Nuclear Physicist Reacts - Chernobyl Episode 5 - Vichnaya Pamyat 

Episode 5!!! It was great reviewing this series and I’d definitely watch it again! Any suggestions for more short series with physics/nuclear engineering concept you’d like me to react to? ☢️👩🏽‍🔬

Stellan Skarsgard as Shcherbina is my favorite part of this show. The character arc is great and the acting is top notch.

As my reactor kinetics professor used to say " you can lie to people as much as you wish, but cant lie a single time to the nature" This story provens his thesis, like, you can lie that it is safe to do the test ;)

"Remove all the control rods." Me with no nuclear physics degree, "JFC, that's not going to work the way they hope."😬

17:51 I like how we saw Dyatlov's genuinely surprised reaction to the AZ-5 fatal flaw revelation. As arrogant and insufferable as he most certainly was, even he would probably not have run the test had he known about it.

Watching this reminded me of a book quote, which I was actually able to find in my 'disintegrating' copy of the novel: _"But he suddenly remembered something that one of the ships designers had once said to him, when discussing 'fail-safe' systems: 'We can design a system that's proof against accident and stupidity; but we can't design one that's proof against deliberate malice....'"_ -- 2OO1: A SPACE ODYSSEY {novel}, by Arthur C. Clarke, Part IV, Chapter 28.

HBO has a documentary called Chernobyl: The Lost Tape. It's exclusively made with real interviews and footage, and was a great supplement to this series. One eerie feature is that many of the films shot on site and around Chernobyl have tiny flickers of light where the film was affected by the local radiation levels. Like a visual Geiger counter.

Dyatlov was so reckless with the reactor because his experience was primarily in submarine nuclear reactors. He was used to dealing with reactors that could be pushed much harder and had much lower power outputs. When he transferred to power plants he kept this attitude and of course ended up running the reactor into the ground.

"And that's how an rbmk reactor core explodes "... got me chills...🙂and we are really lucky to watch this series with a nuclear physicist...❤

Just FYI Ulana Khomyuk (Emily Watson) wasn't an actual person. Instead she was a composite point of view character representing all the Soviet physicists who provided help in the investigation. Which is why she was detecting the initial fire, doing research into the technical design, interviewing the victims, and all the other countless background tasks that all these physicists did. Although their harassment by the KGB and the bureaucracy whilst doing so was all too real.

The thing about brukhanov was that he actually paid money from his own salary into Chernobyl because they were chronically short-staffed, Chronically behind on funds,etc. Viktor loved the staff and Dyatlov was a harsh but loyal man. Also Dyatlov was the most experienced person in the reactor room that night

Maybe fun fact - the scenes for Prypiat city were filmed in Vilnius. I actually live in the neighbourhood and you can sometimes spot things like signs covered

I remember when that happened... I was in the Air Force at the time as an x-ray tech. Quite interesting how little we knew at the time. Great mini series!

The Actor that plays Boris Shcherbina(Ministry of Construction of the Oil and Gas Industries) was played by Stellen Skarsgård, who also played Captain Viktor Tupolev, who was the captain of the Russian Alfa class submarine, Konovalov in "Hunt for Red October". Just a nice film fact.

Thank you for this series! It was your reaction to episode 1 that got me to watch the miniseries multiple times, which in turn made me want to read into the incident and others like it, which knowledge has in turn helped me in my new job! 😊

It's interesting to read about the real Valery Legasov. In the TV show he was surprised by the accident, in real life he was already very concerned about the lack of safety in reactors in the USSR.

Hello Elina, I really like your reaction! Your reaction and explanation sounds so professional. At the same time you are based on a tv series that isn't true mostly, missed steps like AZ5 were pressed twice, missed one more person in the control room(with great experience), missed what happens to other reactors. The TV series lost so many things and details. Before the Chernobyl disaster, RBMK had a different name Soviet union reactor... Anyway thank you for your explanation on it, I really appreciate how scientists react on it😊

This is not a reaction, it's much more than that. It's a critic and an explanation. Congrats. A pity if it gets demotenized.

"why worry about something that isn't going to happen?" "that's perfect, they should put that on our money." THAT WAS COLD HOLY-

Bit late to the game here but what i notice when checking rbmk designs is, that the control rods don´t have a graphite "tip" but more likely a graphite bottom end which is 50% of the hole length of the control rod. They used the graphite as a moderator and as you said correctly it displaced the water.

As always, this was a fantastic reaction video. My favorite part might be when you know what's about to happen or be said next and then play the video confirming that you were right. I'd love to see a video on how or if you were personally affected by the aftermath of this event. Did it have any influence on your decision to become a nuclear physicist? Were any of your family or other people you know personally affected? Are there any day-to-day things you deal with at work that are a direct result of Chernobyl (regulations, procedures, etc.)?

2:45 not all reactors during that time period in USSR were RBMK, they had a lot of (not affected) VVER too

I liked that, “Oh that’s perfect. They should put that on our money.” RIP Valery Legasov. Yea, it still amazes me that you could stand over an RBMK at full power, and the upper biological shield is stopping that much gamma and neutrons from melting you, because that get zapped and become a super hero stuff doesn’t work. Radithor showed a whole bunch of unfortunate people that ya can’t supercharge your body with radiation, or radium and thorium ingestion, just rot your jaws off and make your bones decay. Like your channel!

The control rods were not graphite tipped they had a long graphite section, so when the control rods were removed, a moderator took its place to change that section around the control rod from slowing to accelerating. It's in the bottom of the reactor where the graphite sections of the rods all were, and on their way out of the reactor. The runaway started at the bottom.

Thank you for your analytical review of the events. Finally a real scientist I can understand .

Sorry for my bad english. It’s funny to watch all this. The tests were not for “safety,” the reactor operates without them. The tests were electrical engineering. There was a task they wanted to complete before the reactor went into a long planned maintenance shutdown. The reactor still had to be shut down before the maintenance and upgrade. The reactor in these tests is generally on the side and could have been turned off immediately after the turbine shutdown. Obviously, in the event of an emergency disconnection from the external electricity, the reactor shuts down immediately. Moreover, it shuts down from any power level and any reactivity reserve. The test takes readings from other electric and pump units. A working reactor is not needed in the test. In fact, there were no fools in the room. There was no toxicity; it’s an invention for the show. For higher ratings, an average viewer needs a target for all their hatred. The problem with that society was that the professors and designers in the institutes were perceived as gods. Propaganda assured citizens of the exclusivity and reliability of the products coming out of the scientific design bureaus. It was the same with the RBMK-1000 reactor. The regulations and instructions were written in such a way that the reactor could be widely managed without going beyond these regulations. The reserve rods were perceived in the documents only as a “control reserve” of reactivity. According to the regulations, this parameter was not considered a safety parameter. At that time, there were no computers to calculate this reactivity reserve in real time. Each rod can be lowered to different depths and interacts with many fields inside the reactor; it cannot be calculated as 1 rod = 1 unit of reserve. The computer calculated the reactivity reserve using a bunch of coefficients every 10 minutes. However, the situation develops much faster. By the way, at that moment the reactor had already begun to be less poisoned by xenon. Everyone knew about the test a week in advance, and Dyatlov himself, as the deputy chief engineer, was heavily involved in its description. He also approved this test. Therefore, the fact that Dyatlov decided to change its parameters during the test does not seem so terrible. But it turned out that under such working conditions, the reactor was unstable. Moreover, a couple of years before the incident, operating teams on different units had already begun to notice these instabilities. But the designers in their institutes didn’t care. They covered their scientific asses. Long story short, no one cursed on the block that day. They were conducting a planned electrical engineering test before the reactor went into planned maintenance and upgrade. This test was a good opportunity to shut down the reactor. No serious protections were disabled. They turned off what could be turned off according to the regulations. They raised the rods because it was allowed by the regulations. There is an opinion that everyone knew about the graphite tips; they couldn’t not know. This effect had already been detected. But this parameter was not considered dangerous. The academicians assured that everything was fine with the reactor they designed, plus the regulations were silent. They began conducting the test planned by the reactor manufacturer. But due to poor modeling of what was happening inside the reactor under the given conditions, what happened, happened. The mistake was that the reactor could have been shut down immediately at the start of the test, but it continued operating for another 40 seconds under deteriorating conditions. BUT IT WAS NO LONGER NEEDED. No one gave the command to shut down the reactor; perhaps the operator was waiting for the leader’s command, and the leader was waiting for Dyatlov since he was no longer the chief, as Dyatlov had arrived. So, everyone stood there for a minute, watching the electrical engineering part of the test. And when they shut it down, it exploded. Six seconds before the explosion, all indicators were normal. Do you think it’s normal for a reactor to explode just six seconds after the first indication? Did the designers create a safe reactor? In the end, not a single academic designer was harmed, so as not to diminish the people’s faith in the Academy of Sciences of the USSR. As usual, they wanted to shift all the blame onto the workers. But they couldn’t make it all smooth.

Being born in the early 90’s, this series was an eye opener, the acting itself is phenomenal. Absolutely is a thrilling watch

When the say "MOSCW 27th Of April" - Its not, its actually Kiev, Bogdana Khmelnitskogo street. There is a secret intsitute there, though.

I'd like to hear your take on a scene from Episode 2, where Khomyuk claimed that the corium "lava", when it came into contact with the full water tanks, would produce an explosion of 2-4 megatons. That seems WAY too high for a thermal explosion (by a factor of 10^3 or more). In a reddit AMA, Craig Mazin said he got that figure from a Soviet nuclear physicist, but I haven't been able to find any theoretical justification for it.

I have watched the series several times and I will again. I know nothing of nuclear physics...or any of the physics but I attempt to understand and learn what my tiny, simple brain can comprehend. It has been fun watching your reactions and I appreciate your explanations that help dumb it down even more!

Your reaction to this series is uniquely from the point of view of an expert. It was much appreciated.

This disaster undermined one of the greatest renewable clean energy resources ever created.

Such a wonderful journey with you covering this series. Although I watched the series when it premiered, your explanations and commentary have made the series more impactful for me. Thank you!

Awww, I wanted to see your reaction to the slides in the epilogue. Although based on their testimony, the portrayals of radiation sickness were far more gruesome. Ludmilla's testimony/report was very graphic about that.

I occasionally rewatch some parts of this series. The beginning for what would it have looked like; the miners part; and the trial where they explain what and why did happened.

Thank you very much for the detailed explanation of many points. It was extremely interesting to watch! I really love this show, but it's not something you want to rewatch due emotions... And I was shocked when they told about the really problem in RMBK reactors and this is all about classified materials... It was very interesting when you talked about some non-obvious things that revealed the essence a little more (you did it, it seems, better than Professor Legasov) :) So, thank you again!

At 7:49 _... as if you're running an ice cream making machine ..._ People in North America certainly thought of McDonald's ice cream making machine that are broken down i.e. out of order, most of the time.

Great job of explaining everything a moment before the show explained it lol

Do you know why the most recent video was demonetized? Have you plead your case? Apologies, I haven't been keeping up with your (great!) work.

I read, some time ago, that this was almost unique - virtually all other "explosions" are caused by hydrogen - according to the physicist I read - the initial explosion was the core, at least partially, going "prompt critical" - ie it really was a "nuclear explosion".

The real reason is much more nuts. The tips were not of graphite. Those ractors burned mostly unenriched fuel. Cheap. They had a graphite rod coming in when the control rod was pulled out. All out meant something like centered 4.5m graphite rod over 17m fuel rod so they would have an even neutron flux. But that meant that retracting the rods was not just stepping off the brake, it also floored the gas. The xenon poisoning burned away, the core heated up, the water above became steam, so negative void coefficient, below was light water and in the center is graphite, which shifted the neutron flux to the lower part of the fuel rods. Doppler (increased reactivity of U238) can not stop a runaway reaction, so the fuel temperature coefficient is meaningless at that point especially once they push AZ5 and push the water out from below while jamming a graphite rod between the already very hot lower part of the fuel rods.

People should not think, that problems like this only existed in the Sowjet Union. "Because it was cheaper" is pretty much the cause for most disasters caused by "western" companies too.

Ms. Charatsidou, and open question for everyone: at the moment when AZ-5 was pushed, was there any way the reactor might have been saved? For example, suppose Akimov had known about the design flaw. Could he have inserted the rods in one at a time to slowly reduce the core reactivity, or was the explosion inevitable by then?

After watching the first episode soon after it came out, a colleague asked me what kind of show it was - they were expecting something like a documentary. I told them it was a horror movie. During and after I felt as if I had seen Saw or Nightmare on Elm Street. It is menacing, horrific and at times inhuman. It put on naked display the indifference and evil of that regime. It truly disturbed me. By the third episode I had to talk myself into pressing play.

Thank you for your reactions and for sharing your knowledge!! I’v watched the show a few times and an abnormal amount of Chernobyl reactions. Yours was the best because you understood. 👍🏼

Such a wonderful series. Thank you for covering it.

What I loved Most about the series was the range of people that existed under Soviet boot. The worst of mankind and yet the BEST OF MANKIND. The HEROES.

In a country like Russia you have to understand that you have do what you are told or they will send you to the Gulag. (Siberia) If they were smart they would have let the reactor shut down and just let it sit until they found a way to remove Xeon gas.

It's very enjoyable and interesting to watch your reactions, thx a lot :) One suggestion I have for you, a movie based on actual events, K-19 the Widowmaker. The story of Russia's first nuclear submarine malfunctioning.

I've seen videos of reactor start ups. What makes the blue glow that is seen and what also makes the shock wave?

Starting around 13:20 it appears that you take the dramatic re-enactment at face value. According to journalists in the 80s (and today you can read Masha Gessen's article about this mini-series) to find out that no one in the control room argued at all. Everyone robotically carried out what Diatlov told them to do. But this servile behavior does not make for good television watching so the writers fabricated the control room scenes from whole cloth. I find the reality of how a "shut up and do what you're told" society had nuclear power far more frightening than anything I saw in this mini-series.

Actually the soviets used several different designs: The RBMK, VVER and BN-350/600

"The KGB will kill him before the cancer" - did you forget that the show opened with Legasov hanging himself????

Nice reaction.

A better term for arrogance, especially in this use case, is hubris. It adds a level of intellectual venom, when appropriate.

The real Valery Legasov actually did have a family.

I know some are thinking it. I’d like to snuggle up and watch Chernobyl with her. She can talk to me about nuclear physics all day and I’ll never get bored.

The really sad thing is that if you run the numbers, that reactor was savable up until they shut the pumps off. at that moment the water that was suppressing the reactor was allowed to stagnate and superheat.

If anything, "Chernobyl" demonstrated how in Soviet Russia, propaganda and the greatness of the state and how the state is always right, goes above all reasoning. It hit the nail on the head so hard, it went right through. The people are made stupid out of fear, constantly struggling with their conscience. Putin has done his best the last 20 years to restore this mentality, and he's succeeded by the looks of it.

Do you think there was ever a safe way to run the safety test they tried?

What are the cost of lies? Powerful closing line.

Aw you have no idea how clearly HBO displayed personal relations in Russia. You remember first episode, when Akimov was forced to evaluate reactor status from reactor rooftop in that management bunker? I've been having such episodes since Elementary School in Russia and it took too much time for me to learn how to resist it.

The problems that were mention were actually brought up when Chernobyl was being built. The Soviet Union actually brought in several British nuclear reactor engineers to look over the building of Chernobyl. Several of them said that there very several problems in the design but was ignored, one being that they weren't from the Soviet Union and so they knew better.

13:08 Akimov really tried to stop the experiment, because the actions that led to the instability of the reactor were really "outside the instructions". 6 rods against 211. Imagine, 211 needles were stuck in you, then 205 were taken out, and then they were stuck back in at once. Your reaction? That's right, the reactor of the 4th Chernobyl unit reacted in this way....

Pausing galore.

I know I’m late to this video but back around 14:02 you said something about the devise. You said it detects how much radiation that you are exposed to and that will give them a way to regulate where you work in the plant if your exposed to radiation at all times then if I may ask what do they do to keep you being overly exposed to radiation ? And you all put yourselfs inside a dangerous work environment so you all can come up with safer and more efficient ways to create energy I just fear for your all’s safety and I’m just curious could you explain it to me please 🙏 🥺

As I understand it, Chief Engineer Dyatlov (the arrogant one) was responsible for a previous nuclear incident, at a different plant, in which he was so irradiated that he brought it to his home and exposed his young son and his son died. Ironically Dyatlov lived for many more years.

its cool to see an actual expert talk about the issues and see actual concerns definitely exposed to me how little i knew about the subject lmao - then definitely agree on the female scientist perspective my mom is a chemist and i know from interactions i've seen as summer help as a sample prep and stories she's told that a female scientist's opinions can't go as far as they should most of the time

apparently this supervisor was exposed to high radiation a couple of times before this happened, once on a submarine and had become very arrogant with regards to the dangers of it

Thanks for reviewing the series. In my opinion, it was the scariest horror movie I have ever seen. Forget zombies, zombies are impossible.

As I understand it, the cause of the accident was that the operators did not know that they could not start the reactor back up immediately after shutting it down. So, I'm not sure it was a defect as much as a knowledge problem. Also, you disappoint me that you're going to do the usual "men will not listen to a woman" thing.

3:00 If problem at LAES that happened before that was shared across the ministry at least, there is a pretty good chance that Chernobyl disaster wouldn't had happened and RBMK reactors would be extremely cheap and safe enough. Though I'm grateful that this disaster happened in Chernobyl, not in LAES, otherwise it would cover Leningrad or Tallinn or Helsinki. Or at least 2 of the cities.

Hiding embarrassing or negative information is common, not just in systems like the the USSR. Whistleblowers who expose deficiencies or corruption are punished everywhere. Countries, even those of the so-called "free world", will smear, imprison, and even murder whistleblowers, just to protect their organizations, public image, or personal careers.

It was cheaper, the key line.... And why western reactors are so expensive.

It was fun watching Elina watching Chernobyl...getting so riled up!

In fission reaction 3 neutron will released, xenon absorbs all neutron and gets poison then core must stop the reaction. Graphite act as moderator it absorbs remaining neutron. Why the core got exploded

18:04 Dyatlov was fully aware of the fatal flaw at this point in time.

I love your channel! I love science and have an advanced degree in chemistry, retired. Love the tee shirt & saving to buy it. Best luck on your new venture!

I like how Ulana Khomyuk never existed and the series puts her representing the scientific community and impersonating the work of many scientist.

There is now a RU-vid channel called "The Chernobyl Guy," with a dozen or dozen videos on different aspects. He argues that Anatoly Dyatlov, the reactor control guy, was a scapegoat, that he wasn't as culpable or nasty as the Soviets (and the movie) made him out to be. I would argue the movie wanted a villain and chose him. . According to the Chernobyl guy they seem to have got Mr. Dyatlov's demeanor right but not his arrogant attitude. He did criticize subordinates but was also big on training and quality control. As Chernobyl guy recounts events it was Aleksander Akimov who made the critical errors. . What the movie says about bad design and lack of general understanding seems correct. They movie got that right, it was mostly systematic problems. . ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-N4YUoRH3z-Y.html

Yeah, I really enjoyed the whole Chernovyl series, it was really interesting and they way they presented the trial in this last episode... As for recommendations of what to watch next, I dunno if it's available to you, but this documentary Uranium - Twisting the Dragon's Tail presented by Derek Muller (Veritasium) was great.

Could you make a Video how Nuklear Power Plant is used to make Uran, that is used in Nuklear Wapons?

You should really really really watch the real interview with real Dyatlov. It was done in 1990 after he was back from prison, before he died of cancer. Its on RU-vid. Dyatlov says that everything that happened in the control room on the night of explosion was planned. Dyatlov designed the whole thing as a test of the failsafe AZ-5. He says he was workoholic and carrierist and wanted to do the most thorough test of AZ-5 ever done. He says the test of AZ-5 was confirmed by his bosses. Dyatlovs only mistake was to trust soviet science - everything he ever read told him the AZ-5 is always safe. So if this is true the real situation is even more scary - that means no operator mistake at all - only a fatal flaw of the whole system of society and system of government. And in case it didnt happen this way in reality...it still could have. Which is equally scary. All operators in whole Soviet Union believed the AZ-5 is safe. Noone was thinking about if its a bomb or not.

I'm very glad you alluded to the sheer number of safety systems and redundancies the operating staff had to manually override the evening of the disaster, just to run Unit-4 in such an unstable and hazardous state. That, more than anything, is the one thing I fight to get people to understand when talking about the disaster, and how and why it happened. I mean, there's dumb, and there's "manually disconnect the reactor's process computer because it won't stop reporting the reactor's being operated outside acceptable parameters, and recommending operators to SCRAM" dumb.

I really enjoyed the show as well. thank you for sharing your thoughts

Hey Elina, I would like to your thoughts on the first episode on that actions in 20 20 hindsight could have been done better to mitigate the issues and effects, even to stop the issue from happening at all. Subscribed and liked.

​@YourFriendlyNuclearPhysicist >>> _WHY_ was your video covering episode 4 demonetized?

4:29 To be fair, they didn't want to listen to themale scientist either. Or anyone else for that matter.

Just discovered you. Heading back to the first episode.

there is one major problem with this series while it might try to be historically accurate - and show the decisions that soviets were making at no point has they pointed out a fair few of the decisions made were inaccurate or completely wrong so if they talk about say "thermal explosion" with a yield in megatons of TNT, that would make half the Europe uninhabitable - they should have pointed out while it is true that soviets were afraid of such scenario at the time it was later found out these fears were unfounded, as such a thing was never possible. And as a result, you got millions of people, who watched this show and ended up thinking that nuclear accidents can lead to explosions that would make whole continents uninhabitable - because they've never been told this is false.

Honestly, one of my top series of all time. Short yet extensive, somewhat educational, it hooks you up and you could watch all 6 episodes in a row, even when they are 1h long. Imo even better than Game of Thrones, although that is a high bar to clear :D I've seen it at least 2 times.

I enjoy your videos

2:49 - not all of the Soviet reactors had this issue, just the RBMK. There was another Soviet design (VVER) that was perfectly safe and it's still being developed and exported by Russia to many countries all over the world this day with no serious incident ever happening in any of them.

Recently discovered your channel, very awesome.

Do you have any idea what happened to the control rods after the explosion? Were they recovered? You'd think they'd be launched halfway to Moscow.

To me the most powerful speech was by the physicist Legasov when he spoke about lies being the reason for the explosion. His words still ring true today with many national politicians repeating big lies daily to gain power, money, votes, etc. Valery Legasov : To be a scientist is to be naive. We are so focused on our search for the truth we fail to consider how few actually want us to find it. But it is always there whether we see it or not, whether we choose to or not. The truth doesn't care about our needs or wants, it doesn't care about our governments, our ideologies, our religions. It will lie in wait for all time. And this, at last, is the gift of Chernobyl. Where I once would fear the cost of truth, now I only ask: What is the cost of lies? I've already trod on dangerous ground. We're on dangerous ground right now, because of our secrets and our lies. They are practically what define us. When the truth offends, we lie and lie until we can no longer remember it is even there, but it is still there. Every lie we tell incurs a debt to the truth. Sooner or later, that debt is paid. That is how an RBMK reactor core explodes. Lies.

Elina, you might want to talk someday about the Goiânia accident in Brazil with Cesium 137... in 1987, so soon after Chernobyl

You should have watched the end credits because you didn't seem to pick up from the beginning or the end that Lagasov committed suicide and the consequences of that.

A bnr 800 fast reactor video would be cool. Especially it vs the integral fast reactor.

I'd seriously question whether what happened was an "accident". I think an *incident* due to negligence and recklessness, would be a better description.