means that they're releasing a powerful kind of radiation called ionising radiation. And this can damage our DNA and our health. And those bits of radiation can get into the air and settle on a railing. To prevent that radiation from touching our skin or accidentally getting into our mouth, we had to wear a lot of protective gear before going into the reactor. You're talking coveralls, several layers of gloves,

two layers of booties and safety glasses. We were even given strict instructions not to touch our face or even our glasses while we were in the core. Oh, no, my glasses are falling down and I'm not allowed to touch them. You're not allowed to touch them. All right, come on, nose, do what you're meant to do. It's like a classic nerd problem. Make glasses.

So these layers of protections and safety precautions are for people inside the plant. But when people talk about nuclear power, their main concerns are actually about radiation getting out. So after we toured the reactor and took off our booties, we went to find the man in charge of making sure that radiation stays where it's supposed to. Jack Cadigan is an executive at Palo Verde, and he was keen to tell us about its safety measures. But first, we had a burning question for him. So are you the Mr Burns of Palo Verde?

Mr Burns? Who's the Mr Burns? Like in The Simpsons. Oh, my gosh. Yes, I guess I would be the Mr Burns. That's right. Now with that out of the way, we asked Jack to tell us exactly how they contain radiation. Like if he had to describe it as if he himself was a radioactive particle, what would he have to do to get out of the building? He said once he, as a radioactive particle, escapes from the core...

I'm still inside the big, thick reactor containment building, which is concrete, walls, you know, feet thick, and also with a complete steel liner that's all welded inside. So all of those barriers have to be breached for me as a little radioactive particle to get out. So radioactive particles would have to get through roughly four foot thick concrete as well as steel walls. And Jack tells us about another safety feature. He says that if something did go wrong, like anything serious, a natural disaster, a power failure, then there are these devices called control rods that automatically drop and it cuts off the nuclear reaction. What it does is it sucks up

all the little neutrons. Oh, wow. So all these neutrons like pinging around, pinging around, like splitting all these atoms, making all this heat. And then you just put this in and it's like, you put the rod and it's like a magnet for it. It sucks up all the neutrons into it. And now there's no neutrons to have the chain reaction anymore. So that's how you shut down the chain reaction. Okay, so those are some of the safety features in place that are meant to contain radiation inside nuclear facilities. But what happens when those features are pushed to the limit?

Like what happened at Fukushima Daiichi in Japan. Let's find out exactly how that disaster went down and why the safety features weren't enough. Hello, good afternoon. Japan has been hit by its biggest earthquake since records began. On the 11th of March 2011, a magnitude 9 earthquake shook the northeast of Japan. It cracked a 500 kilometre chunk of the Earth's crust and at the time there were three nuclear reactors up and running at the Fukushima Daiichi power plant. A heightened state of alert has been declared at this nuclear power plant and residents living around it told to leave

their homes. The quake hit the plant and just as planned the shaking triggered the control rods to drop. They sucked up the neutrons and stopped the uranium atoms from splitting. But the reactor was still super hot. You can think of it like a giant kettle, so even if you turn it off, it takes a while to cool down. And because these cores were so hot, the only way to really cool them down was by

pumping in lots of cold water. Now, the earthquake had knocked out some of the plant's power supply, but the team still had backup. Within about a minute, emergency generators automatically kicked in, pumping in more cold water, just as planned. But here's the thing, the earthquake wasn't the only thing to worry about because it had also triggered a 14 metre high tsunami. That's a wall of water about 46 feet high. Extraordinary, I mean, you can see the power lines going down as all of that water roars through.

I mean, this is just extraordinary seeing these pictures as this unfolds before our very eyes. The huge waves smashed the coastline and flooded parts of the power plant, including the basement. And that's where the backup generators were. They were shot, which meant no more cold water pumping past the cores. The heat has to go somewhere, and that heat usually goes into steam. So they have many problems on their hand,

but the most crucial is having a reliable electricity supply to keep those pumps running. But they didn't find that electricity supply, and the temperature in the core soared past 250 degrees Celsius. That's almost 500 Fahrenheit. The fuel in all three cores started melting through its steel casing. In one of them, the radioactive fuel eventually ate through 70cm of concrete.

That's almost 30 inches. And the heat continued to build inside the core. It was like a pressure cooker. The pressure is soaring. We began to see steam, this radiated steam, let out of the containment centre. Valves were opened to release the pressure, which then sent radioactive steam into the air around Fukushima.

And then there was another problem. It got so hot inside all the three reactor containment buildings that hydrogen from the steam started collecting. And hydrogen is highly flammable. So all three reactors exploded. A little while ago, there was another explosion at a damaged nuclear power plant in the northern part of the country and radiation levels have soared to four times their previous level.

Between the release of radioactive steam and then the three explosions which breached containment buildings, radioactive material had escaped into the air. More than 80,000 people were evacuated because of the meltdown at Fukushima. The big question is, though, how likely is it that we could see another Fukushima any time soon? I think a lot of people think of nuclear power plants as just sort of ticking time bombs. And they see the stack on the horizon and steam coming out of it, they feel

kind of uncomfortable. This is Spencer Wheatley. He's at ETH Zurich University in Switzerland, and he studies risk, including the risk of a nuclear power plant melting down. And to Spencer, he sees the risk of a meltdown just like any other risk out there. Risk is unavoidable, but, you know, nuclear is treated as a special case due to human dread of radiation.

So one way that we can look at how risky nuclear power is, is simply by tracking historical accidents that have happened around the world. And according to one analysis, 1.5% of all the reactors that have ever been built around the world have released radioactive materials. Yeah, 1.5%. But some of these accidents probably wouldn't happen today. Like, if we look at the former USSR, and specifically at what happened in Chernobyl, we can see that that plant had some real design problems. So remember all of that concrete and steel at the reactor core at Palo Verde, all that containment? Well... The reactor at Chernobyl didn't have a containment, right?

So that was an old... Didn't have any containment? It didn't have a containment dome, yeah. So that was the design at the time. What?! It wasn't a good safety culture. Let's put it that way. Another way to tell how risky a plant is, is to look at the risk assessments that nuclear power plants make. So each nuclear power plant in the US has to crunch their own numbers to figure

out the likelihood of their nuclear reactor cores getting damaged. It's called a PSA. No, not a public service announcement. Something even cooler. A probabilistic safety analysis. So to make these PSAs, basically nuclear power plants like Palo Verde look at every part of the power plant and think, what if this broke? Or what if that broke? And then they have to consider all the knock-on effects. And at every stage, they're asking, what's the chance of any of those things actually happening? Spencer describes the PSA as a... It's a very, let's say, demanding and involved, I hesitate to say, but brainstorming exercise. So they're thinking, like, what if the control rods don't drop?

Maybe they were damaged. And what if water isn't getting pumped through the core? And maybe you've also lost the backup cooling systems. Then they add up all the probabilities, and that gives them a number that tells them how risky their business is. More specifically, it tells the plant what its risks are for different kinds of accidents. So using the PSA, US nuclear power plants have to show that their reactors are unlikely to have a kind of major accident that releases radioactive material more than once in every 100,000 years.

So this kind of accident is one that could cause serious health problems to people outside the plant. So that's one in every 100,000 years. Now, there's also a rule for if they have smaller accidents, the kind that could damage the reactor core but not actually release any radioactive material outside of the plant. Here, their PSA should say that that kind of accident is only possible once in every 10,000 years. Okay, I'm happy with that. Are you happy with that? Like, if that was actually true? Yeah, I mean, it sounds reasonable.

Except Spencer says that there are 99 reactors in the U.S., each with their own risk assessments. 99 reactors with 99 problems? Spence feels bad for you, son. So once every 10,000 years for an individual reactor, and therefore once every 100 years for the US fleet. But Spencer says it's hard to know how much we can trust these figures because these PSAs, they can miss things. In fact, they can miss a lot of things. In between 2000 and 2010, 30% of experienced events were not captured. 30% of experienced events were not captured. 30%?

30%. And these are events that could be seen as having real safety relevance. So they were not themselves core melt events, but they're so-called precursors. And that 30% is from the Nuclear Regulatory Commission, or the NRC. And in some of those cases the events were small but some were pretty big. Like there was this time at a plant in South Carolina in 2010 where an electric cable failed which set off a fire and an NRC report said that the crew failed to quote properly control the plant, end quote.

Interestingly, we actually had some audio of the workers at that time. Who would have thought a nuclear reactor would be so complicated? Five minutes before critical mass. Critical what? And sometimes these PSAs don't just miss the near misses. Sometimes they're astoundingly off. For Fukushima, they said that a core damage was a one in a million year event. But then, of course, three core damages happened at Fukushima. So in

that case, it's due to a poor analysis. A poor analysis. Yeah. Because ultimately, they didn't consider the idea of a massive earthquake and tsunami. But here's the thing. Even if you know the effects of a natural disaster, some things are just so bloody tricky to predict. Say if we were spitballing things that go wrong, like one of the things you think is, all right, Mary forgets to turn on the light. Like how much can they include human error into their analysis?

Well, it's difficult, right? I mean, so if you think of Fukushima, they lost all off-site power and they were in a blacked-out control room without any information and they were wearing, you know, anti-contamination gear and the site was covered in debris and flooded and so on. So it's clearly extremely difficult to model human reliability in such situations. Conclusion. According to nuclear power plants in the US, they can only operate if their risk analysis says

that each reactor they've got will have a big accident no more than once in every 100,000 years and a smaller accident once in every 10,000 years. But it's really hard to know how much we can trust these numbers. If we look historically, we know that these serious accidents have happened. And Spencer knows that it can be really hard to recover once trust is broken. In safety culture, just like in a relationship, you have to be open about the

possibility that things could go wrong, right? Like, you're with your girlfriend, your wife, and she says, you know, promise me that you'll never hurt me and you'll never do anything wrong. And of course, the easiest thing to say is that you promise, right? It's impossible.

You love her and you could never do that. And then maybe you start putting yourself in situations you shouldn't. And then before you know it, well, you know, you're in trouble. And it's very difficult to maybe to regain trust after that. It's true. Once you've cheated on someone, it's really hard for them to trust nuclear power. After the break, we're looking at the health risks. What happens if something does go wrong?

Like, what are your chances of getting cancer and even dying from radiation exposure? Chiara, it means smart in Italian. Too bad your barista can't spell it right. So you just give a fake name. Your cafe name. Julia. But the more you use it, the more it feels like you're in witness protection.

Wait a minute. What kind of espresso drinks does Julia like anyway? Is it too late to change your latte order? But with an espresso machine by KitchenAid, you wouldn't be thinking any of this. Because you could have just made your espresso at home. Shop now at KitchenAid.ca. At Wealthsimple, we're built for whatever you're building.

Built for Jane, who wants to break into the housing market. We're built for Ted, who's obsessed with what's happening in the global markets. And built for Celine, who just wants to retire and explore the world's flea markets. So take a moment and think about what you're building for. We've got the financial tools to help make it happen. Wealthsimple. Built for possibilities. Visit wealthsimple.com slash possibilities. Welcome back. So we've talked about how nuclear power can go wrong, but what does that mean for the people who live nearby? Yes, if you live near a nuclear power station during a meltdown

and radioactive particles start escaping into the air, how worried should you be? Now, the biggest concern is cancer, And that's because, as we mentioned, the radiation released during a meltdown can break apart DNA, which could turn a cell cancerous. Now, this is different from the radiation that your phone or microwave emits. Radiation from a nuclear meltdown is much more dangerous. And the feeling is the stakes are high. Radiation from any source can attack the thyroid, the skin, the lungs, the spleen, the liver,

the kidneys, the bone, the muscle, the reproductive organs. But here's the question that really matters. How much does your risk of cancer rise if you lived near Chernobyl or Fukushima or the next nuclear meltdown site? One way we can try to predict the dangers of a meltdown is to follow people who lived around the site of one to see if their rates of cancer rise. And scientists did exactly that in Chernobyl. The Chernobyl meltdown remains the worst nuclear accident in history. And yet, when scientists looked at the rates of cancer in hundreds of thousands of people living in the affected areas, they found only one type of cancer spiked.

Thyroid cancer. More than 6,000 people exposed to radiation from Chernobyl were diagnosed with thyroid cancer. But still, when you look at the bigger cancer picture, a report from the United Nations said, quote, there is no scientific evidence of increases in overall cancer, end quote. And another report from the National

Academy of Sciences found the same thing. So why is thyroid cancer spiking? Well, because a lot of radioactive iodine gets released from a nuclear meltdown, and the thyroid needs iodine. It'll absorb it, whether it's radioactive or not. But there's more to the story because many scientists actually think that thyroid cancer isn't the only cancer risk after a meltdown. Scientists like Jonathan Samet. And we can trust him because he told us... I promise not to create any alternative facts. That would be great. Also, because he's the chair of the Department of Preventative

Medicine at the University of Southern California in Los Angeles. And he's done a ton of research on the health effects of nuclear radiation. Jonathan thinks that the reason that more cancers aren't showing up in these large studies, which are called epidemiological studies, is because he thinks the risk of cancer from a meltdown is kind of small. Well... It's small enough that it's unlikely to be detected by conventional epidemiological studies.

So what Jonathan means here is that, yes, the cancer risk is small, but that doesn't mean it's non-existent. You can think about it like this. Take leukaemia. Before the Chernobyl accident, in the region, roughly two in every 100,000 people were diagnosed with it each year. So even if the risk of leukaemia rose by like 10% because of Chernobyl,

we might not detect it because these types of studies just aren't sensitive enough to pick up on it. So what does Jonathan think these studies aren't picking up on? Well, to help figure this out, he looks at other ways that people have been exposed to radiation, including nuclear bomb survivors, people who've had a lot of X-rays, as well as animal studies where animals get exposed to radiation. And from this, he believes that radiation can cause more cancers

than the large epidemiological studies can show. I think these are helpful estimates and they're based on a pretty robust body of science at this point. From all this work, Jonathan says that we know that the more radiation you're exposed to, the higher your risk of all kinds of cancers. But... As we go to lower and lower levels, there's increasing uncertainty. Despite the uncertainty, it seems like the risk of getting cancer, based on the meltdowns we've had so far, has been surprisingly small.

Well, it surprised me. If I lived in Fukushima, what is the likelihood that I will get thyroid cancer? Well, you know, it's not a question for which we yet have the answer, but assuming what we know about doses delivered to the population, and I'm just going to use the word relatively low. Sorry, did you say, you said relatively low, was it? I said, I said relatively low, but I don't think we have, you know, in a sense, a vocabulary. So some, one person says minimal risk, perhaps that's somebody else's unacceptable risk. Jonathan recently wrote a report which brought together estimates

of how many more people will die from cancer as a result of Fukushima. And the calculations are saying that there would be roughly 1,000 extra cancer deaths and perhaps some 1,000 more non-fatal cancers. Keep in mind, the research was considering the health of some one million people in the area that were exposed to radiation. But Jonathan said that we shouldn't take these numbers as gospel. They're estimates and it's just too soon to tell.

Conclusion. The risk of cancer from a nuclear meltdown isn't clear-cut. And because the risk is actually relatively low, it often can't be picked up in big population studies. Still, the number of estimated cancer deaths from Fukushima is around 1,000. So, even when everything is going fine at a plant, no meltdown, what about the health of the workers?

Well, when we were at the plant, we met a man named Seth who scans anyone who works with radiation. The radiation workers, we call them rad workers. Seth oversees the machines that are used to scan rad workers and us to make sure that they don't have radiation on them when they leave. Seth, what's that container there? So, the big foam boat looking thing? That's a portal, a personal... A portal? For what?

To the other side. A personal contamination monitor. So, you're going to step into one of those and it's basically going to check your whole body for contamination. And Seth said that all of these checks made him feel safe to be at work. What does your family think? Do they worry about you working here? No, my wife actually works here too.

Did you meet here? I did. So she doesn't worry? No. So should they be worried? Well, under normal working conditions, rad workers are often exposed to very, very low doses of radiation, if any, and that happens over

years and years and years, which makes it very difficult to study their risk of cancer. And the frustrating thing is that different studies find different things. A 2015 study of more than 300,000 workers in the US, the UK and France, who were followed for 30 years, found that nuclear workers did have a slightly increased risk of cancer. But other studies haven't found that. It's all pretty unclear. But either way, the risks to radiation workers under ideal conditions does seem low.

And there's one final concern when it comes to nuclear power, and that's the waste issue. Radioactive waste. The 99 reactors in the US pump out 2200 metric tonnes of spent fuel each year. It's all sitting on site with really nowhere else to go. 2,200 metric tons. That's like 323 male African elephants worth of nuclear waste sitting around. And Jack Cadigan from Palo Verde doesn't mince words about this nuclear waste issue. He says there's no way around it. It's just inherent in nuclear power. So when we sign up for nuclear power, we have to split atoms. And when you split atoms, part of what is produced is radioactive fragments, the pieces that break basically up.

And those have to be dealt with. Right now, across the US, what happens to that waste is this. First, it gets taken out of the reactor core and then left in a big pool of water for at least five years. And then the waste is moved to concrete casks. And at that point, Jack is pretty optimistic about it. The fuel is fairly benign inside. It's very low energy, but... You couldn't have a bath in the waste, in that waste. Like, it's not safe.

I would recommend not having a bath in anything that has to do with nuclear waste. That's correct. The stuff in these casks is still dangerous. Even after a decade, it is still a thousand times more radioactive than natural uranium, and it will take over a hundred thousand years to go back to its natural level. So what do we do with all this waste? Well, one idea is to dig a deep hole into stable rocks and then shove it in there. You may have heard about a proposal like this in places like Yaka Mountain in the US and another site is currently being built in Finland. So a bunch of radioactive waste in a big hole.

It's far from a perfect solution. Like it's possible that the waste could leak and over time slip into cracks and up into the soil. But still, a report from the National Academy of Sciences said this dig a hole option was, quote, the only scientifically credible long-term solution, end quote. And they also said that if done right, storing waste this way could be safe and secure. And here's something else to think about. That nuclear storage team in Finland told us that they were having these big existential thoughts like, do you put a sign up, don't go here, for future generations of Finns to find?

Or do you just cover it up and hope that for thousands of years no one goes a-digging? Conclusion. Nuclear power creates radioactive waste. And once you have that waste, one of the best solutions that engineers have come up with is to dig a big hole and shove it underground. So, when it comes to science versus nuclear power,

does it stack up? First up, while there are lots of safety mechanisms at nuclear power facilities, there will always be risks. And there will probably be another serious accident in the future. If we look at the regulations and their risk assessments, it would seem that one nuclear reactor core in the US might run into some serious trouble once every hundred years. But it's hard to know how much we can trust those figures. Next, when a meltdown happens and it releases radioactivity into the environment, how dangerous is it? Truth is, we don't really know. But it is predicted that roughly a thousand people will die from cancer as a result of Fukushima. And finally, the waste problem. If we go with nuclear

power, we're going to make radioactive waste. And the long-term solution that scientists are considering is to shove it down a hole. So that's nuclear power. It's such a radioactive topic and at its core, this science is really difficult. But that's nothing to have a meltdown about. And I'm glad you spent the time with us. It's like a spent fuel rod spent time with us. That's science versus nuclear power. and Heather Rogers, original music and mixing by Bobby Lord, extra thanks to Leo Rogers, Joseph LaBelle Wilson,

as well as Stephen Bogalski, Professor Mark Jacobson, Yussi Hainanen and Dr Eric Grant. And next week, we're tackling artificial sweeteners. Could they be making us fat? How long have you been having six to ten Diet Cokes a day for? Probably like 15 years. I literally think of them as little batteries. Do you know what I mean?

Just like not having batteries. And heads up, next week is actually our last week of the season. I know, it's crazy, right? But don't worry, we'll still be around. We're setting up a mailing list so we can send you fun science stories that we get excited about. You can sign up at gimletmedia.com slash newsletter. I'm Wendy Zuckerman. Fact you next time.

Check. Go for it. Science versus... You don't think we should sing it together to line them up or you'll be fine science science versus what's the first note oh is that

that's it? Science versus. Science. Science.