Stuff You Should Know - Short Stuff: Hisashi Ouchi

Episode Date: September 2, 2026

Japanese nuclear worker Hisashi Ouchi is often called on the internet “the world’s most radioactive man.” That’s not exactly true, but it gets the point across about how severe the fatal dose of radiation he received was.See omnystudio.com/listener for privacy information.

This is an I-Heart podcast. Guaranteed Human. Welcome to Decoding Women's Health. I'm Dr. Elizabeth Pointer, chair of women's health and gynecology at the Atria Health Institute in New York City. I'll be talking to top researchers and clinicians and bringing vital information about midlife women's health directly to you. A hundred percent of women go through menopause. Even if it's natural, why should we suffer through it? Listen to Decoding Women's Health with Dr. Elizabeth Pointer on the IHeart Radio,

app, Apple Podcasts, or wherever you get your podcasts. On Big Lives, we take a single cultural icon. People like Jane Fonda, George Michael, Little Richard. And we pull apart the story behind the image. Discovering forgotten interviews that change exactly how we see these giants of our culture. We're here for the messy, the brilliant, the human version of our heroes. I'm Emmanuel Jochi. I'm Kai Wright.

And this is Big Lives. Listen to Big Lives on the IHeart Radio app, Apple Podcast, or wherever you get your podcasts. Hey, and welcome to the Short Stuff. I'm Josh, and there's Chuck and Jerry's sitting in for Dave, and this is Short Stuff. A really sad addition. Yeah, for sure, because this is about a nuclear accident,

and one very famous victim of that accident, a man in Japan named Hisashi Ouchi, who at the time was a 35-year-old worker at a nuclear facility, and he got a massive blast of radiation in 1999. It was called a criticality accident. And what was the name of the town? In Takahimura. Takaiimura.

Okay, great. Yeah. No, Tokai Mura, sorry. And that's called the Tokaimura nuclear accident is what it's called. And like you said, it was a criticality because there wasn't like a nuclear explosion or anything like that, it was an uncontrolled nuclear fission reaction that these guys accidentally created while they were doing their job processing uranium oxide into usable uranium 235 fuel to be used in an actual nuclear reactor. This is not a nuclear plant. It was the kind of plant that

produces fuel for nuclear plants. That's right. This is the morning of September 30th, 1999. And what they specifically were doing in that moment was they were dissolving that uranium oxide, like you were saying. And this was the procedure, what I'm describing now is the approved procedure, actually. So they were supposed to have dissolved that uranium oxide in a geometrically safe vessel. And then what you end up with is urinal nitrite solution. And you put that into a buffer tank and then transfer, you know, little bits of that into a precipitate, tank. This company, is it JCO is the name of the company? Yeah. They said, all right, we're going to speed this up, and this procedure is not approved.

But what we want you guys to do is mix a solution in stainless steel buckets and then pour it directly into the precipitation tank. And not only pour it directly in the precipitation tank, pour so much in there that we have like five to six times the approved amount in that precipitation tank at once, right? I think there's like seven times. Okay, a lot, a lot more than was supposed to be in there. And I just wanted to point out, like you were saying, there was an improved procedure, and JCO said, nuts to that, we're going to do this faster one, right?

That's just what they were doing with their workers. It's crazy because this is nuclear uranium 235 fuel that they're making. And so when they put in, these three workers, including Hissachi Ouchi, when they put in the seventh bucket of this stuff, directly in the precipitation tank, there were 16.6 kilos or 36.6 pounds of uranium in there, which is way more than was allowed to be in there. I think it was 2.4 keys or kilograms that was allowed to be in there.

And they had 16.6, Chuck. Yeah. So that reached critical mass pretty quickly and started a self-sustaining nuclear chain reaction. And like you said, it wasn't like an explosion or anything like that, but it was a huge burst of neutron and gamma radiation, like incredible Hulk levels. Yeah. And it went on and off for about 20 hours until the emergency workers finally drained water from the tank's cooling jacket and then added boric acid to absorb the neutrons. But, you know, very sadly, Ouchi received a dose equivalent of 17.

Seaberts. It's kind of hard to, like, get an exact calculation, but it was an incredibly large amount of radiation, like, so much that they have, he's been called the most radioactive man in history, which is a bit of a misnomer, because he had this burst of radiation, but it's not like he was walking around, like, radioactive to other people or anything like that. That's a little surprising to me, but, okay, well, I'll take that. I did a little bit of Josh Math here, Chuck. Oh, boy.

Well, it's not even Josh math. It's more Josh checking. Okay. So you said that Oichi received 17 siverts of radiation, right? Okay, yeah. So one... I'm not laughing at that. I'm laughing at your math, by the way.

No, I understand. Yeah. One millarim is equal to 0.0001 cverts. Okay. Okay. You get 20 millarims from a chest x-ray. He got 17 c-verts. All at once.

Wow. Do you, I mean, it's just such a mind-boggling amount of radiation that I can't believe he didn't die immediately. I say we take a break and come back and talk about Ochi's agonizing 83 days of life that followed that radiation exposure. All right. All right. The music you love. Your favorite radio stations. Everywhere you go.

The podcasts everyone's talking about. All in one place. And it's free. Whatever you want to hear. Listen anytime, anywhere. Music, radio, podcasts, unlimited audio. It's on the free IHurt Radio app. Let's go!

One app, no subscription. Always free. Grab the free app. I heart radio. Everywhere you go. Always free. Download the free IHard Radio app today. The US Open is back.

That's right. Two weeks of incredible, exciting tennis. Some outrageous overreactions from players and some hot takes from people who have, let's face it, no idea what they're talking about, but it's okay because I'm here for them and you. I'm Renee Stubbs, and on the Renee Stubbs tennis podcast, I'll be breaking down everything that happens after big matches, who's playing the best tennis, who looks like they could possibly win this tournament, the surprise runs, the heartbreaking exits and

all the drama that only the US Open can deliver. Coco looking real good. Her serve looks so much smoother than it has in the past. I was really happy to see Eager back to what she looked like a couple of years ago when she was winning dominantly. Listen, I'm going to let Venus decide when she wants to retire. I'm going to let the tournaments decide when they don't want to give her a while card because she still puts bums in seats. She still sells and people love to see her play. You always say on this show that this is the best predictor of who will do well at the US Open.

If this is a preview, then we are in for a treat. Listen to the Renee Stubbs Tennis Podcast on the IHart Radio app, Apple Podcasts or wherever you get you podcasts. So, Chuck, before we broke, I was saying I was surprised that he didn't die immediately. Yeah. The reason he didn't die immediately is because it takes a little while for the incredible damage that the radiation did to his body to actually to take effect. And but what it did essentially was it blasted through every cell in Hisashi-Oachie's body and damaged the DNA inside so much so that the doctors caring for him said that he, had completely, or the radiation had completely shattered his chromosomes. The actual packets

that hold the DNA in your cells were just shattered. They couldn't find chromosomal structures throughout his body that weren't just totally messed up. Yeah, we should mention there were three guys in the immediate area. He was the one closest to the tank. There was another guy a little less close to the tank, and then I guess the third guy, even less close the tank. Ouchi was taken to a local hospital at first, obviously, like, very quickly, and then transferred to the National Institute of Radiological Sciences in Chiba, but then eventually would end up at the University of Tokyo Hospital for some really extensive specialized treatment, specialized

meaning like they had no roadmap for this, so they were kind of trying anything. Exactly. they got in touch with his sister who was like, hey, he is not really able to produce new white blood cells, basically any fast-growing, fast-regenerating cell. It took the damage to the most. And that's where it showed up first because those are the cells that are dividing.

And now that their DNA is messed up, they're dividing in all sorts of terrible ways. So the things that made up like the lining to his gut, those fast-dividing cells, they started to show problems first. his skin, and then his bone marrow that produces white blood cells, red blood cells, all sorts of really important stuff. That was probably the biggest problem because he was very vulnerable to infection

without a bunch of white blood cells or not producing correct ones anymore. So they went to his sister and said, hey, can you donate some bone marrow? And she did. Yeah. So, you know, like I said, they were trying blood transfusions at first. stem cell transplants, and that's where his sister came into play. And initially, it showed like that transplant produced some new white blood cells, but very quickly they started getting damaged and, you know, basically in the same way.

He was just so riddled with it. And his skin and his intestinal lining couldn't regenerate normally. He had to constantly get fluids like replaced all throughout his body. He was on respiratory support, and like organ failure started to set in. Yeah. So the guy who was second closest when that radiation blast went off, his name was Masato Shinojara, and he died from his injuries in 2000, April 2000. But about four months before, on December 21, 1999, Hisachi Ouchi died at the University of Tokyo Hospital.

and it had been 83 days since he had undergone that blast of radiation. And so, of course, this made really big news around Japan and around the world. Like, this is nuts that anybody even lasted that long, let alone just the grisliness of the whole thing. So everybody was like, how did this happen at all? And they started looking at JCO. It turns out JCO was a terrible, terrible company that had no business doing something as important and dangerous as nuclear fuel production. Yeah, for sure.

That third worker survived, by the way, out of the three. But, yeah, JCO had allowed a lot of shortcuts to happen. Like you said, the instructions just for this were that wasn't the approved procedure. There was not a lot of regulatory approval going on. The workers didn't have safety training that they needed. The facility didn't have a critical incident alarm, which is, crazy. They just, I guess they thought that like there wouldn't be that kind of accident there. That's what happened to Three Mile Island, hubris. Yeah, that's right. That same thing.

They also weren't conducting the kind of inspections routinely that they needed to. And that might have turned up like, hey, this process that we're using is like really unsafe and we should be using the approved process. So I just want to point out, I think it's probably clear, but I just want to make 100% clear. These three workers were not taking their own shortcut. They were doing the procedure that their company was telling them to which was a dangerous shortcut. So the dangerous shortcut was official company procedure, right? Yeah. So as far as the official like blame or whatever, the International Atomic Energy Agency said it was human error combined with serious breaches of safety principles. For JCO's part, they, in 2003, six of the officials got suspended prison sentences for

professional negligence. The company was fined, and they had shut down the plant, didn't they? They did. They would think it was the first time ever that a company lost its license to enrich nuclear fuel in Japan. Yeah. And then also they were like, you know, these safety inspectors that didn't do the proper inspections that were to turn up that issue with the different procedure, they fell down too. So Japan really kind of bulked up its nuclear. stuff and now everything's great. Yeah, I mean, you know, it exposed like what could happen. And I think with every time we do something like this, like it's like they're very sad stories, but it seems like they come out on the other side with like, all right, now we're trying to do it right. Don't you

think? Yeah. I think because in this case, JCO, maybe wasn't powerful enough to try to fight having to change. So it did end up for the best. Yeah. Are you anything else? I got nothing else. say you give it to him. Short Stuff is out. Stuff you should know is a production of IHeartRadio. For more podcasts to My Heart Radio, visit the Iheart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.