Short Wave - Seen Any Nazi Uranium? These Researchers Want To Know

Episode Date: October 25, 2019

NPR science correspondent Geoff Brumfiel shares the story of Nazi Germany's attempt to build a nuclear reactor — and how evidence of that effort was almost lost to history. It's a tale he heard from Timothy Koeth and Miriam Hiebert at the Department of Materials Science and Engineering at the University of Maryland in College Park. Read more on their original story in Physics Today. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Maddie Safaya here with NPR science correspondent, Jeff Brumfield. What's up, Jeff? Hey there. I've got to say today's episode is a lot. So let's not waste time. Take us to the summer day in suburban Maryland where this story starts. Yeah, so right outside D.C., there's this physicist named Timothy Coth.

He works at the University of Maryland. And one day he's out for a jog when he gets this phone call from a friend of his who's kind of a private person, wants to stay anonymous. Anyway, this friend says, I need to meet you as soon as possible. The person said, okay, I knew where you are. Meet me in this parking lot, and about 20 minutes later, we got together. So they meet up. Tim's friend gets out of the car and has something to show him.

Got out of the car, open the trunk of the car, and in this little brown satchel, a lunch satchel wrapped in paper towels, was this cube. A cube. A cube. That's right. I saw this corner of an edge with a little notch in it and this characteristic gray. And I immediately knew what it was. And I looked at my friend and I said, do you know what that is? And they responded to me and said, well, I think so.

Do you know what it is? Jeff, what the is it? Well, let me just say that Tim is a history nerd for all things related to nuclear. stuff. In fact, his office is packed with nuclear memorabilia. And he knew what he is looking at was very rare and, at least to him, potentially, extremely valuable.

But there was this one other clue about how it got in this trunk, in this parking lot, in suburban Maryland. The other sort of clue was the piece of paper that was wrapped out sort of like a ransom note around a rock that would be thrown through somebody's window.

And it says, Gift of Ninninger. A piece of uranium from the reactor Hitler tried to build. So that was the confirmation that I needed. Uranium from the reactor that Hitler tried to build. That is correct. I have a lot of questions. And I have a few answers.

All right, today on the show, the incredible story of the Nazi efforts to build a nuclear reactor. It's a story that contains this really big idea about the way we practice science, but it's also a story that was almost lost to history. Almost. Okay. So, Jeff. We are going to unspool the story of how this uranium cube came into the possession of a physicist in Maryland, who Ninninger was, and what any of this has to do with how we practice science. But first, isn't like just a cube of uranium chilling in a trunk kind of dangerous?

Well, this type of uranium was natural uranium. So it's a little radioactive, but it's not super radioactive. And we'll get to all that. But let's just start with the story, which came to me from Timothy Kempath. Coeth, the guy you met earlier. The jogger. The jogging physicist, who's a professor at the University of Maryland. In the Department of Material Science and Engineering. Tim and his research partner, Miriam Hebert. Do you go by Mimi or Miriam? I will answer to either. Mimi's good. The two of them published this story you're about to hear in the magazine, Physics Today, which is a thrilling publication. You better not throw too much shade on physics

today. It is very well known among physicists. I'll have you know. And the story really starts in the winter between 1944 and 1945, right at the end of World War II. The tank columns span out towards Stuttgart, Schweinfurt, Berfert. The Allies invade Germany, and they're marching toward Berlin. In the southern sector, air attack proceeds in advance. And in the middle of all this is this guy named Werner Heisenberg. Probably Germany's best physicist at the time. Have you heard of Heisenberg?

Yeah, sure. Yeah. Yeah. Well, you may have heard of the Heisenberg uncertainty principle. Yeah, I know some of those words. Keep going. So during World War II for Germany... He became one of the leads of their nuclear effort.

And that nuclear effort was actually not about building a nuclear bomb because at Germany at this point... They did not believe they could build a bomb. What they were trying to do was instead go for nuclear power. nuclear reactors. They could use maybe battleships or submarine stuff like that. And we know this because the Americans would later find plans for a whole series of experimental reactors the Germans were working on. And the very last version of that was the B-8 reactor. The B-8 reactor was the one that used these cubes of uranium, 664 of them, to be exact.

And these cubes were suspended using aircraft cables, like long sort of dangling strings. So describe what that looks like. So I'll let me do it. I think it looks like a chandelier. It's sort of a cylindrical metal top with all of these chains of cubes hanging down around it. I think it's actually kind of pretty. And that whole apparatus would have been submerged into a cylindrical pool of heavy water. So they're dipping this uranium chandelier in heavy water.

How does that actually work? So remember, this use as natural. uranium that they just straight up dug out of the ground. And basically, if you can get enough of this uranium together and you can surround it with the right material, in this case, the Germans thought heavy water, which is a special kind of water that works for nuclear processes, you can ignite a sort of nuclear spark. It's almost like lighting a match. And the sort of nuclear chain reaction will start going, and you'll get heat and energy out of the reactor. So how close did they actually get it to working? Yeah, well, I mean, Tim told me the Germans weren't all that far off.

A safe answer is you needed about 50% more a cube. So if there were 664, you needed another 300. Was that evident from your analysis of this, or did people kind of know that already? So the Germans knew that. And you could infer that from their notes. So if the Germans would have gotten this thing working, that would have been a huge deal, right? I mean, the story we have of World War II is that the Americans, launched the Manhattan Project, their big project for the nuclear bomb, and they developed nuclear power and nuclear weapons and even use them right at the end of the war. If the Germans had gotten nuclear power working,

they might have then become more interested in the bomb. The course of history could have changed. People who watched the man in the high castle on Amazon have some idea of what might have happened. So yeah. So they just needed like 300 more of these cubes and they didn't have them? Well, it turns out. There was another 400 cubes. In Germany.

In Germany. Oh. Oh, yeah. Tim and Mimi found evidence of this in a trove of archive documents at the University of Maryland. The original documents between the German High Command, the OSS, then, the CIA, Atomic Energy Commission, and some field agents. What this means was Germany had enough uranium to make a working nuclear reactor at the end of World War II. So why didn't they just get their cubes together?

Jeff? Well, you know, this is a classic story of science, and this is a scientist, I'm sure you're familiar with it. Heisenberg had his cubes, and he is over in one part of Germany working in his lab. And there were other teams of scientists working separately in separate labs, and they just never got all their stuff together. I mean, that's basically what it comes down to. And, you know, this gets at the big sort of lesson for Mimi Hebert, because when you think about how the Germans tried to build up their nuclear program and get it running, it's all. almost exactly the opposite of what the U.S. do. Here we have that Manhattan project I mentioned,

and it was like this massive effort, 600,000 people working all over the country, all pulling on the same rope. Which is very different than how most science works. It's usually done sort of independently, and independent verification is a big part of the scientific process, but I don't personally believe that that's the best way to approach, like, the grand challenges like climate change,

example, with these sort of competing labs and computing for resources, I think consolidating everything you've got and all the brains that you've got is the best way to really get to an answer quickly. So what happened to all these cubes? Right. So at the end of the war, some of the cubes were seized by the Americans. Those were the ones that were in that B-8 reactor. And they were sent to the U.S. And that's where this note that the cube in Maryland, it was, It was wrapped up in. Oh, yeah. It was like a gift of Ninninger.

Gift of Ninniger, a piece of uranium that from the reactor, Hitler, tried to build. So Tim starts digging, and he turns up the name of this guy, Robert Ninninger, who is in charge of inventory for part of the Manhattan Project. And it turns out Ninniger may have been the person who oversaw the arrival of these cubes back from Germany in 1945. Oh, okay. Now, it's not clear what happened next. Some of the cubes may have ended up fed into the U.S. sort of processing plants that eventually built more American nuclear weapons. But it seems like Ninniger held out to at least one of them. That's the one that ended up in the trunk of the car.

It was traced back to his estate. And there were a few others floating around that may have been kind of passed out as souvenirs. Souvenirs. There's a few that exist in the world. So the Smithsonian has one. Harvard has one, but none of them have had anything to do with the Ninja specifically. So it's likely that he or someone else just sort of handed them out as paperweights because they're cool. What is happening? What kind of secret Santa nonsense is going on that they're just passing out Nazi uranium?

Which sounds nuts to us, but physicists back in the 1940s, it wouldn't have been quite as alarming. What are the options for the bulk of them? Like, I mean, what are some of the... I mean, they genuinely would not shock me at all if they're sitting in a box somewhere and just no one's wanted to move this really heavy box in the past 70 years. That is probably the most likely outcome right now. That jives with what I know about scientific storage rooms. That makes sense to me.

Yeah, yeah. But Tim wants to find these cubes, and I'll tell you why. These things are a really important part of history. What you have to remember is that the Americans were absolutely. absolutely terrified the Germans were going to get the bomb. And that was a big motivation that led them down the road to launch the Manhattan Project to put billions of dollars, unimaginable amounts of money back in the 40s, and hundreds of thousands of people to just throw it all at this building a nuclear bomb. And, you know, Tim really sees the cube, you know, the fear of this cube is what's driven us, propelled us into the nuclear age. This cube weighs five pounds, but it's one of the few remaining physical relics representing why the United States generated the Manhattan Project and everything that came out of that afterwards.

Nuclear weapons and nuclear power, the Cold War, the threat of this nuclear hostage that our planet was held in by. It's all motivated by this effort that produced just these 600 and some cubes. So I think from a historical point of view, it weighs a lot more than five pounds. Whoa. Yeah. Look, here it is. Tim.

Yeah. Cut to the chase. The cube is right there, just sitting on your desk on the paperweight. My favorite part is always just handing that to people and seeing their reaction they never expect it to be as heavy as it is because it's so small. Wow. It's got some weight. Cool story, Jeff. Yeah, thank you.

If you want to read the entire epic tale of these cubes, we have a link in the episode info to Tim Coth and Miriam Hebert's original paper in physics today. Okay, before we go, one thing we're going to do on the show from time to time is answer questions from you about all things science. So if you have a science-related question, email us at shortwave at npr.org. We may answer it for you. Again, shortwave at npr.org. I'm Maddie Safaya. Thank you for listening.