In this episode of C&EN Uncovered, host Craig Bettenhausen speaks with C&EN assistant editor Fionna Samuels about the use of vitrification to safely store nuclear waste at a former weapons site in Hanford, Washington. Fionna and Craig talk about the origins, handling, and ultimate fate of radioactive leftovers and what the current work at this one site can teach us about dealing with nuclear waste long-term as the US renews its interest in nuclear waste as a low-carbon power source. You can find the link to the article here.
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Executive producer: David Anderson
Host: Craig Bettenhausen
Reporter: Fionna Samuels
Video + Audio Producer: David Anderson, Jeremy Barr
Episode artwork: Andrea Starr/Pacific Northwest National Laboratory
Music: Commercial Flow, Shutterstock
Contact Stereo Chemistry: Contact us on social media at @cenmag or email [email protected].
The following is a transcript of the episode. Interviews have been edited for length and clarity.
Craig Bettenhausen: Welcome to C&EN Uncovered. I’m Craig Bettenhausen. C&EN Uncovered is a podcast series from Stereo Chemistry. In each episode, we’ll take another look at a recent story in Chemical & Engineering News and hear from C&EN reporters about striking moments from their reporting, their biggest takeaways, and what got left on the cutting room floor. This episode, we’ll look further into a recent breakthrough at the Hanford Site, one of the biggest plutonium 239 production facilities in the United States.
Nuclear waste is a strange environmental challenge. It’s often less urgent, but usually more intractable than other types of anthropogenic detritus. Certain types of nuclear waste stay hazardous for hundreds of thousands of years. The need to dispose of and mitigate nuclear waste has been a stressor for the chemical and energy communities. How do you design a storage system to last longer than all of human history so far? Thanks to recent breakthroughs at the Hanford Site, it seems like we are finally getting close to finding answers, and one of those answers may be more clear than you’d expect. Here with us to talk more about this is C&EN reporter Fionna Samuels. Fionna, thanks for being with us today.
Fionna Samuels: Thank you so much for having me.
Craig: For anyone that hasn’t had a chance to read your story yet, can you give a brief recap of what’s in the article?
Fionna: Yeah. So back in October of 2025, the Hanford vitrification plant came online, and that’s really exciting, because Hanford was where most of our plutonium in the United States was actually generated. So the story follows the history of the Hanford Site very briefly and then talks a little bit about what vitrification is, and then takes sort of a forward look into how we might think about vitrifying future nuclear wastes.
Craig: So the thrust of this article is about this idea of turning this waste into glass. Why does that help?
Fionna: So there’s a few different ways of dealing with this sort of complex nuclear waste, and glass is something that the nuclear waste community is really interested in, because you basically take these liters and liters of aqueous and mixed-phase waste, evaporate all the water off, and then in theory, you should be able to mix those remaining solids in with some glass precursors, which is called frit. It’s like little pieces of glass, or even sands, because glass originally comes from sand. So mix them in with these pretty abundant starting materials, melt it all down, and then you’d have a solid chunk of waste that can basically be stored in a much smaller amount of area, because it’s smaller than liquid waste, and also encased in some sort of metal, and then safely stored somewhere away from people. So vitrification is a broad term that means transforming something into a glassy solid. And the great thing about glassy solids is that there’s no uniform crystal structure within that solid.
And vitrification goes beyond nuclear waste. So obviously, glass is a vitrified solid, but also in other realms, like in vitro fertilization, all of that stuff is vitrified. So it’s frozen in a way that makes it so crystals don’t form, because crystals can damage cells. So with these glassy solids, when you turn nuclear waste into a glassy solid, the nucleides basically become part of that nonuniform glass matrix, which keeps them really stabilized. And then also, any radiation coming off of those radioactive elements is not going to destroy a crystalline matrix, because the matrix is not crystalline. So it’s not uniform, which makes glass super stable. An alternative technique that people are looking into is turning it into concrete. So basically, mixing the liquids in with dry concrete and then creating concrete blocks, but you don’t get the benefit of the lower volumes in the final product, because you put all that liquid into it. And then also, concrete is not as stable as glass. So my sidewalk needs to be maintained in front of my house, and you don’t want to have to worry about maintaining radioactive concrete.
Craig: I don’t. I really don’t.
Fionna: Yeah. But it is quicker. It’s a very quick way of dealing with nuclear waste and potentially less expensive, depending on how far along the vitrification plant is, like how well developed your infrastructure is.
Craig: Once you have this glass, this vitrified nuclear waste, and what does that look like?
Fionna: So you can’t actually see the glass, because they’re in steel containers. And they’re big steel containers. They’re like human sized, and you pour the hot glass in, you let it cool down, and then they basically take some sort of heavy machinery to move the steel container to a holding facility. Right now, at the Hanford vit plants, they are only processing low-level nuclear waste, which means that the most radioactive material has been removed prior to vitrification. So those glasses are actually pretty safe to handle. You obviously need correct personal protective equipment, and you want to be careful, and you want to have all your shielding, but it’s not something that will kill you off the bat because it’s so radioactive.
Craig: Early on, you described the waste in terms of liters. For at least a chunk of our readers, myself including, that immediately echoes the glowing, ooze-filled drums of Ninja Turtles, Return of the Living Dead, Captain Planet. But what physical form does the waste really take, and what does it look like?
Fionna: So this waste is a mix of liquid and semisolids. In these big tanks that are buried underground, there’s 177 underground tanks at the Hanford Site. And across these 177 tanks, there’s about 200 million liters of this nuclear waste. One source described it to me almost like peanut butter, because of the mix of liquid and semisolids. So it’s not glowing, but it is kind of gross.
Craig: Is the liquid aqueous? Are there other fluids in there? I’m trying to wrap my head around the liquid part.
Fionna: I guess I’m going to go to a little bit of history before getting into the liquid part.
Craig: Sure.
Fionna: So the Hanford Site came online with the B reactor back in 1944. And then from 1944 until 1989, various reactors at the site were producing a bunch of nuclear waste from basically dissolving uranium cores that had been enriched with plutonium. And then, to remove the plutonium, you dissolve the core. So all of that stuff that was not plutonium is basically liquid and semisolid waste. So at the Hanford Site, it was also a research facility, and this is what made it really complicated to start to vitrify, is because that waste is so complex. So there’s aqueous phases, there’s the semisolid phases, and then there’s phases, I mean, not really in between, but stuff that is not necessarily fully dissolved in either. So different sort of experimental wastes that were from dissolving these rods that had the plutonium in them to remove the plutonium. So it’s a big mess, basically, is kind of the takeaway.
Craig: Yeah. So kind of a nightmare nuclear peanut butter, chunky style.
Fionna: And one of the sources told me that it can get stratified in these tanks. So if different things were put in different densities, or they don’t dissolve as well within each other. So each tank is unique and heterogeneous, and has to be characterized, because reactions could have happened before it started to be vitrified last year.
Craig: Now they were after the plutonium.
Fionna: Yes.
Craig: So logically, there’s not going to be much plutonium in the casks. So as far as elements and isotopes, what’s in there?
Fionna: So some of the more worrisome ones, cesium is in there, strontium, uranium, anything that didn’t get fully reacted into plutonium. And then, no reaction is a hundred percent efficient. So it is possible that there’s a little bit of plutonium still in there. There are definitely still radioactive nucleides in there.
Craig: How does the Hanford waste compare to the waste that’s made at a civilian nuclear power plants or the waste from nuclear-powered naval vessels? Is this a potential help, this vitrification for that kind of waste as well?
Fionna: That’s a great question. So my understanding is that the nuclear reactors that are for energy generation produce different kinds of wastes, like the rods. For example, some of those wastes have been considered for recycling processes. That’s an ongoing sort of question of how to reuse those spent fuel rods in energy reactors. In this case, the waste was largely generated from getting the plutonium out of the uranium fuel rods. So I would assume that that’s a pretty different problem than what people are considering today.
Craig: So the Hanford reactor, was it making power or was it just for weapons?
Fionna: It was just for weapons. So the reactor was specifically designed to create plutonium for the US during World War II, and then the B reactor, which was the very first industrial-scale reactor turned online in the whole world. That reactor was the first to come online in 1944, and two more reactors came online shortly after. And then over the years, through World War II and the Cold War, the site built more reactors and more separation facilities.
Craig: So you mentioned in the article that the Hanford Site played a pivotal role in the Manhattan Project. Do we know roughly how much plutonium-239 was produced in this facility, like at its prime?
Fionna: Yes. So over the course of its entire history, which went almost to the end of the Cold War, it produced two-thirds of the US plutonium supply. So that’s just about 66, 67 metric tons of plutonium.
Craig: Thinking about the Yucca Mountain, well, not solution. So this was a site in the US that was fully constructed and almost ready to be commissioned to store a long-term nuclear waste deep within the Yucca Mountain, and the project got shut down in part because of transport of the nuclear waste, but also in part because a very powerful US Senator did not like the idea of lots of nuclear waste being trucked into his state . . .
Fionna: Which is fair.
Craig: . . . and thrown down a mountain. Not thrown, very carefully lowered down into a mountain.
Fionna: Yeah. And that’s a big piece about nuclear waste in general, is how the public perceives nuclear. And in the long run where everything will be stored, also where does the starting material come from? Where are we mining uranium? Who’s being impacted by those mines? Who’s actually doing the mining? Where is the uranium being enriched? How are we guarding the public from accidental releases? So there’s a lot to think about when we’re talking about nuclear, even beyond nuclear weapons.
Craig: I’m curious, we want to talk a bit about the liquid phases, because in Fukushima, Japan, where there was an accident that caused a reactor to melt down and fail, it was the radioactive isotopes that were volatile of iodine, cesium, and strontium that were a big concern. The heavy elements weren’t as much of a problem at that site. So I wanted to ask about those gaseous and liquid components in this vitrification system, these things that you’d expect to vaporize at the temperatures that you need to make glass. What happens to them?
Fionna: All of these processes have been developed over many, many years. And so, by the time this stuff is being vitrified, again, this is the low-level nuclear waste. So a lot of the worst components have actually already been removed, and anything that’s going to be volatile is going to get heated up and off gas, but it’s not necessarily a concern at this point with this type of nuclear waste.
Craig: Interesting. So we touched a little bit on nuclear recycling, but I want to go in a little further, because the US doesn’t currently recycle nuclear waste at any kind of scale, but it is awarding millions of dollars to chemistry start-ups and other groups who are looking to get spent fuel recycling up and running. And Europe has been reprocessing spent fuel for decades. What would vitrification do to the possibility of using some of this nuclear material for a fuel sometime in the future instead of just hiding it? Does this close off the possibility of using some of this material?
Fionna: Yeah, this would not be part of the recycling conversation.
Craig: OK.
Fionna: Yeah, this would be after everything that’s usable has been extracted. What do you do with anything left over? Maybe you vitrify it.
Craig: Yeah. Is there any useful thing that radioactive cesium does for us?
Fionna: I honestly don’t know.
Craig: Seems like probably not. So this sounds like a big story with a lot of interesting tangents. Tell me about some stuff that you learned while reporting this that didn’t quite have a place in the article.
Fionna: Well, so one of the very present things that I learned, which I thought was funny. I talked to Robert Franklin, who’s a historian at the Hanford History Project, and this is a project that’s basically collecting all of these historical items from the Hanford Site, and also helps run the museum, and they accept donations. And so, this facility was running for so long that people would bring things home with them, workers, people who are working there. And so, he told me that there’s a very formal process of making sure that every item that they have and display for the public goes through a rigorous review. So it’s not radioactive and it’s also not sensitive intelligence, because we obviously don’t want our adversaries to get any sensitive information about how to build their own nuclear reactors for making plutonium. So anything on display, you’re sure that they are safe to view.
But sometimes people come, and they bring stuff from their family, or their grandparents, or whatever, and it just so happens that it’s not something that you would want to view or you would want the public to see or deal with. And he said that there have been times where it’s been a problem, which there’s some sensitive topics. He was not going to share exactly what he was talking about, but the implication was it’s not something that you want to be handling on a daily basis. So if you do have historical items from the Hanford Site, just be sure to go through the proper channels to give them back.
And then the other thing, which was much sadder, that he told me about was the Green Run, which I do reference at the very, very end of the article, but it was a time during the Cold War where the US was really interested in understanding if they could detect how far along the Soviets were in building their own bombs, because the Soviets had just demonstrated a successful nuclear bomb test. So this was in 1949, and the US was worried about that, because we’re in the middle of the Cold War. So they decided to put a bunch of instruments on some Air Force planes and fly the planes over Hanford and Oak Ridge, which was the other place that plutonium was being produced in the US.
And when they did that, they realized that they couldn’t detect the really small amounts of radiation that were released when these sites were running regularly, but the Soviets were doing a different kind of processing. So in the US, the workers were waiting 90 to 125 days from enriching the rods with plutonium and then separating the plutonium from the uranium fuel rods. They were waiting for a while, 90 to 125 days. The Soviets were only waiting for 60 days. So it was much greener material. It was much hotter. And to see if their instruments, if the US instruments could detect that kind of production, they asked the Hanford scientists to do the same thing, which was only wait 60 days to process the fuel and then intentionally release whatever comes off. So unfiltered. And what ended up happening was that it was a huge release of iodine-131.
Ultimately, that was 8,000 curies released over the whole area for reference. When the Three Mile Island incident happened, that was 15 curies of radiation. So it was a huge amount of radiation that was released, and none of this information was communicated to the public. No one was evacuated. No one was told for years until the Manhattan Project became public. And then everyone saw that this had happened and they’d all been exposed to huge amounts of radiation. So that was a really bad thing that happened. And importantly, it was kept secret from the public until basically a journalist started digging and got a lot of the Manhattan Project, secret files released. So, looking into the future, obviously, we just need to be, if we’re going to do any nuclear anything, everything needs to be very transparent to the public, because people have experienced really bad things with nuclear projects.
And if we’re expecting people to embrace nuclear energy going forward, there has to be some sort of way to ensure that the people running the energy plants are not doing secretive stuff, right? This is why people are scared of nuclear, is because there’s a history of keeping things secret from the public that had consequences, right? People were exposed to a lot of radiation who otherwise would not have been.
Craig: I mean, you can understand wanting to do that experiment, but wow, also that’s . . .
Fionna: Maybe it would be different if the public was informed and if the public was evacuated once it was clear that it was necessary for people to evacuate.
Craig: Now there’s a lot of nuclear news happening. What else are you watching? It’s a huge area right now. It’s been a huge area, but now it’s every week stuff’s popping off. What are you looking and watching on?
Fionna: There’s so much. So it’s always exciting to see some good news. I think recently there was some news that there’s some reparations for downwinders. So downwinders are the folks who, through the Manhattan Project, and then also in the Cold War, were exposed to radiation from testing and these separation facilities, and that’s been a long time coming. So that was nice to see. And then more recently, there’s two different directions, right? There’s the nuclear energy, but then there’s also the nuclear arsenal. And I am curious about how we’re going to update the nuclear arsenal and what this administration is going to decide with the modernization effort. That was something that was mentioned in Project 2025. So we’ll see what happens there. And then, using nuclear power in rockets and things, like space travel, because that’s fun. That’s cool. So there’s a lot. What are you looking at?
Craig: I think that small modular reactors are really interesting. And there’s people on both—so small modular reactors, it’s not exactly a tiny version of a conventional reactor, but you could think of it that way for the purposes of economics, because there are people on both sides of the debate who are dead certain that it doesn’t make any economic or energy sense. And there are people that are so certain that is the only way forward for nuclear reactivity. And to see that debate play out, it’s difficult as a journalist, because they’re all also very smart and very credible and very passionate, but that’s a really interesting area to watch. And then, these small modular reactors are being built, people are getting their licenses. We wrote about it, that X Energy got a license to fabricate the nuclear fuel for these SMRs. And there’s other players like Kairos.
And these permits are becoming real. These construction projects are starting their shovels in the ground on these things. China has installed an SMR. They’re actually running it. There’s one floating off of the coast of Russia. And so, for a long time, most of our nuclear power fleet has been the same ones we’ve had since the ‘70s. There’s been a few new builds and more new builds in Europe. But yeah, as we think about how to get past climate change or claw back climate change, it’s very attractive to have this fuel that, although nuclear waste is a problem, it’s a much smaller volume, literal volume problem than a lot of other types of energy generation. There’s a lot more radioactivity in the air from coal mining and coal burning in a lot of cases than there is from nuclear power. But at the same time, these risks are real.
Fionna: Yeah. Well, and that’s the interesting thing about talking about nuclear in general, is that the history of nuclear is so sort of in the public mind, I feel like, is so focused on the bombs that it’s to the detriment of nuclear energy. And also, the problems from making all of this fissile material for bombs were real, and people were really hurt by the US ventures into nuclear, and elsewhere as well. But it’s a sensitive topic, and it’s an important topic to talk about. And it’s super import—I mean, just really the most important thing in all nuclear discussions is to acknowledge that we need transparency. And companies building small modular reactors need to be transparent about where the waste is going, like where the spent rods are going, and also where the material is coming from, because uranium mines are hazardous as well. Mining is a really dirty operation and add radioactivity into the mix, and all of a sudden, you need some extra protection and extra consideration.
But it is exciting to see the news about nuclear reactors, energy production, because yeah, it is a green solution. And it’s interesting to see how communities react to it as well.
Craig: Well, Fionna, thanks for diving deep on this with us.
Fionna: No problem. Thanks for having me.
Craig: The people can find me on social media as @CraigofWaffles. Fionna, how can listeners get in touch with you?
Fionna: I’m @FMorningstar on Bluesky.
Craig: You can find Fionna’s story about vitrification of nuclear waste on C&EN’s website. We put a link in the show notes along with the episode credits. I’d love to know what you think of C&EN Uncovered. You can share your feedback with us by emailing [email protected]. This has been C&EN Uncovered, a series by C&EN’s Stereo Chemistry. Chemical & Engineering News is an independent news outlet published by the American Chemical Society. Thanks for listening.
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