Chernobyl Episode 5 - Vichnaya Pamyat - Nuclear Engineer Breakdown/Reaction

[@TheAtomicAgeCM]

Looking for the Comments Review for this episode? Find it here: kzbin.info/www/bejne/bWrZppilbbyGi80 I decided to upload this video with quieter music to my Patreon (don't worry, this quieter music version is free for all to enjoy). KZbin doesn't let you go back and change these things (for good reasons, but small things like these aren't possible). So, head on over and check it out www.patreon.com/posts/85880166 This was my first or second go at adding some background music and it was definitely a bit too loud! Hope you enjoy this.

[@caroline4323]

Thank you. Your commentary was very interesting. When I watched it the first time I was very curious about how accurate the description of what really happened was. I am glad to hear that the scientific/technical reality is not far off (the detail about the graphite rod tips is... well, simplified but it does not kill the "what happened" explanation.) I found the first and last episodes the most terrifying. The first one with the gaping inferno well, the last- the court explanations. One faulty decision after another, piling up to the point where tragedy is inevitable. I am an Eastern Bloc child. I still remember that one of my favourite children´s books was a book that was explaining how a nuclear power plant works. :))). Russians were so proud of their science and achievements...

[@serpent6827]

I realize that this video is older but I just discovered your channel because I wanted an expert's opinion on this masterful show and the Chernobyl incident itself and I found it to be very informative and fascinating. Disasters, such as the Titanic, 9/11, and Chernobyl have always piqued a morbid curiosity in me and I watched your entire analysis on the show and your reaction to the scene in the first episode where the two workers stare into basically the hellish gaping maw of the core pretty much sums up how truly horrifying and dire the situation really was and the music that accompanies that sequence really adds to it as well. It kind of reminded me of a portal to the upsidown in Stranger Things and I was half expecting the mindflayer's tendrils to come out of it. Imo, it's easily the most horrifying, ominous, yet mesmerizing couple of seconds in the entire 5 part series. In all seriousness though, It just baffles me that the higher ups could not take responsibility, acknowledge how serious the situation really was, and admit that they fucked up. Too much concern with self image and not the people smh. Also loved the background music that you inserted in while explaining things in this vid and in fact I'm listening to it right now as I am typing this comment lol. Anyways, thank you for your interesting analysis. Subscribed.

[@TheAtomicAgeCM]

@@serpent6827 well, thank you! yes, lots of horrifying imagery in the series, lots of horrible humans. glad you liked the music! it's a bit loud in hindsight but ya live and ya learn. glad to have you here!

[@serpent6827]

@@TheAtomicAgeCM 👍🙂

[@peteruelimaa4973]

Yeah, the music was really weird. No fade, very loud. Thanks for the reupload!

[@ckhound1]

I think him saying its a "nuclear bomb" that wasn't taken to mean literally. Maybe thats how the show writers meant it, but I took it as an obvious reference to the explosion being imminent. I never thought of it as being a "literal" bomb.

[@hiltibrant1976]

True, looking at the rest of the episode, he's mainly using analogy the laymen (and judges) would understand, even if it is technically incorrect.

[@HoJSimpson]

Agreed. That's how it came along to me too.

[@moose2577]

The modem definition would be more like a dirty bomb.

[@pauladams8573]

Totally agreed

[@webx135]

Regardless, that's how it would have come across to most viewers. People educated in nuclear power are already relatively okay with nuclear power and don't need convincing. But this specifically misleads the people who are already on edge or simply not educated on the matter, and that's where public perception matters. And from THAT perspective, the show is very decidedly a cosmic horror about the dangers of nuclear power.

[@FerretJohn]

No, he wasn't being literal when he said Chernobyl was now a Nuclear Bomb, he was trying to explain what had happened in a way that a group of laymen could understand. As someone who's sat on juries I can tell you that getting too deep in the technical can kill the point you're trying to make.

[@thermobollocks]

"It's not a bomb, it's a supercritical nuclear chain reaction." Oh, so not great, not terrible.

[@oldmandoinghighkicksonlyin1368]

It’s been years, but still funny.

[@MaximGhost]

Well said, Comrade Dyatlov.

[@breadtoast1036]

thank you comrade, its the in-between from bomb to massive chain reaction

[@youtradvostraductions3082]

if you dont like actual explanations of reality, go watch Marvel movies, they keep it simple

[@breadtoast1036]

@@youtradvostraductions3082 woosh

[@Some_Guy6]

He simply used words that the judges and normal people in the court room could understand.

[@greaser3069]

and the common viewer too

[@Phoenix258]

yeah but that wouldnt allow an annoying neckbeard to post crap yt videos about it

[@squamish4244]

@@Phoenix258 Guy's a specialist, but jesus, he needs to chill out.

[@SeruraRenge11]

Something that needs to be said is that like 80% of the Soviet Politburo were people with engineering degrees. So the extent to which he kinda had to "dumb it down" for them says a lot about how much those degrees were worth in terms of the education quality provided.

[@slovakiaballif24]

@@Phoenix258 No need to get your panties in a knot over it

[@maotseovich1347]

Not a nuclear bomb as we call it, but effectively a 0.2 kiloton bomb powered by a nuclear reaction. I think the only reason we can't call it a nuclear bomb is because we only otherwise use that term to refer to the very special highly enriched much more powerful weapons we call nuclear bombs - which we don't really have a good alternative word.

[@raimarulightning]

Exactly. It's a bomb. It's nuclear powered. But it's not precisely a nuclear bomb because that usually means something very specific.

[@MostlyPennyCat]

Well, we do have published science on how this did actually come to be as close to a real nuclear bombs as it's possible to get with a power plant. Analysing the nuclear product collected up around Norway (I think) showed products that require that is a tell tale pointing to uncontrolled prompt criticality.

[@AdhamOhm]

@@raimarulightning A dirty radiological bomb, perhaps. I wouldn't call it a "nuclear bomb" technically because the explosion itself wasn't a runaway supercritical reaction. It was more akin to a very large "BLEVE" type explosion (with steam, hydrogen and red-hot graphite as the catalysts), it just happened to be in a nuclear reactor.

[@Draven84]

@@raimarulightning I think semantics become very important here. A nuclear bomb, emphasis on the Bomb part, is an accurate description. It never approached a nuclear Weapon, though.

[@everydaycompress4259]

if it go boom like bomb and has Nuculer atoms its a Nuculer bomb ..in russia bomb detonates you :D

[@jw870206]

Chernobyl Reactor #4 became more of a "dirty bomb," a bomb whose objective is to spread nuclear radiation, whereas a nuclear weapon is designed for a high yield explosion, where the radiation is a byproduct of the nuclear reaction that causes the nuclear explosion.

[@DJKuroh]

Yeah, in this case (and most media cases) I assume "nuclear bomb" to mean "an explosion involving spread of radiation" and not a description of exactly how an atom bomb works. I don't think the general public makes that distinction either. Radiation exposed+boom = nuclear bomb to the layperson.

[@amaryllis.2259]

its more like a hydrogen bomb

[@Thxtnt]

@@amaryllis.2259 A hydrogen bomb is a type of atomic bomb using fusion......

[@aaroncosier735]

@@amaryllis.2259 In the sense of hydrogen gas mixed with oxygen and ignited.

[@givikap120]

@@aaroncosier735 hydrogen bomb is not igniting hydrogen it's fusing it into helium using thermonuclear reaction

[@OR56]

Similar to the bullet analogy, in the court scene, he was using small words that the politicians and civilians would understand.

[@Pamudder]

The xenon pit was discovered within a few hours after the first Hanford reactor went critical. Fortunately for the program, the engineers had insisted in installing in the reactor about 50% more channels for fuel rods than the nuclear physicists said was necessary, so they were able to add additional fuel rods and overcome the xenon poisoning.

[@cremebrulee4759]

Thank you, engineers!

[@mattbrown817]

"A lot of power in a short time is called an explosion," I love this man.

[@davidhigham1570]

Charlie, you've gotten to a point where your subscribers/viewers are asking very technical questions and you're providing very technical answers. Congratulations, you've become a university professor and your class size is 50-odd thousand!

[@TheAtomicAgeCM]

oh, thank you! I can't call myself a professor, just trying to translate some nuclear stuff for interested people. But I whole heartedly appreciate the kind words.

[@Alex-kd5xc]

A full series explaining the Chernobyl disaster would be great. The entire reason I watch this series is because I like to hear the opinions of someone more informed than I, so I’d love to watch a whole series of that. Of course, it all depends on what you’d prefer to do (a full analysis series seems like it’d be a heck of a lot more work than a simple Q&A)

[@bruja_cat]

Agreed! I’d love to hear an actual nuclear engineer explain it in simple terms

[@Bigweave74]

There is nothing to explain comrade, RBMK reactors don't explode. You go to gulag now.

[@heliotropezzz333]

I think when he said the reactor had become a nuclear bomb he was using a metaphor rather than meaning it literally. He wanted a non technical audience to understand the gravity of what was about to happen.

[@eaglevision993]

Legasov´s analog Powerpoint presentation was a very nice touch in the series.

[@chriz9959]

legends has it , the makers of MS Powerpoint were inspired by the original presentation by Legasov

[@N19htcat]

​@@chriz9959 I want to believe

[@anirudhhhh]

Its just Soviet version of Powerpoint. Cheap and very informative.

[@GioBardZero]

I like how the production value of these videos has increased with each episode. Great info too, of course!

[@TheAtomicAgeCM]

thank you! i got a lot better across the five episodes :)

[@WaywardVet]

"It's not technically correct" Agreed, but he's explaining it well in the show. I knew as much as Boris first time I set foot on a nuclear site. So I like that he breaks it down "Barney Style" as we'd say in the military. But like Boris, I don't want to remain ignorant so that's why I'm here enjoying your explanation.

[@Ghyus01]

I think your conclusion summerises the show perfectly. The show isn't meant to be a documentary, it's ok to have some flaws in it for dramatic effect. It's supposed to shed light on the disaster and show the impact it had to the people there. With how many things the writer's got right, I think it's ok for some things to be dramatized for effect.

[@AlanCanon2222]

Some of the wrong things in the show were believed by those involved at the time. So when they say they're worried about a patient contaminating another person, that's something that was actually said in the book of interviews by Svetlana Alexeivitch. The series doesn't point out the difference in the moment, but it can be seen as added detail, documenting commonly held misconceptions of the day.

[@SynchronizorVideos]

Unfortunately, people treat it as a factual documentary, not a fictionalized drama based on true events. I've been studying the Chernobyl disaster since the '90s, and when discussing it with people, it's super clear when someone has only ever watched the HBO show.

[@ScottMStolz]

My impression is that the show was meant to display what people knew and thought at the time, and not necessarily what we learned later. To basically give us the experience that the people involved had. In that sense, it does an excellent job. It was not meant to be an after-the-fact technical analysis. If you want a technical analysis, other documentaries are more appropriate.

[@valdito_2123]

@@ScottMStolzexactly,people judging with today’s vision is dumb,back then they didn’t have the knowledge,that came with time and bc the accident,same when USA got his accident they learned from it,same when Valery do comparisons with military field,is just trying to explain a bunch of generals how nuclear works,you can’t use scientific words bc they won’t understand shit

[@elric5371]

It got everything about the explosion wrong whilst actively spreading soviet propaganda.

[@Wonkabar007]

Charlie is the perfect guide on a nuclear excursion 👍

[@TheAtomicAgeCM]

thanks so much for that! very nice of you to say. hopefully I don't have to guide anyone through an actual nuclear excursion haha

[@Nicky_Pin_It]

100% agree. Nice work Charlie!

[@lionhead123]

@@TheAtomicAgeCM no? you should do tours at Chenobyl. get paid, be out in the open air, grow a sixth toe. it would be great.

[@jazzitall]

@@TheAtomicAgeCM Well at least it would be nice to have you around 🤣 My thesis concerns nuclear data analysis. All things nuclear attract me naturally but hey you clearly enjoy movies and you're a gamer as well. Simply the best🏆

[@FilmMajor]

@@TheAtomicAgeCM I sent my MCJ WW3 plist to the Union of Concerned scientists, after i spoke to a media contact

[@mplewp]

I fear arrogance /stupidity way more than nuclear reactors .

[@ArcaneAzmadi]

Wise man.

[@natashasullivan4559]

Unfortunately there is a lot of fear mongering around Nuclear power. Even these days.. people reportedly were checking in after this to see where the nearest power station was. Because this scared them.. which, in a way is understandable.. but it gives the wrong kind of message about nuclear power as a whole. Just like that ridiculous 3 mile island "documentary" that came out on Netflix. Where it was basically just interviews of scared people.. rather than what actually happened. There's a KZbin channel who did a really good report on what actually happened at 3 mile island. The name is.. Kyle Hill He also went to Chernobyl, before the most recent war started..

[@RangerMcFriendly]

And that idiocy within governments. It’s abundant. As a former Fed let me tell you that incompetence, stupidity and evil are abundant…

[@kiddfunknyc]

so so right

[@darbyohara]

Machines, tools, computers, reactors, etc are only as reliable as their operators. They simply behave as instructed by the folks using them

[@Lordofthegeeks108]

Outstanding series (Both the HBO episodes and your breakdown of the key moments have been brilliant) The scene where the two technicians look into the burning fuel stack never fails to make my skin tingle with sheer dread and those poor firefighters being told to move up into the shell of reactor 4 in a futile attempt to douse it with water by people completely unaware of the dna shredding hell they were being sent into will always stay with me.

[@raven4k998]

Chernobyl reactor 4 is now a nuclear bomb uuhhhh NO!

[@shvak20mmcannon82]

What's BofA

[@MostlyPennyCat]

When they hit SCRAM, the graphite 'tips' displaced the water that kept the neutron flux low at the bottom of the reactor. Normal design operation kept the flux high in the centre and low at the edges (top and bottom edges) You want this because it's where the reactor core is weakest, where you've punched holes in the reactor walls to feed through control rods and company tubes and fuel and graphite stuff and so on. It's a compromise, you need holes in the reactor core floor, but it weakens the core, remember this design is something that can be built and welded by farmers and plumbers and such. So, to prevent this becoming a serious problem you have water instead of graphite at the edges, keep the heat and pressure lower there by reducing the neutron flux Problem is, when they insert the control rods you first have to push the graphite through to where the water was before the boron arrives. Which is fine. Except if you've run your core up to prompt criticality, now you've got the weakest part of the core and you displaced the water with graphite. Now you have _maximum_ flux at the _weakest_ point which cracks the fuel and those plumber's welds, _jamming_ the graphite where it does the most damage. At this point all that's left is the water acting as an absorber and all that was instantly lost in the first bang. Then it was just fuel and graphite and an even bigger bang. The reaction stopped when all the fuel and graphite was expelled by the 2nd explosion.

[@MostlyPennyCat]

After many years of reading about what happened, that's my best explanation of what happened inside the core of No.4.

[@viperthedragonsamurai.001]

For those who don’t know, the SCRAM is also known as AZ-5.

[@AlanCanon2222]

I'm both a science and a literary / theater type. I appreciate you standing up for the dramatic license. It's safe to say that millions know more about the accident because of this dramatic presentation, who would not have given the event much thought otherwise.

[@Drdoa_lot]

Thanks for taking us through these, I think you hit a perfect balance of breaking down where the writers chose to simplify or dramatise without attacking their choices.

[@gutspraygore]

In 1986 there was a movie called The Manhattan Project about a high school student that builds a nuclear bomb for a science fair. I have a feeling you would enjoy this one if you haven't seen it already. It's quite well done.

[@juliecrowder1432]

That was a good movie

[@ab5olut3zero95]

I showed that to my wife while she was getting her Masters in Nuclear Engineering. She cackled at how inaccurate it was. I still enjoyed it tho.

[@xavrag2225]

Pretty sure there was a flash game based somewhat on that

[@jeffcoleman2263]

Great analysis of the show - the Chernobyl series is one of my favourites and I've both watched it repeatedly and recommended it highly. I think the actors were great - the Brits do a great job with "reality" sometimes and I think they nailed it here. As did you, sir - well done.

[@TheAtomicAgeCM]

Thank you so much! Very nice of you to say. I enjoyed the show a lot but it's one of those shows where I have to prepare myself if I'm going to watch it again.

[@drbadzer]

To answer your question, a video series explaining your analysis would be greatly helpful.

[@raven4k998]

there is no rule!

[@emmitttraynor8939]

Mate I just listened to your entire 5 episode breakdown whilst playing golf and shot 86. Absolute joy to listen to look forward to watching more content on your channel. Loved Chernobyl. The best HBO release I've ever seen.

[@TheAtomicAgeCM]

thank you! Chernobyl is great indeed, but Band of Brothers will always be my favorite

[@darrenjaundrill2010]

Great series of analysis - thank you! I don't think the show was anti-nuclear or even anti-RBMK. I think it was about the final monologue -of the importance to seek truth, openness and transparency or pay the price later. Can we also do a shout out to the soundtrack. It really intensified the series especially this track (kzbin.info/www/bejne/l37CeZuLlKiJapY) where the composer actually went out and sampled the sounds of an actual RBMK. It is truly haunting.

[@MoyAmaro]

I'm new to the channel. I saw Chernobyl then came to KZbin to learn more about what happened and ran into this series. Very cool to see a professional kinda guide us through the show. Definitely looking for to watching more of your videos.

[@giacomopasini_content]

I would definitely prefer a full series explaining in depth the Chernobyl accident with a technical point of view.

[@mickeyhage]

I think Scott Manley made a video like that.

[@Agc2749]

There's a video here on YT called: Chernobyl-how it happened. I believe its an MIT lecture that goes into the technical aspects it is very interesting, a little longer than an hour. Give it a look.

[@christienashgrove3636]

Agreed

[@valdito_2123]

You have 3 books lol tv will never be accurate

[@alexsohn2474]

Love to see another video! Been really enjoying this series. Can't wait to see more content.

[@JonatanGronoset]

I'd watch a series on Chernobyl. And dark synthwave realy fits the nuclear "aestetic". Awesome.

[@raven4k998]

Chernobyl nuclear reactor unit 4 is now a nuclear bomb... uuuhhhh... NO!

[@bv1989ro]

I love this series but this reaction/analysis is such a welcomed companion series. Thank you for the time and energy you put in those videos. You are the proof that KZbin can be a wonderful place for meaningful self-expression.

[@TheAtomicAgeCM]

Thanks so much for such a lovely statement. I'm very glad you've enjoyed these videos so much.

[@nickhowe9986]

Fantastic and interesting series. As someone who loved the show and knew nothing about nuclear engineering this was a phenomenal watch. Thanks a lot Charlie!

[@TheAtomicAgeCM]

you're welcome! and thank you, nick!

[@RenegadeShepTheSpacer]

Just found your channel and subscribed two days ago. I loved the reactions and explanations for episodes 1-4 and have been very excited for this one too. Cheers!

[@JimmyKip]

Me too, great timing to get episode 5 after just finishing 4 yesterday.

[@gregcampwriter]

What the miniseries did for me was to ask me to imagine what the incident and aftermath were like for the people of the region. I was thirteen at the time and only got to see American news reports. It turns out that we knew so little.

[@joshtherahrah]

I think the writers meant nuclear bomb as in a bomb happens to have nuclear material contain within, not a fission bomb. There is U-235 present, and when it go boom it will distribute it around, equals nuclear bomb.

[@frazerguest2864]

I’ve watched all five of your episodes reviewing HBOs Chernobyl over the last four nights. It’s a 10/10 from me, and I don’t give those out very often. I’ll also say that I sleep better at night knowing there are people like you in charge of our nuclear safety.

[@TheAtomicAgeCM]

Well, thank you! That's very nice of you to say, I appreciate it.

[@richjohnax]

Really enjoyed this series about Chernobyl and would look forward to a more in depth series. Thank you for your work on these.

[@raven4k998]

reactor unit 4 is now a nuclear bomb um no!

[@erichall090909]

A full series explaining would be better than a QA I think. Would love that

[@jacquelinewood1]

i dont know how your series didnt come across my youtube sooner. but it definitely made me subscribe. as layman who just takes an interest in these things you explain it all very well

[@daniellassander]

A better way to think of the graphite "tipped" control rods is this. RBMK is a huge reactor so it will have hot and cold pockets in terms of reactivity, if we add to that that it has a positive void coefficient the reactor has a tendency to run hotter at the top and being cold at the bottom, so by having those graphite tips they can increase reactivity at the bottom and decrease it at the top. For the control of the reactor it solves a lot of problems, but in hindsight it was a bad decision with no easy work around.

[@HT-jj5sx]

Great video man, I was super impressed on how well the series did to explain really complicated topics to the layman very effectively, you've just really doubled-down on that and gone into so much more depth. Thanks man, what a cool 30 min!

[@hokkikokki]

As a half-Estonian, visiting Soviet Estonia since 1980's the life and details are 100% like the Soviet life was then. This series brings back so many memories from my childhood.

[@KindredKeepsake]

I love this series, and I love how you broke everything down in it. This was a very fun last couple of days watching it!

[@TheAtomicAgeCM]

thank you!

[@KindredKeepsake]

@@TheAtomicAgeCM Hello! You're welcome!

[@thedrunkenbunny9351]

Why not go into nuclear plant disasters through their history? As the science evolved, what we learned, how we improved, the implications of said disasters for us and future generations :D

[@TheAtomicAgeCM]

Yes! I want to go into not only reactor accidents but also accidents more directly related to my field - criticality accidents.

[@rocketdog2116]

@@TheAtomicAgeCM Maybe a video on the Demon Core?

[@thedrunkenbunny9351]

@@TheAtomicAgeCM Love it!

[@bigfootape]

@@TheAtomicAgeCM Hmm... would the criticality accidents at Tokai and Mayak be interesting?

[@GGigabiteM]

A series on the full nuclear supply chain of accidents would be better. Many of the worst nuclear accidents are largely unknown because they're forgotten or covered up. Church Rock, NM being one of the worst that released over 93 million gallons of acidic radioactive tailings and 1000 tons of solid uranium waste into the Puerco river back in 1979. United Nuclear barely even attempted to clean the mess up before resuming operations for several more years and ultimately abandoning the hot mess in 1988 and leaving it to the US taxpayers to clean it up, which to this date still hasn't been dealt with. But that wasn't the only disaster they caused, and wasn't the only company to cause a disaster. The whole industry is mired in gross negligence, incompetence and takes zero accountability for their actions. If something bad happens, they just go crying to the NRC for help and force taxpayers to hold the bag, while they declare bankruptcy, change their name or sell out and wash their hands of the matter. There are spicy nuclear hot spots all over the midwest and western US from nuclear testing, accidents and mining.

[@EXRazeBurn]

I mean it WAS a "nuclear bomb". It had become an explosive powered by a nuclear based mechanism. It just wasn't a weapon designed to intentionally trigger a runaway fission or fusion cascade reaction. Honestly I would say its the same situation as the "bullet" analogy earlier in the series: Yes its not a perfect analogy and would be irritating to experts in the field. But our speaker isn't doing this for the benefit of experts. He is trying to impress the full gravity of the situation upon laymen in a VERY short amount of time. Nuances can and will be sacrificed in such a situation.

[@midian879]

The ending monologue, goosebumps. Fantastic series.

[@dirtbagdeacon]

I just want to say that I REALLY appreciate your ability to say 'this is a dramatic piece, not an accident report.' I feel like our culture has gotten so literal that we don't even understand the purpose of art anymore, and are too busy picking apart single threads to appreciate the whole tapestry. Your commentary on this series has been very interesting for me, a person without a nuclear background. Thank you for being a thoughtful engineer!

[@TheAtomicAgeCM]

thank you! couldn't agree more. glad you enjoyed it, and thanks for the thoughtful comment

[@Whatever_works]

I think a full overview of the timeline of the disaster would be great!! Thanks so much for all of the wonderful details you contribute on this series! 🌞

[@christianromero6604]

Hey man, i just found ur channel on a short ...man im glad i took the time to listen/ and pay attention to how u laid it out.Job well done my friend, u just earned a sub) Keep on t

[@TheAtomicAgeCM]

that's awesome! thank you so much, really appreciate it. (i gotta make more shorts hehe)

[@whistletom]

Awesome series of videos. A perfect companion guide to the dramatisation. I think some people in the comments forget that the purpose of drama is to hone in on the emotionally resonant aspects. Chernobyl is very much a story about people. The details have a lot of technical aspects but the story of is one of subterfuge, arrogance, personal loss, horror, heroism and sacrifice. Thanks again for the this fantastic series of videos.

[@joseluislopes3956]

24:00 I don't think the intended meaning of thar sentence was to say that a containment structure would help in this situation. It was just enumerating various cases were budget was more focus than security. That's what I THINK they meant but the writers could also have some source that told them a containment structure would "help".

[@elbryan9]

I really enjoyed this series, especially this episode as I thought the way Legasov explained the concept of reactivity was pretty good. I haven't had anything to do with the nuclear community since 2005 and it's amazing just how much you forget so I really enjoyed your take on this series. I remember near the end of Power School we got a brief presentation of the Chernobyl disaster. That was back in 1999 so my memory of it is pretty fuzzy but I do remember they taught us the plant didn't just go supercritical but prompt critical and that it was engineered with a positive temperature coefficient of reactivity which, knowing how heat works, never really made any sense to me. How would somebody engineer something like that? Looking up the incident now as a civilian, I realize they must have mistaken positive _temperature_ coefficient of reactivity with positive _void_ coefficient of reactivity. They sound kind of similar so I guess it's understandable? I don't know. I know how S8G reactors work but I'm still trying to wrap my head around the physics of a positive void coefficient so I would definitely be interested in a video or a series explaining in depth what happened at Chernobyl.

[@TheAtomicAgeCM]

Thank you! I can't imagine how much I would forget leaving my job for a few years haha. Yes, Legasov's presentation is quite good. The red and blue cards are simple but effective. A positive temperature coefficient sounds weird, indeed. I'd be curious to see an example of that. For the positive void coefficient, I kind of gloss over it in the video, but the RBMK was designed to be very close to optimally moderated purely from a fuel/graphite standpoint. So, the water in the fuel channels had enough neutron capture to make it act like over moderated and gave way to the positive void coefficient.

[@saksham1252]

5:18 nuclear fuel becomes less reactive when it becomes hotter! Can someone tell why?

[@elbryan9]

​@@saksham1252Reactor power is dependant on how many neutrons there are that are available to cause additional fission reactions. Anything that changes the population of neutrons in the core effects what is called reactivity. Too many neutrons (positive reactivity), reactor power goes up. Too few neutrons (negative reactivity), reactor power goes down. And of course, there can be just enough neutrons in the core to sustain criticality. When uranium-238 gets hotter, it absorbes more neutrons making it behave like a poison (nuclear poison are materials that absorb neutrons such as the control rods). Fewer neutrons means negative reactivity or, put another way, less reactive fuel.

[@saksham1252]

@@elbryan9 first of all thank you for replying! So by my understanding as heat raises and reactivity increasing causing number of neutrons in fuel or core to decrease and thus eventually slowing the reactivity. And what does it mean by u238 absorbing more neutron. doesnt absorbing more neutron cause more atom to split

[@elbryan9]

@@saksham1252 Yeah no worries. This stuff is interesting. That really depends on if the material is fissile or not. Fissile just means it'll fission (or split), if it absorbs a neutron. Uranium-238 isn't a fissile material. If it absorbs a neutron it'll become the isotope uranium-239 (another non-fissile material) and that'll be that. Uranium-235, on the other hand, is fissile so when it absorbs a neutron, it'll fission into two different elements which releases additional neutrons in the process. This is why enriched uranium is so important because uranium ore is almost entirely comprised of the isotope uranium-238 (more than 99% in fact), whereas uranium-235 is a little under 1%.

[@yakumoyukari4405]

13:16 there are, they were confiscated and classified by KGB and now under procession of FSB

[@teboots1]

I would LOVE a deep dive into the actual event. Also, exploring the designing/construction/placement of the sarcophagus would be awesome, too.

[@ExAstrisScientia]

Having just watched the show, I really wanted to see if someone had done an episode by episode breakdown that had credible knowledge in the nuclear field. I have to say I really appreciate your viewpoint and your understating that a show has to explain things to its audience like the scientist did to the politicians. As only an enthusiast of nuclear engineering and science, I can even point out some of the issues you mentioned, but I can look past them for the sake of dramatic story telling. Once I saw the "Lighting Fast VCR Repair" shirt I knew why I liked your perspective from the start. And that Episode 1 poster fading in had me laughing for a minute. Thank you for taking the time to make these videos, and I look forward to exploring the rest of your channel.

[@MichaelVLang]

A series taking a deep technical dive would be interesting especially into the mechanics and controls.

[@Dudewithnoface1]

I am not a nuclear physicist, chemist, engineer, or anything even remotely close to that. By trade, I am a clinical psychologist. However, I cant help but to be fascinated by this kind of stuff, and this series was outstanding. You provided excellent, easy to digest answers for a topic and field that is often inaccessible for people who do not work in this field. Thank you! 🙏

[@chris2klee]

Started watching this series on Monday, and it's Friday, was a good wind down to my weekdays. UNLIKE CHERNOBYL! AM I RIGHT! I'll see myself out.

[@mynameisix]

Got this series recommended to me by KZbin. It was a great watch, I enjoyed learning some more technicalities about how nuclear plants and power works. Thanks for sharing your knowledge and insights!

[@joshuaanderson9587]

A video series on the Chernobyl incident itself would be awesome! I vote yes

[@sheogorath979]

IMHO, arguing Chernobyl was not a nuclear bomb is only an academic discussion, for the layman, which make most of the jury present in the dramatization a nuclear reactor that explodes and spreads nuclear fallout equals a nuclear bomb, it doesn't matter if the mechanisms are different... The effects are the same

[@TheAtomicAgeCM]

the primary purpose of a nuclear bomb is not to spread radioactivity, it's to destroy vast numbers of buildings with an enormous pressure wave

[@nedames3328]

As I understand it, the reactor core hosted an uncontrolled chain reaction that only ended when the supercritical mass got blown apart. So technically "nuclear powered" and technically an "explosion. "Nuclear bomb" seems an apt description. Definitely not a "weapon" though and "bomb" implies weapon. Cheers.​@@TheAtomicAgeCM

[@ReaverLordTonus]

When the "judge" or whoever presiding over the hearing asks "why?" and he's told "it's cheaper" I love the look he gives those guys. Like "wtf, if there's one place we shouldn't be cutting corners, it's this $hit!" It really says a lot about the Soviet Union, they were so determined to catch up with the rest of the world while also maintaining this delusion of superiority, that they allowed so many reckless and potentially fatal decisions.

[@dunning-kruger551]

It’s my favourite show, I’ve seen it so many times. I’ve watched many videos on the subject, your version was the best. Look forward to more content.

[@TheAtomicAgeCM]

Thanks so much! That means a lot to me

[@alicewilliams1597]

They knew four years before Chernobyl.Another nuclear reactor had incident not as bad as Chernobyl, Lack of communication of this problem kept other operators in the dark.

[@paulrasmussen8953]

Because image was mlre inportant then safety. By sheer irony the soviet union made the same mistakes of thw imperial russia. Wrong people in charge

[@canda83]

Also I would just like to thank you for all your reactions! I have found them very informative and appreciate that you see that some things are done for dramatic impact and respectfully discribe how this actually works in real life!! Keep up the great work

[@TheAtomicAgeCM]

You're welcome! and thank you!

[@TWFydGlu]

Regarding the lava explosion it's also important to realize that it is irrelevant if it was possible or not. What matters is if they at the time thought it was possible. It may fail on that metric too, but that's what you are measuring against.

[@mckenzie.latham91]

It was beleived at the time because the plant was used as part of the Soviet H-Bomb project That the tanks of water underneath were filled with irradiated water which they thought could have allowed for a thermal explosion of that magnitude when the lava hit it...

[@JohnSchuster-g8g]

If there was one thing to say about your reaction, you took a topic that I can only imagine a very very VERY small percentage of people could break down and understand, and delivered it in a way that most could easily understand. That was awesome 🤙

[@FSUFAN-gr2vp]

I would love to see a stand-alone Chernoby video or video series on this accident. I've always had a weird interest in this accident. So seeing a video explaining the incident would be interesting.

[@markwatkins6882]

Great job on explaining everything,really fascinating stuff !!! The series was really well done and chilled me to the bone...

[@TheAtomicAgeCM]

Well thank you! Yes, it was quite terrifying

[@herrbrahms]

Dyatlov's dereliction of responsibility with the gravest stakes always makes me laugh. Here he is working the night shift with a bunch of f$%^ing greenhorns and he hasn't even had his coffee. I think of Dante from Clerks: "I'm not even supposed to BE here today!"

[@Hustlexz]

Hey Charlie, I had your episode 1 video randomly pop up on my KZbin algo one day and I’m glad it dude. I binged your episode 1-5 and subbed, thanks for doing this series it’s fantastic and feeds my obsession/curiosity with Chernobyl.

[@TheAtomicAgeCM]

hi, hustle. Thank you so much, and you're welcome! Glad I was able to add something to your understanding.

[@mcs081485]

More like a "pressure cooker" than a bomb. I've read about this, watched the series Zero Hour: Chernobyl, and watched this HBO miniseries. This event fascinated me from the get go.

[@bluesrocker91]

Would definitely like to see a full series on the Chernobyl disaster (and other nuclear accidents for that matter). There are some good videos out there explaining the physics and engineering behind it, but they tend to condense it all into a single 15 minute video, whereas a series on the matter could really take a deep dive.

[@Dobviews]

Would love to see this done for the SL-1 reactor accident in Idaho in 1975.

[@TheAmazingSnarf]

love ya, Charlie. thanks for being our Nuclear Safety Engineer. The world's a far better place with you, your knowledge, and your sharing of your knowledge.

[@TheAtomicAgeCM]

Thanks so much! Very nice of you to say.

[@simonh317]

The issue though is this is Soviet Russia, and whilst she `should `have access, the state wants to keep secrets of previous problems, so therefore she wont have that access. She doesnt need to know what happened before, as it said in the episode. The same ethos was said previously with the meeting Legasov and the KGB. Blame human error, nothing else needs to be known as it`ll get fixed

[@Dularr]

That is one of the nits about the show. The scientist were aware of the design problem. They just follow the propaganda response

[@simonh317]

@@Dularr it was that or a bullet

[@SammiCPC79]

@The Atomic Age, Hi Charlie! I really appreciate your videos, thank you. It's a real privilege to get the take from an actual nuclear engineer/physicist. This series really gripped me, I was 7 years old at the time it happened and I remember vividly the news reports from the time, and my father trying to explain to me about a sort of fire that was for some reason nearly impossible to put out. We measured the fallout in the hills in Wales where I grew up. I gotta tell you, the news was crazy back then. I remember seeing videos of the helos dropping sand, doors sliding open on the Mi-8 and bare hands shoving sandbags out before slamming the doors shut again. The next year Challenger blew up, that I was watching live. I remember seeing people somewhere in the middle east being decked by rubber bullets earlier that decade, all on BBC. Crazy times. Now that you've done Chernobyl by HBO I wondered if you ever saw the BBC production docudrama Surviving Disaster: Chernobyl ? kzbin.info/www/bejne/jKfGaKZvbayXrtk It's a lot shorter and less detailed, and a lot older - but it captures the horror really well. Takes a few artistic liberties here and there, is a bit more sympathetic to Dyatlov and so on. Would be interested to hear your take on it. Was supposedly based on Legasovs tapes at least in part. Before HBOs excellent series this was pretty much the only good dramatisation of the events. And I'd love to hear your intuition on the exact events and processes of the Chernobyl explosion. Thanks again, looking forward to any videos you put out :) Sam.

[@TheAtomicAgeCM]

Hi MadSammi! Sorry for the late reply, I'm scrolling through comments for a corrections/follow-up video and somehow missed yours. I have seen the Surviving Disaster docudrama before, I enjoyed it a lot. It could definitely be something to do in the future.

[@davidbaca7853]

We will probably never know but I’m still curious as to who is in possession of the actual AZ-5 button from control room 4 since the control room has be scavenged and looted. Reason being it is something that created something that will probably be here forever. The detonator.

[@langdalepaul]

I’m not convinced of this. I’ve read a number of papers that say a prompt excursion was inevitable by the time they hit the reactor scram. The graphite follower issue just exacerbated it. The show made a big deal of this point, but it was only one of many factors that led to the accident.

[@paulheitkemper1559]

@@langdalepaul inevitable because the rods jammed with the graphite near the fuel? Or that it would've happened even if the rods descended all the way?

[@langdalepaul]

@@paulheitkemper1559 the emergency shutdown rods were too far withdrawn and took too long to motor into the core. The biggest factor in the reactivity of the core was the positive void coefficient. The positive feedback loop that this created was taking the reactor inevitably towards prompt criticality and the control systems were not fast enough to react. By the time they hit the scram, the reactor was already experiencing an excursion. The graphite followers certainly accelerated the problem in the lower part of the core, but a few seconds later and it was going to happen anyway. It took 18 seconds for the control rods to fully insert into the core. That reactor didn’t have 18 seconds to live.

[@paulheitkemper1559]

@@langdalepaul thanks for the follow-up 👍

[@shevek5934]

This is your first video I've seen. Subscribed in hopes for the detailed analysis!

[@willerwin3201]

"As Temperature increases, reactivity decreases." My understanding was that this is due to thermal swelling; as the fuel gets hotter, it expands, decreasing the density of the fuel and increasing the probability of neutrons escaping. I was not familiar with resonances for U238 increasing in energy bin width for peaks.

[@elric5371]

That’s just wrong, increase in temperature = increase in reactivity, chernobyl had a positive fast power coefficient.

[@willerwin3201]

@@elric5371 It’s complicated. Chernobyl had a positive temperature coefficient in certain conditions, like those of the accident. Specifically, it was designed to operate with steam bubbles, known as voids. When the reactor didn’t have those bubbles present due to being at low power, the water absorbed more neutrons. So when the power went up, bubbles formed, and fewer neutrons got absorbed, leading to higher reactivity. This is known as a positive void coefficient. Eventually, thermal expansion of the fuel in the reactor did help kill the reactivity. Unfortunately, this didn’t happen until the core was destroyed.

[@elric5371]

@@willerwin3201 correct.

[@hitmontree3736]

I'd really like to know what background music you play when you start explanations. An example is at 23:56

[@TheAtomicAgeCM]

Sure! it's called Digifunk by DivKid

[@DogmaBeoulve]

Something that always tickled me about the supposed dangers of Chernobyl that they echoed in the miniseries is the incredible difference that was missed between a *nuclear bomb* and a *dirty bomb* - and this is only because I was deeply fascinated by World War II and the advent of the nuclear weapons used, so I knew at least a little. I was a bit ruffled when anyone in the show suggested that, somehow, a nuclear reaction/explosion would or could be triggered simply by the presence of nuclear/radioactive materials and an explosion. Both are bad things and, when put together, they're really awful things, but haphazardly stuck together outside of specific circumstances and an engineered reaction, you're not getting kilotons or megatons of nuclear explosion, you're getting a really big, fairly radioactive, regular-but-dirty explosion that's *still* not good for anyone, but a far cry from nukes going off in your backyard.

[@HeWhoShams]

You seem to forget who he is talking to, a bunch of people that do not understand how nuclear reactors work. Using common speech to get his point across does not make him wrong if it gives the intended effect as if he was speaking to a expert in the field and gave your summary.

[@amrider2099]

If this guy was writing this show the show would have been doomed

[@toolthoughts]

nice work once again, cheers. would love more detailed videos of the event itself

[@toolthoughts]

it would also be interesting to hear any comments you might have on Dyatlov's interview from 1994, where he gives his account of what happened. it's on youtube with english subtitles

[@thehollownet9403]

Oh!! Been Looking forward to this one! Thanks Sir!

[@thrasius8856]

Heck yeah! great way to start a Friday afternoon. Thanks!

[@LegitTapeSplicer]

IMO, the show main theme was exposed at the end when Prof. Legasov asks, "What is the cost of lies." The show came out in 2019, and we all know what happened a year later.

[@credit__devin]

Been waiting so long for this thank you

[@enoughothis]

The long awaited much anticipated conclusion!

[@nickweston6472]

Plainly difficult has done some really good videos explaining the accident as well.

[@drtidrow]

14:00 That's exactly what happened with the first plutonium production reactor at Hanford - they started the reactor on Sept. 27, 1944, but by the following evening xenon poisoning had shut it down. The next morning (9/29) the reactor started back up again on its own, after enough xenon-135 had decayed away. They tracked down the poison as xenon-135, and were able to add additional fuel elements to overcome the poisoning effect.

[@TheAtomicAgeCM]

Awesome, I hadn't heard about this story specifically before.

[@drtidrow]

@@TheAtomicAgeCM Look up "iodine pit" on Wikipedia, they have the story there, along with a link to an interview with the DuPont physicist who figured it out with Fermi.

[@ZhekUA]

Well, it was definitely a military experiment testing of workability after airstrike. And as I know, building is designed to withstand an impact of supersonic (1 Mach) MiG-21

[@dagallgray]

Fascinating commentary - Thank you. Yes to both video ideas. I had family with nuclear industry background, but not myself. Still, learning more and more about this reactor design, the concerns and complexities has been riveting. Thanks for clarifying important points like how this isn't technically like nuclear bomb design, but at the same time recognizing environment impact. I'm involved with local EMA groups in a region where we have several nuclear power plants. They've operated for decades with overall few incidents, so safety culture is a key point I'm glad you mentioned.

[@christopherjohns1566]

If I remember correctly, the time it takes for a nuclear bomb to detonate was described as "3 shakes", taken from something happening in 3 shakes of a lamb's tail. A shake was defined as 10 nanoseconds, so a bomb completes it's nuclear portion in 30 nanoseconds, or 30 billionths if a second.

[@TheAtomicAgeCM]

something absurdly fast like that

[@1995rwt]

A Chernobyl explainer from someone with your expertise would be awesome to see

[@drbadzer]

Finally! Was waiting for this since forever!

[@nomad_lyfe]

Anatoly Dyatlov enters the control room Employees: Why do I hear boss music