1 00:00:02,560 --> 00:00:03,680 Speaker 1: Happy Saturday. 2 00:00:04,400 --> 00:00:07,160 Speaker 2: Coming up, we have an episode that has some parallels 3 00:00:07,200 --> 00:00:11,320 Speaker 2: to our previous episode on the Demon Core. Both of 4 00:00:11,360 --> 00:00:14,680 Speaker 2: these involved a nuclear incident, and both of them also 5 00:00:14,800 --> 00:00:18,000 Speaker 2: have discussions of the Cold War rush to develop nuclear 6 00:00:18,040 --> 00:00:22,439 Speaker 2: technologies that led to some dangerous shortcuts. This episode came 7 00:00:22,480 --> 00:00:29,240 Speaker 2: out on October twelfth, twenty twenty. Enjoy Welcome to Stuff 8 00:00:29,240 --> 00:00:35,560 Speaker 2: You Missed in History Class, a production of iHeartRadio. 9 00:00:38,960 --> 00:00:41,479 Speaker 1: Hello, and welcome to the podcast. I'm Tracy B. 10 00:00:41,600 --> 00:00:43,400 Speaker 2: Wilson, and I'm Holly Frye. 11 00:00:43,680 --> 00:00:45,280 Speaker 1: My friend Adrian, who. 12 00:00:45,159 --> 00:00:48,600 Speaker 2: Is a science educator, asked me years ago at this 13 00:00:48,720 --> 00:00:51,559 Speaker 2: point whether we had ever thought about doing an episode 14 00:00:51,560 --> 00:00:55,480 Speaker 2: on the Demon Core, which sounds terrifying, and I kept 15 00:00:55,520 --> 00:00:59,520 Speaker 2: thinking it might make a good October episode because nuclear 16 00:00:59,560 --> 00:01:04,840 Speaker 2: critical accidents can be terrifying, like they expose people to 17 00:01:05,240 --> 00:01:08,880 Speaker 2: possibly lethal doses of radiation and just a fraction of 18 00:01:08,920 --> 00:01:12,959 Speaker 2: a second, usually completely by surprise and before anybody can react, 19 00:01:12,959 --> 00:01:15,880 Speaker 2: and then that leads to just a horrifying and gruesome 20 00:01:15,920 --> 00:01:21,119 Speaker 2: and sometimes prolonged death. So then every October I kept 21 00:01:21,200 --> 00:01:23,480 Speaker 2: moving on in other directions and not getting to the 22 00:01:23,520 --> 00:01:24,080 Speaker 2: demon Core. 23 00:01:25,000 --> 00:01:25,880 Speaker 1: Here it finally is. 24 00:01:26,800 --> 00:01:31,600 Speaker 2: The Demon Core was a sphere of plutonium gallium alloy 25 00:01:31,800 --> 00:01:34,640 Speaker 2: that the United States made for an atomic bomb during 26 00:01:34,680 --> 00:01:38,200 Speaker 2: World War Two, and then after the war, researchers at 27 00:01:38,200 --> 00:01:43,160 Speaker 2: Los Alamos National Laboratory had two separate fatal criticality accidents 28 00:01:43,160 --> 00:01:46,680 Speaker 2: while working with it. Those accidents are also part of 29 00:01:46,720 --> 00:01:50,440 Speaker 2: a greater history of criticality accidents, most of which took 30 00:01:50,480 --> 00:01:52,600 Speaker 2: place in the nineteen fifties and sixties. So we're going 31 00:01:52,680 --> 00:01:57,520 Speaker 2: to talk about that progression today just to set some expectations. 32 00:01:58,080 --> 00:02:01,600 Speaker 2: Nuclear reactor melt down like the disasters at Three Mile 33 00:02:01,680 --> 00:02:05,000 Speaker 2: Island and Chernobyl and Fukushima, those are a slightly different 34 00:02:05,040 --> 00:02:08,440 Speaker 2: thing from what we're talking about today. Some of them 35 00:02:08,600 --> 00:02:11,880 Speaker 2: could technically be classified as criticality accidents, but they're also 36 00:02:12,000 --> 00:02:14,360 Speaker 2: just a little bit bigger than the topics that were 37 00:02:14,400 --> 00:02:17,400 Speaker 2: focused on. So to make sense of how these incidents 38 00:02:17,400 --> 00:02:19,440 Speaker 2: play out, we need to walk through a little bit 39 00:02:19,440 --> 00:02:23,760 Speaker 2: of science history. In nineteen thirty two, James Chadwick discovered 40 00:02:23,760 --> 00:02:27,720 Speaker 2: the uncharged sub atomic particle known as the neutron, and 41 00:02:27,800 --> 00:02:32,160 Speaker 2: soon physicists were using neutrons to study atoms, including bombarding 42 00:02:32,240 --> 00:02:36,320 Speaker 2: atomic nuclei with neutrons to study the results. It was 43 00:02:36,400 --> 00:02:40,239 Speaker 2: through this work that ottohon Lee's Meiitner and Fritz Strassmann 44 00:02:40,360 --> 00:02:44,600 Speaker 2: discovered nuclear fission in nineteen thirty eight. Hahn had been 45 00:02:44,600 --> 00:02:48,120 Speaker 2: working with uranium samples that had been bombarded with neutrons, 46 00:02:48,160 --> 00:02:52,520 Speaker 2: and for reasons that he couldn't really explain, barium isotopes 47 00:02:52,600 --> 00:02:56,680 Speaker 2: started appearing in his samples as well. Meiitner and Strasman 48 00:02:56,880 --> 00:03:00,000 Speaker 2: made the connection that barium has about half the time 49 00:03:00,320 --> 00:03:03,880 Speaker 2: mass of uranium, so the uranium atoms were splitting into 50 00:03:03,919 --> 00:03:07,880 Speaker 2: two roughly equal parts. The idea that an atom could 51 00:03:07,919 --> 00:03:10,880 Speaker 2: split in this way had been suggested before, but it 52 00:03:11,000 --> 00:03:13,640 Speaker 2: was not really taken seriously at the time because it 53 00:03:13,680 --> 00:03:18,560 Speaker 2: seemed absolutely contrary to how people understood nuclear physics at 54 00:03:18,560 --> 00:03:22,760 Speaker 2: that point. This breakdown of uranium into barium didn't answer 55 00:03:22,800 --> 00:03:26,480 Speaker 2: all the questions, though Meitner also calculated that the two 56 00:03:26,680 --> 00:03:29,800 Speaker 2: new barium nuclei would be slightly less massive than the 57 00:03:29,840 --> 00:03:34,760 Speaker 2: original uranium nucleus, with the difference converted into energy. Atto 58 00:03:34,840 --> 00:03:37,520 Speaker 2: Haan was awarded the Nobel Prize in Chemistry for the 59 00:03:37,560 --> 00:03:41,880 Speaker 2: discovery of nuclear fission in nineteen forty four. Although Meiitner 60 00:03:41,920 --> 00:03:44,560 Speaker 2: and Strassman were mentioned in the speech, they were not 61 00:03:44,640 --> 00:03:49,640 Speaker 2: included in that award. Nuclear fission can happen spontaneously in 62 00:03:49,760 --> 00:03:52,680 Speaker 2: the natural world, and the details can play out a 63 00:03:52,680 --> 00:03:56,000 Speaker 2: little bit differently in different elements and isotopes, but in 64 00:03:56,120 --> 00:03:58,800 Speaker 2: terms of what we're talking about today, it typically starts 65 00:03:58,800 --> 00:04:02,720 Speaker 2: with neutrons. Neutrons interact with the atom's nucleus, causing it 66 00:04:02,720 --> 00:04:07,160 Speaker 2: to split. That split releases one or more other neutrons, 67 00:04:07,200 --> 00:04:10,040 Speaker 2: and in the right conditions, those neutrons can reach the 68 00:04:10,120 --> 00:04:14,240 Speaker 2: nuclei of other nearby atoms, causing them to split. That 69 00:04:14,320 --> 00:04:17,840 Speaker 2: can continue on in a chain reaction. If there's enough 70 00:04:17,880 --> 00:04:22,000 Speaker 2: material in one place to support a regular, ongoing, self 71 00:04:22,000 --> 00:04:26,120 Speaker 2: sustaining chain reaction, that's known as critical mass. In a 72 00:04:26,279 --> 00:04:30,599 Speaker 2: supercritical mass, this chain reaction unfolds at an escalating rate 73 00:04:30,680 --> 00:04:34,000 Speaker 2: instead of a steady one. It's not just about how 74 00:04:34,080 --> 00:04:37,839 Speaker 2: much physical material is in one place, though. The volume 75 00:04:37,880 --> 00:04:42,240 Speaker 2: of the material, it's geometry, its concentration, its surroundings, and 76 00:04:42,320 --> 00:04:46,080 Speaker 2: other factors all play a part. As a hypothetical example, 77 00:04:46,200 --> 00:04:49,080 Speaker 2: if you have a very thin sheet of uranium two 78 00:04:49,120 --> 00:04:51,880 Speaker 2: thirty five, a lot of the neutrons that are released 79 00:04:51,960 --> 00:04:54,520 Speaker 2: during fission are going to fly off into the surrounding 80 00:04:54,560 --> 00:04:58,320 Speaker 2: air without hitting any uranium atoms. But if you have 81 00:04:58,360 --> 00:05:01,559 Speaker 2: the same amount of uranium two thirty five packed into 82 00:05:01,600 --> 00:05:05,159 Speaker 2: a tight sphere, the neutrons from the interior are far 83 00:05:05,200 --> 00:05:08,400 Speaker 2: more likely to interact with other nuclei as they travel, 84 00:05:08,720 --> 00:05:12,599 Speaker 2: potentially starting a chain reaction. So the elements that break 85 00:05:12,640 --> 00:05:16,080 Speaker 2: down and these interactions are radioactive, and the products of 86 00:05:16,160 --> 00:05:21,280 Speaker 2: fission are generally radioactive as well. The energy that's released 87 00:05:21,480 --> 00:05:24,200 Speaker 2: during nuclear fission, which there can be a lot of, 88 00:05:24,720 --> 00:05:29,359 Speaker 2: also includes ionizing radiation, and while ionizing radiation has some 89 00:05:29,440 --> 00:05:34,400 Speaker 2: beneficial uses, it can also be incredibly destructive to living cells. 90 00:05:35,000 --> 00:05:39,520 Speaker 2: Criticality accidents can expose people and objects to just enormous 91 00:05:39,560 --> 00:05:43,120 Speaker 2: amounts of radiation in an instant, so facilities that handle 92 00:05:43,160 --> 00:05:46,400 Speaker 2: these types of materials have to take a lot of 93 00:05:46,480 --> 00:05:50,160 Speaker 2: precautions to protect people from radiation and to prevent an 94 00:05:50,200 --> 00:05:54,280 Speaker 2: accidental criticality, which is sometimes also called a power excursion. 95 00:05:54,880 --> 00:05:57,960 Speaker 2: This includes restrictions on how much material can be in 96 00:05:58,000 --> 00:06:02,040 Speaker 2: a particular place and how its to be handled. Containers 97 00:06:02,080 --> 00:06:04,080 Speaker 2: to hold the material have to be shaped in a 98 00:06:04,080 --> 00:06:07,960 Speaker 2: way that is unfavorable for criticality and made of materials 99 00:06:07,960 --> 00:06:11,160 Speaker 2: that won't reflect too many sub atomic particles. Back into 100 00:06:11,200 --> 00:06:14,800 Speaker 2: the material, and people handling the material have to be 101 00:06:14,880 --> 00:06:19,120 Speaker 2: trained on how to prevent criticality accidents. Some of this 102 00:06:19,320 --> 00:06:24,320 Speaker 2: can be a little counterintuitive to outside observers. For example, 103 00:06:24,400 --> 00:06:28,040 Speaker 2: if you saw some plutonium rods placed near each other 104 00:06:28,240 --> 00:06:31,160 Speaker 2: in a way that could potentially lead to a criticality, 105 00:06:31,279 --> 00:06:35,120 Speaker 2: your first instinct might be to move them apart so 106 00:06:35,160 --> 00:06:37,440 Speaker 2: that they would not do that. But a person's own 107 00:06:37,600 --> 00:06:41,120 Speaker 2: body can also reflect neutrons back at the material, so 108 00:06:41,200 --> 00:06:44,440 Speaker 2: that very act of trying to prevent a criticality accident 109 00:06:44,520 --> 00:06:48,480 Speaker 2: could actually wind up causing one instead. This is a 110 00:06:48,480 --> 00:06:52,000 Speaker 2: real example. It happened at Los Alamos National Laboratory in 111 00:06:52,120 --> 00:06:55,279 Speaker 2: August of twenty eleven after somebody made an arrangement of 112 00:06:55,320 --> 00:07:00,080 Speaker 2: plutonium rods for a photo op. Fortunately, while what what 113 00:07:00,279 --> 00:07:03,719 Speaker 2: happened was outside the bounds of safety guidelines, it did 114 00:07:03,760 --> 00:07:08,719 Speaker 2: not cause a criticality accident. Because nuclear fission releases energy, 115 00:07:08,839 --> 00:07:12,920 Speaker 2: its discovery had immediate and obvious implications for both energy 116 00:07:12,960 --> 00:07:17,160 Speaker 2: production and warfare, and multiple nations started trying to develop 117 00:07:17,280 --> 00:07:21,040 Speaker 2: nuclear reactors and atomic bombs. In the United States, the 118 00:07:21,080 --> 00:07:23,440 Speaker 2: effort to develop an atomic bomb was code named the 119 00:07:23,480 --> 00:07:27,920 Speaker 2: Manhattan Project, which also involved the construction of nuclear reactors 120 00:07:27,960 --> 00:07:32,160 Speaker 2: to produce the necessary radioactive materials for the bomb. For 121 00:07:32,200 --> 00:07:36,239 Speaker 2: the most part, the reactors converted naturally occurring uranium into 122 00:07:36,440 --> 00:07:40,880 Speaker 2: uranium and plutonium fuel. Most of the natural uranium that 123 00:07:41,040 --> 00:07:43,960 Speaker 2: was used in American projects during World War II was 124 00:07:44,040 --> 00:07:46,960 Speaker 2: mined in what was then the Belgian Congo, and then 125 00:07:47,000 --> 00:07:50,080 Speaker 2: after the war that source shifted to the Navajo Nation 126 00:07:50,400 --> 00:07:55,680 Speaker 2: and surrounding areas. The environmental, human rights, and health consequences 127 00:07:55,720 --> 00:07:59,240 Speaker 2: of these uranium mining operations, some of which are extreme, 128 00:07:59,280 --> 00:08:02,559 Speaker 2: are still on going today. For example, there are still 129 00:08:02,760 --> 00:08:07,200 Speaker 2: hundreds of abandoned uranium mines on or near the lands 130 00:08:07,200 --> 00:08:11,000 Speaker 2: of multiple indigenous nations in the US, and even though 131 00:08:11,000 --> 00:08:14,520 Speaker 2: the EPA has entered into settlements totaling one point seven 132 00:08:14,680 --> 00:08:19,480 Speaker 2: billion dollars, those settlements covered cleanup for fewer than half 133 00:08:19,600 --> 00:08:22,800 Speaker 2: of these mines, and almost none of them have actually 134 00:08:22,880 --> 00:08:26,520 Speaker 2: been addressed at this point. Although nuclear research took place 135 00:08:26,560 --> 00:08:30,440 Speaker 2: at multiple facilities around the country, the primary lamb for 136 00:08:30,480 --> 00:08:33,520 Speaker 2: atomic bomb development in the US was in Los Alamos, 137 00:08:33,559 --> 00:08:38,199 Speaker 2: New Mexico. Simultaneously, researchers had to figure out the technology 138 00:08:38,280 --> 00:08:41,040 Speaker 2: for the bomb, produced the nuclear material to power it, 139 00:08:41,480 --> 00:08:44,520 Speaker 2: and figure out how to handle that material safely without 140 00:08:44,640 --> 00:08:48,880 Speaker 2: accidentally allowing it to go critical or supercritical, all while 141 00:08:48,920 --> 00:08:52,040 Speaker 2: trying to create a weapon that was supposed to go supercritical. 142 00:08:52,679 --> 00:08:55,240 Speaker 2: One of the bombs that was created through the Manhattan 143 00:08:55,280 --> 00:08:58,079 Speaker 2: Project was known as Little Boy. Then it was detonated 144 00:08:58,080 --> 00:09:02,320 Speaker 2: over Hiroshima, Japan, on August six, nineteen forty five. This 145 00:09:02,400 --> 00:09:06,800 Speaker 2: bomb contained a subcritical mass of enriched uranium along with 146 00:09:06,880 --> 00:09:12,559 Speaker 2: a subcritical uranium projectile. A gun fired the projectile into 147 00:09:12,559 --> 00:09:16,360 Speaker 2: the mass, and together the mass and the projectile were supercritical. 148 00:09:17,200 --> 00:09:22,040 Speaker 2: This bomb was equivalent to about fifteen thousand tons of TNT. 149 00:09:22,360 --> 00:09:26,120 Speaker 2: It killed an estimated one hundred and fifty thousand people 150 00:09:26,360 --> 00:09:29,800 Speaker 2: and leveled much of the city. The Manhattan Project also 151 00:09:29,840 --> 00:09:33,600 Speaker 2: produced three plutonium cores to be used in implosion style 152 00:09:33,640 --> 00:09:37,480 Speaker 2: bombs during World War II. In this setup, the plutonium 153 00:09:37,520 --> 00:09:42,400 Speaker 2: core is surrounded by conventional explosives. When those explosives detonate, 154 00:09:42,559 --> 00:09:45,640 Speaker 2: they compress the core, causing it to go from subcritical 155 00:09:45,720 --> 00:09:49,760 Speaker 2: to supercritical. One of these cores was detonated at a 156 00:09:49,800 --> 00:09:53,160 Speaker 2: test at the Alamogordo Bombing and Gunnery Range also called 157 00:09:53,160 --> 00:09:57,840 Speaker 2: the Trinity Site, on July sixteenth, nineteen forty five. Another 158 00:09:58,040 --> 00:10:00,240 Speaker 2: was used in the bomb known as Fat Man, which 159 00:10:00,280 --> 00:10:04,480 Speaker 2: was detonated over Nagasaki, Japan, on August ninth, nineteen forty five, 160 00:10:04,880 --> 00:10:09,360 Speaker 2: killing an estimated seventy five thousand people. The third plutonium 161 00:10:09,440 --> 00:10:13,720 Speaker 2: core was nearing completion when Japan announced its surrender on 162 00:10:13,760 --> 00:10:16,800 Speaker 2: August fifteenth, nineteen forty five, meaning that it was no 163 00:10:16,880 --> 00:10:21,320 Speaker 2: longer needed for World War two. Later, the US started 164 00:10:21,320 --> 00:10:25,600 Speaker 2: planning Operation Crossroads, which was a test of nuclear weapons 165 00:10:25,640 --> 00:10:30,079 Speaker 2: effects on warships at seed to take place off Bikini Atoll. 166 00:10:30,200 --> 00:10:32,360 Speaker 1: This third core, the one. 167 00:10:32,160 --> 00:10:34,679 Speaker 2: That would later be nicknamed the Demon Corps, was slated 168 00:10:34,720 --> 00:10:38,080 Speaker 2: for use in these tests, but in the meantime it 169 00:10:38,080 --> 00:10:41,560 Speaker 2: was used for criticality research. It was during that research 170 00:10:41,760 --> 00:10:44,840 Speaker 2: that they nicknamed it the Demon cor even though to 171 00:10:44,880 --> 00:10:49,800 Speaker 2: be clear, did not kill nearly as many people as 172 00:10:49,920 --> 00:10:53,760 Speaker 2: the other two that were detonated over cities. And we're 173 00:10:53,800 --> 00:10:55,800 Speaker 2: going to talk more about the Demon Corps after we 174 00:10:55,880 --> 00:11:08,760 Speaker 2: first pause for a sponsor break. The plutonium core that 175 00:11:08,880 --> 00:11:14,040 Speaker 2: was eventually nicknamed the Demon Core was originally nicknamed Rufus. 176 00:11:14,440 --> 00:11:17,520 Speaker 2: I don't know why, but so many sources have said 177 00:11:17,559 --> 00:11:22,840 Speaker 2: that that seems legitimate. It was a six point two 178 00:11:23,040 --> 00:11:28,160 Speaker 2: kilogram or thirteen point seven pound sphere really two hemispheres 179 00:11:28,600 --> 00:11:33,240 Speaker 2: made of refined plutonium and gallium. Under normal conditions, it 180 00:11:33,280 --> 00:11:36,200 Speaker 2: was ninety five percent of a critical mass, so it's 181 00:11:36,240 --> 00:11:39,559 Speaker 2: often described as having a hair trigger, although it had 182 00:11:39,600 --> 00:11:42,319 Speaker 2: been created for use in a bomb. This hair trigger 183 00:11:42,400 --> 00:11:47,199 Speaker 2: also made the core useful for criticality experiments. Physicists could 184 00:11:47,320 --> 00:11:50,800 Speaker 2: intentionally reflect neutrons back at the core to push it 185 00:11:50,920 --> 00:11:54,600 Speaker 2: close to criticality and gather data about what was happening. 186 00:11:55,320 --> 00:11:58,920 Speaker 2: Physicist Richard Feynman, who's work with the Manhattan Project included 187 00:11:58,920 --> 00:12:03,200 Speaker 2: helping to work out stand to prevent criticality accidents, reportedly 188 00:12:03,320 --> 00:12:08,360 Speaker 2: nicknamed these types of experiments tickling the Dragon's Tail. On 189 00:12:08,480 --> 00:12:12,200 Speaker 2: August twenty first, nineteen forty five, twenty four year old 190 00:12:12,240 --> 00:12:16,440 Speaker 2: graduate student Harry Dallion Junior was working by himself in 191 00:12:16,520 --> 00:12:18,880 Speaker 2: the lab. Because of the nature of the work that 192 00:12:19,000 --> 00:12:21,360 Speaker 2: was being done at Los Alamos, like it was critical 193 00:12:21,400 --> 00:12:23,840 Speaker 2: to the war effort, it involved part of the nation's 194 00:12:23,880 --> 00:12:28,120 Speaker 2: nuclear material stockpile, it was standard for security guards to 195 00:12:28,200 --> 00:12:31,640 Speaker 2: always be present, so even though Dallian was working alone 196 00:12:31,640 --> 00:12:34,320 Speaker 2: on this experiment, there was one other person in the 197 00:12:34,400 --> 00:12:37,920 Speaker 2: room that was twenty nine year old Private Robert Hemerley, 198 00:12:38,000 --> 00:12:40,720 Speaker 2: who was sitting at a table about twelve feet away 199 00:12:40,720 --> 00:12:44,640 Speaker 2: from the core. Dallian was using tungsten carbid bricks to 200 00:12:44,679 --> 00:12:48,199 Speaker 2: build a reflective wall around the plutonium core by hand. 201 00:12:49,040 --> 00:12:52,200 Speaker 2: The bricks reflected neutrons back at the core, inching it 202 00:12:52,280 --> 00:12:55,880 Speaker 2: closer to criticality. The more bricks he added, the more 203 00:12:55,920 --> 00:12:58,920 Speaker 2: neutrons were reflected, and the closer the core got to 204 00:12:58,960 --> 00:13:02,600 Speaker 2: going critical. As Dallian was about to add the last 205 00:13:02,720 --> 00:13:06,880 Speaker 2: brick in this structure, his instruments showed that doing so 206 00:13:07,360 --> 00:13:09,760 Speaker 2: was going to cause the core to go critical, so 207 00:13:10,320 --> 00:13:13,520 Speaker 2: he tried to pull that last brick away, but as 208 00:13:13,559 --> 00:13:16,520 Speaker 2: he did, it slipped out of his hand and dropped 209 00:13:16,679 --> 00:13:20,480 Speaker 2: directly onto the core. Dallian used his other hand to 210 00:13:20,600 --> 00:13:23,120 Speaker 2: knock the dropped brick away, but it was too late. 211 00:13:23,679 --> 00:13:25,959 Speaker 2: There was a wave of heat and a brief flash 212 00:13:26,000 --> 00:13:28,720 Speaker 2: of blue light all around the exterior of the sphere. 213 00:13:29,360 --> 00:13:32,440 Speaker 2: That light was probably Chirinkov radiation, which is the result 214 00:13:32,440 --> 00:13:35,280 Speaker 2: of charged particles moving faster than the speed of light 215 00:13:35,640 --> 00:13:40,520 Speaker 2: through a transparent medium like air. In that brief moment 216 00:13:40,840 --> 00:13:43,800 Speaker 2: between when he dropped the brick and when he knocked 217 00:13:43,800 --> 00:13:47,480 Speaker 2: it away, Dallian was hit with a blast of neutron radiation. 218 00:13:48,200 --> 00:13:51,480 Speaker 2: He disassembled the reflector that he had built, and that 219 00:13:51,679 --> 00:13:55,320 Speaker 2: continued to expose him to gamma radiation while he was 220 00:13:55,360 --> 00:13:59,760 Speaker 2: doing so. Today, absorbed radiation is measured in gray, with 221 00:14:00,000 --> 00:14:03,720 Speaker 2: its one gray being equivalent to one hundred rads. A 222 00:14:03,760 --> 00:14:07,080 Speaker 2: sudden whole body dose of zero point seven gray is 223 00:14:07,200 --> 00:14:11,679 Speaker 2: enough to cause acute radiation sickness. Sometimes symptoms can develop 224 00:14:11,800 --> 00:14:15,800 Speaker 2: at as little as zero point three gray. Dallian's dose 225 00:14:15,920 --> 00:14:20,000 Speaker 2: was estimated at five point one gray. He died twenty 226 00:14:20,000 --> 00:14:23,880 Speaker 2: five days after the accident on September fifteenth, nineteen forty five. 227 00:14:24,760 --> 00:14:28,480 Speaker 2: Private Hammerley's dose was estimated at zero point five gray. 228 00:14:29,160 --> 00:14:33,360 Speaker 2: He survived this incident apparently without serious injury at the time. 229 00:14:33,440 --> 00:14:36,880 Speaker 2: If you read older articles that were published before his 230 00:14:37,080 --> 00:14:40,560 Speaker 2: death later on like they'll say that he wasn't seriously harmed, 231 00:14:41,080 --> 00:14:43,640 Speaker 2: but he wound up dying of leukemia, which might have 232 00:14:43,680 --> 00:14:48,440 Speaker 2: been related to this radiation exposure, when he was sixty two. Afterward, 233 00:14:48,600 --> 00:14:53,239 Speaker 2: criticality experiments continued at Los Alamos in spite of this fatality. 234 00:14:53,320 --> 00:14:57,080 Speaker 2: Although some new safety standards were put into play, the 235 00:14:57,200 --> 00:15:00,120 Speaker 2: list of people allowed to do these kinds of experiments 236 00:15:00,200 --> 00:15:03,640 Speaker 2: was shortened, with two sets of monitoring equipment required for 237 00:15:03,720 --> 00:15:08,000 Speaker 2: each experiment. The new standards reiterated that at least two 238 00:15:08,120 --> 00:15:11,120 Speaker 2: people in addition to the guard, had to be present 239 00:15:11,160 --> 00:15:14,880 Speaker 2: for this kind of work. Researchers also started discussing whether 240 00:15:14,920 --> 00:15:17,840 Speaker 2: it would be better to do these kinds of experiments remotely, 241 00:15:18,240 --> 00:15:20,640 Speaker 2: so that if a criticality did happen, it would be 242 00:15:20,680 --> 00:15:24,680 Speaker 2: too far away from people to hurt them. Operation Crossroads 243 00:15:24,760 --> 00:15:27,640 Speaker 2: was scheduled to start in July of nineteen forty six, 244 00:15:28,280 --> 00:15:31,040 Speaker 2: but before the core was sent to the Marshall Islands 245 00:15:31,040 --> 00:15:34,960 Speaker 2: to be used there, physicists were doing one last set 246 00:15:35,000 --> 00:15:38,920 Speaker 2: of criticality experiments with it. On May twenty first, nineteen 247 00:15:39,000 --> 00:15:43,280 Speaker 2: forty six, Canadian physicist Lewis Slowten was using a hollow 248 00:15:43,360 --> 00:15:47,240 Speaker 2: beryllium sphere to mostly cover up the core and reflect 249 00:15:47,360 --> 00:15:51,680 Speaker 2: neutrons back into it. The sphere had two halves, The 250 00:15:51,720 --> 00:15:54,480 Speaker 2: core was sort of resting in the bottom half, and 251 00:15:54,520 --> 00:15:57,360 Speaker 2: he had his thumb threaded through a hole in the 252 00:15:57,400 --> 00:16:00,200 Speaker 2: top half so that he could adjust the positioning this 253 00:16:00,280 --> 00:16:03,640 Speaker 2: sort of dome with his hand. He knew that if 254 00:16:03,640 --> 00:16:07,720 Speaker 2: the sphere closed completely it could cause a criticality, so 255 00:16:07,760 --> 00:16:11,200 Speaker 2: he used the end of a screwdriver to keep the 256 00:16:11,240 --> 00:16:13,200 Speaker 2: two halves slightly separate. 257 00:16:13,680 --> 00:16:14,400 Speaker 1: This sounds like the. 258 00:16:14,400 --> 00:16:16,240 Speaker 2: Kind of thing I would do at my house with 259 00:16:16,280 --> 00:16:18,680 Speaker 2: something that is not dangerous, And even so my husband 260 00:16:18,720 --> 00:16:20,360 Speaker 2: would go, are you sure that's how you want to 261 00:16:20,400 --> 00:16:20,640 Speaker 2: do it? 262 00:16:21,080 --> 00:16:21,320 Speaker 1: Yes? 263 00:16:21,640 --> 00:16:26,160 Speaker 2: Yes, I have a story on this subject about myself 264 00:16:26,280 --> 00:16:28,600 Speaker 2: that I will probably tell in our Friday behind the 265 00:16:28,640 --> 00:16:31,080 Speaker 2: scenes fabulous. 266 00:16:30,720 --> 00:16:32,120 Speaker 1: While I have. 267 00:16:33,560 --> 00:16:36,000 Speaker 2: Some understanding of how a person might do a really 268 00:16:36,040 --> 00:16:39,280 Speaker 2: foolish thing, knowing how foolish it is, I was not 269 00:16:39,560 --> 00:16:47,400 Speaker 2: handling potentially critical nuclear weapons cores at the time. As 270 00:16:47,480 --> 00:16:51,360 Speaker 2: he was doing this, the screwdriver slipped and the dome 271 00:16:51,680 --> 00:16:55,000 Speaker 2: totally closed. There was a brief flash of blue light 272 00:16:55,080 --> 00:16:57,800 Speaker 2: that was visible over the normal illumination of the room. 273 00:16:58,360 --> 00:17:01,000 Speaker 2: This lasted only a moment as and flipped the dome 274 00:17:01,120 --> 00:17:05,480 Speaker 2: off of the core. Slowden seems to have immediately understood 275 00:17:05,520 --> 00:17:09,159 Speaker 2: that he was not going to survive this accident, saying, well, 276 00:17:09,640 --> 00:17:14,280 Speaker 2: that does it. In general, a whole body radiation dose 277 00:17:14,320 --> 00:17:18,080 Speaker 2: of more than ten gray is inevitably fatal, and his 278 00:17:18,280 --> 00:17:22,560 Speaker 2: has been estimated at twenty one gray. At the same time, 279 00:17:22,680 --> 00:17:25,200 Speaker 2: he had the presence of mind to try to document 280 00:17:25,240 --> 00:17:28,400 Speaker 2: where the other seven observers in the room had been 281 00:17:28,480 --> 00:17:31,000 Speaker 2: standing at the time, and then to try to calculate 282 00:17:31,080 --> 00:17:34,520 Speaker 2: how large of a dose of radiation each of them received. 283 00:17:35,280 --> 00:17:38,840 Speaker 2: Their doses have been estimated as ranging between zero point 284 00:17:38,920 --> 00:17:43,160 Speaker 2: three seven and three point six gray. Slowden also tried 285 00:17:43,160 --> 00:17:46,879 Speaker 2: to detect how much radiation was present in other objects 286 00:17:46,920 --> 00:17:49,840 Speaker 2: that were in the room, but the detectors themselves had 287 00:17:49,880 --> 00:17:53,320 Speaker 2: been contaminated in the accident. At the same time, he 288 00:17:53,560 --> 00:17:57,520 Speaker 2: wasn't thinking entirely clearly. He asked a colleague to scatter 289 00:17:57,640 --> 00:18:01,760 Speaker 2: film badges used to detect radiation exposure around the area, 290 00:18:02,040 --> 00:18:04,359 Speaker 2: and that required the colleague to get close to the 291 00:18:04,440 --> 00:18:08,680 Speaker 2: radioactive corps to do so. Slotin died nine days after 292 00:18:08,720 --> 00:18:11,760 Speaker 2: this accident at the age of thirty five, and although 293 00:18:11,760 --> 00:18:14,359 Speaker 2: he was the only person killed, three other people in 294 00:18:14,400 --> 00:18:18,600 Speaker 2: the room had to be hospitalized for acute radiation exposure. 295 00:18:18,440 --> 00:18:20,040 Speaker 1: And one of them was Alvin C. 296 00:18:20,359 --> 00:18:23,639 Speaker 2: Graves, who was the closest to Slowtin physically. When this 297 00:18:23,760 --> 00:18:28,520 Speaker 2: accident happened, Slowtin had actually been training Graves as his replacement. 298 00:18:29,280 --> 00:18:32,080 Speaker 2: Graves was seriously injured and for a time it was 299 00:18:32,160 --> 00:18:34,760 Speaker 2: not certain whether he was going to survive. He later 300 00:18:34,840 --> 00:18:38,600 Speaker 2: developed cataracts and thyroid issues, and his death from a 301 00:18:38,600 --> 00:18:41,840 Speaker 2: heart attack nineteen years later may also have been related. 302 00:18:42,400 --> 00:18:46,520 Speaker 2: In general, people have viewed Harry Dallion Junior's accident with 303 00:18:46,560 --> 00:18:50,680 Speaker 2: a bit more sympathy than Lewis Slotin's. Dallian was working alone, 304 00:18:50,680 --> 00:18:54,159 Speaker 2: which was against protocol, but he was also a graduate student, 305 00:18:54,280 --> 00:18:58,440 Speaker 2: so he was not as experienced as many of his colleagues. Slowtin, 306 00:18:58,520 --> 00:19:00,920 Speaker 2: on the other hand, was not only as senior scientist, 307 00:19:01,080 --> 00:19:03,760 Speaker 2: but had also co authored the official report on the 308 00:19:03,880 --> 00:19:07,960 Speaker 2: accident that had killed Harry Dallion, so he definitely understood 309 00:19:08,000 --> 00:19:11,879 Speaker 2: the risks and the potential for accident. His experiment was 310 00:19:11,960 --> 00:19:14,959 Speaker 2: meant to be done with two one inch spacers between 311 00:19:15,000 --> 00:19:18,400 Speaker 2: the two halves of the beryllium sphere, but Slotin had 312 00:19:18,440 --> 00:19:21,639 Speaker 2: removed these and was using the screwdriver in their place. 313 00:19:22,640 --> 00:19:26,280 Speaker 2: Multiple other scientists who were aware of the criticality experiment 314 00:19:26,359 --> 00:19:29,840 Speaker 2: he was doing thought it was inordinately dangerous, and in 315 00:19:29,920 --> 00:19:32,960 Speaker 2: general he had a reputation for being a little too 316 00:19:33,040 --> 00:19:38,119 Speaker 2: cavalier around things like atomic bomb cores. Scientists nicknamed this 317 00:19:38,240 --> 00:19:41,199 Speaker 2: corps the demon Corps, not just because it had been 318 00:19:41,280 --> 00:19:44,439 Speaker 2: part of both of these fatal accidents, but also because 319 00:19:44,480 --> 00:19:48,480 Speaker 2: of some eerie similarities between them. Both accidents took place 320 00:19:48,560 --> 00:19:50,919 Speaker 2: on the twenty first of the month and on a Tuesday, 321 00:19:51,440 --> 00:19:54,280 Speaker 2: and Slotin and Dallion both died in the same hospital 322 00:19:54,359 --> 00:19:58,040 Speaker 2: room at the US Engineer's Hospital at Los Alamos. By 323 00:19:58,040 --> 00:20:02,720 Speaker 2: this point, work had started on remote facility for criticality experiments, 324 00:20:02,760 --> 00:20:06,159 Speaker 2: and after the second accident with the demon Core, hands 325 00:20:06,160 --> 00:20:10,720 Speaker 2: on criticality experiments like this were banned. In nineteen forty seven, 326 00:20:10,840 --> 00:20:15,560 Speaker 2: criticality experiments resumed at the newly completed critical Experiments facility 327 00:20:15,640 --> 00:20:19,680 Speaker 2: at what was known as the Paharito Site. Criticality experiments 328 00:20:19,720 --> 00:20:22,600 Speaker 2: there were handled with machinery and took place a quarter 329 00:20:22,680 --> 00:20:25,040 Speaker 2: mile from the control room where the people doing the 330 00:20:25,080 --> 00:20:29,439 Speaker 2: experiments were. Since the amount of radiation drops dramatically the 331 00:20:29,560 --> 00:20:32,280 Speaker 2: farther you are away from the source, this was much 332 00:20:32,320 --> 00:20:36,399 Speaker 2: safer than doing something like stacking reflective blocks with your hands. 333 00:20:36,840 --> 00:20:39,840 Speaker 2: Dallian and Slotan were the only two people to die 334 00:20:39,920 --> 00:20:45,080 Speaker 2: from acute radiation exposure at Los Alamos during the Manhattan Project. 335 00:20:45,400 --> 00:20:48,359 Speaker 2: Although there were numerous other deaths in and around the 336 00:20:48,400 --> 00:20:51,480 Speaker 2: facility during those same years, a lot of them were 337 00:20:51,480 --> 00:20:55,240 Speaker 2: from accidents that had nothing to do with radioactive materials 338 00:20:55,320 --> 00:21:00,040 Speaker 2: or bombs. This included motor vehicle accidents, construction accidents, and 339 00:21:00,119 --> 00:21:03,040 Speaker 2: in one case, a ten year old who drowned when 340 00:21:03,040 --> 00:21:07,720 Speaker 2: a canoe capsized. In nineteen forty six, three custodians also 341 00:21:07,880 --> 00:21:11,439 Speaker 2: died of ethylene glycol poisoning after drinking wine that was 342 00:21:11,480 --> 00:21:14,960 Speaker 2: mixed with antifreeze. In terms of the demon Core, for 343 00:21:15,200 --> 00:21:17,760 Speaker 2: years after this incident happened, it was believed that it 344 00:21:17,800 --> 00:21:20,560 Speaker 2: was sent on to Bikini Atoll for use in Operation 345 00:21:20,680 --> 00:21:24,720 Speaker 2: Crossroads as planned, and while it was described as quote 346 00:21:24,760 --> 00:21:27,520 Speaker 2: a little hot but not too hot to handle, after 347 00:21:27,560 --> 00:21:30,960 Speaker 2: that second accident, it was saved for the last detonation, 348 00:21:31,359 --> 00:21:34,080 Speaker 2: just in case that was going to affect the results. 349 00:21:34,560 --> 00:21:37,480 Speaker 2: That last test wound up being canceled, and the demon 350 00:21:37,560 --> 00:21:41,040 Speaker 2: Cor was later melted down and reintegrated into the nuclear 351 00:21:41,080 --> 00:21:45,320 Speaker 2: material stockpile. At some point it was probably incorporated into 352 00:21:45,400 --> 00:21:48,879 Speaker 2: other weapons. Before we move on, we should note that 353 00:21:48,880 --> 00:21:52,880 Speaker 2: there have been ongoing issues with safety at Los Alamos 354 00:21:53,000 --> 00:21:56,840 Speaker 2: National Laboratory in more recent years. Aside from that twenty 355 00:21:56,840 --> 00:22:01,560 Speaker 2: eleven plutonium photo op that we mentioned earlier. In twenty seventeen, 356 00:22:01,640 --> 00:22:05,360 Speaker 2: it was rated does not meet expectations in the Department 357 00:22:05,359 --> 00:22:10,159 Speaker 2: of Energy Nuclear Criticality Safety Programs annual report that was 358 00:22:10,240 --> 00:22:14,360 Speaker 2: raised up to adequate but needs improvement in twenty eighteen 359 00:22:14,440 --> 00:22:18,280 Speaker 2: and twenty nineteen. Also, that second accident with the demon 360 00:22:18,359 --> 00:22:21,639 Speaker 2: core is dramatized in the nineteen eighty nine film Fat 361 00:22:21,680 --> 00:22:24,960 Speaker 2: Man and Little Boy, with John Cusack as a fictionalized 362 00:22:25,000 --> 00:22:28,480 Speaker 2: SLOTIN who is named Michael Merriman in the film. Yeah, 363 00:22:28,480 --> 00:22:31,199 Speaker 2: I watched just that scene while I was working on this, 364 00:22:31,280 --> 00:22:34,000 Speaker 2: and even knowing literally what's going to happen, I found 365 00:22:34,040 --> 00:22:40,159 Speaker 2: it very tense. Yeah, so we're gonna take a quick break. 366 00:22:48,600 --> 00:22:51,800 Speaker 2: The two incidents that we already talked about happened during 367 00:22:52,000 --> 00:22:56,720 Speaker 2: criticality experiments. The researchers were intentionally pushing the limits to 368 00:22:56,800 --> 00:23:00,240 Speaker 2: do tests and gather data. But many of the other 369 00:23:00,400 --> 00:23:05,040 Speaker 2: nuclear criticality accidents have happened while nuclear material was being 370 00:23:05,200 --> 00:23:09,240 Speaker 2: processed in some way. So these are people working at 371 00:23:09,280 --> 00:23:14,240 Speaker 2: facilities that were actively trying to avoid a criticality. However, 372 00:23:14,280 --> 00:23:16,560 Speaker 2: in a lot of cases, the workers who were actually 373 00:23:16,600 --> 00:23:21,480 Speaker 2: handling this material also were not nuclear physicists. In some cases, 374 00:23:21,520 --> 00:23:24,920 Speaker 2: they hadn't really been trained in criticality safety at all. 375 00:23:25,040 --> 00:23:28,320 Speaker 2: They didn't necessarily know that something like the size and 376 00:23:28,440 --> 00:23:31,879 Speaker 2: shape of a container could be an integral part of 377 00:23:31,920 --> 00:23:36,920 Speaker 2: preventing a disaster. For example, on March fifteenth, nineteen fifty three, 378 00:23:37,080 --> 00:23:41,040 Speaker 2: at the Mayak Enterprise facility in Russia, two workers were 379 00:23:41,040 --> 00:23:45,879 Speaker 2: transferring plutonium solution from one vessel to another. Vessels had 380 00:23:45,920 --> 00:23:48,679 Speaker 2: been arranged in a row along a wall, and every 381 00:23:48,720 --> 00:23:52,480 Speaker 2: other vessel was supposed to be left empty to prevent criticality. 382 00:23:53,440 --> 00:23:56,359 Speaker 2: The vessels were also supposed to contain at most five 383 00:23:56,480 --> 00:24:00,359 Speaker 2: hundred grams of plutonium, but neither of those limits was 384 00:24:00,400 --> 00:24:04,600 Speaker 2: actually being followed. Vessels contained plutonium when they weren't supposed to, 385 00:24:05,200 --> 00:24:08,320 Speaker 2: and also contained more than that five hundred grand limit, 386 00:24:08,840 --> 00:24:13,160 Speaker 2: So when a criticality occurred during this plutonium transfer, workers 387 00:24:13,320 --> 00:24:16,639 Speaker 2: not only did not know that it had happened, but 388 00:24:16,720 --> 00:24:18,840 Speaker 2: they also did not know that it had caused a 389 00:24:18,920 --> 00:24:22,080 Speaker 2: serious problem because they had not been trained on this. 390 00:24:22,640 --> 00:24:25,800 Speaker 2: They just noticed that one of the vessels became warm 391 00:24:25,920 --> 00:24:29,360 Speaker 2: to the touch, so they started removing the plutonium solution 392 00:24:29,600 --> 00:24:33,040 Speaker 2: out of it and kept on working. They only reported 393 00:24:33,080 --> 00:24:35,840 Speaker 2: the incident two days later when one of them suddenly 394 00:24:35,880 --> 00:24:39,040 Speaker 2: became ill. The worker who was closer to the vessel 395 00:24:39,080 --> 00:24:41,520 Speaker 2: when it went critical ultimately had to have both of 396 00:24:41,560 --> 00:24:45,480 Speaker 2: his legs amputated because of extreme tissue damage from this exposure. 397 00:24:46,000 --> 00:24:46,520 Speaker 1: But in some. 398 00:24:46,640 --> 00:24:50,720 Speaker 2: Cases, the staff involved in these incidents were trained. That 399 00:24:50,880 --> 00:24:53,399 Speaker 2: was the case with Cecil Kelly, who received a lethal 400 00:24:53,480 --> 00:24:56,800 Speaker 2: radiation dose in a criticality accident at Los Alamos on 401 00:24:56,840 --> 00:25:00,560 Speaker 2: December thirtieth, nineteen fifty eight. Kelly he had more than 402 00:25:00,560 --> 00:25:03,600 Speaker 2: a decade of experience, but the tank he was working 403 00:25:03,600 --> 00:25:06,760 Speaker 2: with had a concentration of plutonium that was more than 404 00:25:06,800 --> 00:25:09,760 Speaker 2: two hundred times what it should have been. For reasons 405 00:25:09,760 --> 00:25:13,840 Speaker 2: that are not entirely clear, this happened during a physical 406 00:25:13,840 --> 00:25:17,359 Speaker 2: inventory when liquids from two holding vessels were moved into 407 00:25:17,400 --> 00:25:21,159 Speaker 2: one larger vessel. So Kelly was standing on a small 408 00:25:21,280 --> 00:25:24,080 Speaker 2: ladder to see into a viewing window on a tank 409 00:25:24,160 --> 00:25:28,280 Speaker 2: that was being used to chemically separate plutonium from other compounds, 410 00:25:28,800 --> 00:25:32,200 Speaker 2: and when he turned the stir on inside the tank, 411 00:25:32,720 --> 00:25:36,840 Speaker 2: the shape of the plutonium layer inside this solution allowed 412 00:25:36,840 --> 00:25:40,320 Speaker 2: it to go critical. The radiation dose to his upper 413 00:25:40,320 --> 00:25:43,600 Speaker 2: body has been estimated at one hundred and twenty gray. 414 00:25:44,240 --> 00:25:47,199 Speaker 2: Kelly either fell or was knocked to the floor and 415 00:25:47,359 --> 00:25:51,840 Speaker 2: was completely disoriented after the criticality. He kept saying I'm 416 00:25:51,880 --> 00:25:55,120 Speaker 2: burning up, and his colleagues, and a nurse who arrived 417 00:25:55,160 --> 00:25:57,920 Speaker 2: thought he had sustained some kind of a chemical burn. 418 00:25:58,600 --> 00:26:01,879 Speaker 2: The nurse even commented that he had nice pink skin. 419 00:26:02,680 --> 00:26:05,199 Speaker 2: This was actually a sign of radiation exposure, like a 420 00:26:05,240 --> 00:26:09,840 Speaker 2: mild sunburn, and not a sign of being in good health. Yeah, 421 00:26:09,840 --> 00:26:13,160 Speaker 2: because of the all of the safety measures and his 422 00:26:13,200 --> 00:26:15,959 Speaker 2: training and all this other stuff. Like his colleagues, it 423 00:26:16,040 --> 00:26:18,199 Speaker 2: was like it took a while for them to be like, 424 00:26:18,440 --> 00:26:22,240 Speaker 2: did a criticality happen and we didn't realize it. Kelly 425 00:26:22,359 --> 00:26:25,680 Speaker 2: died thirty five hours after his exposure, and his death 426 00:26:25,800 --> 00:26:30,359 Speaker 2: actually sparked the Human Tissue Analysis project at Los Alamos. 427 00:26:30,920 --> 00:26:34,439 Speaker 2: They would keep tissue samples for further study, and that 428 00:26:34,480 --> 00:26:38,760 Speaker 2: actually led to a lawsuit. Kelly's family had authorized an 429 00:26:38,800 --> 00:26:42,440 Speaker 2: autopsy to determine his cause of death, but they did 430 00:26:42,480 --> 00:26:46,119 Speaker 2: not imagine that that was going to include tissue samples 431 00:26:46,160 --> 00:26:50,760 Speaker 2: being retained for further study through this program. Other criticality 432 00:26:50,840 --> 00:26:54,680 Speaker 2: accidents during the nineteen fifties and sixties stemmed from workers 433 00:26:54,760 --> 00:26:59,520 Speaker 2: intentionally bypassing safeguards meant to prevent them. Once such accident 434 00:26:59,520 --> 00:27:02,280 Speaker 2: happened on July twenty fourth, nineteen sixty four, at a 435 00:27:02,320 --> 00:27:06,560 Speaker 2: facility that recovered uranium from scrap metal in Wood River Junction, 436 00:27:06,760 --> 00:27:10,320 Speaker 2: Rhode Island. This facility had been in operation for about 437 00:27:10,359 --> 00:27:14,359 Speaker 2: four months, and part of the process involved workers manually 438 00:27:14,480 --> 00:27:19,359 Speaker 2: shaking eleven liter bottles full of contaminated solvent. This was 439 00:27:19,400 --> 00:27:23,119 Speaker 2: a tedious process that no one particularly enjoyed, so a 440 00:27:23,160 --> 00:27:26,440 Speaker 2: worker had the idea to combine the contents of several 441 00:27:26,560 --> 00:27:30,120 Speaker 2: eleven liter bottles into a large tank and to use 442 00:27:30,160 --> 00:27:34,359 Speaker 2: a stir. Running Concurrently with that decision, one of the 443 00:27:34,400 --> 00:27:38,600 Speaker 2: plant's evaporators had not been working properly, and it turned 444 00:27:38,640 --> 00:27:41,000 Speaker 2: out that this was because it was plugged with uranal 445 00:27:41,080 --> 00:27:46,359 Speaker 2: nitrate crystals, that is, a uranium salt. Fixing that problem 446 00:27:46,560 --> 00:27:51,600 Speaker 2: involved filling several bottles with a concentrated ural nitrate solution. 447 00:27:52,000 --> 00:27:55,920 Speaker 2: As that plug was dissolved and removed. Even though those 448 00:27:55,960 --> 00:27:59,600 Speaker 2: bottles were labeled, someone mistook them for the ones that 449 00:27:59,640 --> 00:28:03,520 Speaker 2: contained the contaminated solvent, which was being mixed in the 450 00:28:03,600 --> 00:28:08,080 Speaker 2: large tank. When the concentrated urinal nitrate solution was dumped 451 00:28:08,119 --> 00:28:11,520 Speaker 2: into the tank, it went critical, causing a blue white 452 00:28:11,520 --> 00:28:14,840 Speaker 2: flash of light and splashing liquid up and out of 453 00:28:14,880 --> 00:28:18,879 Speaker 2: the tank and directly onto the worker. The criticality alarm 454 00:28:19,000 --> 00:28:22,159 Speaker 2: sounded and the worker ran to a nearby emergency shack. 455 00:28:22,880 --> 00:28:25,760 Speaker 2: A supervisor who came in to investigate turned off the 456 00:28:25,760 --> 00:28:29,160 Speaker 2: stirr in the tank, which caused a second criticality as 457 00:28:29,160 --> 00:28:32,240 Speaker 2: the solution changed shape. But no one knew about the 458 00:28:32,280 --> 00:28:35,280 Speaker 2: second criticality at the time because the alarm was still 459 00:28:35,320 --> 00:28:38,719 Speaker 2: going off from the first one. Yet there were multiple 460 00:28:38,880 --> 00:28:44,600 Speaker 2: multiple failures in the process and the safety measures that 461 00:28:44,640 --> 00:28:48,440 Speaker 2: were involved in this incident. The technician who had been 462 00:28:48,480 --> 00:28:52,200 Speaker 2: working the tank during that first criticality died of acute 463 00:28:52,280 --> 00:28:55,920 Speaker 2: radiation exposure two days later after a radiation dose of 464 00:28:55,960 --> 00:29:00,320 Speaker 2: about one hundred gray. The supervisor's dose was somewhere around 465 00:29:00,440 --> 00:29:04,800 Speaker 2: one gray. Other people nearby were also exposed to lesser 466 00:29:04,920 --> 00:29:08,320 Speaker 2: doses as well. A similar incident took place at the 467 00:29:08,360 --> 00:29:13,600 Speaker 2: Mayac Enterprise facility on January second, nineteen fifty eight. Workers 468 00:29:13,640 --> 00:29:16,040 Speaker 2: decided to drain a tank that had been used to 469 00:29:16,080 --> 00:29:20,440 Speaker 2: hold material from criticality experiments faster than it was designed 470 00:29:20,440 --> 00:29:23,600 Speaker 2: to drain. They removed the bolts that were holding the 471 00:29:23,640 --> 00:29:26,160 Speaker 2: tank to the structure and tipped it over to drain 472 00:29:26,200 --> 00:29:30,160 Speaker 2: it into containers. The shape of the material created in 473 00:29:30,200 --> 00:29:34,160 Speaker 2: this process allowed a criticality which ejected a huge amount 474 00:29:34,200 --> 00:29:37,600 Speaker 2: of material from the tank. Three of the four people 475 00:29:37,600 --> 00:29:40,320 Speaker 2: who were doing this task died as a result, and 476 00:29:40,400 --> 00:29:43,000 Speaker 2: the fourth, who was about three meters away at the time, 477 00:29:43,280 --> 00:29:46,080 Speaker 2: was blinded and had long term damage to the systems 478 00:29:46,080 --> 00:29:48,800 Speaker 2: and organs on the left side of her body, which 479 00:29:48,880 --> 00:29:51,000 Speaker 2: was closer to the tank when it went critical. 480 00:29:51,480 --> 00:29:51,680 Speaker 1: Yeah. 481 00:29:51,720 --> 00:29:55,120 Speaker 2: I took notes on so many other incidents as I 482 00:29:55,200 --> 00:29:59,240 Speaker 2: was working on this, and it's really like almost the 483 00:29:59,280 --> 00:30:02,040 Speaker 2: same story over and over and over. A lot of 484 00:30:02,040 --> 00:30:08,120 Speaker 2: it involves containers of the wrong size or shape being 485 00:30:08,240 --> 00:30:11,240 Speaker 2: used when they should not have been. So the good 486 00:30:11,280 --> 00:30:16,120 Speaker 2: news is criticality accidents like this are far less common 487 00:30:16,160 --> 00:30:19,440 Speaker 2: today than they were during the nineteen fifties and sixties. 488 00:30:20,000 --> 00:30:21,680 Speaker 2: Some of this is thanks to the end of the 489 00:30:21,680 --> 00:30:25,080 Speaker 2: Cold War, so the rush to develop and produce nuclear 490 00:30:25,120 --> 00:30:28,720 Speaker 2: weapons meant the United States and the Soviet Union in particular, 491 00:30:28,800 --> 00:30:31,280 Speaker 2: had a lot of facilities that were working with these 492 00:30:31,400 --> 00:30:36,160 Speaker 2: kinds of materials. As we noted earlier, the accumulation of 493 00:30:36,320 --> 00:30:39,360 Speaker 2: enough material to even be able to cause a criticality, 494 00:30:39,960 --> 00:30:43,240 Speaker 2: and an understanding of what it took to prevent a criticality. 495 00:30:43,320 --> 00:30:46,800 Speaker 2: Those two things were happening in tandem. In some cases, 496 00:30:46,840 --> 00:30:50,760 Speaker 2: these facilities were basically working out safety standards as they went, 497 00:30:51,240 --> 00:30:54,720 Speaker 2: and others, though they were disregarding safety standards in order 498 00:30:54,760 --> 00:30:58,080 Speaker 2: to get work done faster or more cheaply. But it's 499 00:30:58,080 --> 00:31:02,320 Speaker 2: also because as these incidents happened, the governments and facilities 500 00:31:02,360 --> 00:31:06,120 Speaker 2: involved got better at designing procedures and protocols to prevent 501 00:31:06,160 --> 00:31:09,320 Speaker 2: them in the future, like instead of having a line 502 00:31:09,320 --> 00:31:12,000 Speaker 2: of containers half of which were meant to be left empty, 503 00:31:12,720 --> 00:31:15,600 Speaker 2: just not having containers arranged in a way that a 504 00:31:15,640 --> 00:31:20,520 Speaker 2: criticality could ever result, or not allowing containers with geometry 505 00:31:20,560 --> 00:31:23,720 Speaker 2: that could allow a criticality into the facility at all. 506 00:31:24,800 --> 00:31:27,760 Speaker 2: As a result, when it comes to criticality accidents during 507 00:31:27,800 --> 00:31:31,479 Speaker 2: processing and handling, the world has gone from multiple fatal 508 00:31:31,520 --> 00:31:35,640 Speaker 2: accidents every year to fewer than one per decade. The 509 00:31:35,680 --> 00:31:38,600 Speaker 2: other side of that progression, though, is that when criticality 510 00:31:38,640 --> 00:31:42,000 Speaker 2: accidents have happened since then, a lot of times they've 511 00:31:42,000 --> 00:31:45,560 Speaker 2: been just totally unexpected. In nineteen ninety nine, there was 512 00:31:45,560 --> 00:31:49,240 Speaker 2: a criticality at the fuel conversion test building at the 513 00:31:49,320 --> 00:31:55,400 Speaker 2: JCO Fabrication Plant Company site and Tokamura, Japan workers were 514 00:31:55,520 --> 00:31:59,520 Speaker 2: using containers with unfavorable geometry because the ones they were 515 00:31:59,520 --> 00:32:03,360 Speaker 2: supposed to be using were more difficult to fill, and 516 00:32:03,440 --> 00:32:06,600 Speaker 2: the criticality accident that resulted from this was ongoing, with 517 00:32:06,720 --> 00:32:11,080 Speaker 2: criticalities recurring over the course of twenty hours. Two of 518 00:32:11,120 --> 00:32:13,960 Speaker 2: the three workers who were nearby when it started died, 519 00:32:14,320 --> 00:32:18,840 Speaker 2: and radiation was released into surrounding neighborhoods around the plant. 520 00:32:19,320 --> 00:32:22,760 Speaker 2: Although this nineteen ninety nine incident was similar to earlier 521 00:32:22,800 --> 00:32:25,840 Speaker 2: ones in that workers had been using the wrong containers 522 00:32:25,920 --> 00:32:29,440 Speaker 2: to make their jobs easier, it was also really an outlier. 523 00:32:30,160 --> 00:32:33,080 Speaker 2: There were so many procedures and standards in place at 524 00:32:33,120 --> 00:32:36,080 Speaker 2: the facility that people didn't think a criticality was even 525 00:32:36,160 --> 00:32:40,320 Speaker 2: possible there. Because of this belief, there weren't even criticality 526 00:32:40,440 --> 00:32:44,280 Speaker 2: alarms at the facility. The sensors that reported something amiss 527 00:32:44,480 --> 00:32:49,240 Speaker 2: were gamma detectors. Yeah, so we're going to have to 528 00:32:49,280 --> 00:32:53,320 Speaker 2: have nuclear facilities doing such work. 529 00:32:54,960 --> 00:32:57,120 Speaker 1: The good news is we're better at it now. 530 00:32:58,040 --> 00:33:00,800 Speaker 2: Glofully, as I was worried on this and I was 531 00:33:00,840 --> 00:33:03,960 Speaker 2: going through all of these, all of these criticality incidents, 532 00:33:03,960 --> 00:33:06,120 Speaker 2: I got to this point where I was like, man, 533 00:33:06,280 --> 00:33:12,640 Speaker 2: what what's an outcome that can be here? Because just 534 00:33:12,800 --> 00:33:16,760 Speaker 2: having one after another of these incidents was it just 535 00:33:16,840 --> 00:33:20,560 Speaker 2: incredibly grim, and it really is like, if you look 536 00:33:20,720 --> 00:33:24,200 Speaker 2: at sort of a timeline, it goes from just a 537 00:33:24,240 --> 00:33:28,320 Speaker 2: block of multiple every year through the fifties and sixties 538 00:33:28,360 --> 00:33:30,080 Speaker 2: to like, we get to the seventies and it's like 539 00:33:30,200 --> 00:33:33,880 Speaker 2: one and then a whole long time and then one. 540 00:33:35,480 --> 00:33:40,600 Speaker 2: So fingers crossed, we are past this as a society 541 00:33:40,640 --> 00:33:50,280 Speaker 2: and a global world culture. Sure, thanks so much for 542 00:33:50,400 --> 00:33:53,160 Speaker 2: joining us on this Saturday. If you'd like to send 543 00:33:53,240 --> 00:33:57,080 Speaker 2: us a note, our email addresses History Podcast at iHeartRadio 544 00:33:57,240 --> 00:34:00,160 Speaker 2: dot com, and you can subscribe to the show on 545 00:34:00,200 --> 00:34:03,520 Speaker 2: the iHeartRadio app, Apple Podcasts, or wherever you listen to 546 00:34:03,640 --> 00:34:04,640 Speaker 2: your favorite shows.