21:11 "the baby in utero would be pulling a lot of resources from its mother" - pregnancy described by an engineer

“The baby absorbed the radiation.” This isn’t true, but it was a commonly held belief at the time, even among nuclear scientists, so it makes sense that she would say that

Regarding Lyudmila's baby, ionizing radiation damages rapidly dividing cells, regardless of where they are found. The GI tract, the epidermis, and bone marrow suffer profound damage from radiation because these cells are replenished often. ARS patients lose their hair because hair follicles fall into that category, too. But fetal cells divide more rapidly than any of these. That's why they ask women if they are pregnant before taking an X-Ray or performing a CAT scan. A developing fetus is uniquely vulnerable to radiation. Lyudmila's baby did not absorb the radiation instead of her, the baby was just more vulnerable to it. Lyudmila did not increase the risk to her child by spending time with her husband or even by touching him, the damage was done before she ever left Pripyat for Moscow. At the time, she was in her first trimester, the most vulnerable phase of her pregnancy. She is fortunate to have borne a healthy son in the years since, but the odds of it might not have been as remote as original estimates portrayed. A woman is born with all the eggs that she will ever have and they do not begin to develop until they are activated by lutenizing hormones, so the Chernobyl explosion might not have much impact on eggs that were still dormant at the time.

Scientist: How can me make measuring radiation dosage as confusing as possible? Other scientists: YES

When he says "I did everything right", it sort of reminds me of the main character from Falling Down. In the end, he says "I did everything they told me to." Both of them were lied to and taken advantage of by systems much bigger than them.

CIVIL ENGINEER REACTS *graphite scene* “Yup, that’s not concrete”

Can't wait for your thoughts on episode 5 when they really dive into the more technical details of the reactor and explosion!

One small correction: Even when reactor stopped, new atoms of Xenon are still produced from other radioactive elements, so even after 8~9 hours the levels of Xenon would still be high.

There's one extra reason that they may have wanted to classify their RBMK 1000 reactor documents. They were designed to produce electricity, yeah, but they were also used to produce weapons-grade plutonium for the military use. That, plus the incidents at Ignalina and Leningrad involving said reactors, where the SCRAM procedure actually produced a spike in power before shutting down the reactors. Definitely not as safe as they were made to be to the public/west.

About the stalled reactor: Xenon is not a direct product of the fission. Iodine135 is. Iodine135 decays into Xenon135 with a half life of about 6.5h. Xenon135 IS the strongest known neutron absorber. Xenon135 can be removed from the reactor ether by burning it by neutron capture, or by waiting till it decays into caesium135. The production of neutrons (neutron flux) and iodine135 is proportional to the current reactor power. Xenon135 burns away proportional to the neutron flux. And now comes the problem: The 'production' of Xenon135 is a not proportional to the current reactor power. It's production rate is a delayed function of the average reactor power several hours ago. So whenever you lower the power of an reactor, you 'inherit' a delayed 'neutron debt' from all the produced Iodine135 'waiting' to decay into the neutron absorber Xenon135.

21:00 From a biology standpoint, babies and children are growing rapidly, their cells are dividing constantly and generating more human mass to make them grow up. Radiation damages DNA inside cells and so as children are dividing fast that damage materialises much more quickly than in adults who have stopped growing and whose cells divide very slowly. As for a foetus saving the mother, what I think the logical concept here is the mother would not be suffering as much damage from radiation as she's older, the foetus is dividing very very rapidly and so it's cells would be all messed up by the radiation, there was a massive spike in horrific birth defects directly after and as a consequence from chernobyl for exactly this reason. Also check out Chernobyl Heart Syndrome which children born to this day are suffering from. TLDR: the younger you are the more radiation affects you.

The RBMK was designed both to produce power and breed nuclear fuel, either for reactors or weapons. This dual nature may have contributed to the secrecy of some of its specifications, but it’s more likely that the scene is showing the irrational information control that was a daily reality in the Soviet Union, especially as it dealt with the shame of the reactor accident.

I believe your explanation of the positive void coefficient is simple enough to be understood yet informative. Kudos to you for the excellent effort and for the series as a whole.

I've been following Chernobyl for about the last decade or so and the New Safe Confinement building (shed looking building) was built for two purposes. First it was created to basically kind of replace the crumbling concrete sarcophagus which had been leaving pretty badly since the 90s. It also has a VERY interesting system in place on the inside that they designed specially to be able to start dismantling both the sarcophagus and to start emptying out the inside of the old reactor building. It basically a supersized crane system. I'd look it up it's actually fascinating how they built it.

How this show didn't hit every horror list that year, and a ton of Top-10+ horror lists since then is beyond me. The way they depict the core is pure cosmic horror. Certainly plenty of body horror. It's apocalyptic horror. It's arguably true crime. For something not technically in the horror genre, it is absolutely terrifying.

The best explanation I've heard of the "positive void coefficient" in the RBMK 1000 reactor was that water *_BOTH_* moderates and absorbs neutrons (if it's not heavy water). In a PWR reactor, water is basically the ONLY moderator (and it's heavy water so it doesn't absorb). If it goes away, the reaction just stops. This seems to be true of boiling water reactors as well. Less moderation but also less absorbtion. The loss of moderation wins, though. In an RBMK 1000 reactor, graphite is the primary moderator. Water absorbs neutrons, so if it goes away, the graphite is still there so reactivity goes up. More reactivity → more heat → more steam → more reactivity → more heat → more steam...

One of the things I like about this show is how the directors wanted it to be as real as possible. The control room from the beginning was the exactly the same as the Chernobyl control room. What they say in the control room was almost exactly what was said. The speech the general gives to the soldiers before they go on the roof is exactly what he said in real life, and the scene on the roof is shot in real time and we as the viewer are on the roof for exactly 90 seconds with the soldiers.

The new cover is called the ‘New Safe Confinement’ and is the largest moving land object ever constructed (apparently). I read somewhere that part of the reason that the Sarcophagus deteriorated so badly was that the concrete and steel was denatured by the intense radiation. I don’t know if this is correct though and would your thoughts (or others) on this. It is very clearly visible from the air! Although I’m well versed in this accident through my own research, I have immensely enjoyed your patient commentary, and consideration of the radiation, doses, exposure using the chart, and learned even more through it. Great series

There is actually a really interesting documentary somewhere about the new containment's construction and moving it over the old sarcophagus. It's was designed with an inner crane that is designed to slowly dismantle the old sarcophagus and reactor. Not sure how that project is actually going, but that was the intention of the new containment. Not to simply cover the accident for another 100 years, but to actually dismantle the wreckage altogether. I believe the documentary is a PBS NOVA episode called Building Chernobyl's MegaTomb.

I’m a layman, but I loved the Chernobyl series, and I’m loving your reaction series. Great videos! Thank you!

The US government does own the reactors on nuclear submarines, and those are highly classified.

I knew someone growing up whose mother was a nurse in Poland at the time of the disaster. The problem with radiation and pregnancy is down to metabolic rates of the fetus and the mother. A pregnant woman's body is already functioning at its maximum capacity with regards to immune function and metabolism, well above the rates seen in men and children. There is a very fine line that exists between a body's ability to compensate in that state, not entirely dissimilar to the elderly, except recovery occurs post-pregnancy. Therefore, pregnant women are considered to be at significant risk to adverse effects from a variety of causes. This is why certain treatments, drugs, and inoculations are avoided while pregnant. Now, the unborn child due to the nature of human gestation is vulnerable to the lifestyle and diet of the mother-to-be, and her environment. Just as toxins and pathogens (and immunities) can be passed to the child, so to can absorbed radiation, which can occur at a faster rate within the child. While I'm uncertain of specific case studies, due to the rarity of such incidents, it was supposed in Poland and the Soviet Union that the fetuses would draw radioactive iodine into their systems away from the mothers, and that modest exposure of the adult could adversely effect the child, due to their faster metabolism and the concentration of radioactivity in their developing cells. This theory is put into use for more positive outcomes when doctors give high doses of anti-viral drugs to HIV+ mothers as a means to prevent their children from being born with that disease. The nurse from Poland unfortunately recalled many healthy mothers choosing to abort their babies during the Chernobyl incident, even if they were not considered as high risk of exposure at the time, due to their location.

The speech General Tarakanov gives to the liquidators before they start to work in the roof has been kept identical by the series to the one you will find in the documentaries from the accident. You can see it in “Chernobyl 3828” a documentary made by Valery Starodumov, a dosimetrist that worked on the roof cleaniing. He actually is the guy that “ringed the bell” hitting a piece of steel to warn the liquidators they have completed the “safe time” on the roof.

always a good day when I see an update in this series

Can’t wait for the next one! Rewatched the series just because of your prior videos

I binged all 4 of your reactions back to back, please come out with the last one as soon as you can!

Steam voids in the coolant channels can also help with heat transfer in a process called nucleate boiling when the steam voids created on the channel walls leave the walls and enter the coolant channel and transfer the heat to the water turning the steam voids back to water. However depending on conditions of the coolant it can lead to dryout of the coolant channel or a departure from nucleate boiling causing steam voids not to leave the channel walls, both reducing overall heat transfer.

Just recently discovered this series, watched through it all and now I can’t wait for episode 5. Peaked my interest in science for sure.

Hi, I’m not a nuclear physicist, nor do I do anything in this field at all. I am also not a nuclear reactor myself. However, I just came across these videos today and have watched them all and I hope part 5 is coming soon☺️

Thanks for explaining all of this! Love the show and really appreciate knowing how everything works.

The two producers of Xenon are directly from uranium, but most Xenon is produced by the decaying of Iodine 135; usually, Xenon directly from fission is so low you can ignore it for most calculations. So the source of your Xenon is determined by the power you had around 8-10 hours ago. The most significant way of removing Xenon is by absorbing a neutron, so your current power level with another option of waiting for it to natural decay. So when power was much higher 8 hours ago than it is now, you have much more Xenon being produced than is being removed, increasing the concentration and lowering reactivity. So when power 8-10 hours ago was much lower, you are removing Xenon faster than it's being produced, reducing concentration and increasing reactivity. When power has been around the same level for a while, the incoming Xenon will equal the Xenon being burned, and you are at a state known as equilibrium xenon. I operated a reactor for the US Navy, and we had much more power changes that would be experienced at a typical power plant and saw the effects of Xenon changes a lot.

Gosh that took a minute… glad you are back doing these!! You make it much easier for my lameness understanding of nuclear material

Love your content, can’t wait to see your reaction to Episode 5.

Great job! Love your videos on this series. Your insight on this series really answers a lot of questions. I Binge-Watched the whole series in one night when it came out on HBO. Have followed what occured at Chernobyl for some years. Watching the series was like seeing a real life horror movie unfold right before your eyes. Am so glad that this is under control now. A lot of people sacrificed their lives and careers so that others would live. Grateful for them.

I love these videos. Thank you for doing this!

Ahhhh!! I just found you today and binge watched your reaction to this series and now I’m at the end :( can’t wait for the next one!!

Hey man really enjoy the series, glad you took the time and effort and continue it.

I've been anxiously waiting for this video

bout dang time. been waiting for this.

Thank for this video, i love your commentaries on this series

My recollection from nuclear safety at orientation ~15 years ago is that developing humans (fetuses, children) and the very old are more sensitive to radiation. Thus the NRC maximum dose for a pregnant woman is half that (during the pregnancy) than a non-pregnant worker. So it's incorrect to say the baby "absorbed the radiation that would have killed the mother" but completely possible that radiation that caused minimal acute symptoms in the mother ultimately killed the baby. Is that because of the mass differences (increased probability the radiation would interact with critical anatomy)? Or that genetic anomalies caused by irradiation propagate much quicker in developing bodies than developed ones? Someone in medical physics will have to answer that question.

I just wanted to say as someone who is learning more about nuclear physics for personal interest, your videos are very very good and incredibly interesting. Keep on going!

Charlie Murphy! Interesting mental picture, "the baby absorbed the radiation", I see the liquidators on the roof holding up babies as radiation shields. "It's 90 seconds without a baby, 90 minutes with a baby!" grab a baby and get to work boys!

3:23 yep, fluorine fires are no joke. One of the most volatile substances is basically just fluorine and can make concrete “catch on fire” ,for lack of a better term

Awesome reaction and analysis bro! Definitely learned a lot about how it all works in relation to nuclear reactors - just subbed already bro'! Looking forward to the finale!

Been waiting for this for a week

Thanks for doing these.

The new editing style looks great! Well done!

Good video. Many thanks

Regarding access to science books being controlled: In the 1990s, in an attempt to save money on textbooks, some Canadian engineering students tried to buy their books directly from the publisher (McGraw Hill) rather than the university bookstore. All of the books they ordered were available for purchase in the university bookstore (in Canada), but McGraw Hill shipped from the US. The US State Department denied export to some of the chemistry books on the grounds that the students did not possess permits to export military secrets.

Another great video!

Awesome series man ! I’m a dental practitioner and my past time is nuclear physics thanks for helping me through some tough times !!

Love these. Keep it up please.

Hey buddy! Love your work. Thank you

Well done! Thank you!

thanks for the video dude :)

I just recently discovered the mini series Chernobyl, and as a layperson I appreciate your simple explanations of this complex topic.

Finally! Please finish up the whole series

One of the flaws in the Soviet structure of the day was that the authority above you (state/party) was always right. Even when they were wrong, they had to be right. So if they said the design was perfect, or the risk of an operation was low, it had to be whatever they said or else you would be replaced with someone who would unquestionably think that.

Excellent work Charlie!!! You got some talent for sure!

I’ve been absolutely loving this series!

I’m so hyped for this last episode. I love getting educated on this part of stuff. I honestly think the science is so nutty.

what a timing, just finished the first 3 reaction this morning haha

Ladies and gents he's back! fantastic video!

have watched all of these so far, good break down of most of the stuff that made my head split in half as BS. Good resource for public info on responses here in the US is the FEMA site. Most of the plans are just very general and high level, but gives you a way to contrast and compare how it would be dealt with here, were it to happen. We also do have specialized teams that are trained up and on stand by for a call from NIST that are US Army and USMC active duty units, they have a wide breadth of specialist that are assigned from medical to weapons specialist if needed by NIST.

YESSSSSSSS I've been waiting

absolutely great content. stay with your expertise and mixing it with a passion and you'll do well on youtube

Keep up the good work! 👍

Great video.

That concrete "Sarcophagus" originally erected over the ruins of Reactor 4 is still there, but it is slowly crumbling. How much of that is due to the radiation is debatable, but the major factors are weather and water related. Plus parts of that containment building rest on compromised structures and/or other items not designed to indefinitely support the weight. The New Safe Confinement not only covers the structure, it has ventilation systems the Sarcophagus lacks to prevent dust and contaminants from escaping into the atmosphere. It also supports two huge, remotely operated gantry cranes, which will slowly dismantle the old containment structure and the ruins of the reactor building beneath it, as well as the parts of the reactor itself. Most of this will be placed in permanent dry storage casks and taken to a long-term storage facility. Once all of the nuclear waste is completely removed, and everything stripped down to the foundations, the site will be permanently capped off, most likely with concrete. This process is expected to take a few decades.

Thanks for the insight.

Been on a bender of nuclear physics videos ever since I wathed an MIT lecutre about the chernobyl disaster. Your channel is one of the best I've come across. Keep up the good work!

Yes! Delighted this just popped up. I only subbed a few days ago and am enjoying your work so very much. You are very good at engaging the audience and presenting your information in an interesting and thought provoking way. You can tell how well you know your stuff because you can explain quite complex topics very clearly. Also the fact you do corrections is brilliant. Very very few people would do that and it brings a hell of a lot of class to your channel. The channel is really brilliant and I wish you nothing but the best for the future. KZfaq needs excellent and informative channels like this and you have the talent and knowledge for sure. All the best from 🇮🇪 👍( I still remember the orange boxes of iodine tablets the Irish government sent out to the east coast because they were so scared of Sellafield being attacked.i bet my mam has them in her 'everything drawer!)

I'm trying to envision the kid friendly animated graphic explaining the "egg basket." Dozens of little particles bouncing off a cod piece like bullets bouncing off Superman's chest.

Very nice!

The reason why she wasn't allowed to see certain reports and reading materials has to do with the fact that in the Soviet Union civil nuclear power was seen as a state secret and as such fell under direct KGB jurisdiction. They even had a special department called "Ministry of Medium Machine Building" erected for it. Everything was highly Top Secret and on a Need-to-Know basis only. As to your question about the baby. Yes, this is a true event. I have several books about the Chernobyl disaster and one of them has direct eyewitness accounts in it from the actual people involved like the Liquidators, family of the firefighters, control room staff, evacuees etc.. The eyewitness account of Ignatenko's wife, Lyudmila, is it too. She very vividly describes how her husband, Vasily, deteriorated by the hour in the later stages. And it is every bit as gruesome as we think it is. She also explains about the death of her newborn child. It has to do with that radiation attacks the fastest dividing living cells first. That's why things like the thyroid and bone-marrow get attacked first compared to, say, muscle tissue. That divides a lot slower compared to the first two. Since the baby has the fastest dividing cells compared to the mother, the radiation went there first. It was born and lived for four hours. It had severe cirrhosis of the liver and a badly malformed heart. If you're interested, the book is "Chernobyl Prayer" by Nobel Laureate Svetlana Alexievich.

14:14 actually the new cover was built with the purpose of finally dismantling the core and removing all of the nuclear waste for permanent storage. So let hope no new building will be needed

I respect this guy so much for not nitpicking at things that are clearly there for cinematic purposes!

I’d love to see further episodes on other nuclear incidents!

You'd be surprised at the seemingly trivial things that were considered secret back in the days of Cold War paranoia. Or at the things that were not secret but nobody talked about anyway out of fear that someone would decide that actually it was secret after all.

Prior to this series Chernobyl was something that had my interest but after watching your series covering the show and more so the disaster itself my interest in the disaster and the physics behind it all has skyrocketed to something more a strong interest in radiation and the physics of it and the way it works and truly I just want to say thank you for that because it’s not necessarily something I would think I would’ve gotten interested in if it weren’t for your videos

Nope, I don't want to wait longer to see your next episode. This is too interesting.

Every time I hear you say "from the Atomic Age" in my head I add "OF RENEGADES!" and I go down a Tom Morello rabbit hole. BTW excellent explanation of positive void coefficient - I was able to see it clearly in my head when you were explaining it (having studied RBMK and CANDU type reactor schematics did help with imagining the localization of the components) - not many people can do that. :D

Oh man I laughed wit h the egg basket xD It's really good that there are not many big earthquakes in that area... Building a dome like that, that can withstand quakes, must be so much more difficult to build

Nice new set up man

“The baby pulls a lot of resources from the mother. I want to learn more about this process.” Dude, you need to get out more. :) :)

Why must you upload RIGHT before i got to bed WHYYYYYY :'(... time to watch lol

Thanks for the fun commentary! How necessary do you think was the culling of animals like the stray dogs? I can understand not wanting them to transport radioactive material out of the area around Chernobyl, but on the other hand there will always be a lot of animals like birds that you aren't going to be able to cull.

The New Safe Confinement Building was built with special cranes on the inside to start tearing down the sarcophagus built in 86. The NSC was built in two large pieces then slid over the old sarcophagus covering the damaged reactor. It is so far the largest building ever to be moved laterally into position using teflon like sliders creeping a few inches per hour over a course of days.

new containment facility was build on the side and then moved over the reactor on large tracks. It is airtight now. It was specifically engineered and build to contain everything, including the old Sarcophagus. Now, the work of carefully deconstructing, decontaminating and preparing for safe storage of everything that can be processed that way is ongoing, including the parts of the old structure. There`s been rumors about old Sarcophagus collapsing, yet they`ve been disproven as far as i know. However the construction wasn`t in great shape. Basically, every country in the world helped to build new containment facility. en.wikipedia.org/wiki/Chernobyl_New_Safe_Confinement its referred as NSC or, rarer, the Arch ("Akra" locally). NSC was placed over the reactor in September 2017.

great channel name

If a reactor falls below the lower limit or is scrammed, it has to be kept shut down for 3 days for Xe-135 to naturally decay away.

Was beginning to worry whether or not we'd see a new episode!

The steam void discussion was interesting, it's not completely dissimilar from the water cooling system on an automotive engine. It's important push all the air bubbles out of the system before sealing it up, because they will cause voids in the water jackets around the cylinders and lead to the engine overheating.

Thank you very much! :) Quick feedback: I personally preferred the previous layout, with a miniaturized player on the right. Don't really like the blurred background. Waiting for the last one!!!!!

Just want to say that I've watched a lot of reaction videos on the chernobyl series and these were done by regular folks, KZfaq reactors without any first hand knowledge of nuclear physics. Those reactions are fine, and convey the emotional impact that the series was intended to create, but lack depth or substance. Your reactions are done with a critical eye for detail and a healthy amount of criticism on the perhaps more exaggerated parts of the series. It's very informative and helpful. I also like that you point out the gaps in your own knowledge. I think all intelligent people freely admit the limits of their knowledge while the ignorant are convinced their knowledge is absolute. All this is to say very good job! I've enjoyed your reaction to this series and looking forward to the conclusion.

Really enjoying this series! I really appreciate how you can break down complex concepts, and you don't pretend to know what you don't know. Regarding the death of the baby, I agree that it's more likely that the baby had a fatal dose purely based on size, rather than it being some kind of radiation sponge for the mother. It also might have died from something totally unrelated and they just assumed this was why it died. But yeah it would be much easier to knock out the bone marrow and thyroid of a baby (which would normally have a poor immune system having just been born), baby could have died from sepsis and/or severe hypothroidism. edit: or bleeding and anaemia! forgot about the other important stuff in marrow lol. birth is very traumatic, and a baby with no platelets could die from a brain haemorrhage very swiftly.

The replacement cover is the called the NSC New Safe Confinement.

i have faint memory that the xenon problem was also what cause the Windscale fire. They were also cutting corners (and fins) and bypass safety measures to increase productivity because there was nuclear (friendly) competition between US and UK.

Great presentation. Also a good example of why engineers shouldn’t be screenwriters. That’s not a criticism, my father in law was a nuclear submariner, it’s though to watch a submarine movie with him - he starts criticizing the pipe layout on the set. 😉