Chernobyl Accident - Simulation only (no talk)

[@Higgsinophysics]

Turn on caption or see: kzbin.info/www/bejne/hmTSfIF7bJd4sLc to understand this video. I don't use commercial sponsors. Let's keep it that way. Support here: Per video: www.patreon.com/Higgsino One time: ko-fi.com/higgsino

[@Archangel657]

Why don't you have the graphite moderator end caps on the underside of the control rods absence for most of the simulation? You should keep them on for the whole duration to make the simulation accurate while remaining simple.

[@Chitose_]

this simulation is plain awesome, even despite the tragedy responsible for the creation of this

[@GrogorijF]

Only Bruce Lee could solve this ping pong challenge.... Unfortunately he wasn't around....

[@kiryukazuma6078]

@@Archangel657 go make the video yourself then, stop complaining

[@hansbrackhaus8017]

perhaps edit your subtitles to explain the lack of graphite rods at the beginning...

[@XD152awesomeness]

It really does demonstrate how quickly exponential functions get out of hand. It was all under control until it wasn’t

[@Higgsinophysics]

You phrased that really well.. Yes it's so crazy! My computer agrees. Before the accident: 0.1 seconds render time per frame. During the accident: 10 minutes render time per frame lol. (My code is not the best, but still wow)

[@jprobles4152]

only that they were never really in control. so much human error and violations with nuclear safety. the video also shows that the control rods are not used properly which is the biggest fcator of the failure.

[@GustafUNL]

@@jprobles4152 They were still in control, just not using their control wisely. And because they used their control foolishly, they lost their control.

[@lambda653]

That reminds me of the common parable that's told about AGI safety. It's all under control because the AI is a lot more stupid than humans are, until it's not under control, and then you have an exponentially self improving intelligent agent that is fundamentally misaligned with humanity.

[@huuuuuuuuuuuuuuuuuuuuuuuuuuuhn]

really terrifying if you think about how the entire planets fate depends on a couple of guys shoving or pulling regulation rods in and out of some reaction chamber

[@sarahb.1602]

The last few seconds of this video are even more terrifying with no narration :D Wonderful.

[@b.j.880]

Holy crap yeah, the sudden cut off like a "you already know what happens next" type of deal.

[@Legal_Sweetie333]

You people need to work on your vocabulary.

[@Poloxamine-tg8dh]

​@@Legal_Sweetie333You know, not everyone on youtube isn't american.

[@1080pol]

It's like a fever dream

[@quadro1493]

It kinda sounds like a coffee machine, it's just a bit more dangerous and overkill to heat a cup of water

[@notaplasticexistence]

Turning off the warning alarm instead of the exploding reactor is fantastic, what a real meeting of the minds over there.

[@freshrockpapa-e7799]

That's how things are done literally everywhere, maybe nowadays in some sectors it isn't.

[@ultimateearrapechannel31]

@@freshrockpapa-e7799 definitely not true safety wasnt nearly as much of a concern as it is nowadays. we have safety things everywhere now. they wouldnt even be able to lift the rods manually if this was after 2000

[@ShuberFuber]

​@@ultimateearrapechannel31also modern design placed more focus on not sending spurious alarm/warnings. So the moment an alarm actually went off everyone is on high alert.

[@freshrockpapa-e7799]

@@ultimateearrapechannel31 You literally just repeated what I said.

[@notaplasticexistence]

@@freshrockpapa-e7799 You said it with a smarmy attitude though so really I'd just prefer if you stopped responding entirely or removed your comment. You normies on the internet always having to be correct is annoying.

[@ccrouzet]

2:40 : "the computer warns them to shut down immediatly, so they shut down the computer instead" 😭😭

[@samuraijack6871]

Ain't no stupid ass computer telling me what to do 😂😂😂

[@DonVigaDeFierro]

"warning!!! Shut down immediately!!!" "WHATEVER YOU SAY MR. COMPUTER!!!"

[@DomTVdotTV]

@@samuraijack6871"pfft that's for amateurs i know what i'm doin"

[@ArtUniverse]

Soviet problem-solving at its finest.

[@marshmallowbudgie]

Comrade Computer is your friend

[@r.b.ratieta6111]

Aside from the ending, the part that really creeps me out is when all the control rods are pulled, because you can almost sense the engineers were kinda scratching their heads at that point like, "Hmmm. Why isn't it working as expected?" You can almost sense a debate going on between the engineers in the control room as the rods just linger there, with half of the group saying, "We need to stop NOW. This is NOT good. Sure, it doesn't look dangerous, yet, but who knows what will happen if we keep the reactor like this?" And the other half, or whoever was in charge (Dyatlov?), is basically saying, "It's not as bad as you think. Look, the reactor is still stable." Only when you start to see steam voids can you see the engineers saying, "Okay, okay, shut it down. Not worth it." They hit AZ-5, the control rods go down and -- wait they haven't gone all the way down. What is happeni--" *KABOOM!!*

[@dstods]

There’s also the fact that the rods when fully withdrawn are not only less effective at neutron absorption but actually make the reactor more reactive at the beginning of being absorbed due to them displacing water on the way down.

[@Maxikxng]

​@@dstodsnot only that in the end in the video, a few more moderator rods appeared, wich irl where about 2/3 of the controll rod lenght and attached below the controll rods for more efficency. but since they didnt reach the reactor bottom when the controll rods were fully pulled out, at the bottom a bunch of fast neutrons could accumilate and when the az-5 was pressed, the displacement moderator from the controll rods caused them all to slow down and rapidly react, creating tons of heat boiling ALL of the water in the reactor at once (wich was not boiling due to the running at low power as it was xenon poisones at the top) ,wich let to the multi ton reactor top being blown through the god darn roof . . . All in all the accident was caused, by the reactor design, and the issue with the controll rods/controll rod moderator displacer, wich they knew about but didnt tell the operators so there was no way for them to know that the az-5 could in some cases be a detnation button. Even with my previous statement the crew on shift at the time could have realised that the reactor was unspable due to being xenon poisoned and shut it down completely, wait 12 hours and then start it up slowly to prevent damage. Conclusion: chernobyls accident was caused by design flaws, keeping said flaws secret from operators and in the end Human error. And yes this is a very long text but ive always been facinated by the accident and nuclear stuff in general :)

[@isaowater]

Plenty of this has been disproven. The control staff was all pretty calm, yet tired. The decision to shut it down came when control shift chief, A.F. Akimov gave a simple shutdown order once turbine testing rounded up. Dyatlov had no real hold on reactor operation, he was more there on account of his position, he left all decisions to Akimov.

[@mr.roboto209]

One key thing to remember is this taking place in Communist Russia. If you don't meet your power quota, kiss your job/life goodbye

[@christopherhoward8526]

@@isaowater And all operations were within the operational protocol! The RBMK design flaws were not known by any of the staff and mitigations were not in the operations manual. When things went tits up, the operators were blamed, not the government body responsible for developing operational protocols! This blame shift persisted into the HBO miniseries turning many of the good/innocent guys into victims and vice versa. All RMBK were bombs ready to go off given the right conditions until modified with upward control rods to prevent the bottom of the pile from going inadvertently critical! Dig in here www.youtube.com/@thatchernobylguy2915

[@MisterBigwolf]

After 3 minutes of exposure to the video, my face turned red and I started having headaches and vomiting.

[@syrup_710]

It's from the feed water I've seen worse you'll be fine

[@jewiesnew3786]

Did you happen to taste metal?

[@davidmendozamendez156]

FALLOUT MENTIONED 🦅🦅🦅🦅🦅🦅🦅🦅🦅

[@danielventura7310]

Dont worry. It means its time to go to bed

[@ringspecies]

Three minutes? Not great, not terrible.

[@StefanoMei]

The end actually freaked me out 😅

[@ChaseThePinballWizard]

its so god damned loud thats why

[@JackBond1234]

It's just the simulation. It was much more peaceful at the real power plant.

[@ultimateearrapechannel31]

@@JackBond1234 yeah sure...

[@SeanVito]

​@@JackBond1234yes radiation exposure is very peaceful until your body starts to just fall apart. Everyone was freaking out, they knew how horrifying this was.

[@freakguitargod]

5000+ rads will kill you in seconds, cant imagine how it would feel.

[@deitznuts7133]

"Hey, lets prank the guys on the reactor floor!"

[@galactic-guy]

It's just a prank bro

[@HaSTaxHaX]

"you'll love their reaction"

[@That_One_Guy...]

More like trying to prank the world

[@snakeplissken1933]

When the rods begin to move up and down like crazy in reactor room.

[@kang6088]

PRANK EM JOHN

[@senseii_philippines5353]

"The computer warns to shut down immedietly, instead they shut down the computer off" bro 😥

[@isaowater]

No such computer warnings happened, the SKALA system didn't make warnings. That bit of information came from Mr. Grigori Medvedev, a known liar in the Chernobyl field.

[@PC-coolant-pipe-sucker]

@@isaowater The computer DID warn them. I will give a source later.

[@dyfrigshandy]

​@@isaowaterbla bla russian sympathizer bot You're the liar dyatlov boot licker

[@andymarquez9902]

Computer don't warned about it (that technology wasn't available at the time), the Nuclear Safety Regulation of the Soviet Union demanded that as mandatory in that situation: regulation was violated, including minimum of 30 control roads, 700 MWt and other important rules.

[@stephenlafleur9028]

>press any button to shutdown reactor >press the power button >computer turns off

[@straightpipediesel]

Please keep the legend visible through all the events. 1 minute wasn't enough to memorize what everything was.

[@Higgsinophysics]

Thanks for the suggestion. Too late to add now, but for everyone confused I would refer to the full video: kzbin.info/www/bejne/hmTSfIF7bJd4sLc

[@neonatom8646]

good thing there's a 16 minute video explaining it..

[@ermwhatdaheck]

you can just pause it man

[@Sweetthang9]

@@ermwhatdaheck They very politely requested something quite valid. Feedback isn't always negative and should be welcomed by content creators. Why do you feel the need to be snarky to them?

[@TumbleTrashOfficial]

@@Sweetthang9 Its the truth though, that's one way to memorize it.

[@c.lynnmiller5677]

“The chain of disaster is now complete.”

[@hallgat89]

Achievement unlocked

[@albatross8]

THE CHAIN CANNOT BE BROKEN !! 🎉🥂🌊

[@Florin20D]

"No one in the room that night...knew...the shut down button can act as a detonator.They didn't know it because it was kept from them"

[@armechaia4646]

“When I left you I was but a learner.”

[@DrCruel]

A nuclear reactor is like a huge Cenobite puzzle box. You screw with them at your peril.

[@nolyspe]

I really hate it when my chernobyl accident simulations have people talking in them, so thanks for releasing the audio only version

[@matturner6890]

plus it's way too hard to hear anyone during the explosion!

[@Mike_B-137]

3:29 rip headphones. And also rip to all people who died to Chernobyl NPP accident.

[@nukegamereactor7750]

And his Pc

[@amramjose]

There are two very well written books about it, one's title is Chernobyl: The History of a Nuclear Catastrophe. The other is Midnight at Chernobyl. I preferred the 1st title but both are outstanding.

[@PsychoticDreams0]

What like, 20 people?

[@nonconnahordeath]

@@PsychoticDreams0 ...yeah, bad news about that...

[@PsychoticDreams0]

@@nonconnahordeath More?.......25?

[@thedemolitionsexpertsledge5552]

Gordon! Get away from the-

[@Arc_5]

Shutting down! It's not-

[@Aquatarkus96]

"let me see your passport"

[@NikoPeludo]

“Prepare for unforeseen consequences.”

[@spythere]

@@Aquatarkus96 Ah, fellow HLVRAI viewer

[@SvendleBerries]

Gordon doesn't need to hear all of this, he is a highly trained professional.

[@mr.voidout4739]

I'd like to see this kind of visualization in a horror game. A huge swath of buzzing particles rapidly escalating into an unbearable swarm, signifying a terrible fate.

[@K._Oss]

Chernobylite is pretty close!

[@Lftarded]

Build a reactor. You got a certain amount of funds, buy materials and make one... If it fails, delete system32

[@chrissysonicutdrloz]

You've met with a terrible fate- Ok, I'll leave now.

[@TadyChick]

Well done and very informative. Puts a new perspective and better understanding of the biggest nuclear catastrophe of the last century.

[@meowsqueak]

Last century?

[@simulify8726]

The biggest nuclear catastrophe of the new century is Fukushima Chernobyl happened in 20th century

[@aflac82]

​@@simulify8726 Also, it wasn't even the worst. (looking at Mayak disaster in 1957)

[@TadyChick]

@@meowsqueak Yes thanks for correcting me

[@ethanblair981]

Which caused a greater loss of life, Chernobyl, or Hiroshima? Deliberate tragedies are still tragedies.

[@thelurker3795]

idk why this popped up in my feed, i am clueless when it comes to physics, and yet i am absolutely horrified.

[@Omgseriosly]

Because this is straight up terrifying, and wow so much invisible death

[@uploader11459]

fr, not exactly sure what I just watched?

[@Omgseriosly]

@ the worst thing that could ever happen which just so happens to have happened. It’s a nice visual of the worst thing in history to happen.

[@Saint_Wolf_]

​@@uploader11459 a simulation of what was happening inside the Chernobyl reactor, in the description there is a video that explains everything about this video.

[@justduro1527]

​@@Omgseriosly i wouldnt say worst thing to happen in history but i guess it could be *one* of them

[@JimOutofControl]

This video recommendation means I’ve levelled up. I think I’m now an adult.

[@joefalchetto94]

ahah nice one

[@UnIimited_Power]

As someone with zero knowledge of nuclear stuff, "wow so pretty when it starts changing colors!"

[@MegaJani]

"Hey, I'm blue now!"

[@PKTraceur]

The fuel rods are constantly cooled with water, when heated up enough; they create steam, that steam rotated turbines just like any other power plant. The problem here is; without the control rods slowing down/stopping the fission, they got way too hot, and then completely out of control, Vaporising all water and melting everything around them.

[@juanitobarragan9538]

@@PKTraceurthx, now i can understand better

[@artyom2801]

The previous comment stated the steam engine principle, which is true but they neglected the entirety of this means. So from scratch I'll be brief as I can and as objectively correct as I can so sorry any nuclear physicist if I get something wrong. So to start, the Uranium is Fuel, when it fissions (as in it splits, it's the opposite of fusing), it creates fission products, AKA what is left of the uranium after being split apart and because the number of protons in a nucleus dictates what element of the periodic table is, you'll definitely get elements with a lower atomic number (IE the aforementioned number of protons) than Uranium. If you add them all up including the neutrons released, it adds up to the same sum of neutrons and protons (not gonna dip into radioactive decay of why sometimes there's one more and one less proton and neutron). Some of those products are so unstable that they are readily available receivers of neutrons, in the video there was Xenon, more specifically Xenon-135 as it's so unstable that ironically, getting another neutron (for reasons I won't get into) will make it a lot more stable. Basically what happened before removing the control rods was that the reactor got "Poisoned out" which isotopes like those are called reactor poisons. From my understanding, the engineers didn't know this was partially used fuel because of failure in the communication and were basically operating blind and shocked that it poisoned out. Here's more theory, so every fission in Uranium releases on average 2.3 something, can't remember, but it's a wildly varying variable but is frequently 2 to 3 neutrons. You will notice there's two types of neutrons. One of them is the fast neutrons, which are recently released fissioned while the other is thermal neutrons, whom have slowed down or "thermalized" releasing some energy as well. There's also delayed neutrons which is the fission products which unfortunately the video doesn't seemingly cover that but they basically just decay by neutron emission as opposed to the uranium fission. Finally there's the control rods and moderators you saw in the video. Control rods are the easiest, they basically just absorb the neutrons quite readily, like the poisons do, without the radioactive decay that is. Moderators are a slighty complicated because certain reactors use different ones but they just thermalize the fast neutrons, some are way better than others and others are a happy compromise. Water is an example, it's a moderator that doubles as coolant. RBMK (chernobyl model reactor and any russian reactor) didn't use water as a dedicated moderator, more so as a moderator by happenstance but a coolant first and using a different moderator. Here's a brief run down on the events. The reactor poisoned out while working at low power, with engineers deciding to pull the rods out (this has to be done slowly) and restarting the reactor. It works, but due to their ignorance cus they didn't get the memo, the slightly poisoned fuel was completely poisoned and was basically outputting power now because now the poisons serve as control rods and because poisons can be "burnt out" by having them capture neutrons, the reactor is on borrowed time. Finally, the power spikes and the engineers hit what is effectively the scram button where they drop the rods back in before things get much worse. One thing the video didn't communicate is that they jammed partway through and because they are graphite (another moderator but not intentional) "tipped", those tips just feed the reaction by slowing the neutrons more for reactions, which caused that huge fuckfest of a reaction of balls.

[@terrancestodolka4829]

Have to admit at the 2:40 time point when the SAFETY COMPUTER tells them to shut it down... They acknowledge by going and turning off the computer! Amazing...!!!

[@freshrockpapa-e7799]

That's how things are done all the time everywhere

[@dankay2697]

@@freshrockpapa-e7799it is?

[@freshrockpapa-e7799]

@@dankay2697 yep.

[@basedcheese1]

@@freshrockpapa-e7799 spreading misinformation is crazy

[@freshrockpapa-e7799]

@@basedcheese1 What misinformation?

[@faultyinterface]

Worked on nuclear reactors for 5 years in the military, and the bad decisions in both design and operation of this reactor never ceases to amaze me.

[@Anton43218]

Mind explaining how the design of this reactor is bad?

[@faultyinterface]

@@Anton43218 The first thing that immediately comes to mind is the use of graphite tips on the control rods. They were used as a moderator, that is, they were used to reflect neutrons back into the core in order to generate more fission reactions. Water is used for the same things, but water flows and also acts as a coolant. Both have a negative temperature coefficient of reactivity, meaning that as temperature goes up, the ability to reflect neutrons goes down, which is good. Having graphite on the tips of the rods allowed for faster startups because at the same temperature, graphite is more reflective than water and therefore allows for a more rapid initial increase in power. This also leads to a problem with their design, where power spikes upwards when the rods are inserted from the fully withdrawn position because the more reflective graphite displaces the less reflective water. Part of the purpose of control rods is to displace the moderators with the neutron absorbent material of the control rod, but when the reactor was SCRAMed, the graphite tips shattered and spread the highly reflective moderator all over the inside, which led to the massive spike in power and was a large factor for the meltdown. To make matters worse, graphite is very flammable when heated enough and exposed to oxygen, which led to graphite fires and the further spread of radioactive material after the meltdown.

[@faultyinterface]

​@@Anton43218 The first thing that immediately comes to mind is the use of graphite tips on the control rods. They were used as a moderator, that is, they were used to reflect neutrons back into the core in order to generate more fission reactions. Water is used for the same things, but water flows and also acts as a coolant. Both have a negative temperature coefficient of reactivity, meaning that as temperature goes up, the ability to reflect neutrons goes down, which is good. Having graphite on the tips of the rods allowed for faster startups because at the same temperature, graphite is more reflective than water and therefore allows for a more rapid initial increase in power. This also leads to a problem with their design, where power spikes upwards when the rods are inserted from the fully withdrawn position because the more reflective graphite displaces the less reflective water. Part of the purpose of control rods is to displace the moderators with the neutron absorbent material of the control rod, but when the reactor was SCRAMed, the graphite tips shattered and spread the highly reflective moderator all over the inside, which led to the massive spike in power and was a large factor for the meltdown. To make matters worse, graphite is very flammable when heated enough and exposed to oxygen, which led to graphite fires and the further spread of radioactive material after the meltdown.

[@KNylen]

@@faultyinterface Thanks for explaining! One question: maybe its a misunderstanding on my part, but you said the water is reflective/increase the fission reactions, when my understanding from the video explanation was it slowed it down?

[@faultyinterface]

@@KNylen It has to do with a few principals working together. The aforementioned temperature coefficient of reactivity and reactivity specifically. Having a negative coefficient means cooler water is more dense, and therefore is able to reflect more neutrons back into the core, while warm water is less dense and allows more neutrons to escape. In this way, a negative coefficient allows reactors to be semi-self regulating, as the hotter it gets, the more difficult it is to generate reactions. Another design flaw of the reactor was that when the water boiled, the steam voids had a positive coefficient. When they turned the pumps off and heat built up there was more steam, reactivity went up generating more neutrons, burning more xenon, allowing more fuel to be fissioned, generating more heat and steam, increasing reactivity, and so on. Burning the xenon was the intended goal, but doing it this way was foolish because reactivity was going up from both xenon burnout and steam buildup in the reactor, and these kinds of feedback loops tend to near instantly get out of control. For clarity, xenon-135 is a byproduct of fission and the decay of another fission byproduct, iodine-135, and has a very large cross section for absorbing neutrons. At lower powers for extended periods of time, xenon can build up quite a lot and reduce reactivity, but at higher powers, enough neutrons are generated to burn it off nearly instantly. Due to all these factors, they SHOULD have just increased power more slowly or just shut it off for 6 hours for the xenon to decay away naturally.

[@kirby89000]

It's so insane how it goes from fine to completely ballistic. It reminds me of those brick games where you have the ball hits the blocks and get power up

[@opalwinterart]

This was utterly riveting. I remember studying nuclear physics in highschool and became a bit obsessed with understanding precisely what happened in the Chernobyl event, among others nuclear accidents. A lot of the information was detailed and precise, but often felt a little distanced from what actually occurred. Seeing and hearing a model process the actual reaction connects me much more emotionally to the reality Chernobyl's techs would have experienced! Chilling 😱 Thank you for the insight

[@imsuperkoolguy10841]

That last second is like when you overload your computer and run out of storage, and the blue screen of death pops up.

[@supersaiyangandhi4481]

Just like a blue flash of death when a nuclear reaction goes haywire

[@Kaldisti]

"Not bad, not terrible" that good old Dyatlov

[@enyaratna]

Not good not terrible

[@eluberimabib4070]

@@enyaratna not GREAT, not terrible.

[@enyaratna]

@@eluberimabib4070 da, you are the rightest, tovarisch

[@agustinfrusto]

​@@enyaratnaNah, that's actually what she said me last night

[@maxd2215]

You didn't see graphite on the rooftop ruble. You didnt. Because it's not there.

[@Auroral_Anomaly]

By the time they pressed AZ-5, the reactor was already so far into the runaway state that the control rods couldn’t get into the reactor, meaning that they got stuck in place and the reactor went out of control.

[@isaowater]

No runaway started until the displacers brought it on. You mention an outdated looking at the chain of events, it was disproven in 1992 with INSAG-7.

[@MrRedeyedJedi]

They were graphite tipped, as soon as they began lowering, it caused a massive spike

[@Auroral_Anomaly]

@@MrRedeyedJedi Actually, the graphite got stuck leading to the displacement of things that regulated the reaction.

[@MrRedeyedJedi]

@@Auroral_Anomaly yes, but the graphite itself caused the runaway to compound in the reaction, which is why they did away with it on control rods

[@Auroral_Anomaly]

@@MrRedeyedJedi No, they didn’t actually know that the reactor was stuck.

[@KNylen]

Here’s my attempt at a very quick explanation (after watching the full video): neutrons= moving dots, subatomic particles with energy Uranium 🔵 Eject three neutrons when collision occurs Xenon ⚫️ when a Uranium atom “disappears”/decays, there is a chance it will appear. It absorbs neutrons, which causes it to disappear, so its overall effect on the system is a slowdown. Water [ ] slows down neutrons, but the more neutrons there are, the hotter it gets, until it evaporates (into a steam void)- which is like an immediate ‘off’ switch on its effect. control rod | An impenetrable wall that absorbs neutrons (Extra detail: moderators (white bars) cause the initially input neutrons (white moving dots), which move too fast to react, to slow down upon impact to a speed that will react (become black dots). Only adding this as a P.S. since it’s not completely required to understand the sim.)

[@NotHughesy]

thank you, this helped me piece is together between the two videos.

[@Sn0w424]

And the new moderator bars appearing at 3:20, those are at the tips of the control rods when the emergency stop button was pushed?

[@KNylen]

@ Yes, in the full video he explains that he only decided to add them in at that point of the sim. I guess they were irrelevant before that point or something

[@cowboystormchaser]

They did the equivalent of turning up the radio to drown out a concerning mechanical noise in the car.

[@nymalous3428]

With the captions, that was very informative for someone with little background knowledge of the subject.

[@BryenRafael]

Are you an expert on nuclear bombs?

[@ddebnath11]

@@BryenRafael he said "little background knowledge", doesn't exactly equate to being an expert does it?

[@BryenRafael]

@ddebnath11 yeah it was a joke four eyes, I couldn’t load any captions, in order to understand the video without captions you would have to be an expert DUH anyways see you later bye y’all, CYL BFF

[@ddebnath11]

@@BryenRafael lol

[@wlane55]

Outstanding explanation!! Thanks so much for this

[@Keru-5829]

I’m happy I was able to understand at least half of this video with my knowledge

[@Shadowwand]

I think you need to keep the legend up, and maybe add counters to each one, so we can see numerically how much Xenon is poisoning the reactor. Etc.

[@kolomoetsan]

Я родился в 1981 году в СССР в городе Свердловск. Ныне Екатеринбург. Когда произошла эта авария, то шатало всю страну. Я был маленьким, но понимал, что произошла беда! А после вся страна работала на ликвидацию последствий чернобыльской катастрофы. Спасибо всем тем, кто боролся, страдал, отдал свою жизнь, но выстоял! А прошедшем летом я повез своих детей на Митинское кладбище, где похоронены под огромной бетонной плитой пожарники, которые отдали свою жизнь в Чернобыле. Без этого подвига мир не был бы прежним! Мы возложили цветы и поклонились.... Такой подвиг не должен быть забыт!

[@ulanabdrakhmanov720]

В первую очередь не должна быть забыта ошибка

[@Argentum46]

Правильно - пожарные. Пожарники - это совсем другое

[@kolomoetsan]

@@Argentum46, я с вами соглашусь. Но в данном случае эти нюансы из серии, корабли не плавают, а ходят - это не главное. Моё отношение к этому подвигу очень серьёзное.

[@Argentum46]

@@kolomoetsan да я не сомневаюсь, но пожарные могут очень резко негативно отреагировать на такое обращение, при мне в девяностых журналистам лица разбивали во время репортажа. Отец был пожарным, а друг его, который привёл в профессию - один из ликвидаторов. Обоих уже нет.

[@MrScarabey]

@@Argentum46вообще должно быть насрать, кто там на что в интернете обидится. Нормальные люди из-за сленговых разночтений лица не бьют. Распускаешь руки - в клетку, животное, к поехавшим вдвшникам, ходящим по воде морякам и прочим офанателым, подальше от журналистов и прочих мирных граждан.

[@mkng2k]

This no-talk simulation makes for a hell of an analogue horror video

[@adamantiuscloudcat1799]

The fast development of events should remind us how fast things escalate out of control in life. It just takes a bad move.

[@skruffytiger2002]

this was a sequence of carelessness that predated the event but normalized the behavior that caused it

[@ramr7051]

​@@skruffytiger2002it's ok, blurting out platitudes is apparently cool on this website

[@dougmasters4561]

Wasnt this an entire series of bad moves? It seems rhe surge was sudden but the event itself was not.

[@shashankpujari9970]

The final surge is actually due to insertion of the control rods. It happened to their graphite tips or something. That increased everything so much that lot of energy was released and unimaginable thing happened. The entire core exploded. Insane stuff and also terrifying.

[@joemash4193]

Not exactly sure what I’m watching but I’m here for it

[@Leon玲央]

You‘ve watched a simulation of the Chernobyl nuclear reactor and how the reactor went out of control.

[@gir2005]

@@Leon玲央 clearly to everyone else it just looks like dots on a screen.

[@dougmasters4561]

This was an attempt to simulate several nations deciding the outcome of AI fought wars by various AIs playing a psycho game of breakout against each other Kinda like War Games with tic tac toe. At the end, the whole world is destroyed

[@Leon玲央]

@@gir2005 I was kidding, it is actualy a modern take on Pong.

[@HelloThere-pf9sm]

This is the loudest video I’ve heard on KZbin 😂 Keep up the good work ❤

[@spywhere]

The sound reminded me of Geiger Counter though. Not sure if that's actually what it does.

[@Higgsinophysics]

It is!! Nicely spotted :D

[@c64cosmin]

Not a physicist but afaik, the way the Geinger Counter does make a bleep impulse sound when a particle collides with a detector, the particle has enough energy to activate and move some electricity to a speaker, we measure the amount of bleeps per minute I think to determine radioactivity in an area, might be very wrong, but that is my understanding of the whole process.

[@codefeenix]

@@c64cosmin activate and move some electricity

[@borincod]

@c64cosmin particles do not have enough energy to move electricity to a speaker... Speaker works exclusively from the batteries. A particle should have enough energy just to ionize a single atom of gas in the tube. This causes avalanche ionization in the tube due to externally applied electric field. Thus, a particle role is comparable to a tiniest domino piece, which falls and causes other dominoes to fall afterwards

[@34silesia]

This one changed my life, thank you for your service

[@Ogolero]

Also… when the system was powered down to 30% there was still latent Xenon build up that caused the failure process to begin. Had they powered down AND limited the water circulation by 20% would be be able to assume everything would’ve stayed stable?

[@Higgsinophysics]

Tons of stupid things happened that day, and I think the total "system" (reactor and operator) is too complex to guess what would have happened if a few things changed. But experts have said it was a matter of time until the reactor would blow up, if not this day then another. Because of the unsafe reactor and unsafe culture

[@deipalladium8362]

Unsafe culture? Like in Threemile island and Fukushima?

[@NotSure416]

@@deipalladium8362 Tepco were actually good operators.

[@W4lt3r89]

@@deipalladium8362 Elaborate. How "unsafe culture" did Fukushima in? or Three-mile Island.

[@Higgsinophysics]

@@deipalladium8362 No. There is no way you would be allowed and it's probably not even possible to turn off safety systems and its safety protocols. Only in USSR this flies

[@spacecadet1968]

That was the best explanation I've seen. Bravo!

[@mikajlod25]

Thank you, this is amazing

[@kakazi2170]

What they did was just as smart as lifting a beryllium lid over a nuclear core with nothing but a screwdriver

[@EmanuelSN]

This really shows how the engineers really just didn't know how wrong things had gone It was all just so fast

[@TheGologozo]

Yes, they had no way of knowing, and no way of controlling it quickly enough and even the scram was basically faulty.

[@cityofghosts4037]

Oh the end of this video is terrifying. Great video.

[@JMUDoc]

"Power level?" "... twenty-eight thousand percent." "... not great, not terrible."

[@Blaser_Radio]

how it slowly loses quality is terrifying

[@Essonence]

This is actually extremely unsettling. Very informative but thinking about this actually happening in the moment...

[@joyous-444]

Jesus Christ, the sound in this really puts it into perspective for me

[@busybillyb33]

Engineer: Comrade Dyatlov, Computer is asking us to shut down immediately! What should we do? Dyatlov: It is delusional! Shut down the computer and take it to the infirmary!

[@ayushchaudhary2466]

That was so informative !! I felt the anticipation being built inside me until the Event 5 went haywire.

[@TchaikovskyFDR]

What I love is how you casually throw in what everyone generally talks about -- the Graphite Tipped Control Rods. "Like oh, this is the detonator we've created. Oh this is the detonate--" Really puts the point across how every RBMK Reactor was also therefore just casual bombs sitting in the Soviet Union suddenly. Lmfao.

[@mehbleh4809]

I need a 3 hour long version of this. It scratches a part of my brain I didn’t know existed ✨

[@jayjaayjaaay94]

My feeling after watching last 5 seconds of the video : not great not terrible

[@ОлегДробіна]

Nice video from Daneya, thank you author!

[@hotfightinghistory9224]

Thats some scary popcorn I tell ya...

[@s.n.8128]

Hey dude, super fed channel. Så din 16 mins video inden, kanon forklaring på laymans terms. mere af det!

[@skrafis]

> the computer warns them to shut down immediately, so they turned off the computer instead This is a completely wrong statement. At least because such computer did not exist at all. There was kind of a statistical computer placed in a different room which gave out periodic non-critical information. The general reasons of the disaster are: 1) miscalculated grid pitch of the reactor channels 2) positive steam effect 3) effect made by end parts of the rods Please also check INSAG-7 report for the correct reasons of the disaster. Here is a part of the report: The Chernobyl disaster was caused by the by the developers' choice of the RBMK-1000 reactor of a concept that, as it turned out, did not take safety issues into account sufficiently, resulting in physical and thermal-hydraulic characteristics of the reactor core that contradict the principles of creating dynamically stable safe systems. In accordance with the chosen concept, a reactor control and protection system was designed that did not meet safety goals. The physical and thermal-hydraulic characteristics of the reactor core, unsatisfactory from a safety point of view, were aggravated by errors made in the design of the control and protection system. The RBMK-1000 reactor, with its design characteristics and design features as of April 26, 1986, had such serious non-compliance with the requirements of safety standards and regulations that its operation was possible only in conditions of an insufficient level of safety culture in the country. The personnel actually committed violations of the regulations, and the Commission notes them in the report. Some of these violations did not affect the occurrence and development of the accident, and some allowed the creation of conditions for the implementation of negative design characteristics of the RBMK-1000. The violations committed are largely determined by the unsatisfactory quality of the operating documentation and its inconsistency, caused by the unsatisfactory quality of the RBMK-1000 design. The personnel did not know about some dangerous properties of the reactor and, therefore, did not understand the consequences of the violations committed. But this is precisely what testifies to the lack of safety culture not so much among the operating personnel, but among the reactor developer and the operating organization.

[@tsergv]

The point is not in the "culture", but in the fact that nuclear science is developing and not all the knowledge that we know now was known, modeled and tested in those years when those nuclear power plants were built. Each incident provided new knowledge, which was implemented in subsequent station projects. Unfortunately, a nuclear reaction cannot be carried out in a test tube. The nuclear reactor of the plant is the scientific test tube in which scientists study the physics of the reaction. The nuclear power plant of those years is not only a source of electricity, but also a scientific laboratory for scientists. Studying huge energies is always a possibility of incidents. Similarly, the history of aeronautics is a series of plane crashes.

[@skrafis]

​@@tsergv This is yet another completely wrong statement. There were some reports and warnings from the engineers about dangerous processes and negative design features that were ignored by management in the period between 1975 (accident on LAES station) and 1986. Management knew about the problems and did nothing to prevent the negative consequences produced by them.

[@Cucumber02746]

Can I have your sources for this??

[@fresh_dood]

@@tsergv effects of the Soviet bureaucracy were very much the cause, not the state of nuclear science. Chernobyl was very much a product of politics, not science. Case in point: the lack of any other reactors of its type in the world at the time. The very concept of a graphite moderated water-absorber reactor is inherently unsafe. It's well discussed and understood that Chernobyl was the final nail in the coffin for the USSR as much as it was its brainchild.

[@SilentStorm98]

I don’t know about anyone else but that sounded like 15 different ways of saying something was wrong and not really explaining how it was wrong, the only thing actually mentioned was the hydraulics, but no mention of how it actually failed nor is the any mention of how anything failed, this comment is just a giant nothing burger

[@daulet3016]

this is really simple to understand. Thanks!

[@89TStefan]

I remember very well when we had this in high school in physics class. That was 20 years ago. And when you hear about it, it basically had to happen one day like that with this design and how they operated the reactor. In the end, the design traded safety for efficiency and they lost both with it...

[@samelis6546]

I don't know what I was looking at. I don't know what to expect. The end freaked me out better than most horror movie. What even happened.. Anyone want to just give a one liner for each of the legends' functions in the system?

[@KNylen]

I’ll try neutrons= moving dots, subatomic particles with energy Uranium 🔵 Eject three neutrons when collision occurs Xenon ⚫️ when a Uranium atom “disappears”/decays, there is a chance it will appear. It absorbs neutrons, which causes it to disappear, so its overall effect on the system is a slowdown. Water [ ] slows down neutrons, but the more neutrons there are, the hotter it gets, until it evaporates (into a steam void)- which is like an immediate ‘off’ switch on its effect. control rod | An impenetrable wall that absorbs neutrons (Extra detail: moderators (white bars) cause the initially input neutrons (white moving dots), which move too fast to react, to slow down upon impact to a speed that will react (become black dots). Only adding this as a P.S. since it’s not completely required to understand the sim.)

[@crystalseitz5232]

- "How many times have you watched this video?" - Me: "Yes"

[@PH4RX]

When you say "only a minute after the test started" it makes it sound like the test was supposed to be longer. It was however only 45 seconds, to see if that gap could be bridged during a blackout. So the test was over and the reactor was meant to be shut down for maintenance via scram.

[@koneeche]

Holy crap. Even if it's just a bunch of dots depicting a nuclear reactor, those last few seconds were jaw dropping.

[@ericnewton5720]

Why were the pumps shut down as part of the test? I thought the whole point of the test was seeing if what was left of the steam reaction could keep the turbines generating enough power until the diesel generators could spin up and take over.

[@Higgsinophysics]

Maybe shut down is an overstatement. But yea, you are correct. Test was trying to power the system by inertia of the turbines.. But what I wanted to capture in the simulation is this (from the wiki en.wikipedia.org/wiki/Chernobyl_disaster) "As the momentum of the turbine generator decreased, so did the power it produced for the pumps. The water flow rate decreased, leading to increased formation of steam voids in the coolant flowing up through the fuel pressure tubes"

[@isaowater]

@@Higgsinophysics Thank God we've had folks working to correct that wikipedia page, knowing that you're using it as a source.

[@rextransformation7418]

Boy, these ASMR videos are a blast!

[@GregMatoga]

What happened at 3:17? The "moderator" suddenly appearing under rods?

[@juliuszkocinski7478]

IRL control rods had Graphite (moderator) tips. It was irrelevant up to this point, but they got stuck even more accelerating the reaction instead of controlling it

[@dachhh]

Dude just igored them, so the first 3 mins is incorrect. The reactor looked nothing like that. The simulation here also doesn't show the true cause, the graphite rods moved down into the lower core, displacing the water and increasing the reactivity there. This simply isnt shown. The video suggests the graphite rods getting stuck caused the runaway, but these rods were there the whole time. i think the "simulation" is not based on the actual reactor physics.

[@camus83489]

i was wondering this too

[@seeriktus]

Chernobyl's RMBK had graphite tips, which is bad design but cheap. They could have used another material, it's argued that this information was kept from the engineers and people running the reactor. So for the sake of money, the very SCRAM safety device that was meant to save them actually accelerated it and blew up the reactor.

[@dachhh]

@@seeriktus this was not kept from the engineers. The control rod was half graphite, the purpose was to accelerate the reaction as it entered the core, so the rod did double duty as brake and accelerator, increasing its effectiveness, and they knew all about that. You watch too much tv.

[@zenout3463]

this was the entire story portrayed in a mere 3 minutes of little balls bouncing around the screen. omg when the balls sped up and there was no stopping it, the entire panic and explosion and death of what I imagine of the horrific event just flashed before my own eyes, my heart panicking. what an absolutely unique and interesting way to tell the Chernobyl story. my son introduced me to this simulation. very interesting! thank you

[@markrobertson6664]

I heard comrade Diatlov was in the toilet

[@n7346e]

I doubt they had toilet technology

[@Redstarka22]

Funnily enough, he was basically a fall guy. He was nominally in charge of the test by virtue of his position, but the actual lead engineer running the test and giving orders was A.F. Akimov; the guy who in the show asks Dyatlov to give his orders in writing.

[@strengthfactor1315]

@@n7346e There were toilets at the nuclear power plant. But a strange fact: instead of toilet paper, for some reason, the flags of the USA and Great Britain were used there.

[@presistancelydeccer7338]

The computer warning them to shut down get shut down instead is the same vibe as you warning up the company about something and they decided to fire you instead.

[@crazysimilartoafox]

lol Oceangate vibes

[@IgnorantBoot]

Finally, some decent music

[@shivam6565]

"The computer warned them to shut down the reactor, they shut down the computer instead"😂. That's called Killing the Messenger.

[@QuantumRads]

Didn't they shut all the control rods that cause the chain reaction with the graphite tips?

[@ShawnsLoop]

It would be helpful to include the legend on this animation that you did in your full video with the audio commentary. Just a thought. Great visualization and explanation. It helped a lay person like myself understand a very complex interaction and sequence of events that lead to the disaster.

[@ShawnsLoop]

Nevermind LOL. I missed that the legend is there at the start of the video.

[@Brian_Equator]

Hi, nice video, but factually not quite right if I may say so. The explosion was actually finally triggered by insertion of the control rods which interacted with water in the reactor, and the water acted as the moderator. This is the difference between designs that have positive and negative void coefficients. One gets colder as the water boils, the other gets hotter (like Chenobyl). Cheers, Brian.

[@onishroom1657]

Holy shit that ending is unironically terrifying

[@WhiteDragon103]

thanks for the hearing damage

[@Higgsinophysics]

Any time

[@elephant1851]

it's nothing compared to the heat damage

[@bsimic29]

1:38 - I am puzzled by power drop to 1%, as a just scrammed reactor typically drops to 4 - 7% of nominal power, depending on fuel state: 4% when the fuel is fresh and 7% when fuel is at the end of life. As the unit 4 reactor was running at 50% up to that moment and the fuel was about to be replaced (end of life), it should have dropped to 3 - 4% of nominal power, not 1%. 2:42 operators did not turn off the computer, it continued to operate to the very end. They simply ignored warnings (if there were any). They disconnected automatic control rod system and moved rods manually - and they did it an hour earlier - when power dropped to 1%. 2:46 they agreed to raise the power to 200 MWt and start the test, as they were in a hurry to finish it. They could've reached more that 200 MWt, but they had to wait longer. 200 MWt was chosen as it was minimal power at which one turbine could operate. 2:51 some pumps were turned off as they weren't needed for reactor running at half power. Water cooling wasn't slower because of that, actually running all pumps when reactor was at half/low power could trigger cavitation effect. Two pumps were turned back on as a part of the experiment, exaggerating the power drop issue.

[@Cucumber02746]

Can I have your sources? This correction sounds interesting but I don’t want to spread misinformation.

[@ryang3666]

So this is what is happening in my stomach when I eat taco bell after midnight and decide to have a milkshake afterwards.

[@R.M.S_Titanic1912]

I really enjoyed this video, great simulation, do you think you can make it public for people who want to play around with this, I know I do, and if so, can you add the ability to choose different types of reactors as well as make it available for mobile, if you can do this then i would love to play around with this, but if you can't, then I understand 👍, keep up the awesome work!

[@haven9256]

That last part was straight up horror, I have never been more terrified by anything like this in such a while

[@SOU6900]

The coolest game of Pong I've ever seen.😅

[@ruperterskin2117]

Have watched the original version - really interesting. Thanks for sharing.

[@Silanael]

A nice animation, but you're further promoting the misconception that there was a power surge before EPS-5 was pressed. According to what we know, the reactor was stable prior to that, the insertion of the control rods triggering the event - though the operators unknowingly created the circumstances for that, a shutdown system should under no circumstances add reactivity.

[@ericnewton5720]

Kinda defies logic, saying the reactor was stable prior to the scram button being pressed. It may have seemed stable but any small deviation causes a runaway criticality event because there’s absolutely not enough control able to be asserted due to the boron parts of control rods being pulled.

[@Silanael]

@@ericnewton5720 The reactor was kept under control with the automatic regulator (AR) without any issues, but it was running with most of the manual rods pulled completely out of the core. This is by itself not bad; low ORM means that you can insert a lot of negative reactivity if need be. The thing with the boron followers was that they did not entirely cover the core, leaving a water column above and below them. Water in this case is primarily a neutron absorber while the graphite acts as a moderator. Due to this design flaw, when you insert a fully pulled rod, you get a reactivity increase. When the EPS-5 was pressed, it simultaneously inserted all the rods that were withdrawn, resulting in a spike in power at the lower part of the reactor that was enough to make it prompt-critical.

[@BillyBob-bd1hj]

Exactly, if the reactor was totally stable, why hit the scram button?​@@ericnewton5720

[@valentinaselektrikas]

"It has not been established why the scram button (EPS-5, also referred to as AZ-5) was pressed at 1:23:40. Annex I of the INSAG-7 report (see Reference 1 below), Report by a Commission to the USSR State Committee for the Supervision of Safety in Industry and Nuclear Power (SCSSINP), states: "Neither the reactor power nor the other parameters (pressure and water level in the steam separator drums, coolant and feedwater flow rates, etc.) required any intervention by the personnel or by the engineered safety features from the beginning of the tests until the EPS-5 button was pressed." The report adds: "The Commission was unable to establish why the button was pressed." However, according to Anatoly Diatlov, the plant's Deputy Chief Engineer at that time: "There was actually one reason for dropping the protection rods: a wish to shut down the reactor when work was finished" world-nuclear.org/information-library/appendices/chernobyl-accident-appendix-1-sequence-of-events

[@nemo-x]

What. Most investigations and the controllers in the soviet investigation mentioned a surge before scram.

[@kyoto9916]

This reminds me of a fever dream I once had when I was really sick. Dreamt that the room at night was full of big balls bouncing around and making noise waking everyone up.

[@amramjose]

The RBMK were known, albeit not openly, to be dangerous and unstable at low power; Dyatlov ignored the test protocol and decide to bring the reactor down below the 700MW outlined in the test. Instead he brought it down below 200 and even lower when it was xenon poisoned. The rest is prolob.

[@Frank-blabla]

very very impressive simulation. To read about the "Xenon-trap" is interesting, to see the Xenon burn away in the simualtion is scary!

[@guguigugu]

as I understand it, they reached the Xe pit because they tried to reach the low power state too quickly. a slower power down would have gradually burned most of the Xe by the time the reactor reached a low power level. this was the seminal error. then, trying to get out of the Xe pit too quickly again, they made the reactor unstable and it blew.

[@isaowater]

Increased water flow played a very heavy hand too, don't forget that.

[@isaowater]

Oh, I realized too late what you meant. The xenon from the power drop never burnt off, no power-spikes before AZ-5 was pressed. Remember the INSAG-7 chain of events.

[@blockstacker5614]

They were under tremendous pressure to get the test done as it had already been significantly delayed and the reactor was also needed for grid power. I suppose they were somewhat put into a position of either rushing the test, or expecting visitors from Moscow.

[@isaowater]

@@blockstacker5614 the reactor wasn't being rushed back onto the grid, the tests (there were multiple) were selected to be done at the time they were because the reactor was being REMOVED from the grid for maintenance & repairs. This is typical for soviet power plants to do. Also the delay wasn't all that significant, it was just 12 hours, the only difference was that not all necessary personnel had appeared to conduct the tests and the control staff present weren't well versed in the details of the testing.

[@fawnfoxmatter]

Chernobyl workers watching the reactor make 30 years worth of energy in few seconds.

[@iexist_nt]

microseconds*

[@AntTheFanOfMurderDrones.]

Straight to the point, no useless yapping. i respect that 👍

[@EnterpriseTNG]

Water = blue, Uranium = green metalic, Xenon = magenta, Non-Uranium = grey, thermal neutron = yellow, fast-neutron = orange, Moderator = pink, control-rod = red

[@joereedsmith1531]

Horrifyingly brilliant work.

[@Risk437]

Do you taste metal?

[@Davoodoox1]

Impossible. Now go back to work.

[@bq1013]

And that ladies and gentleman is how the impossible becomes possible and a RBKM reactor explodes

[@Etrehumain123]

I know the reactor was bigger than the smiluation, but I just wondering if this matches somewhat reality about time event, or if chernobyl was like this, but in an instant

[@huuuuuuuuuuuuuuuuuuuuuuuuuuuhn]

really terrifying if you think about how the entire planets fate depends on a couple of guys shoving or pulling regulation rods in and out of some reaction chamber

[@Ogolero]

Great explanation. Everything makes sense but out of curiousity… why did the hydraulic system fail at the end to lower the rods? What was the system failure that prevented the rods from lowering as planned?

[@Higgsinophysics]

No hydraulic fail. As far as I recall, the litterature debates if it's either cause by melted rods, or fractured rods blocking the path

[@Ogolero]

@@Higgsinophysicsthank you

[@deipalladium8362]

Graphite channels deforming

[@jimskywaker4345]

I'd heard that the fuel rods and steam channels started to expand and blocked the rods from moving in further.

[@notme5844]

The graphite tips on the control rods caused a dramatic spike in reactivity, causing massive heating and damage to the rods, preventing them from inserting all the way.

[@jrod8807]

My fiancé in the other room asked if I was ok because she heard this noise. I told her we gotta move now. Thanks Higgs