They were carrying out a safety test on reactor no.4 to test how effectively the pumps could keep the coolant water flow through the reactor in case of the power supply being knocked out until the backup generators could take over. The engineers didn't know the reactor had a hidden design flaw, making it unstable at low power levels. The chief engineer, Anatoly Dyatlov, wanted to carry out the test at only 200 megawatts, despite the safety guidelines told them the test should be done at 700-1000 megawatts. But Dyatlov didn't know about the reactors hidden flaw, and he thought he would preserve coolant water at lower power levels. When carrying out the preparations for the test by lowering power to the level the chief engineer wanted the test to be carried out at, they lowered the power to fast, making the reactor come to a complete stop. The chief engineer orders all of the control rods to be pulled out to restart the reactor. The only few rods that were partially inserted in the reactor core created a hotspot. The test started and the power to the pumps were shut down. Less and less water were now pumped through the core, the steam pressure in the hotspot keeps rising every second. More and more steam were created from less and less water. The heat and pressure keeps rising and the reactor now starts to boil dry. The reactor now is getting more and more unstable and the power doubles every second. Several fuel rods inside the reactor were torn apart from the enormous steam pressure and the pressure couldn't be contained anymore causing an explosion which blew the reactor lid off. Now with the safety cap blown off, air were sucked down into the reactor making it a giant blow torch which blew more than 8 tons of radioactive materials into the atmosphere. That's basically a short explanation of what happened.
Minor correction about the sequence of events. The reactor didn't meltdown when the control rods were removed, it occurred when the rods were reinserted after it became clear that there was an overheating problem. The rods were tipped with a material that was not a neutron moderator. Before the rods made it all the way down, the tips displaced the water inside the control rod shafts that was acting as a neutron moderator and sent the reactor into prompt criticality. Once the rods were removed and the power of the reactor reached a certain level, the design of the reactor made it impossible for an explosion not to happen. It was a bad reactor design in concert with poor decisions that caused the accident
Not poor decision making; the operators had no idea about the instability at low power levels caused by the control rod's graphite tip. This was kept secret by the Soviets. When they were setting up for the test power level dropped so they pulled out control rods which meant higher water flow was needed. The operator controlling the water pumps put in too much water stalling the turbines (low steam flow). So the reactor operator "helped out" by pulling out more control rods. Only 6 rods remained in the core. RMBKs also have a positive moderator feedback so as the core heats up power goes up. When the test started, the lack of water resulted in the core heating up causing power to increase. The rector operator noticed the power increase and did the right thing turning the AZ-5 switch which inserted all the control rods. But when the graphite tips on all the withdrawn control rods entered the fuel area, power spiked doubling about every second. This created so much heat the water instantly turned to steam which ruptured the core and blew off the reactor lid or cap. The graphite moderator then started to burn when exposed to the air.
So although paradoxal, would it have been avoided if the rods were sequentially inserted? Interesting comment! I knew of the displacement issue but not of any moderator 'tip'
If you have ever read The Holy Bible’s Book of Revelations, You might know about the 7 angels with 7 trumpets. The Third angel causes a star to fall on the earth, poisoning the Waters, land, and livestock. The Star is called “Woomwood” Which, in Ukrainian translates to Chernobyl.
It wasn't the meltdown that blew the roof. A nuclear reactor is akin to a vast boiler system, which is in a sense like a steam engine. When the control rods where all removed in order to raise the core temperature, the temperature increased at an uncontollable speed. As a result, all of the water being heated in the water tank by the exothermic heating element (the plutonium rods) was completely boiled off. Dry heating without water caused immense pressure to build, and eventually the heat and pressure blew the roof upwards. When the reactor #4 blew with its tanks and exothermic heating rods, everything had been thrown upwards and the disaster had occured. The meltdown was a chain reaction that happened moments afterwards as the plutonium continued to output intensive radiation and heat and burn down into the ground - threatening ground water and any land that lay beneath the facility. I had to research the Chernobyl disaster while studying for my boiler license and my engineer's license.
Your graphics are great, but the narration has some factual and omission errors, if it was indeed meant to cover "How it happened". - It wasn't a test of "backup cooling system", it was a test to make sure the pumps forcing coolant through the reactor could be powered by the generators for the 40 seconds or so until diesel generators could come on line if there is an emergency reactor shutdown. The test was failed twice before; it was not a "routine safety drill". - "A nuclear reactor is like a massive steam engine." That's an oxymoron and a non-sequitur in a single statement. - You don't say why the control rods were removed, and thereby loose the narrative and the reason for the accident. It's vital to know the why of that, else it just sounds like a happenstance, done on a whim. - "...and extreme heat began to melt the core. At 1:23 Am reactor 3 exploded." But why did it explode? And what was the nature of the explosion? If you don't answer those questions, you allow the CTs out there to do it, with all kinds of fantastical ideas.
@@croakingfrog3173 Only resembles a "steam engine" if one is using the reactor generated steam to boil water (or or some other medium), make steam and turn a turbine. A reactor in itself does not necessarily have to produce steam as its only function; many are used to make other elements used in medicine (Mo99 which produces Tc99m is the most widely made), I 131, I123, xenon, thallium, gallium, etc. They are also used for research, and some to make atomic fuel for nuclear bombs.
Basically like a giant steam pressure cooker, which doesn't stop until it explodes. Instead of your vegetables and rice popping out, it was graphite and uranium.
Do not watch the show in hopes of finding out what happened, don't read the books the show is based off of, they are both false, with one actually being based off of the other. The show is entertainment.
There is one thing the whole world has to know. Just how hard Russian people worked to save this planet. The miners the when their country called on them to come do a deadly task they willingly came and did a job by hand that could not have been done by machine in the time it was needed to be completed. The workers that went out on the roofs and only could work for 15 seconds before they had to drop what they were moving and leave. Over and over the workers of Russia took care of the world by working on that sight. Many just plane workers died trying to tame that out of control pile of pollution and poison. This is not the place to argue for or against this kind of power, it’s just the place we should all recognize what the Russian peoples did for the world and we should tell them thank you.
Das Maverick that is not correct. Chernobyl was not the mistake of the brave Russians who cleaned the mess up. We all owe alot of gratitude for the innocents who sacrificed their lives/health to prevent everyone else from losing theirs. P.S. no offense. It is easy to forget the suffering many of those innocent volunteers went through.
It happened in occupied Ukrainian territory and most of liquidators were Ukrainians. Its correct to say Soviet citizens, but there were people of different nationalities.
Incorrectly stated that it was a routine test of the 2ndary water cooling system. It was a test supposed to be done at lower power of 700MW, and seeing if the turbines could continue to turn and generate power as they cost down during the period before the backup diesel generators could be completely online. There was nothing routine about this test, the engineer in charge shut down the emergency cooling system, the reactor's design flaw was not kept in mind and the reactor went into a runaway situation, creating a hot spot which melted the core, fuel and caused an explosion. The lack of concrete containment vessel was also a design shortcut/flaw of this type. See a very good explanation below written by Stonkish.
Exactly. I start this video and keep hearing them say routine and I'm like "are we talking about the same reactor here?" This was not routine. This was a special test and it was screwed up on several levels.
First of all, it wasn't a meltdown. It was a steam explosion. Second, they were trying to do a routine safety test in case of war, to see for how long the reactor can be cooled until the diesel generators take over. They didn't know that the reactor had a fatal flaw. It was unstable at low power, and Dyatlov, the chief deputy engineer said the test to be done at 200MW. However, Dyatlov did not look over the safety guidelines which said the test to be done at between 700-1000MW. They accidentally stalled the reactor, and Dyatlov ordered to remove all of the control rods. Then, the power was increasing too fast and eventually they got a power surge. They pressed the AZ-5 button which inserted all of the control rods. The control rods, tipped with graphite, caused an even bigger power surge which means that the reactor started producing a lot of steam. That steam pressure eventually blew the 50 ton reactor cap in to the air. And third of all, the old chimney did not get removed.
It was not a routine safety check. It was 2 years overdue and had to be done with commisioning. And this type of reactor was also unstable sometimes during normal operation. At most at the end of the fuel lifetime cycle. But most stupid of all they kept this problems quite and just acted if they didn’t exist. accidont.ru/ENG/LAES.html
It was not a "routine safety check". It was an experiment with back-up systems that had never been successful. In fact, it had already failed 5 times before.
The greatest respect for all liquidators who have given their lives is that we can dream our dreams further! The HBO series commemorates them and makes sure that we don't forget!
I find it interesting that this is the first source to state clearly with no bullshit that the other three reactors remained online despite number 4 being absolutely destroyed. Tough fuckers, can't blame them but must be eerie as hell knowing one went up in your workplace like that.
That's not the end of the story. The insertion of the too hot core afterwards resulted in the cooling water, which they put to a max after one pump died, to combust in huge ammounts of steam, resulting in a huge pressure which detonated the reactor building. That's the first explosion.The second and more powerful explosion occured because of the steam, which was burnt to hydrogen, exploding. It resulted in a chain reaction, not a nuclear one, but any burnable thing was exploding at once which huge pressure. The meltdown of the core is known as the elephant's foot. The fires burnt for many hours, needing much clay and sand to put down, and resulted in further radioactive contamination of the area. Additionally, there was an earthquake (not strong, but information was classified in the Soviet Union because the seismograph was designated to scan for nuclear detonations in Europe) with it's epicenter about 8 km under the reactor building. So there were 3 different things that came together to cause such a desaster. With todays technology, there is practically no way that such a disaster could occur. Technology is safe, as long as we build and maintain and run it properly. And better not build it in an area prone to earthquakes or tsunamis (thanks russia and japan).
This reactor design was cheap and fast to build but hardly safe, besides the design flaws with respect to the control rod design, etc, the lack of safety containment makes it hardly safe.
Exactly. This was a formula for disaster. A positive coefficient tin roof reactor, poor management, poor training, bad design, you name it. This was not a matter of if, but when. No sane country would license a reactor like that but the good ol USSR had no problem with it.
Your video has errors They never removed the graphite rods in fact they are removed the whole time It was when an employee forget to set a controller to 30% power which rested to 1% power this caused a tad increase in power but they decided to continue the test they shut down wind turbine 8 which caused a massive increase in power and heat as the water that is converted to steam begans to create a massive amount of still moving steam after that they shut down the reactor which lowered the 5 radioactive graphite rods into the reactor when they lowered they had no idea it would cause a monumental increase in power at that time near 1000mw as each reactor was capable of producing once the rods were lowered not raised (as you stated in your video) it caused a power and heat increase which caused the high void build up to explode the cover of the reactor flipping it on its side
Not a “routine safety drill”. It was a special experiment to find out if the circulating water could cool the reactor if the pumps went down. There were errors of design, training, execution that contributed to this failure. Not an accident due to chance causes. Humans were operating the control system up to the excursion.
One thing I remember hearing was that the graphite control rods caught fire, exacerbating the situation. I don't know how accurate that information is. I would appreciate if someone could clarify this for me. Also, I had heard the reactor was using Plutonium. Was that just one of those wildly inaccurate rumors or something?
This doesn’t explain what happened. The reason it exploded is because this type of reactor uses graphite tips on its Boron control rods. They were doing a safety test to see if the turbines could power the cooling pumps if the Plant lost all its power as in a Nuclear Attack. The generators took too long to warm up from a cold start, and would not get water circulating again quick enough. The problem was the amount of Xenon 135 that built up, a by product or “poison” of a Nuclear Reactor. Xenon is an accelerant of the Nuclear Rxn, along with steam, and even graphite. Water and Boron Control rods slow the reaction down. The test was to bring the reaction in the Core down to 700MW from 3,200MW. Normally this would be done in a short period of time in one shift, but because the Russian higher ups needed more power that day, it was done in TWO shifts. The Reactor had been sitting at half speed all day, creating Xenon Gas, and not fully burning it off, as it would at full speed. An overnight crew was assigned to run the test and had NEVER performed it before. They came in and were given no clear instruction and were rushed. They went to lower the Reactor to 700MW to mimic a power loss. It didn’t stop at the 700 mark though. The extra Xenon Gas that didn’t burn off all day brought the reaction way below 700MW, uncontrollably to single digits. At this point the reaction should have been shut down and started another day, but this was the 4th attempt at this test since the plant had opened. The Forman was not about to allow the test to not be completed. He ordered the test to push on. The water pumps were totally shut down when the turbines were not up to the proper speed. No water was circulating in the core and the Reactor STALLED! Now the Forman flustered, he ordered that Boron Control rods start to be removed to bring the reaction back up to the 700MV mark. It didn’t work, so he kept removing more and more control rods until there was an out of control Reactor on his hands. No water was circulating to cool as the pumps were off and had NO residual power coming from non moving Generators, PLUS A SHITLOAD of built up Xenon Gas. The reaction surged into the 10’s of Thousands, totally on the brink of destruction. The final straw was attempting to Emergency Shut down the whole reaction by hitting one button. This slammed all the Control Rods into the reactor at once. Remember those Graphite Tips? Those increase reactivity, and when they hit the ALREADY out of control U-235, it caused the straw that broke the Camels back, and the plant fissioned into a small nuclear bomb. This is how a RBMK Type Nuclear Power planet can be pushed to explode!
Before the disaster, the thermal power (MW) increased to 33,000 megawatts and here it is shown that megawatts do not increase before the explosion, and 2 is that the rods when they are at the top increase the reactivity, and when they are at the bottom (i.e. in the core) they reduce the reactivity, but in animation it's the other way around
All you say is "when the tests began the control rods were removed and the reactor overheated". You need to explain to viewers how and why the test unfolded in this fashion. It's explained in the Netflix Chernobyl series. The rest of this video is a history lesson which makes the title misleading.
So what you're saying is, Chernobyl turned from a nuclear reactor into a kettle gone wrong, shit when i push too much power through my kettle i'll evacuate the entire town next time, thanks! Chernobyl Reactor No.4>Kettle
This video isn't very accurate. It doesn't explain the experiment that was run for restarting the reactor or how the protocol wasn't followed. I would recommend further reading on this topic, as this video is way too simplified.
True, thats the problem with most of these short "summary" videos.....what still buffles me about the whole accident is how some people in Soviet Union knew exactly how unstable the reactors could be if the protocols and rules were not followed, yet others have given direct orders to go against those protocols to perform this test....I quess it tells most about all the secrecy and other bullshit attitude towards neglecting safety in Soviet Union. That those who order this test to be performed and those who performed it were not fully aware how fatally dangerous that test really was.
The video is titled "how it happened", but despite the fancy graphics, it contains almost zero information. "almost all of the control rods were removed, and technicians lost control of the flow of coolant". No, that's not how it happened.
Yeah believe it or not but it was the reinserting of all the rods at once with the lack of cooling that caused the meltdown, you see the rods were graphite coated and temporally produced more heat when intentionally reinserted, the heat generated by re inserting them all at one was far more than leaving them out, when the turbine is spinning enough coolant flow is present to barely keep everything from getting to hot, power to the water pumps was cut. It would take 40 seconds for the diesel generators to be able to start and pump water again, even with the generators running only a fraction of the coolant would be moved, but until they started up it had to coast. The minimum required 700 mw was enough to keep the water pumps flowing long enough for the generators to take over, power to the generators was cut at 200 mw, not enough coasting power to keep the pumps going long enough for the generators, combined with the rapid heat produced from a5 reinsertion what little water there was
Was not sufficient enough to last until flow could be restored, at 5200 degrees the reactor core begins to break down, that temperature was reached and there was still another 30 seconds before a fraction of the water required to prevent a meltdown would be present, it began to meltdown as a result the power rods began to melt causing a mini explosion inside the reactor, all the remaining fuel was exposed to the heat which caused many radioactive gasses to be generated inside the reactor until the pressure caused it to burst, once open the radioactive gasses and dust took off into the atmosphere and oxygen fueled the fire causing everything to melt to lava that burned through the floor of the reactor and many meters thick of concrete
Also xenon poisoning of the neutron flux occurred at one point, essentially shutting down the reactor; then the engineers decided to remove all the control rods to restart the reactor. From then on , the flaws in the reactor design and running an already dangerous test without following the instructions all resulted in this disaster.
Okay, i understand why they had to remove the chimney... what i don't understand is why they built a new smaller chimney in its place? Why do they need it when the power plant is not operational?
They only evacuated the city 3 days afer the explosion. Not oly that but everyone was told that things are under control and everyone was encouraged to participate in may day celebrations !
Evacuation was on April 27th, 50,000 people within a few hours were evacuated from the city. Where are you getting these 3 days thing from? Also, in Kiev, Gorbachev forced the local party leader to hold celebrations, if he didn't, then he would have been forced to turn in his party badge.
Ha! Now we are an army of HBO viewers that can explain in more detail than this video what really happened! Until we forget it all when next show comes along
Alex Yallop after a turbine stalled due to an excess of xenon accumulated in the reactor (this was because they had left the reactor at 50% power for 10 hours and it was not hot enough to burn it off as usual) and dropped the power to 1% or 30 MW. The rods are removed and put back in regularly. This is how they control the rate of reactions in the reactor (as well as other things such as water). The mistake here was that they removed 205 out of 211 control rods which is insanity. The test should’ve been stopped multiple times but due to pressure to get the test done as well as arrogance by the deputy lead engineer Anatoly Dyatlov, it wasn’t.
Also when the low enriched uranium fuel they used (2%) was at of the life cycle they need to pull more and more control rods out of the core to maintain the power level. So you get less and less control at the end.
Except of course containment buildings of this sort have been around for decades prior to this and the design was a really bad one. No sane country would license a positive coefficient reactor like this one. This is not a matter of second guessing after the fact. This was something that could easily be foreseen well ahead of time.
@@NickFrom1228 I agree that is was a dangerous design. But on top of that in the US a reactor has to have a heavy reinforced steel and concrete containment building not just some flimsy building like the Russian reactor did.
Not all reactors was in operation until year 2000. Unit 2 shut down in 1991 after being damaged by a fire. Unit 1 closed in 1996 amidst international outcry about the health effects radiation poisoning, including elevated rates of thyroid cancer among children. The last unit, Unit 3, operated until 2000, when international negotiations finally shut down the plant for good.
There's a place where the rocks of Caithness lie beside the ocean on summer's day a waiting grave in the layers and the pains of generation gone before us uranium your age has come there's salt and spray on the beaches of the island that I came from ceesium your age will come and from hollow mouths of gray it's the future and it's safe so let the children play. Move a mountain fill the ground take death on wheels recreate the land . And we will all be long blown rushes when all the world's a flame move a mountain
Dyatlov *hears loud explosion*: - You blow the hydrogen tank, reactor is fine. Reactor cooling system, luck and control rods: - CHEEKI BREEKI. * Go for a party * Dyatlov * 3 hours later, vomiting blood * : - Reactor is better than ever! Told you!
@Shaboi_Mike Actually, comrade Dyatlov is dead for 25 years, he died after having heart attack. Also, he was in prison, but only 10 years. PS Polonium is not mined, its made in nuclear reactors
You can’t blame it all on Dyatlov. The design flaws of this reactor were already know before this accident. They just acted like nothing was wrong, the Soviet way.
@@mrscientific4956 Dyatlov was not incompetent, he was highly experienced and new almost everything about the operation of RBMK reactors. He was there to supervise a test, he wasn't stupid, he didn't yell at anybody or force people to do things. He was there to conduct a test that he had previously conducted (successfully, but without proper documentation) in November of 1985. Dyatlov was not completely innocent, but the soviets turned him into a scapegoat for the disaster, had Akimov and Toptunov survived to see trial, they would likely be standing there next to the man, with people like you insisting that they were to stupid for their jobs. Oh, and there are still people that think that.
Also shutting down those other 3 reactors would have meant serious power shortages around the region, so it really wasnt on option....there was simply no easy way to replace them quickly with other options. As for the safety issues, well obviosly the safety of the reactors were improved, but also its important to understand that while the RMBK reactors were the most "unsafe" reactor types, operating the reactors under the RULES that were given made them safe enough.....whats important to undersand about what happened in reactor 4 was how they purpously went against those regulations and rules to test something that should have never been tested with that reactor type
This is an entirely too simplistic froduction for a "how it happened" video if this was really produced by a Quasi Government operation (RFE/RL) of the US Government. The root cause and initial failure mode is not revealed.
fools everyone knows an RBMK reactor cannot explode
L.M Shut up
@@pablobram This man's delusional. Take him to the infirmary
Theoretically, it's impossible
It's not great, not terrible either.
@@johndanes2294 you are an nuclear phycisist after watching the show, just like me, so tell me... how can an rbmk-reactor explode...
The videomaker is definitely delusional, take him out of here.
They were carrying out a safety test on reactor no.4 to test how effectively the pumps could keep the coolant water flow through the reactor in case of the power supply being knocked out until the backup generators could take over.
The engineers didn't know the reactor had a hidden design flaw, making it unstable at low power levels. The chief engineer, Anatoly Dyatlov, wanted to carry out the test at only 200 megawatts, despite the safety guidelines told them the test should be done at 700-1000 megawatts. But Dyatlov didn't know about the reactors hidden flaw, and he thought he would preserve coolant water at lower power levels. When carrying out the preparations for the test by lowering power to the level the chief engineer wanted the test to be carried out at, they lowered the power to fast, making the reactor come to a complete stop. The chief engineer orders all of the control rods to be pulled out to restart the reactor. The only few rods that were partially inserted in the reactor core created a hotspot.
The test started and the power to the pumps were shut down. Less and less water were now pumped through the core, the steam pressure in the hotspot keeps rising every second. More and more steam were created from less and less water. The heat and pressure keeps rising and the reactor now starts to boil dry. The reactor now is getting more and more unstable and the power doubles every second. Several fuel rods inside the reactor were torn apart from the enormous steam pressure and the pressure couldn't be contained anymore causing an explosion which blew the reactor lid off. Now with the safety cap blown off, air were sucked down into the reactor making it a giant blow torch which blew more than 8 tons of radioactive materials into the atmosphere. That's basically a short explanation of what happened.
Why did they think removing all of the rods would stop it?
This was a great read, i need more, all of it, every detail you can give
You watched that episode of Zero Hour didn't you?
have you tried wikipedia (@luske)
Ye im not goona read all that
Description is way too simplified to understand what happened.
So how long until the elephants foot is ok to play with
When the elephant is sleeping XD
Nubbins lol
Yeah somewhere about a billion years
50,000 years, since dere Is a half life in utanium and it is 25,000 years for 1 half life
Nubbins it'll be safe around the year 22,000
3.6 Roentgen not great, not terrible either
Its- Showtime , dyatlov the asshole
Minor correction about the sequence of events. The reactor didn't meltdown when the control rods were removed, it occurred when the rods were reinserted after it became clear that there was an overheating problem. The rods were tipped with a material that was not a neutron moderator. Before the rods made it all the way down, the tips displaced the water inside the control rod shafts that was acting as a neutron moderator and sent the reactor into prompt criticality. Once the rods were removed and the power of the reactor reached a certain level, the design of the reactor made it impossible for an explosion not to happen. It was a bad reactor design in concert with poor decisions that caused the accident
Finally someone gets it👏🏼👏🏼👏🏼👏🏼
Not poor decision making; the operators had no idea about the instability at low power levels caused by the control rod's graphite tip. This was kept secret by the Soviets. When they were setting up for the test power level dropped so they pulled out control rods which meant higher water flow was needed. The operator controlling the water pumps put in too much water stalling the turbines (low steam flow). So the reactor operator "helped out" by pulling out more control rods. Only 6 rods remained in the core. RMBKs also have a positive moderator feedback so as the core heats up power goes up. When the test started, the lack of water resulted in the core heating up causing power to increase. The rector operator noticed the power increase and did the right thing turning the AZ-5 switch which inserted all the control rods. But when the graphite tips on all the withdrawn control rods entered the fuel area, power spiked doubling about every second. This created so much heat the water instantly turned to steam which ruptured the core and blew off the reactor lid or cap. The graphite moderator then started to burn when exposed to the air.
So although paradoxal, would it have been avoided if the rods were sequentially inserted? Interesting comment! I knew of the displacement issue but not of any moderator 'tip'
Louis Descamps potentially yes but they didn't want to wait any second longer than they had to
true
The very word Chernoble just sounds horrible scary by itself.
Blazeitup420 Chernobyl*
Aleksandra Dicheva stupid
If you have ever read The Holy Bible’s Book of Revelations, You might know about the 7 angels with 7 trumpets. The Third angel causes a star to fall on the earth, poisoning the Waters, land, and livestock. The Star is called “Woomwood” Which, in Ukrainian translates to Chernobyl.
Everything scares the mentally weak and easily frightened :(
The Monolith Wormwood. But great Bible references.
Hell of way to boil water
I like my tea with cancer and ARS
I hear people say this but it really makes no sense when you think about it.
Now featuring nuclear reactor kettles
@@Tomc1278 coated with uranium for a nice radioactive taste
@@absinthe7266 yeah because added minerals are sooooo bland lol
Who else is here after watching the HBO series Chernobyl?
YES DUDE! Its fucking crazy!
me me
Yes, well done show, I feel Chernobyl could have killed the Earth, many thanks to men and women that gave their lives to save us........
Me
Yes
Tell me how an RBMK reactor explodes
It can’t because it’s physically impossible
Well you do know after last episode
LIES.
Graphite tipped boron Rods.... that’s how
cosmin12365 those that are fascinated by this stuff knew already...
Some guy probably whispered “prepare for unforeseen consequences” to one of the technicians before the test
2:46 Titanic... another fine memory
Horribly inaccurate description of the cause of the accident.
It wasn't the meltdown that blew the roof. A nuclear reactor is akin to a vast boiler system, which is in a sense like a steam engine. When the control rods where all removed in order to raise the core temperature, the temperature increased at an uncontollable speed. As a result, all of the water being heated in the water tank by the exothermic heating element (the plutonium rods) was completely boiled off. Dry heating without water caused immense pressure to build, and eventually the heat and pressure blew the roof upwards. When the reactor #4 blew with its tanks and exothermic heating rods, everything had been thrown upwards and the disaster had occured. The meltdown was a chain reaction that happened moments afterwards as the plutonium continued to output intensive radiation and heat and burn down into the ground - threatening ground water and any land that lay beneath the facility.
I had to research the Chernobyl disaster while studying for my boiler license and my engineer's license.
Your graphics are great, but the narration has some factual and omission errors, if it was indeed meant to cover "How it happened".
- It wasn't a test of "backup cooling system", it was a test to make sure the pumps forcing coolant through the reactor could be powered by the generators for the 40 seconds or so until diesel generators could come on line if there is an emergency reactor shutdown. The test was failed twice before; it was not a "routine safety drill".
- "A nuclear reactor is like a massive steam engine." That's an oxymoron and a non-sequitur in a single statement.
- You don't say why the control rods were removed, and thereby loose the narrative and the reason for the accident. It's vital to know the why of that, else it just sounds like a happenstance, done on a whim.
- "...and extreme heat began to melt the core. At 1:23 Am reactor 3 exploded." But why did it explode? And what was the nature of the explosion? If you don't answer those questions, you allow the CTs out there to do it, with all kinds of fantastical ideas.
You could start with wikipedia, "Chernobyl Disaster". It has it right, and all the statements are backed up with sources. Then start prying into them.
Good remarks! I hate the way everything is converted to Discovery Channel simplifying shit.
How is a nuclear reactor not like a steam engine? They both rely on heat to produce steam which then generates power.
@@croakingfrog3173 exactly
@@croakingfrog3173 Only resembles a "steam engine" if one is using the reactor generated steam to boil water (or or some other medium), make steam and turn a turbine. A reactor in itself does not necessarily have to produce steam as its only function; many are used to make other elements used in medicine (Mo99 which produces Tc99m is the most widely made), I 131, I123, xenon, thallium, gallium, etc. They are also used for research, and some to make atomic fuel for nuclear bombs.
Basically like a giant steam pressure cooker, which doesn't stop until it explodes. Instead of your vegetables and rice popping out, it was graphite and uranium.
What useless information this video brings.
No explanation at all
I find this more scary than all horror movies combined in the last 2 decades
Dont fall for it. It's a scam. Research the lack of cancer and deformities. The wildlife is thriving there today. It's fear propaganda.
I find YOUR MOM more scary than all horror movies combined in the last 2 decades
This is so much oversimplyfied and wrong. Just watch the show or read the comments.
Do not watch the show in hopes of finding out what happened, don't read the books the show is based off of, they are both false, with one actually being based off of the other. The show is entertainment.
There is one thing the whole world has to know. Just how hard Russian people worked to save this planet. The miners the when their country called on them to come do a deadly task they willingly came and did a job by hand that could not have been done by machine in the time it was needed to be completed. The workers that went out on the roofs and only could work for 15 seconds before they had to drop what they were moving and leave. Over and over the workers of Russia took care of the world by working on that sight. Many just plane workers died trying to tame that out of control pile of pollution and poison. This is not the place to argue for or against this kind of power, it’s just the place we should all recognize what the Russian peoples did for the world and we should tell them thank you.
David Christensen It was their fuck up, they should be the ones to pay the price, not the world.
Das Maverick that is not correct. Chernobyl was not the mistake of the brave Russians who cleaned the mess up. We all owe alot of gratitude for the innocents who sacrificed their lives/health to prevent everyone else from losing theirs. P.S. no offense. It is easy to forget the suffering many of those innocent volunteers went through.
It happened in occupied Ukrainian territory and most of liquidators were Ukrainians. Its correct to say Soviet citizens, but there were people of different nationalities.
Incorrectly stated that it was a routine test of the 2ndary water cooling system. It was a test supposed to be done at lower power of 700MW, and seeing if the turbines could continue to turn and generate power as they cost down during the period before the backup diesel generators could be completely online. There was nothing routine about this test, the engineer in charge shut down the emergency cooling system, the reactor's design flaw was not kept in mind and the reactor went into a runaway situation, creating a hot spot which melted the core, fuel and caused an explosion. The lack of concrete containment vessel was also a design shortcut/flaw of this type. See a very good explanation below written by Stonkish.
Exactly. I start this video and keep hearing them say routine and I'm like "are we talking about the same reactor here?" This was not routine. This was a special test and it was screwed up on several levels.
3:05 So that’s what happen to that cooling tower? Ah. Figures.
this is the best one. nice work on the summary of how the reactor works and how it overheated .
Now explain the Fukushima disaster
First of all, it wasn't a meltdown. It was a steam explosion. Second, they were trying to do a routine safety test in case of war, to see for how long the reactor can be cooled until the diesel generators take over. They didn't know that the reactor had a fatal flaw. It was unstable at low power, and Dyatlov, the chief deputy engineer said the test to be done at 200MW. However, Dyatlov did not look over the safety guidelines which said the test to be done at between 700-1000MW. They accidentally stalled the reactor, and Dyatlov ordered to remove all of the control rods. Then, the power was increasing too fast and eventually they got a power surge. They pressed the AZ-5 button which inserted all of the control rods. The control rods, tipped with graphite, caused an even bigger power surge which means that the reactor started producing a lot of steam. That steam pressure eventually blew the 50 ton reactor cap in to the air. And third of all, the old chimney did not get removed.
It did eventually melt down after a few days though didn't it? That's what the "elephants foot" is.
It was not a routine safety check. It was 2 years overdue and had to be done with commisioning. And this type of reactor was also unstable sometimes during normal operation. At most at the end of the fuel lifetime cycle. But most stupid of all they kept this problems quite and just acted if they didn’t exist.
accidont.ru/ENG/LAES.html
The worst nuclear accident :(
THEY KEPT THE OTHER REACTORS RUNNING WITH THE SAME FLAWS ARE YOU KIDDING ME?!?!?
It was not a "routine safety check". It was an experiment with back-up systems that had never been successful. In fact, it had already failed 5 times before.
What the hell are you talking about? It didn't fail five times before. In fact, the whole test was successful.
From the creators of "the Titanic is unsinkable" and the "RBMK reactors cannot explode", now "the Coronavirus is weaker than a simple flu".
Write Chornobyl not Chernobyl please!
Чорнобиль is transliterated into Chornobyl in English!
#KyivNotKiev #CorrectUA
Yeah, they left out a lot of stuff about why the reactor exploded.
Of course they did because RBMK reactors don’t explode
Oh wow so the other side of reactor is still operational until 2000 i thought the whole facility is completely abandoned after the incident
Not really the decomposition take over 20 to 30 years of all units
The greatest respect for all liquidators who have given their lives is that we can dream our dreams further! The HBO series commemorates them and makes sure that we don't forget!
lot if them were lied to as it was safe
I find it interesting that this is the first source to state clearly with no bullshit that the other three reactors remained online despite number 4 being absolutely destroyed. Tough fuckers, can't blame them but must be eerie as hell knowing one went up in your workplace like that.
Well? How did it happen? I could tell by the length of the video it couldn't be much information. Think of a new name for your video.
That's not the end of the story. The insertion of the too hot core afterwards resulted in the cooling water, which they put to a max after one pump died, to combust in huge ammounts of steam, resulting in a huge pressure which detonated the reactor building.
That's the first explosion.The second and more powerful explosion occured because of the steam, which was burnt to hydrogen, exploding. It resulted in a chain reaction, not a nuclear one, but any burnable thing was exploding at once which huge pressure. The meltdown of the core is known as the elephant's foot. The fires burnt for many hours, needing much clay and sand to put down, and resulted in further radioactive contamination of the area.
Additionally, there was an earthquake (not strong, but information was classified in the Soviet Union because the seismograph was designated to scan for nuclear detonations in Europe) with it's epicenter about 8 km under the reactor building. So there were 3 different things that came together to cause such a desaster.
With todays technology, there is practically no way that such a disaster could occur. Technology is safe, as long as we build and maintain and run it properly. And better not build it in an area prone to earthquakes or tsunamis (thanks russia and japan).
This reactor design was cheap and fast to build but hardly safe, besides the design flaws with respect to the control rod design, etc, the lack of safety containment makes it hardly safe.
Exactly. This was a formula for disaster. A positive coefficient tin roof reactor, poor management, poor training, bad design, you name it. This was not a matter of if, but when. No sane country would license a reactor like that but the good ol USSR had no problem with it.
Your video has errors
They never removed the graphite rods in fact they are removed the whole time
It was when an employee forget to set a controller to 30% power which rested to 1% power this caused a tad increase in power but they decided to continue the test they shut down wind turbine 8 which caused a massive increase in power and heat as the water that is converted to steam begans to create a massive amount of still moving steam after that they shut down the reactor which lowered the 5 radioactive graphite rods into the reactor when they lowered they had no idea it would cause a monumental increase in power at that time near 1000mw as each reactor was capable of producing once the rods were lowered not raised (as you stated in your video) it caused a power and heat increase which caused the high void build up to explode the cover of the reactor flipping it on its side
This is not what happened
Not a “routine safety drill”. It was a special experiment to find out if the circulating water could cool the reactor if the pumps went down. There were errors of design, training, execution that contributed to this failure. Not an accident due to chance causes. Humans were operating the control system up to the excursion.
Title: how it happened
Video: what happened
Me: do not recommend channel
One thing I remember hearing was that the graphite control rods caught fire, exacerbating the situation. I don't know how accurate that information is. I would appreciate if someone could clarify this for me. Also, I had heard the reactor was using Plutonium. Was that just one of those wildly inaccurate rumors or something?
This doesn’t explain what happened. The reason it exploded is because this type of reactor uses graphite tips on its Boron control rods.
They were doing a safety test to see if the turbines could power the cooling pumps if the Plant lost all its power as in a Nuclear Attack. The generators took too long to warm up from a cold start, and would not get water circulating again quick enough.
The problem was the amount of Xenon 135 that built up, a by product or “poison” of a Nuclear Reactor. Xenon is an accelerant of the Nuclear Rxn, along with steam, and even graphite. Water and Boron Control rods slow the reaction down.
The test was to bring the reaction in the Core down to 700MW from 3,200MW. Normally this would be done in a short period of time in one shift, but because the Russian higher ups needed more power that day, it was done in TWO shifts. The Reactor had been sitting at half speed all day, creating Xenon Gas, and not fully burning it off, as it would at full speed.
An overnight crew was assigned to run the test and had NEVER performed it before. They came in and were given no clear instruction and were rushed. They went to lower the Reactor to 700MW to mimic a power loss. It didn’t stop at the 700 mark though. The extra Xenon Gas that didn’t burn off all day brought the reaction way below 700MW, uncontrollably to single digits.
At this point the reaction should have been shut down and started another day, but this was the 4th attempt at this test since the plant had opened. The Forman was not about to allow the test to not be completed. He ordered the test to push on. The water pumps were totally shut down when the turbines were not up to the proper speed. No water was circulating in the core and the Reactor STALLED!
Now the Forman flustered, he ordered that Boron Control rods start to be removed to bring the reaction back up to the 700MV mark. It didn’t work, so he kept removing more and more control rods until there was an out of control Reactor on his hands. No water was circulating to cool as the pumps were off and had NO residual power coming from non moving Generators, PLUS A SHITLOAD of built up Xenon Gas. The reaction surged into the 10’s of Thousands, totally on the brink of destruction. The final straw was attempting to Emergency Shut down the whole reaction by hitting one button. This slammed all the Control Rods into the reactor at once.
Remember those Graphite Tips? Those increase reactivity, and when they hit the ALREADY out of control U-235, it caused the straw that broke the Camels back, and the plant fissioned into a small nuclear bomb.
This is how a RBMK Type Nuclear Power planet can be pushed to explode!
Before the disaster, the thermal power (MW) increased to 33,000 megawatts and here it is shown that megawatts do not increase before the explosion, and 2 is that the rods when they are at the top increase the reactivity, and when they are at the bottom (i.e. in the core) they reduce the reactivity, but in animation it's the other way around
Damn you Dyatlov
Subtitles pleaaseee!
CHEAP VIDEO!!!!
There is NO info about "How It Happend" eh...
you dont really answer to HOW DISASTER HAPPENDED
What's worse: living with perpetual radioactive poisioning, or a killer Chinese biological weapon (Apr. 9, 2020)?
if anyone still reads this does anyone know what program he used to make this
All you say is "when the tests began the control rods were removed and the reactor overheated". You need to explain to viewers how and why the test unfolded in this fashion. It's explained in the Netflix Chernobyl series. The rest of this video is a history lesson which makes the title misleading.
26th april 1986...
a day that is forever etched into history.
Routine safety drill?
You know what's funny it happen at 1:23 am
So what you're saying is, Chernobyl turned from a nuclear reactor into a kettle gone wrong, shit when i push too much power through my kettle i'll evacuate the entire town next time, thanks!
Chernobyl Reactor No.4>Kettle
This video isn't very accurate. It doesn't explain the experiment that was run for restarting the reactor or how the protocol wasn't followed. I would recommend further reading on this topic, as this video is way too simplified.
True, thats the problem with most of these short "summary" videos.....what still buffles me about the whole accident is how some people in Soviet Union knew exactly how unstable the reactors could be if the protocols and rules were not followed, yet others have given direct orders to go against those protocols to perform this test....I quess it tells most about all the secrecy and other bullshit attitude towards neglecting safety in Soviet Union. That those who order this test to be performed and those who performed it were not fully aware how fatally dangerous that test really was.
Incomplete, misleading, oversimplified and obsolete.
More like "What happened"... This video explains nothing. But the visuals are nice.
No!, this explanation is wrong the explosion was caused by the insertion of the control rods.
Americans really out here measuring things in Statues of Liberty and Titanics
50 thousand people used to live here now it's s ghost town
Red Descent exploring with josh??
Red Descent COD Modern Warfare reference?
Red Descent surely you can't be serious...
Thanks to Communism.
@@nigel900 Almost as bad as capitalism!
Horrible " explicatión ".Was an terrible experiment not son routine
The video is titled "how it happened", but despite the fancy graphics, it contains almost zero information.
"almost all of the control rods were removed, and technicians lost control of the flow of coolant". No, that's not how it happened.
better title "An over simplified brief mention of how the plant disaster happened"
everyone is chilly until the caps start jumpin
The chimney is still there though.
Yeah believe it or not but it was the reinserting of all the rods at once with the lack of cooling that caused the meltdown, you see the rods were graphite coated and temporally produced more heat when intentionally reinserted, the heat generated by re inserting them all at one was far more than leaving them out, when the turbine is spinning enough coolant flow is present to barely keep everything from getting to hot, power to the water pumps was cut. It would take 40 seconds for the diesel generators to be able to start and pump water again, even with the generators running only a fraction of the coolant would be moved, but until they started up it had to coast. The minimum required 700 mw was enough to keep the water pumps flowing long enough for the generators to take over, power to the generators was cut at 200 mw, not enough coasting power to keep the pumps going long enough for the generators, combined with the rapid heat produced from a5 reinsertion what little water there was
Was not sufficient enough to last until flow could be restored, at 5200 degrees the reactor core begins to break down, that temperature was reached and there was still another 30 seconds before a fraction of the water required to prevent a meltdown would be present, it began to meltdown as a result the power rods began to melt causing a mini explosion inside the reactor, all the remaining fuel was exposed to the heat which caused many radioactive gasses to be generated inside the reactor until the pressure caused it to burst, once open the radioactive gasses and dust took off into the atmosphere and oxygen fueled the fire causing everything to melt to lava that burned through the floor of the reactor and many meters thick of concrete
Also xenon poisoning of the neutron flux occurred at one point, essentially shutting down the reactor; then the engineers decided to remove all the control rods to restart the reactor. From then on , the flaws in the reactor design and running an already dangerous test without following the instructions all resulted in this disaster.
😠 all fissi nuke are lol.. scientist lol assumptions
Sequence of events is incorrect.
Massively oversimplified...
Some dud working in chernobyl:
"Im gonna do what called a pro
gamer move"
Not a great video not terrible tho. I'd give it 3.6 out of 10
Lol.. this explanation is not complete
Wow man! I didn't thought that the power plant is so high
Okay, i understand why they had to remove the chimney... what i don't understand is why they built a new smaller chimney in its place? Why do they need it when the power plant is not operational?
It's a ventilation stack, the building still needs to be ventilated.
They only evacuated the city 3 days afer the explosion. Not oly that but everyone was told that things are under control and everyone was encouraged to participate in may day celebrations !
Evacuation was on April 27th, 50,000 people within a few hours were evacuated from the city. Where are you getting these 3 days thing from? Also, in Kiev, Gorbachev forced the local party leader to hold celebrations, if he didn't, then he would have been forced to turn in his party badge.
Steam explosion, not nuclear.
But the nuclear fuel and graphite did burn and melt.
pepe cohetes okay but that’s not a nuclear explosion.
Why they used chemicals to heat the water? , it can boil by fire.
how do you think that fire would be lit?
this is a really bad explanation
Ha! Now we are an army of HBO viewers that can explain in more detail than this video what really happened! Until we forget it all when next show comes along
Only the show provided a more detailed yet more inaccurate explanation.
why were all the control rods removed?
Alex Yallop after a turbine stalled due to an excess of xenon accumulated in the reactor (this was because they had left the reactor at 50% power for 10 hours and it was not hot enough to burn it off as usual) and dropped the power to 1% or 30 MW. The rods are removed and put back in regularly. This is how they control the rate of reactions in the reactor (as well as other things such as water). The mistake here was that they removed 205 out of 211 control rods which is insanity. The test should’ve been stopped multiple times but due to pressure to get the test done as well as arrogance by the deputy lead engineer Anatoly Dyatlov, it wasn’t.
Jj Jj thank you, good explanation
Also when the low enriched uranium fuel they used (2%) was at of the life cycle they need to pull more and more control rods out of the core to maintain the power level. So you get less and less control at the end.
@@JjJj-pc8cv Should have been stopped multiple times? What on earth are you talking about?
I saw graphite on the ground
They should have built the large containment structure BEFORE the reactor blew up. Just like everyone else does.
Easy to say afterwards you stupid bitch
Except of course containment buildings of this sort have been around for decades prior to this and the design was a really bad one. No sane country would license a positive coefficient reactor like this one. This is not a matter of second guessing after the fact. This was something that could easily be foreseen well ahead of time.
@@NickFrom1228 I agree that is was a dangerous design. But on top of that in the US a reactor has to have a heavy reinforced steel and concrete containment building not just some flimsy building like the Russian reactor did.
@@joevignolor4u949 Three Mile Island...no problem at all.
@@pgoindi True. TMI had a serious meltdown and some radiation was released, but it was not a catastrophic explosive release like Chernobyl.
3 billion? Hell for 50 bucks you can toss it in my sideyard....(:
Not all reactors was in operation until year 2000. Unit 2 shut down in 1991 after being damaged by a fire. Unit 1 closed in 1996 amidst international outcry about the health effects radiation poisoning, including elevated rates of thyroid cancer among children.
The last unit, Unit 3, operated until 2000, when international negotiations finally shut down the plant for good.
This is just like fallout 4
Raise the power
400 Hiroshima bombs? I'm pretty sure it's only 9...
I love this
There's a place where the rocks of Caithness lie beside the ocean on summer's day a waiting grave in the layers and the pains of generation gone before us uranium your age has come there's salt and spray on the beaches of the island that I came from ceesium your age will come and from hollow mouths of gray it's the future and it's safe so let the children play. Move a mountain fill the ground take death on wheels recreate the land . And we will all be long blown rushes when all the world's a flame move a mountain
Dyatlov *hears loud explosion*:
- You blow the hydrogen tank, reactor is fine.
Reactor cooling system, luck and control rods:
- CHEEKI BREEKI. * Go for a party *
Dyatlov * 3 hours later, vomiting blood * :
- Reactor is better than ever! Told you!
@Shaboi_Mike Actually, comrade Dyatlov is dead for 25 years, he died after having heart attack. Also, he was in prison, but only 10 years.
PS Polonium is not mined, its made in nuclear reactors
You can’t blame it all on Dyatlov. The design flaws of this reactor were already know before this accident. They just acted like nothing was wrong, the Soviet way.
@@roybm3124 I KNOW, but he was too stupid for this job. Even before his death he thought he was innocent
@@mrscientific4956 Dyatlov was not incompetent, he was highly experienced and new almost everything about the operation of RBMK reactors. He was there to supervise a test, he wasn't stupid, he didn't yell at anybody or force people to do things. He was there to conduct a test that he had previously conducted (successfully, but without proper documentation) in November of 1985. Dyatlov was not completely innocent, but the soviets turned him into a scapegoat for the disaster, had Akimov and Toptunov survived to see trial, they would likely be standing there next to the man, with people like you insisting that they were to stupid for their jobs. Oh, and there are still people that think that.
I am shocked to learn that the power plant continued to work for more than a decade after the explosion :O
Also shutting down those other 3 reactors would have meant serious power shortages around the region, so it really wasnt on option....there was simply no easy way to replace them quickly with other options.
As for the safety issues, well obviosly the safety of the reactors were improved, but also its important to understand that while the RMBK reactors were the most "unsafe" reactor types, operating the reactors under the RULES that were given made them safe enough.....whats important to undersand about what happened in reactor 4 was how they purpously went against those regulations and rules to test something that should have never been tested with that reactor type
What's even scarier to me is that reactor 3 shares a wall with reactor 4...
They say it was accident, it seems to me more likely a sabotage.
Sabotage? How is the idiocy of NIKIET and Kurchatov sabotage?
earthquake
Umm the trouble is this. One moderator is stucked. Hot+stucked moderator=☢️
Thank God it's 2018 for me now boiz.
Wow
This is an entirely too simplistic froduction for a "how it happened" video if this was really produced by a Quasi Government operation (RFE/RL) of the US Government. The root cause and initial failure mode is not revealed.
Great animations!
Филм за бавноразвиващи американци