My father, a U.S. Navy aviator, piloted an aircraft loaded with scientists and instruments at the Castle Bravo nuclear weapon test. 6 megatons were expected; we got 15. Turns out there's a difference between Lithium-6 and Lithium-7. Turns out that extra neutron matters. And lots of folks in the test got a lot more irradiated than expected. He died at age 49 (when I was very young) with half a dozen kinds of cancer. Lung cancer, kidney cancer, melanoma, leukemia, CRC, pancreatic. VA tried to say it wasn't service related to deny benefits.
We owe so much to the early pioneers that risked their lives, often unknowingly, for all the knowledge we've gained from their sacrifices. The government should recognize them all retroactively and compensate families that had loved ones become ill and die from exposure to toxic or radioactive materials while working for or serving our country. Especially for those who became terminally ill and were told it wasn't related to their service and denied any recognition or benefits. Even today our veterans still aren't being taken care of the way they deserve to be.
@kristianniss5201 zero empathy moment. I bet you'd be the kind of person to deny benefits to veteran families who lost their loved ones due to their time in service
I was lucky to read an article in "The New Treasury of Science" as a kid called "The Death of Louis Slotin". This was a good thing for a science kid to read. It not only gave me a healthy respect for radiation, but tended to moderate all the dangerous things I was doing with chemistry and electricity that could have harmed be the old fashioned way :) Thanks for the video!
As a licensed electrician and avid organic chemistry fan,(as well as a nerd with everything science, all aspects) I can say that some of the incidents I had as a young guy, while minor, helped keep from from making sincerely bad mistakes when older !
I can _kind of_ understand the first accident. It was the very early days of a new technology; the regulations hadn't yet been written; society was much less safety-conscious in general (fun fact: when Ford began offering seat belts as a option in 1955, fewer than 2% of buyers opted for them). What I can't fathom is watching your friend and colleague die a preventable, slow, horrific death, then going on to do something even _more_ senselessly dangerous-and putting seven other people at risk! It's simply unthinkable.
The "flat-head screwdriver incident" is directly referenced in a mid-game level in the civil-engineering-'em-up _INFRA._ You find a _suspiciously familiar_ half-dome and sphere setup in a certain spoilery area, along with a written note that ends with "I don't care how good your 'prestidigitation' is. If that reflector locks in, WE'RE ALL DEAD!". Being a video game, you can, ahem, do the obvious thing (complete with blinding flash of white as Mark dies), and get an achievement for it!
+1 on Plainly Difficult. He was one of my first introductions to the science behind chernobyl (though Kyle Hill admittedly cemented it via his old Because Science channel)
Great review of an equally well done Kyle Hill video. His Half-life series is very well researched and a pleasure to watch. You might want to do a few more of them. I really like how you explain in a clear, concise manner what would be done today, and how experiments like this would not be even almost allowed, full stop. Your channel has fast become one of my favourites because of it👍
The "dollie parton curve for reasons that are highly scientific" 😂😂😂😂 that made my night... U could be the first nuclear studied comidien and youll hit hard at the stand up shows 😂
That peer checking and oversight is because of incidents like this. Rules and laws are made because someone did something that necessitated it. Also. My grandfather was at Bikini and was on deck to witness several tests. They gave them welding goggles as their only PPE. He died of a weird form of Parkinson's at 79, which is weird because it not only doesn't run in the family, but most of his brothers and sisters lived into their 90s and 100s.
@@exxor9108 That's the assumption. That and/or defoliants used at guadalcanal and experimental firefighting chemicals in the CDF... or aboard ships. He was exposed to a lot of crazy shit in the 50s and 60s.
The accident is shown in the movie Fat Man and Little Boy. It stars Paul Newman and John Cusack. Btw, 40+ years ago I attended the only high school in America with a radiation lab which had a Cobalt source. Teacher was a physicist who worked at Oakridge during the summer building bombs and taught physics during the school year. Her name was Barbara Reed. High School is Riverview high School in Sarasota. She convinced the school board to have the lab installed so they can study the effects of phosphate mining which is big in that area and what it was doing to the environment because when you dig up phosphate, you dig up the whole uranium decay chain. At the time she told us that there had not been any American civilian deaths from radioactive material. But one day she did a lecture on the accidents that happened to government contractors. With slides. Anyway, because of her in that class I decided to become a radiographer and I was one for 25 years.
That's really cool. You know, as far as she knew, there probably weren't any civil deaths due to radiation. The demon core and other Los Alamos deaths due to radiation were classified into... I think the 70's or 80's.
They didn't build bombs at Oak Ridge. They enriched uranium there. The details of Daghlian and Slotin's deaths were kept secret for a long time after they happened in 46-47. Cool memories.
@@puncheex2 Yes I understand that they didn't actually build bombs there, it was urnium production. This was back during the Cold war. I also met another scientist that had worked at oak ridge. That's when I became an x-ray tech and worked at a doctor's office. We were both talking about being exposed to radiation is how that came up when I was x-raying his knees.
iirc the main advantage to using water as a reflector and moderator is that, when the core gets too hot, the water boils and evaporates, meaning it doesn't reflect or moderate anymore, and stops the reaction from going out of control.
I was in grad school in the late 1980s and had a professor that had work at Los Alamos starting in 1945. He used to tell us all these stories of stuff going on there. Like how they used to align particle accelerator beams by sticking their head into the beam and adjusting ito to get the most light from scintillations from the fluid in their eyes
He never brought up the subject of that mysterious object that crashed near the Trinity site in 1945, did he? Of course, not, he probably never even heard of it. Jacques Vallée wrote a book, recently, about it. It's pretty interesting.
There was a Russian physicist that got zapped in the head by a full strength particle beam because his colleagues didn't know he was working on it at the time. But maybe our host has covered that? Didn't kill him, but it did something to the nerves in his face, like a permanent botox?
Hello! I'm newly subscribed to this channel, but I was wondering if you had any plans to make videos explaining some nuclear engineering concepts? I'm currently a college sophomore, but I plan on majoring in nuclear engineering after I get my gen-ed's out of the way and transfer. Maybe just a video explaining what classes you had to take and why they're relevant or something like that. I think a lot of people would be interested - or at least - curious about that. Loving the channel so far!
Have fun on your journey into nuclear engineering! I’ve done a few shorts on some nuclear engineering concepts and misconceptions: Nuclear Engineer Explains ru-vid.com/group/PLqzw97Uv36MmaSbNpNYtEzK8xS6DcDuPc
Google "nuclear engineering curriculum" at any of the more prestigious engineering schools, ie MIT, Illinois, Purdue, Michigan etc and that will give you the semester by semester course listing of their respective nuclear engineering curricula.
Fun fact: The Bikini Atoll mentioned at timestamp 20:18 is where Sponge Bob takes place. Depressing fact: Bikini Atoll was populated, and the residents were forcefully relocated for the tests to an island, but then they started starving to death and were then relocated again. Afterwards they were placed back on Bikini Atoll, but then later when it was noticed the residents carried abnormal amounts of Caesium-137 and the well water carried abnormal counts of Strontium-90 they were evacuated and subsequently lost their homes forever. The Bikini Atoll is now only visited by divers and scientists.
@@Bassalicious A quick google search tells me the most nuked place is Semipalatinsk, but maybe bikini atoll has another situation going on that I don't know about.
@@Bassalicious It might have been known as the most nuked place on earth by Westerners before the fall of the USSR, so Semipalatinsk was probably not well known at the time.
Engineer 1: "Hey, want to see something cool?" Engineer 2: "Yeh, wait..... is that a screwdriver holding a top metal dish slightly ajar? Is that a core in the middle?" Engineer 1: "Yup, now the only thing keeping us from getting irradiated and killed is that screwdriver. Hope no one knocks it over.... Oh crap" Engineer 2: "Congrats you just doomed us in the room"
Kyle Hill has a t-shirt, poster, and coffee cup you can buy that hss a diagram drawing of the scientists standing in thier respectively positions around the Demon Core prior to it going critical with the caption "Go ahead, f*ck with it. See what happens!"😊
My Father-in-Law was a chemist that worked on the Manhatten Project. He helped design the implosion explosives that detonated Fat man. He had so many awesome stories about his time there. He told me of one of his visits to a neuclear reactor where he viewed the core from a catwalk above and could see the blue glow of the reaction below. He passed form liver cancer which no doubt was from his exposure at Los Alamos.
The recognition of cancers caused by radiation exposure go back to 1902. After WWII, and with names like Feynman, and Enrico Fermi involved in these projects, they most definitely knew about the possible consequences.
Indeed. They didn't treat the risk like we would today because their mindset was different. Their primary concerns were things like the end of the world as we know it, not maybe getting cancer in 20 years. They all knew guys who had gone into greater danger, and guys who hadn't come back.
I find it interesting how you're pointing out to all the things that wouldn't happen today because of rules, laws, protocols, etc. in place. However, the primary reason these safety protocols exist today is because of all of these accidents, that claimed a lot of lives and caused a lot of damage.
That’s how things evolve. Americans would be the first in line trying to collect money and blame somebody else for their mistake or for lack of regulations etc. Rules… they are for the other guy… mother nature 1:0 humans…Saturday afternoon matinee😂
Hey just found this channel a couple days ago and I'm loving the videos! I was thinking maybe you could check out a video about the US making a nuclear powered plane back in the 40-50s, pretty sure Real Engineering has a video on it thats good. Oh also sometimes you edit/cut out the end of a word when your talking and its a little jarring, other than that I'm looking forward to more nuclear themed videos!
Just think about how scary this situation is. You see that flash of light - you know you're a dead man walking at that point. I can't imagine how that feels.
It wasn’t really because of poor regulations that contributed to bad safety practices directly. He’s scientists were the pioneering experts in this field, and so the practices that they followed were of their own design there was no external authority that existed to regulate activities or have any kind of expertise in this field. The other nature fact that contributed to the east, is that 100% of the existence of all of this was classified. As far as anyone outside of the program was concerned, none of this existed and thus it’s extremely hard to regulate somethings that is not supposed to exist in the first place. Incorporating more people into the program to oversee its activities, was a higher security risk than the risk of health and safety violations due to bad actions. This is unfortunately a common side effect in covert operations. You can’t commonly have a high level of officials over seeing them, because it makes them no longer covert.
Talking about things being less red tape then: The prof who taught me nuclear technology in the early eighties had been one of Fermi's student workforce that piled up the graphite blocks under that stadium in Chicago. He told us an anecdote about when they were looking for a water leak in the plumbing of a university building. They mixed a radioisotope in the water, let it circulate for some time, then flushed with clean water and the went looking for the leak with a Geiger-Müller counter...
Perusing the comments, it is especially noteworthy the number of people who see Slotin as a lazy physicist-slob. Yeah, he was still essentially a teenager at heart, but the urgency of the Los Alamos goal was also very pressing. There was a war on, they cut corners and did things expeditiously under great pressure. It is sort of like the bomb disposal expert faced with "Which wire should I cut??!??" as the big LED window was ticking through "00:00:10" and the music was crescendoing a screaming pitch, except that the war was real. College drinking buddies were being shot to death in droves and you are on an extended vacation to scenic New Mexico. "Wasting" time on elaborate safety probably seemed like tempting hell. Yeah, the accident happened after the war (by about five months), but they'd all spent three years in the pot getting hot before last August.
There is an exceptition for fuel enrichment rate in reactors though. Reactors used in submarines and ships also sometimes use highly enriched fuel. The S6W reactor which is a naval reactor used for subs in the US Navy runs 93.5% enriched uranium. As submarines have limited space, naval reactors are hard to service. High enriched fuel will allow the sub to just perform a single fuel rod change during it's whole service time. It has the downside though that prior to it's service you basically need to produce weapons grade uranium unless material from old dismantled nuclear weapons is used.
I think we kind of have to chalk this cavalier approch to safety to two major factors: 1) The risks weren't always well understood - and even where they were understood, these people hadn't been trained in an environment that drilled the reality of those dangers into them at a deep level. Humans are pretty bad at risk assessment unless it's heavily reinforced. 2) The Manhattan Project was a 'crash' project to develop as superweapon as quickly as possible during the course of the largest conflict the world had ever seen. Hundreds if not thousands of soldiers were dying every day. Thus the projects were looking for results, and results only. Safety was a secondary if not tertiary consideration, and some of the people they'd hired in for them would have been among the least risk-averse in the physics community, much like test-pilots and race car drivers are not known for their reserved driving habits. At this point of course the war was over, and these projects should have been reigned in and restructured to incorporate a much more normal work environment with actual safety in mind - but that wasn't the culture that had created any of this, so it was probably always going to take some harsh lessons of this sort to kick them in the ass and get them to change approach.
I read in the book "the secret that exploded" that the guy using the blocks was supposed to have used 1/8th blocks, 1/half blocks and full blocks of reflector. he was supposed to build the reflector with the 1/8ths slowly checking each time on criticality until he had a 1/2 block which he would then replace the 4 1/8th blocks with a half and build up the rest of the block then replace the 4 8ths and 1 half with a whole. i also read the guy didnt do this and began using full blocks each step and slowly loweing the block into place and stopping when criticality got higher. Sad to see the next guy just kept doing the experiment in an almost equally dangerous way with a freaking screwdriver.
I worked at Los Alamos from 1993 to 2000 for the Dept. of Energy as a nuclear engineer doing safety oversight. One of my assigned areas was TA-18, the Critical Experiments Area, or as it was referred to in the video, Pajarito Site. At about 11 minutes into the video a comment is made that experiments involving prompt criticality are not controllable and would not work, which is not entirely true. During my time there, multiple experiments were completed at prompt critical using the Godiva IV critical assembly. I observed several of them. The Godiva assembly used a safety block that was ejected from the machine by the energy shock wave created when the machine went prompt critical. Since then, the critical experiments facility has been moved to the Nevada National Security Site (previously known at the Nevada Test Site). Obviously, all experiments involving criticality are now done remotely.
6:38 You know, they say Alfred Nobel invented dynamite in 1867... i could bet my left nut that a whole lot more people invented dynamite. Nobel just happened to survive the invention.
I love Kyle Hills nuclear videos, the medical equipment allowed to poison a town, the blue laser through brains and Nuclear experiments are what I listen to at work a lot fo the time.
Critical mass. This is where people started to understand critical mass and how dangerous it was. Louis Slotin is like Stockton Rush on nuclear engineering.
How dangerous? Hell, it's critical mass which brought the idea of an atomic bomb, to begin with. What could be more dangerous than an instant disintegration? I'd say this was were they started to get the idea of the radiation hazard.
One thing about this, when talking about how this would never be allowed to happen like this happen, is the consideration that these very events are exactly why all those strict procedures are in place.
As someone who once lived 20 minutes from Los Alamos Labs, and have know people employed there in more recent times, I'm curious, what likely would have been the outcome if he had not swatted the brick away at that moment? Assuming neither him nor the security guard stopped the reaction, but ran instead. How different would New Mexico be today? I moved farther since, but still only about 400 miles away, Would my current town have been effected? Also, I am very much liking your channel after stumbling into it. Thank you.
It's just a small, unshielded, uncooled reactor that's prompt critical. It would probably melt down rapidly, or thermally expand to the point where it's no longer prompt critical. Even if it stabilized at power levels low enough for passive cooling it would take years to react as much as an actual bomb, so it shouldn't exceed that level of fallout. The military would probably just shoot it or something (an irradiated garden solved a problem with their Co-60 source getting stuck exposed by shooting the rope). Based on other criticality accidents (these are from Wikipedia's list) with long excursion times, it would make the accident worse, but only the people nearby would suffer from it 16 June 1958 criticality incident at Y-12 plant: 20 minute excursion due to uranium collecting in a 55 gallon drum. 3 January 1961 SL1 meltdown: a technician lifts a control rod by hand too far, resulting in prompt criticality, a steam explosion destroying the reactor, a few years of cleanup work, significant radiation exposure to rescue workers, and 3 fatalities due to the explosion. 30 September 1999 Tokaimura nuclear accident: workers deviate from procedures for the production of uranium fuel, leaving a precipitation tank of critical uranium to react for several hours until the water jacket was drained, boric acid was dumped on the tank, and sandbags were put up to allow residents back into the area.
Actually it could end up being like how the "nuclear bonfire" was handled, where you have a team of people practice using custom tools to dismantle and stick the assembly in a shielded box as quickly as possible (there's a video of the rehearsals and actual recovery on this site, and a reaction on this channel, look up "Lia radiological accident").
That pit was remelted and used in one of the tests. Since the pit was in critical excursions, it had the unusual effect that the mass/energy conversion was more efficient, ie there were more "generations" of the chain reaction. The reason for using the implosion system in the Pu device is contamination with Pu240, which is self-fissile and leads to pre-detonation, i.e. the number of generations is reduced, the fissile material is "dispersed" below the critical mass density and further reaction is not possible. When unplanned critical excursions occurred, a large part of the Pu240 contaminant was "burned off" and repeated chemical treatment was required to remove the fission products. The final pit had a reduced proportion of Pu240, and during the implosion, the critical density/mass was maintained for a longer time, which resulted in a higher efficiency of the chain reaction compared to the initial mass of the pit
The movie showed him hiding behind "bricks" of lead, if i remember right, manipulating the "demon core" which was, a sphere of burilium cut in 1/2 sections, with a ..screwdriver. Measuring the levels of alpha? Neutrons coming off of it as he changed the angle? Then there was a noise that caused him to drop the top half into the bottom, causing a semi critical mass. He grabbed it and pulled it off the other one, but it was too late for him. Lethal dose of radiation. At least that is my understanding. Correct me if i am wrong.
They could have done the experiments in a way where prompt criticality wasn't possible, and you know, not have balanced the neutron reflector with a screwdriver and bare hands... I agree that the experiments had to be done, just not that they did it the most reckless way possible.
Damn, great review. Had no idea about the "Demon core", happy the nuclear scientists community with people like you deliver this to us rest, like Kyle Hill too, wouldn't know about it otherwise. But it was hard to watch indeed. I can't imagine the pain they went afterwards radiation poisoning and how much pain it was. Would prefer honestly a bullet rather than that to be done.
In the 1920s - 1940s we had Shoe-fitting Fluoroscopes that people would use. They put on a new pair of shoes and then put their feet in a box that shot x-rays at their feet to get a "perfect fitting shoe." However, these boxes were just wood and emitted a lot of x-rays so people working with them were exposed to A LOT of radiation and we had little knowledge of how radiation worked at that time.
One physics point - the damage done by gamma rays is more than simple heat. Because of the high energy, Compton scattering becomes a factor, and this can cause short period catastrophic ionization of any atoms in the way with loosely bound outer electrons, e.g. the iron atoms in your blood. This would be as destructive as simple kinetic collisions with neutrons. When Compton scattering is not a factor, you just have either no interaction, or "knock off" ionization via the photoelectric effect. The scattered gamma rays and downshifted some but successive events happen until the energy has been lowered enough. IOW gamma rays are bad news when they are dense enough.
Learning curves are dangerous. I saw the Kyle Hill video long ago. I hear echos of the early work on some infectious agents. Experiments were only roughly designed and how could they know to design away the danger they did not yet know.
I've been watching for a while.. just realized i'm not subscribed and have been algorithmically watching D: Great content! I'm a nuclear physics enthusiast with a portable gamma spectrometer, I found a rock that's 300 uSv/hour Do you think that's a lot?
The average background radiation is 2.8 mSv/year in the USA. 300 uSv/hour = 0.3 mSv/hr. This rock could deliver a yearly background radiation dose in 9.3 hours. If a person would be near a source with such activity for a year, person would receive about 2628 mSv additionally on top of background radiation per year. When given at once, a dose of 2.6 Sv is categorized as HIGH by health physicists. If this dose is spread over a year, it will increase one’s chances of getting cancer, genetic abnormalities (for future children). Some radionuclides will decay over a year, and the activity will be reducing, but anyway don’t hang out near this rock. Give it away to a university for studying.
Tyler repeating ''demon core'' at the start is like one of thoses old japaneses godzilla movie where the camera switches to several people saying ''GODZILLA!'' 😆
I remember a long time ago reading a sci-fi fantasy book where a guy made a crude nuke in a granite mountain by boring a hole into the side of it. Cant remember if he had a metal cylinder or not to line the hole. Somehow had plutonium disc, enriched uranium disc or something then a small explosive charge in that order. Sealed it up and deleted part of the mountain for some reason. Cannot remember the name of that book, but as a kid I was like that seems way too easy. It was my first exposure to nuclear and nuclear weaponry. I was pretty young and thought it was really cool, albeit crude that you could do that and make it work. Of course that was before I learned how hard it is to get plutonium and weapons grade uranium. Ill have to search for that book to get the title, or if someone knows the book I am talking about. I'm really bad at remembering author names and titles lol plus this was back in the 90s and I was like 10 years old or younger. And that is the only thing I remember from the book lol. 😋 But it did get me more engaged into science. As always love your content!
sounds remotely similar to the nightlord series, which the titular character Halar/Eric creates a nuclear .....power source not a reactor but... its hard to explain.
the gun-type weapon used on Hiroshima is similar to what you describe, simply one piece of enriched uranium shot at another by an explosive charge to form a combined critical mass. the efficiency is much lower than more advanced implosion devices, but it's by far the simplest and most reliable way to design a weapon.
Heh, Dolly Parton curve. Reminds me of my 7th grade math teacher, Mrs. Johnson... she called improper fractions "dolly parton fractions" because they were top heavy.
When you compress/implode a plutonium sphere you get a spherical plasma, but what happens in a gun type bomb like little boy? Is the initial plasma a taurus shape? I have always wondered this but there is basically no information on gun type bombs other than little boy and that available info is pretty vague, I guess owing to it only being used in combat and not tested under full scientific observation.
I remember seeing a movie about the development of Fat Man and Little Boy many years ago that showed the second accident, when the screwdriver slipped and he tossed everyone chalk to mark where they were standing in the room. I don’t remember it mentioning the prior accident, but it was clearly shown that he knew what his fate would be as a result of his proximity to the core
Great commentary, mister engineer. Amazing how we can't blame this on ignorance, for as soon as they achieved criticality, they immediately knew what they've done.
This reminds me of the period in the 1800s when the progress towards isolating elemental fluorine could be followed via the obituaries column of the newspapers.
Of course, this wouldn't be allowed today and of course today we look at this and see "bad idea" written all over it, but that is because these incidents have already happened and we have learned from those mistakes. Before they were made however, while a disaster could have been predicted, we simply didn't know what would happen and the only real way to find out was to test it, and then find out the hard way.
Another bit of forgotten history is all of the patent medicines that featured the use of radium In various ways and also all of the people, mostly women, who painted the hands and numbers on wrist watches with radium paint for nighttime viewing not to mention the wearers too. The women were said to wet the tips of their paint brushes on the tongues to bring the hair to a fine point before dipping in the radium paint. Over time they would ingest this radium just like those who had ingested the radium infused medicines.
8:13 ... and WHY do you think that is??? It's BECAUSE of what happened here that those guidelines came into effect ... EVERYTHING has to start SOMEWHERE, and this was one such point that lead to better safety when handling sub-critical masses. 21:12 Marie Curie wasn't the ONLY one who died of radium poisoning ... there were also a bunch of women, the RADIUM GIRLS who worked in watch factories painting the luminous numbers on the watch and clock faces with RADIUM PAINT. Nobody told them about radiation, in fact they were assured it was perfectly safe, and they were licking the tips of their brushed to get a finer point ... and swallowing small amounts of radium paint which led to them getting sick and dieing, which led directly to the creation of OSHA
Uh, Mr Folse, 5:12 not true (reusable prompt critical assemblies contrinue to be used at the DAF). The reason to do the hand/incremental stacking tests was so they could figure out how to assemble fatman.
What was Slotin trying to achieve, at what point would he stopped lowering the sphere? He must have known that he had to avoid supercriticality. It's like igniting a firecracker without a fuse, and trying to recognize the point of ignition right in time to pull the match away.
I do wish he and others would be more specific. Just going critical doesn't create a bomb. Neither does going supercritical. Or prompt critical. Prompt supercritical is required, a state of unimaginably rapid increase in reactivity. Anything less and the core will just blow apart without a proper explosion. Bombs have to force this to happen, which is why a powerplant physically cannot, even if using - hypothetically - more enriched fuel, create an nuclear bomb.
Yeah though peoples risk tolerance varies a lot and in a lot of cases you kind of do need people who are willing when something is new to test things and see what happens. Reminds me of the wild stuff they got up to in military weapons testing at this time where they would do stuff like shoot each other to test protective vests out and the likes. Which is a little too spicy for people in the modern day.
He did know better. He chose to ignore all the protocols that were in place. He was so arrogant and his success(12 times he did the same thing)that he kept doing it.
Peaked Interest did a great video on Hisashi Oichi worth a watch. One of the few on youtube that does not slander the doctors that found themselves in such an unprecedented, extraordiary situation (I'm looking at you, Infographics Show.)
The Cold War of course was a reason why even allies did not trust each other, for the fear that the other side would get useful information not only about what was possible, but what you were doing.
Would the experiments even be valid given the time constant of the delayed neutrons? They could have assembled a supercritical geometry but not have a valid instrument response because they adjust the geometry faster than the system could respond. Or were they manipulating a core that was already in the delayed critical regime, looking for the prompt critical dragon? Are there currently any 'Approach to Criticality ' experiments being done? Jon
I believe there are current 'approach to criticality' experiments, hopefully with much more stringent controls and safety procedures: organizations.lanl.gov/ncerc/
Question sir?? Are these reactions of the scientists continually doing more and more dangerous things, because back then they knew what could happen, or are they based on our updated knowledge of today?
Yeah, this should never happen today because we have learned form mistakes like this. During the beginning of the cold war, it would be unlikely that these incidents would be shared with other facilities due to the hush-hush top-secret nature of the work. In the second incident, everybody in the room, except one, died of various forms of radiation poisoning or cancer. A private acting as security would die about 20 years later as a sergeant in the Viet Nam war, before the cancer could get him.
Something I think they didn't really understand at that point was that even low levels of radiation can be harmful if you're around it long enough. The demon core wasn't an on/off thing, it was always emitting SOME radiation. It's like being around a bonfire vs being in a burning building. The smoke is bad for you regardless, but the more of it there is, the faster it's going to kill ya.
With all the nuclear incidents/disasters out there, I notice that a blue light is typically the described visible light that is emitted from highly radioactive content, why is the colour blue? I figured with where Gamma rays are on the wave spectrum that the emitted light should be violet as the violet wavelength is closer to the gamma wavelength than blue is. (probably a silly question but I want to know).
Short version, it's the sonic boom of radiation. Cherenkov radiation in specific, go look it up if you want the full details. I probably got the spelling wrong but it should be close enough.
The radiation itself is invisible, but as the excited particles hit air they fission atoms in the air/water surrounding them causing a microseconds blue flash... a subcritical assembly is simply not releasing that many particles, so the flashes are only visible to very sensitive detectors, but once the assembly goes hot there are enough reactions that it is visible to the naked eye. Somewhere like a spent fuel pool, where the items are hot due to residual reactiveness, the blue glow is the warning that you would seriously not enjoy being there, but it is not a safe warning measure because the light comes well after dangerous levels of radioactivity. Consider the Lia Incident for details of where that blue glow was not present, and it was still VERY lethal, or any of the half dozen cobalt 30 accidents.
@@leechowning8728 Cherenkov radiation has nothing to do with fission products. It's caused by charged particles moving through a medium faster than light (air and water are not vacuum). It's an excitation and the blue glow is bleeding off the excitation.
