Speaker 1: Happy Saturday.
Speaker 2: Coming up, we have an episode that has some parallels
Speaker 2: to our previous episode on the Demon Core. Both of
Speaker 2: these involved a nuclear incident, and both of them also
Speaker 2: have discussions of the Cold War rush to develop nuclear
Speaker 2: technologies that led to some dangerous shortcuts. This episode came
Speaker 2: out on October twelfth, twenty twenty. Enjoy Welcome to Stuff
Speaker 2: You Missed in History Class, a production of iHeartRadio.
Speaker 1: Hello, and welcome to the podcast. I'm Tracy B.
Speaker 2: Wilson, and I'm Holly Frye.
Speaker 1: My friend Adrian, who.
Speaker 2: Is a science educator, asked me years ago at this
Speaker 2: point whether we had ever thought about doing an episode
Speaker 2: on the Demon Core, which sounds terrifying, and I kept
Speaker 2: thinking it might make a good October episode because nuclear
Speaker 2: critical accidents can be terrifying, like they expose people to
Speaker 2: possibly lethal doses of radiation and just a fraction of
Speaker 2: a second, usually completely by surprise and before anybody can react,
Speaker 2: and then that leads to just a horrifying and gruesome
Speaker 2: and sometimes prolonged death. So then every October I kept
Speaker 2: moving on in other directions and not getting to the
Speaker 2: demon Core.
Speaker 1: Here it finally is.
Speaker 2: The Demon Core was a sphere of plutonium gallium alloy
Speaker 2: that the United States made for an atomic bomb during
Speaker 2: World War Two, and then after the war, researchers at
Speaker 2: Los Alamos National Laboratory had two separate fatal criticality accidents
Speaker 2: while working with it. Those accidents are also part of
Speaker 2: a greater history of criticality accidents, most of which took
Speaker 2: place in the nineteen fifties and sixties. So we're going
Speaker 2: to talk about that progression today just to set some expectations.
Speaker 2: Nuclear reactor melt down like the disasters at Three Mile
Speaker 2: Island and Chernobyl and Fukushima, those are a slightly different
Speaker 2: thing from what we're talking about today. Some of them
Speaker 2: could technically be classified as criticality accidents, but they're also
Speaker 2: just a little bit bigger than the topics that were
Speaker 2: focused on. So to make sense of how these incidents
Speaker 2: play out, we need to walk through a little bit
Speaker 2: of science history. In nineteen thirty two, James Chadwick discovered
Speaker 2: the uncharged sub atomic particle known as the neutron, and
Speaker 2: soon physicists were using neutrons to study atoms, including bombarding
Speaker 2: atomic nuclei with neutrons to study the results. It was
Speaker 2: through this work that ottohon Lee's Meiitner and Fritz Strassmann
Speaker 2: discovered nuclear fission in nineteen thirty eight. Hahn had been
Speaker 2: working with uranium samples that had been bombarded with neutrons,
Speaker 2: and for reasons that he couldn't really explain, barium isotopes
Speaker 2: started appearing in his samples as well. Meiitner and Strasman
Speaker 2: made the connection that barium has about half the time
Speaker 2: mass of uranium, so the uranium atoms were splitting into
Speaker 2: two roughly equal parts. The idea that an atom could
Speaker 2: split in this way had been suggested before, but it
Speaker 2: was not really taken seriously at the time because it
Speaker 2: seemed absolutely contrary to how people understood nuclear physics at
Speaker 2: that point. This breakdown of uranium into barium didn't answer
Speaker 2: all the questions, though Meitner also calculated that the two
Speaker 2: new barium nuclei would be slightly less massive than the
Speaker 2: original uranium nucleus, with the difference converted into energy. Atto
Speaker 2: Haan was awarded the Nobel Prize in Chemistry for the
Speaker 2: discovery of nuclear fission in nineteen forty four. Although Meiitner
Speaker 2: and Strassman were mentioned in the speech, they were not
Speaker 2: included in that award. Nuclear fission can happen spontaneously in
Speaker 2: the natural world, and the details can play out a
Speaker 2: little bit differently in different elements and isotopes, but in
Speaker 2: terms of what we're talking about today, it typically starts
Speaker 2: with neutrons. Neutrons interact with the atom's nucleus, causing it
Speaker 2: to split. That split releases one or more other neutrons,
Speaker 2: and in the right conditions, those neutrons can reach the
Speaker 2: nuclei of other nearby atoms, causing them to split. That
Speaker 2: can continue on in a chain reaction. If there's enough
Speaker 2: material in one place to support a regular, ongoing, self
Speaker 2: sustaining chain reaction, that's known as critical mass. In a
Speaker 2: supercritical mass, this chain reaction unfolds at an escalating rate
Speaker 2: instead of a steady one. It's not just about how
Speaker 2: much physical material is in one place, though. The volume
Speaker 2: of the material, it's geometry, its concentration, its surroundings, and
Speaker 2: other factors all play a part. As a hypothetical example,
Speaker 2: if you have a very thin sheet of uranium two
Speaker 2: thirty five, a lot of the neutrons that are released
Speaker 2: during fission are going to fly off into the surrounding
Speaker 2: air without hitting any uranium atoms. But if you have
Speaker 2: the same amount of uranium two thirty five packed into
Speaker 2: a tight sphere, the neutrons from the interior are far
Speaker 2: more likely to interact with other nuclei as they travel,
Speaker 2: potentially starting a chain reaction. So the elements that break
Speaker 2: down and these interactions are radioactive, and the products of
Speaker 2: fission are generally radioactive as well. The energy that's released
Speaker 2: during nuclear fission, which there can be a lot of,
Speaker 2: also includes ionizing radiation, and while ionizing radiation has some
Speaker 2: beneficial uses, it can also be incredibly destructive to living cells.
Speaker 2: Criticality accidents can expose people and objects to just enormous
Speaker 2: amounts of radiation in an instant, so facilities that handle
Speaker 2: these types of materials have to take a lot of
Speaker 2: precautions to protect people from radiation and to prevent an
Speaker 2: accidental criticality, which is sometimes also called a power excursion.
Speaker 2: This includes restrictions on how much material can be in
Speaker 2: a particular place and how its to be handled. Containers
Speaker 2: to hold the material have to be shaped in a
Speaker 2: way that is unfavorable for criticality and made of materials
Speaker 2: that won't reflect too many sub atomic particles. Back into
Speaker 2: the material, and people handling the material have to be
Speaker 2: trained on how to prevent criticality accidents. Some of this
Speaker 2: can be a little counterintuitive to outside observers. For example,
Speaker 2: if you saw some plutonium rods placed near each other
Speaker 2: in a way that could potentially lead to a criticality,
Speaker 2: your first instinct might be to move them apart so
Speaker 2: that they would not do that. But a person's own
Speaker 2: body can also reflect neutrons back at the material, so
Speaker 2: that very act of trying to prevent a criticality accident
Speaker 2: could actually wind up causing one instead. This is a
Speaker 2: real example. It happened at Los Alamos National Laboratory in
Speaker 2: August of twenty eleven after somebody made an arrangement of
Speaker 2: plutonium rods for a photo op. Fortunately, while what what
Speaker 2: happened was outside the bounds of safety guidelines, it did
Speaker 2: not cause a criticality accident. Because nuclear fission releases energy,
Speaker 2: its discovery had immediate and obvious implications for both energy
Speaker 2: production and warfare, and multiple nations started trying to develop
Speaker 2: nuclear reactors and atomic bombs. In the United States, the
Speaker 2: effort to develop an atomic bomb was code named the
Speaker 2: Manhattan Project, which also involved the construction of nuclear reactors
Speaker 2: to produce the necessary radioactive materials for the bomb. For
Speaker 2: the most part, the reactors converted naturally occurring uranium into
Speaker 2: uranium and plutonium fuel. Most of the natural uranium that
Speaker 2: was used in American projects during World War II was
Speaker 2: mined in what was then the Belgian Congo, and then
Speaker 2: after the war that source shifted to the Navajo Nation
Speaker 2: and surrounding areas. The environmental, human rights, and health consequences
Speaker 2: of these uranium mining operations, some of which are extreme,
Speaker 2: are still on going today. For example, there are still
Speaker 2: hundreds of abandoned uranium mines on or near the lands
Speaker 2: of multiple indigenous nations in the US, and even though
Speaker 2: the EPA has entered into settlements totaling one point seven
Speaker 2: billion dollars, those settlements covered cleanup for fewer than half
Speaker 2: of these mines, and almost none of them have actually
Speaker 2: been addressed at this point. Although nuclear research took place
Speaker 2: at multiple facilities around the country, the primary lamb for
Speaker 2: atomic bomb development in the US was in Los Alamos,
Speaker 2: New Mexico. Simultaneously, researchers had to figure out the technology
Speaker 2: for the bomb, produced the nuclear material to power it,
Speaker 2: and figure out how to handle that material safely without
Speaker 2: accidentally allowing it to go critical or supercritical, all while
Speaker 2: trying to create a weapon that was supposed to go supercritical.
Speaker 2: One of the bombs that was created through the Manhattan
Speaker 2: Project was known as Little Boy. Then it was detonated
Speaker 2: over Hiroshima, Japan, on August six, nineteen forty five. This
Speaker 2: bomb contained a subcritical mass of enriched uranium along with
Speaker 2: a subcritical uranium projectile. A gun fired the projectile into
Speaker 2: the mass, and together the mass and the projectile were supercritical.
Speaker 2: This bomb was equivalent to about fifteen thousand tons of TNT.
Speaker 2: It killed an estimated one hundred and fifty thousand people
Speaker 2: and leveled much of the city. The Manhattan Project also
Speaker 2: produced three plutonium cores to be used in implosion style
Speaker 2: bombs during World War II. In this setup, the plutonium
Speaker 2: core is surrounded by conventional explosives. When those explosives detonate,
Speaker 2: they compress the core, causing it to go from subcritical
Speaker 2: to supercritical. One of these cores was detonated at a
Speaker 2: test at the Alamogordo Bombing and Gunnery Range also called
Speaker 2: the Trinity Site, on July sixteenth, nineteen forty five. Another
Speaker 2: was used in the bomb known as Fat Man, which
Speaker 2: was detonated over Nagasaki, Japan, on August ninth, nineteen forty five,
Speaker 2: killing an estimated seventy five thousand people. The third plutonium
Speaker 2: core was nearing completion when Japan announced its surrender on
Speaker 2: August fifteenth, nineteen forty five, meaning that it was no
Speaker 2: longer needed for World War two. Later, the US started
Speaker 2: planning Operation Crossroads, which was a test of nuclear weapons
Speaker 2: effects on warships at seed to take place off Bikini Atoll.
Speaker 1: This third core, the one.
Speaker 2: That would later be nicknamed the Demon Corps, was slated
Speaker 2: for use in these tests, but in the meantime it
Speaker 2: was used for criticality research. It was during that research
Speaker 2: that they nicknamed it the Demon cor even though to
Speaker 2: be clear, did not kill nearly as many people as
Speaker 2: the other two that were detonated over cities. And we're
Speaker 2: going to talk more about the Demon Corps after we
Speaker 2: first pause for a sponsor break. The plutonium core that
Speaker 2: was eventually nicknamed the Demon Core was originally nicknamed Rufus.
Speaker 2: I don't know why, but so many sources have said
Speaker 2: that that seems legitimate. It was a six point two
Speaker 2: kilogram or thirteen point seven pound sphere really two hemispheres
Speaker 2: made of refined plutonium and gallium. Under normal conditions, it
Speaker 2: was ninety five percent of a critical mass, so it's
Speaker 2: often described as having a hair trigger, although it had
Speaker 2: been created for use in a bomb. This hair trigger
Speaker 2: also made the core useful for criticality experiments. Physicists could
Speaker 2: intentionally reflect neutrons back at the core to push it
Speaker 2: close to criticality and gather data about what was happening.
Speaker 2: Physicist Richard Feynman, who's work with the Manhattan Project included
Speaker 2: helping to work out stand to prevent criticality accidents, reportedly
Speaker 2: nicknamed these types of experiments tickling the Dragon's Tail. On
Speaker 2: August twenty first, nineteen forty five, twenty four year old
Speaker 2: graduate student Harry Dallion Junior was working by himself in
Speaker 2: the lab. Because of the nature of the work that
Speaker 2: was being done at Los Alamos, like it was critical
Speaker 2: to the war effort, it involved part of the nation's
Speaker 2: nuclear material stockpile, it was standard for security guards to
Speaker 2: always be present, so even though Dallian was working alone
Speaker 2: on this experiment, there was one other person in the
Speaker 2: room that was twenty nine year old Private Robert Hemerley,
Speaker 2: who was sitting at a table about twelve feet away
Speaker 2: from the core. Dallian was using tungsten carbid bricks to
Speaker 2: build a reflective wall around the plutonium core by hand.
Speaker 2: The bricks reflected neutrons back at the core, inching it
Speaker 2: closer to criticality. The more bricks he added, the more
Speaker 2: neutrons were reflected, and the closer the core got to
Speaker 2: going critical. As Dallian was about to add the last
Speaker 2: brick in this structure, his instruments showed that doing so
Speaker 2: was going to cause the core to go critical, so
Speaker 2: he tried to pull that last brick away, but as
Speaker 2: he did, it slipped out of his hand and dropped
Speaker 2: directly onto the core. Dallian used his other hand to
Speaker 2: knock the dropped brick away, but it was too late.
Speaker 2: There was a wave of heat and a brief flash
Speaker 2: of blue light all around the exterior of the sphere.
Speaker 2: That light was probably Chirinkov radiation, which is the result
Speaker 2: of charged particles moving faster than the speed of light
Speaker 2: through a transparent medium like air. In that brief moment
Speaker 2: between when he dropped the brick and when he knocked
Speaker 2: it away, Dallian was hit with a blast of neutron radiation.
Speaker 2: He disassembled the reflector that he had built, and that
Speaker 2: continued to expose him to gamma radiation while he was
Speaker 2: doing so. Today, absorbed radiation is measured in gray, with
Speaker 2: its one gray being equivalent to one hundred rads. A
Speaker 2: sudden whole body dose of zero point seven gray is
Speaker 2: enough to cause acute radiation sickness. Sometimes symptoms can develop
Speaker 2: at as little as zero point three gray. Dallian's dose
Speaker 2: was estimated at five point one gray. He died twenty
Speaker 2: five days after the accident on September fifteenth, nineteen forty five.
Speaker 2: Private Hammerley's dose was estimated at zero point five gray.
Speaker 2: He survived this incident apparently without serious injury at the time.
Speaker 2: If you read older articles that were published before his
Speaker 2: death later on like they'll say that he wasn't seriously harmed,
Speaker 2: but he wound up dying of leukemia, which might have
Speaker 2: been related to this radiation exposure, when he was sixty two. Afterward,
Speaker 2: criticality experiments continued at Los Alamos in spite of this fatality.
Speaker 2: Although some new safety standards were put into play, the
Speaker 2: list of people allowed to do these kinds of experiments
Speaker 2: was shortened, with two sets of monitoring equipment required for
Speaker 2: each experiment. The new standards reiterated that at least two
Speaker 2: people in addition to the guard, had to be present
Speaker 2: for this kind of work. Researchers also started discussing whether
Speaker 2: it would be better to do these kinds of experiments remotely,
Speaker 2: so that if a criticality did happen, it would be
Speaker 2: too far away from people to hurt them. Operation Crossroads
Speaker 2: was scheduled to start in July of nineteen forty six,
Speaker 2: but before the core was sent to the Marshall Islands
Speaker 2: to be used there, physicists were doing one last set
Speaker 2: of criticality experiments with it. On May twenty first, nineteen
Speaker 2: forty six, Canadian physicist Lewis Slowten was using a hollow
Speaker 2: beryllium sphere to mostly cover up the core and reflect
Speaker 2: neutrons back into it. The sphere had two halves, The
Speaker 2: core was sort of resting in the bottom half, and
Speaker 2: he had his thumb threaded through a hole in the
Speaker 2: top half so that he could adjust the positioning this
Speaker 2: sort of dome with his hand. He knew that if
Speaker 2: the sphere closed completely it could cause a criticality, so
Speaker 2: he used the end of a screwdriver to keep the
Speaker 2: two halves slightly separate.
Speaker 1: This sounds like the.
Speaker 2: Kind of thing I would do at my house with
Speaker 2: something that is not dangerous, And even so my husband
Speaker 2: would go, are you sure that's how you want to
Speaker 2: do it?
Speaker 1: Yes?
Speaker 2: Yes, I have a story on this subject about myself
Speaker 2: that I will probably tell in our Friday behind the
Speaker 2: scenes fabulous.
Speaker 1: While I have.
Speaker 2: Some understanding of how a person might do a really
Speaker 2: foolish thing, knowing how foolish it is, I was not
Speaker 2: handling potentially critical nuclear weapons cores at the time. As
Speaker 2: he was doing this, the screwdriver slipped and the dome
Speaker 2: totally closed. There was a brief flash of blue light
Speaker 2: that was visible over the normal illumination of the room.
Speaker 2: This lasted only a moment as and flipped the dome
Speaker 2: off of the core. Slowden seems to have immediately understood
Speaker 2: that he was not going to survive this accident, saying, well,
Speaker 2: that does it. In general, a whole body radiation dose
Speaker 2: of more than ten gray is inevitably fatal, and his
Speaker 2: has been estimated at twenty one gray. At the same time,
Speaker 2: he had the presence of mind to try to document
Speaker 2: where the other seven observers in the room had been
Speaker 2: standing at the time, and then to try to calculate
Speaker 2: how large of a dose of radiation each of them received.
Speaker 2: Their doses have been estimated as ranging between zero point
Speaker 2: three seven and three point six gray. Slowden also tried
Speaker 2: to detect how much radiation was present in other objects
Speaker 2: that were in the room, but the detectors themselves had
Speaker 2: been contaminated in the accident. At the same time, he
Speaker 2: wasn't thinking entirely clearly. He asked a colleague to scatter
Speaker 2: film badges used to detect radiation exposure around the area,
Speaker 2: and that required the colleague to get close to the
Speaker 2: radioactive corps to do so. Slotin died nine days after
Speaker 2: this accident at the age of thirty five, and although
Speaker 2: he was the only person killed, three other people in
Speaker 2: the room had to be hospitalized for acute radiation exposure.
Speaker 1: And one of them was Alvin C.
Speaker 2: Graves, who was the closest to Slowtin physically. When this
Speaker 2: accident happened, Slowtin had actually been training Graves as his replacement.
Speaker 2: Graves was seriously injured and for a time it was
Speaker 2: not certain whether he was going to survive. He later
Speaker 2: developed cataracts and thyroid issues, and his death from a
Speaker 2: heart attack nineteen years later may also have been related.
Speaker 2: In general, people have viewed Harry Dallion Junior's accident with
Speaker 2: a bit more sympathy than Lewis Slotin's. Dallian was working alone,
Speaker 2: which was against protocol, but he was also a graduate student,
Speaker 2: so he was not as experienced as many of his colleagues. Slowtin,
Speaker 2: on the other hand, was not only as senior scientist,
Speaker 2: but had also co authored the official report on the
Speaker 2: accident that had killed Harry Dallion, so he definitely understood
Speaker 2: the risks and the potential for accident. His experiment was
Speaker 2: meant to be done with two one inch spacers between
Speaker 2: the two halves of the beryllium sphere, but Slotin had
Speaker 2: removed these and was using the screwdriver in their place.
Speaker 2: Multiple other scientists who were aware of the criticality experiment
Speaker 2: he was doing thought it was inordinately dangerous, and in
Speaker 2: general he had a reputation for being a little too
Speaker 2: cavalier around things like atomic bomb cores. Scientists nicknamed this
Speaker 2: corps the demon Corps, not just because it had been
Speaker 2: part of both of these fatal accidents, but also because
Speaker 2: of some eerie similarities between them. Both accidents took place
Speaker 2: on the twenty first of the month and on a Tuesday,
Speaker 2: and Slotin and Dallion both died in the same hospital
Speaker 2: room at the US Engineer's Hospital at Los Alamos. By
Speaker 2: this point, work had started on remote facility for criticality experiments,
Speaker 2: and after the second accident with the demon Core, hands
Speaker 2: on criticality experiments like this were banned. In nineteen forty seven,
Speaker 2: criticality experiments resumed at the newly completed critical Experiments facility
Speaker 2: at what was known as the Paharito Site. Criticality experiments
Speaker 2: there were handled with machinery and took place a quarter
Speaker 2: mile from the control room where the people doing the
Speaker 2: experiments were. Since the amount of radiation drops dramatically the
Speaker 2: farther you are away from the source, this was much
Speaker 2: safer than doing something like stacking reflective blocks with your hands.
Speaker 2: Dallian and Slotan were the only two people to die
Speaker 2: from acute radiation exposure at Los Alamos during the Manhattan Project.
Speaker 2: Although there were numerous other deaths in and around the
Speaker 2: facility during those same years, a lot of them were
Speaker 2: from accidents that had nothing to do with radioactive materials
Speaker 2: or bombs. This included motor vehicle accidents, construction accidents, and
Speaker 2: in one case, a ten year old who drowned when
Speaker 2: a canoe capsized. In nineteen forty six, three custodians also
Speaker 2: died of ethylene glycol poisoning after drinking wine that was
Speaker 2: mixed with antifreeze. In terms of the demon Core, for
Speaker 2: years after this incident happened, it was believed that it
Speaker 2: was sent on to Bikini Atoll for use in Operation
Speaker 2: Crossroads as planned, and while it was described as quote
Speaker 2: a little hot but not too hot to handle, after
Speaker 2: that second accident, it was saved for the last detonation,
Speaker 2: just in case that was going to affect the results.
Speaker 2: That last test wound up being canceled, and the demon
Speaker 2: Cor was later melted down and reintegrated into the nuclear
Speaker 2: material stockpile. At some point it was probably incorporated into
Speaker 2: other weapons. Before we move on, we should note that
Speaker 2: there have been ongoing issues with safety at Los Alamos
Speaker 2: National Laboratory in more recent years. Aside from that twenty
Speaker 2: eleven plutonium photo op that we mentioned earlier. In twenty seventeen,
Speaker 2: it was rated does not meet expectations in the Department
Speaker 2: of Energy Nuclear Criticality Safety Programs annual report that was
Speaker 2: raised up to adequate but needs improvement in twenty eighteen
Speaker 2: and twenty nineteen. Also, that second accident with the demon
Speaker 2: core is dramatized in the nineteen eighty nine film Fat
Speaker 2: Man and Little Boy, with John Cusack as a fictionalized
Speaker 2: SLOTIN who is named Michael Merriman in the film. Yeah,
Speaker 2: I watched just that scene while I was working on this,
Speaker 2: and even knowing literally what's going to happen, I found
Speaker 2: it very tense. Yeah, so we're gonna take a quick break.
Speaker 2: The two incidents that we already talked about happened during
Speaker 2: criticality experiments. The researchers were intentionally pushing the limits to
Speaker 2: do tests and gather data. But many of the other
Speaker 2: nuclear criticality accidents have happened while nuclear material was being
Speaker 2: processed in some way. So these are people working at
Speaker 2: facilities that were actively trying to avoid a criticality. However,
Speaker 2: in a lot of cases, the workers who were actually
Speaker 2: handling this material also were not nuclear physicists. In some cases,
Speaker 2: they hadn't really been trained in criticality safety at all.
Speaker 2: They didn't necessarily know that something like the size and
Speaker 2: shape of a container could be an integral part of
Speaker 2: preventing a disaster. For example, on March fifteenth, nineteen fifty three,
Speaker 2: at the Mayak Enterprise facility in Russia, two workers were
Speaker 2: transferring plutonium solution from one vessel to another. Vessels had
Speaker 2: been arranged in a row along a wall, and every
Speaker 2: other vessel was supposed to be left empty to prevent criticality.
Speaker 2: The vessels were also supposed to contain at most five
Speaker 2: hundred grams of plutonium, but neither of those limits was
Speaker 2: actually being followed. Vessels contained plutonium when they weren't supposed to,
Speaker 2: and also contained more than that five hundred grand limit,
Speaker 2: So when a criticality occurred during this plutonium transfer, workers
Speaker 2: not only did not know that it had happened, but
Speaker 2: they also did not know that it had caused a
Speaker 2: serious problem because they had not been trained on this.
Speaker 2: They just noticed that one of the vessels became warm
Speaker 2: to the touch, so they started removing the plutonium solution
Speaker 2: out of it and kept on working. They only reported
Speaker 2: the incident two days later when one of them suddenly
Speaker 2: became ill. The worker who was closer to the vessel
Speaker 2: when it went critical ultimately had to have both of
Speaker 2: his legs amputated because of extreme tissue damage from this exposure.
Speaker 1: But in some.
Speaker 2: Cases, the staff involved in these incidents were trained. That
Speaker 2: was the case with Cecil Kelly, who received a lethal
Speaker 2: radiation dose in a criticality accident at Los Alamos on
Speaker 2: December thirtieth, nineteen fifty eight. Kelly he had more than
Speaker 2: a decade of experience, but the tank he was working
Speaker 2: with had a concentration of plutonium that was more than
Speaker 2: two hundred times what it should have been. For reasons
Speaker 2: that are not entirely clear, this happened during a physical
Speaker 2: inventory when liquids from two holding vessels were moved into
Speaker 2: one larger vessel. So Kelly was standing on a small
Speaker 2: ladder to see into a viewing window on a tank
Speaker 2: that was being used to chemically separate plutonium from other compounds,
Speaker 2: and when he turned the stir on inside the tank,
Speaker 2: the shape of the plutonium layer inside this solution allowed
Speaker 2: it to go critical. The radiation dose to his upper
Speaker 2: body has been estimated at one hundred and twenty gray.
Speaker 2: Kelly either fell or was knocked to the floor and
Speaker 2: was completely disoriented after the criticality. He kept saying I'm
Speaker 2: burning up, and his colleagues, and a nurse who arrived
Speaker 2: thought he had sustained some kind of a chemical burn.
Speaker 2: The nurse even commented that he had nice pink skin.
Speaker 2: This was actually a sign of radiation exposure, like a
Speaker 2: mild sunburn, and not a sign of being in good health. Yeah,
Speaker 2: because of the all of the safety measures and his
Speaker 2: training and all this other stuff. Like his colleagues, it
Speaker 2: was like it took a while for them to be like,
Speaker 2: did a criticality happen and we didn't realize it. Kelly
Speaker 2: died thirty five hours after his exposure, and his death
Speaker 2: actually sparked the Human Tissue Analysis project at Los Alamos.
Speaker 2: They would keep tissue samples for further study, and that
Speaker 2: actually led to a lawsuit. Kelly's family had authorized an
Speaker 2: autopsy to determine his cause of death, but they did
Speaker 2: not imagine that that was going to include tissue samples
Speaker 2: being retained for further study through this program. Other criticality
Speaker 2: accidents during the nineteen fifties and sixties stemmed from workers
Speaker 2: intentionally bypassing safeguards meant to prevent them. Once such accident
Speaker 2: happened on July twenty fourth, nineteen sixty four, at a
Speaker 2: facility that recovered uranium from scrap metal in Wood River Junction,
Speaker 2: Rhode Island. This facility had been in operation for about
Speaker 2: four months, and part of the process involved workers manually
Speaker 2: shaking eleven liter bottles full of contaminated solvent. This was
Speaker 2: a tedious process that no one particularly enjoyed, so a
Speaker 2: worker had the idea to combine the contents of several
Speaker 2: eleven liter bottles into a large tank and to use
Speaker 2: a stir. Running Concurrently with that decision, one of the
Speaker 2: plant's evaporators had not been working properly, and it turned
Speaker 2: out that this was because it was plugged with uranal
Speaker 2: nitrate crystals, that is, a uranium salt. Fixing that problem
Speaker 2: involved filling several bottles with a concentrated ural nitrate solution.
Speaker 2: As that plug was dissolved and removed. Even though those
Speaker 2: bottles were labeled, someone mistook them for the ones that
Speaker 2: contained the contaminated solvent, which was being mixed in the
Speaker 2: large tank. When the concentrated urinal nitrate solution was dumped
Speaker 2: into the tank, it went critical, causing a blue white
Speaker 2: flash of light and splashing liquid up and out of
Speaker 2: the tank and directly onto the worker. The criticality alarm
Speaker 2: sounded and the worker ran to a nearby emergency shack.
Speaker 2: A supervisor who came in to investigate turned off the
Speaker 2: stirr in the tank, which caused a second criticality as
Speaker 2: the solution changed shape. But no one knew about the
Speaker 2: second criticality at the time because the alarm was still
Speaker 2: going off from the first one. Yet there were multiple
Speaker 2: multiple failures in the process and the safety measures that
Speaker 2: were involved in this incident. The technician who had been
Speaker 2: working the tank during that first criticality died of acute
Speaker 2: radiation exposure two days later after a radiation dose of
Speaker 2: about one hundred gray. The supervisor's dose was somewhere around
Speaker 2: one gray. Other people nearby were also exposed to lesser
Speaker 2: doses as well. A similar incident took place at the
Speaker 2: Mayac Enterprise facility on January second, nineteen fifty eight. Workers
Speaker 2: decided to drain a tank that had been used to
Speaker 2: hold material from criticality experiments faster than it was designed
Speaker 2: to drain. They removed the bolts that were holding the
Speaker 2: tank to the structure and tipped it over to drain
Speaker 2: it into containers. The shape of the material created in
Speaker 2: this process allowed a criticality which ejected a huge amount
Speaker 2: of material from the tank. Three of the four people
Speaker 2: who were doing this task died as a result, and
Speaker 2: the fourth, who was about three meters away at the time,
Speaker 2: was blinded and had long term damage to the systems
Speaker 2: and organs on the left side of her body, which
Speaker 2: was closer to the tank when it went critical.
Speaker 1: Yeah.
Speaker 2: I took notes on so many other incidents as I
Speaker 2: was working on this, and it's really like almost the
Speaker 2: same story over and over and over. A lot of
Speaker 2: it involves containers of the wrong size or shape being
Speaker 2: used when they should not have been. So the good
Speaker 2: news is criticality accidents like this are far less common
Speaker 2: today than they were during the nineteen fifties and sixties.
Speaker 2: Some of this is thanks to the end of the
Speaker 2: Cold War, so the rush to develop and produce nuclear
Speaker 2: weapons meant the United States and the Soviet Union in particular,
Speaker 2: had a lot of facilities that were working with these
Speaker 2: kinds of materials. As we noted earlier, the accumulation of
Speaker 2: enough material to even be able to cause a criticality,
Speaker 2: and an understanding of what it took to prevent a criticality.
Speaker 2: Those two things were happening in tandem. In some cases,
Speaker 2: these facilities were basically working out safety standards as they went,
Speaker 2: and others, though they were disregarding safety standards in order
Speaker 2: to get work done faster or more cheaply. But it's
Speaker 2: also because as these incidents happened, the governments and facilities
Speaker 2: involved got better at designing procedures and protocols to prevent
Speaker 2: them in the future, like instead of having a line
Speaker 2: of containers half of which were meant to be left empty,
Speaker 2: just not having containers arranged in a way that a
Speaker 2: criticality could ever result, or not allowing containers with geometry
Speaker 2: that could allow a criticality into the facility at all.
Speaker 2: As a result, when it comes to criticality accidents during
Speaker 2: processing and handling, the world has gone from multiple fatal
Speaker 2: accidents every year to fewer than one per decade. The
Speaker 2: other side of that progression, though, is that when criticality
Speaker 2: accidents have happened since then, a lot of times they've
Speaker 2: been just totally unexpected. In nineteen ninety nine, there was
Speaker 2: a criticality at the fuel conversion test building at the
Speaker 2: JCO Fabrication Plant Company site and Tokamura, Japan workers were
Speaker 2: using containers with unfavorable geometry because the ones they were
Speaker 2: supposed to be using were more difficult to fill, and
Speaker 2: the criticality accident that resulted from this was ongoing, with
Speaker 2: criticalities recurring over the course of twenty hours. Two of
Speaker 2: the three workers who were nearby when it started died,
Speaker 2: and radiation was released into surrounding neighborhoods around the plant.
Speaker 2: Although this nineteen ninety nine incident was similar to earlier
Speaker 2: ones in that workers had been using the wrong containers
Speaker 2: to make their jobs easier, it was also really an outlier.
Speaker 2: There were so many procedures and standards in place at
Speaker 2: the facility that people didn't think a criticality was even
Speaker 2: possible there. Because of this belief, there weren't even criticality
Speaker 2: alarms at the facility. The sensors that reported something amiss
Speaker 2: were gamma detectors. Yeah, so we're going to have to
Speaker 2: have nuclear facilities doing such work.
Speaker 1: The good news is we're better at it now.
Speaker 2: Glofully, as I was worried on this and I was
Speaker 2: going through all of these, all of these criticality incidents,
Speaker 2: I got to this point where I was like, man,
Speaker 2: what what's an outcome that can be here? Because just
Speaker 2: having one after another of these incidents was it just
Speaker 2: incredibly grim, and it really is like, if you look
Speaker 2: at sort of a timeline, it goes from just a
Speaker 2: block of multiple every year through the fifties and sixties
Speaker 2: to like, we get to the seventies and it's like
Speaker 2: one and then a whole long time and then one.
Speaker 2: So fingers crossed, we are past this as a society
Speaker 2: and a global world culture. Sure, thanks so much for
Speaker 2: joining us on this Saturday. If you'd like to send
Speaker 2: us a note, our email addresses History Podcast at iHeartRadio
Speaker 2: dot com, and you can subscribe to the show on
Speaker 2: the iHeartRadio app, Apple Podcasts, or wherever you listen to
Speaker 2: your favorite shows.