Did Pressing AZ-5 Twice Doom Chernobyl?

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  • čas přidán 23. 02. 2024
  • This video uses the WIP Hydroproject Control Room as footage. You can view the map here: www.roblox.com/games/15392801...
    It is a little-known fact that the SKALA computer system operates on a one second delay; the DREG computer system does not. This means that the infamous time of 01:23:40 being when the AZ-5 button was pressed is factually incorrect. The computers actually recorded it at 01:23:39. But this is not the subject of today’s video.
    Our subject stays focused on the data recorded around this time, and the subtle data input two seconds later. At 01:23:41, a second AZ signal is input, however the last number has been lost due to the power outage that occurred when the reactor exploded.
    This begs the question: was this the AZ-5 button being pressed for a second time? If so, why? Today we will explore another Chernobyl mystery: the AZ-5 Double Press.

Komentáře • 211

  • @duffmcbaine4865
    @duffmcbaine4865 Před 2 měsíci +96

    ‘This button makes a nice clicking sound’ proceeds to press button with no sound 😂

    • @rdspam
      @rdspam Před 2 měsíci +13

      “You can even hear the little clicking sound again” - more silence 😂

    • @tonywade7473
      @tonywade7473 Před 27 dny +2

      Stalker enters power plant, sees button, presses button" hehe cool sound" presses button again, instant blowout.

  • @LeCharles07
    @LeCharles07 Před 2 měsíci +82

    AZ5 Double Press sounds like a great name for a metal album or an (american) football play.

    • @thing_under_the_stairs
      @thing_under_the_stairs Před 2 měsíci +5

      It would've been particularly good for a (sadly now defunct) industrial band I knew called Reactor 4! 😆

    • @timecode37
      @timecode37 Před 2 měsíci +1

      sounds like a coffee machine too🤔🤨

    • @thing_under_the_stairs
      @thing_under_the_stairs Před 2 měsíci +1

      @@timecode37I would drink that coffee, and I would love every drop.

  • @srenkoch6127
    @srenkoch6127 Před 2 měsíci +79

    If it really is possible to 'stop' the AZ5 signal by stop pressing the button, then that is a critical design flaw!
    Such a system should have a hold-down system where you have to do an active action (other than pressing, such as rotating the button) in order to release it.
    I have until now always assumed that there was a digital version of this system for the AZ-buttons and that somewhere else you could reset them after pressing them once.
    Even 30 years ago that was mandatory for emergency shutdown buttons for production equipment.
    Those you could slam for shutdown and you had to physically twist them (with considerable force) in order for the button to be released so it could not in any way happen accidentally.

    • @namelesske
      @namelesske Před 2 měsíci +6

      We need clarification on this. Because this is beyond stupid. As a kid in designed better safety stops for my lego stuff.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +26

      Yes, it was possible. It was never self latching until they replaced it with the switch in 1987.

    • @srenkoch6127
      @srenkoch6127 Před 2 měsíci +7

      @@thatchernobylguy2915How could they mess that design up so badly????
      It is 101 in safety systems that an emergency stop (of any system) should be self latching!
      Even for Soviet Russia, that is almost unbelievable...

    • @namelesske
      @namelesske Před 2 měsíci +3

      @@srenkoch6127 Maybe its cultural or something, they trust humans more than crap soviet machines. I guess the operator would follow the servo displays (i dont know how would they check more than 200 rods during a scram) and prevent some serious damge by cancelling the operation in case of broken end switch or something. I have no words on this detail. I try to reason it, but really messed up...

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +13

      @@srenkoch6127 Making your "emergency stop" system into a general power reduction system that was just the normal method to shut down the reactor means such things as self-locking systems don't come to mind. Other emergency systems, such as the KOM system that released the control rods so they fell manually into the core, were self locking switches.

  • @Mr.HaraldTheMan
    @Mr.HaraldTheMan Před 2 měsíci +59

    7:47 That Fukushima Guy

  • @Yazovheimer
    @Yazovheimer Před 2 měsíci +20

    7:47 i know that somebody make joke about this with that fukushima guy, BUT The apple does not fall far from the tree, so if reactor4 did not explod, there would be no safety modifications on rbmk reactors so rbmk would remain the same dangerous, so maybe, you would maybe be that sosnovyj bor guy, or that leningrad guy, depends on what name you would have chosen in an alternate universe,
    Ir that kostroma guy

  • @Stoney3K
    @Stoney3K Před 2 měsíci +27

    The odd thing I find here is that *if* the AZ-5 was intended to be a reactor trip (so shut down no matter what) that the signal to drop the rods is directly tied to the button, and releasing the button would halt the rods from moving. If it's an emergency stop control, that doesn't make sense.
    A decently designed trip button would only have to be pressed once and the rods would fall, and it would remain in that tripped state unless it was deliberately reset, in the same way as a circuit breaker.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +11

      It's hard to say if AZ-5 was meant purely as a trip. It was used for a general shutdown/power reduction button before the accident, and today is still used for such.

    • @renton9999
      @renton9999 Před 2 měsíci

      @@thatchernobylguy2915 AZ-5 WAS and still is designed as an interrupt signal for the computer. you would only need to press it to trip the shutdown process, not press and hold. the design of the button itself doesn't matter as the computer only needed to receive the signal on initial press. pressing again would do nothing, nor would releasing it halt the process. the log only indicates the computer detected the signal twice, but that means little if it had already started the process on the first press.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +4

      @@renton9999 It's not; it's cited by former Reactor Control Engineers, the former deputy chief of safety and, the biggest of all, the Soviet scientists that worked to upgrade the reactors, that the signal was terminated if you let go.

    • @silfvro1963
      @silfvro1963 Před 2 měsíci

      @@thatchernobylguy2915 Could you provide some citations, or articles I could read about the buttons having to be pressed and held?

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +6

      @@silfvro1963 Revenge of the Peaceful Atom page 357, available here:
      accidont.ru/memo/Karpan_04.html
      "Knowing that repeated registration of a message of one name is possible only if the initiating signal disappears for a period of at least several milliseconds, we can assume that: - the AZ-5 signal was generated at 01:23:39 sec;
      - disappeared in the interval 01h 23m 39 - 41s;
      - reappeared at 01:23:41."
      Then there's this which is a text adaptation of Fattakhov's work.
      certus.livejournal.com/36911.html
      And in this video, I believe Fattakhov says it directly.
      czcams.com/video/nqD0OpOF1Oo/video.htmlsi=9zzLwuUvnqPEIExJ

  • @ThatBloodyCat
    @ThatBloodyCat Před 2 měsíci +31

    I knew Homer Simpson worked at the Springfield power plant but I didnt know that Ned Flanders worked at Chernobyl.

    • @thing_under_the_stairs
      @thing_under_the_stairs Před 2 měsíci +3

      I think I need to listen to some Okily Dokily now...

    • @KrolKaz
      @KrolKaz Před 2 měsíci +5

      Homer's Ukrianian brother worked at Chernobyl, Homyr Symsinov

    • @user-mf2to2ju9k
      @user-mf2to2ju9k Před 2 měsíci +1

      ​@@thing_under_the_stairs holy shit I looked it up and seeing a bunch of ned Flanders playing heavy metal is just 😘👌🏼

    • @thing_under_the_stairs
      @thing_under_the_stairs Před 2 měsíci

      @@user-mf2to2ju9kKinda incredible, aren't they?

    • @andy99ish
      @andy99ish Před 27 dny +1

      diddly-doodlysky, shodilly-ruski AZ five- sky !

  • @saschakrause2374
    @saschakrause2374 Před 2 měsíci +9

    Again. Great work sir. A nice explanation of the double press situation. Thanks for the new video man.

  • @davidbaca7853
    @davidbaca7853 Před 2 měsíci +2

    GREAT CONTENT!!!!! I always look forward to your videos.

  • @669karlos
    @669karlos Před 2 měsíci +26

    At 0:58 seconds you said the reactor exploded. RBMK reactors don’t explode comrade you must be mistaken.
    No you’re drunk.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +16

      I will take myself to the infirmary

    • @giomac
      @giomac Před 2 měsíci

      Actually that is true. Reactor didn't explode - there was no nuclear explosion, it just melted. On the other hand - hydrogen exploded and steam rushed out.

  • @theweirdbrit
    @theweirdbrit Před 2 měsíci +1

    Yet another amazing video! Love it!

  • @GelloMania
    @GelloMania Před 2 měsíci +7

    It’s like this guy worked there at the time, Keep it up!

  • @SteelSmoker
    @SteelSmoker Před 2 měsíci +1

    Wow....if you're right......just wow.
    Really changes how I look at it all.
    Good job, nice video.

  • @poyplanecrazy
    @poyplanecrazy Před 2 měsíci +1

    nice video as always

  • @user-jv4hs8ky8h
    @user-jv4hs8ky8h Před 2 měsíci +7

    very good video mr dyatlov

  • @gingernutpreacher
    @gingernutpreacher Před 2 měsíci +6

    Never say never with a RBMK reactor

  • @cpt.rogers1396
    @cpt.rogers1396 Před 2 měsíci +5

    10:22
    Hi I'm from the future.
    This will later become your most famous quote.

  • @proskub5039
    @proskub5039 Před 2 měsíci +27

    Toptunov any% 0.5xAZ-5 press Chernobyl wr confirmed

  • @Sypaka
    @Sypaka Před 2 měsíci +2

    This begs the question, if someone slapped his hand away and then he placed it again after shoving away someone.

  • @djscottdog1
    @djscottdog1 Před 2 měsíci +3

    The AZ5 should be like any emergency stop , you dont have to hold it down.

  • @swokatsamsiyu3590
    @swokatsamsiyu3590 Před 2 měsíci +1

    Thank you for another excellent video. It's always a good day when a new video drops on your channel. And thanks to the source list you always put at the end, my personal library is expanding more and more. "Monolith" is a very good word to describe the RBMK. They built the thing so large, it should have come with its personal zip code. No wonder it was so grumpy^^

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +2

      As a naval engineer said when he saw the RBMK for the first time "What is this and why did they leave it in the hands of civilians?"

    • @swokatsamsiyu3590
      @swokatsamsiyu3590 Před 2 měsíci

      @@thatchernobylguy2915
      I remember reading that quote somewhere. The guy was positively horrified when he met the RBMK for the very first time.

  • @yarost12
    @yarost12 Před 2 měsíci +7

    They tried to open the reactor folder

  • @tinyjr8618
    @tinyjr8618 Před 2 měsíci +2

    this video has a nice vibe to it i like it

  • @maximusflightymus3892
    @maximusflightymus3892 Před 2 měsíci +7

    Keep questioning!. you are doing a great job. The Devil is always in the detail !!.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +3

      Thank you, an you're right, these small details can completely change the story of the disaster

  • @vidastien
    @vidastien Před 2 měsíci +1

    Where did you get that 3d model of the control room?

  • @johngaltline9933
    @johngaltline9933 Před 2 měsíci +4

    Might want to look in to what folks designing electronic devices call "bounce" and "debouncing". Modern systems most commonly use programing to compensate for bouncing in the mechanical contacts of switches and buttons, however in the period it was mostly done with analog components, typically a capacitor that would hold the state for the fraction of a second for a bounce, or very often in industrial equipment a "snap action" mechanical contact was often used on things where a fraction of a second break wouldn't matter. I have no idea how the system here was set up, but it seems like a computer recording could easily register two or three presses where no debounce is used, even on a switch rather than a button. The question is, how does the scram system respond to the button contacts opening and closing a couple times within a hundredth of a second, or is there documentation on what, if any, debounce method was used?

    • @randomchannel1712
      @randomchannel1712 Před 2 měsíci

      I dont think low current devices have actuall bounde, yet that would be in the msec range

    • @bobsyouruncle1574
      @bobsyouruncle1574 Před 2 měsíci

      The computer we're talking about was entirely analog, designed with 1970s technology. It might take a few hundredths of a second for a signal to propagate much less be registered by a system outputting at 1Hz.

    • @johngaltline9933
      @johngaltline9933 Před 2 měsíci +1

      @@randomchannel1712 they do. It is one of the first things one has to deal with when and a very early lesson for anyone learning electronics. The current has nothing to do with it, it is a mechanical issue, the physical metal in the switch or button bouncing from the sudden movement.

    • @johngaltline9933
      @johngaltline9933 Před 2 měsíci

      @@bobsyouruncle1574 the system may output at 1hz, but even 70’s tech actually runs in the thousands of hertz internally. It just lags behind in reporting the results. The refresh time for the “display”, a teletype printer in this case, has nothing to do with how quickly the system registers inputs.

    • @randomchannel1712
      @randomchannel1712 Před 2 měsíci

      @@johngaltline9933 these buttons don't bounce

  • @Altezza1999
    @Altezza1999 Před 2 měsíci +11

    I can't hear anything when you press the button.

  • @SamwiseOutdoors
    @SamwiseOutdoors Před 2 měsíci +4

    I wonder if the AZ-5 button's successful function would have led to an alternate present where your channel is That Winscale Fire Guy.

    • @SamwiseOutdoors
      @SamwiseOutdoors Před 2 měsíci +2

      *Windscale* goddam it.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +3

      I mean, I do plan to do some Windscale videos, so maybe 🤔

    • @SamwiseOutdoors
      @SamwiseOutdoors Před 2 měsíci +1

      @@thatchernobylguy2915 I think that you'd do a fantastic job, I appreciate your attention to detail and the variety of sources that you're able to procure.

    • @thing_under_the_stairs
      @thing_under_the_stairs Před 2 měsíci +1

      @@thatchernobylguy2915Cool, I'd love some videos on Windscale with your usual level of detail and accuracy!

  • @thebestcayplays
    @thebestcayplays Před 2 měsíci +2

    Where did you buy your AZ-5 button?

  • @nyckhusan2634
    @nyckhusan2634 Před 15 dny

    Reason of double pressing of AZ-5 button by Toptunov is already clarified. At 1:23:39 he pressed button first time for one second and at 1:23:41 pressed it second time and hold AZ-5 button in depressed position until explosion occurred at 1:23:43. Toptunov was not let to press AZ-5 button to shut down reactor at 1:23:04 when " Turbine TG-8 rundown test " began by the order of Dyatlov, who tended to repeat test second time and even third time if it failed first time. Dyatlov was under immense pressure to complete test on that day before May 01 and before reactor#4 will be put out of operation for maintenance. Pressure was from 3 sides: from high ranking officials of Communist Party of USSR, from representatives of Kharkov Turbine Plant, which sent workers to perform measurement of turbine vibration during test, from supervisors of experiment by its author : Moscow Hydroproject, which were sent from Volgograd ( its affiliate office) , presented during test and quietly left hotel in Pripyat morning to never come back. At 1:23:39 Toptunov pressed button AZ-5 by his own initiative when he observed rising of heat power by reactor.

  • @walt-sv3dj
    @walt-sv3dj Před 2 měsíci

    You should do a video on the different report timeliness and compare them

  • @andreacaldarone4909
    @andreacaldarone4909 Před 2 měsíci

    Chernobyl had 4 reactors, Kursk NPP its twin, Ignalina quite similar, was this rundown test run only at chernobyl and only at r4?

  • @9TDF
    @9TDF Před 2 měsíci +3

    The button also had 2 connections one where 1 where pressing breaks the signal one where the press activates the signal.
    Maybe there was an AZ-5 signal from braking one circuit and another AZ-5 from bridging the circuit. Redundancy.

    • @namelesske
      @namelesske Před 2 měsíci

      I dont know the soviet safety standards but machine from that age usually had two cicuits one for the system and one for the safety relay. There was no true redundancy, just the control system stopped the machine because one safety was not in, but actually can happen the safety relay is still up, so usually the control system turns the relay off with removing the ready signal.

  • @KurisuYamato
    @KurisuYamato Před 2 měsíci +8

    This makes me wonder, what you personally feel was the last moment that the explosion of Reactor 4 could have been stopped was. We know it was doomed before AZ-5 was pressed... but there was certainly a final point where a non-catastropic shutdown was reasonable.

    • @MinSredMash
      @MinSredMash Před 2 měsíci +8

      It was by no means doomed before AZ-5 was pressed. They could have inserted the USP rods from underneath the reactor, then dropped groups of controls rods in succession. This would have counteracted the tip effect.

    • @KurisuYamato
      @KurisuYamato Před 2 měsíci +4

      @@MinSredMashSee this is the kind of info I was hoping for; I had totally forgotten about the lower rod set!
      Of course, the operators had no real way of knowing exactly what was going on inside that behemoth machine, so they didn't know that the lower portion of the reactor was that unstable but had they had a clue then, well, history may indeed be different.

    • @namelesske
      @namelesske Před 2 měsíci +5

      @@MinSredMashThe issue with that, by the time they see the power increase and act there is a high chance of damaged fuel channels and would jam the lower rods even faster.

    • @randomchannel1712
      @randomchannel1712 Před 2 měsíci +5

      @@MinSredMashyou first needed to max out the pumps which would take around 30sec I dont know if during the rundown there was enough power available to do so

    • @MinSredMash
      @MinSredMash Před 2 měsíci +1

      @@randomchannel1712Without the added reactivity of the tip effect, the reactor was not going to be destroyed.

  • @robinwells8879
    @robinwells8879 Před 2 měsíci +1

    So, let me get this straight! The failsafe emergency button is not of the latching variety? Why? In case you have second thoughts about the desirability of preventing catastrophe?
    All emergency stop buttons I have ever encountered are latching and many require a key resetting process. Here we have to keep pressing the emergency stop whilst Armageddon unfolds around us. I take it that FMEA was not a Soviet thing as failure was not allowed. 😮

  • @AsbestosMuffins
    @AsbestosMuffins Před 2 měsíci +1

    huh, you'd think with the az-5 being the reactor scram button would not be a signal that can be undone by pressing it again or releasing it. guess they didn't consider it a problem

  • @XXXXLance
    @XXXXLance Před 11 dny

    I am in the middle of „Midnight at Chernobyl”, and the reason why I am watching this video is, that AZ-5 was used twice according to the book. First time, to shut down reactor after the test, and second time, moments later, when there was a sudden power increase. It is described that it was done, because after second press, control rods are lowered not “automatically”, but are released to drop under their own weight faster.

  • @Povilaz
    @Povilaz Před 2 měsíci +1

    Very interesting!

  • @aperitifs
    @aperitifs Před 2 měsíci

    Chernobyl only had a small number of thermal couples across the 96 tonn of fuel rods.. there was hot spots that the control room didn't know about .. and removing all the fuel rods to get the heat to go back up.. actually had the reactor overheating and the channels for the control rods was warped.. they wouldn't go back in ..... They were doing a low level reactor test ... Same as a. Ebike battery or scooter with not enough temperature sensors to shut down the battery management system charging when cells are too hot

  • @tomclanys
    @tomclanys Před 2 měsíci

    That's what I thought, that it could be a simple "slip" of the finger, or rather a jerk, hestitation, whatever. What is crazy for me is that this button isn't a Normally Closed design with at least 3 sets of contacts, where in case any of them breaks circuit it would cause the shutdown... Even a simple switch with a lock, like the model used later or any other "emergency shutdown" button would be better than this. It's what we were told through my engineering school and in my job. Soviets just did it their way it seems, and I was taught by at least two post-soviet masters of engineering... Where one worked on MiGs and told us how all the moving parts were done with moving linkages. Not even a steel cable, but sets of bars/rods running through the plane.

  • @jonathannathan1754
    @jonathannathan1754 Před 21 dnem

    “There is no chance of an RBMK exploding”
    I can’t help but feel like I’ve heard that before

  • @donaldhoot7741
    @donaldhoot7741 Před 2 měsíci

    Shoulda pressed AZ-5 then AZ-6, oh well! Cool viddy!

  • @SunBear69420
    @SunBear69420 Před 2 měsíci +4

    Damn we got a hand reveal!!

  • @andrewallen9993
    @andrewallen9993 Před 2 měsíci

    No debounce circuit on the AZ5 button ?

  • @randomchannel1712
    @randomchannel1712 Před 2 měsíci +3

    Wait do you need to keep the AZ-5 pressed or is it a latching command?
    I thought it was a latching command, the mommentary button energized a latching activator until the rods went to their full depth.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +2

      It became latching in 1987, when they replaced the button with a switch. Until then, you could initiate and uninitiate the AZ-5 signal simply by pressing and letting go.

    • @randomchannel1712
      @randomchannel1712 Před 2 měsíci +1

      @@thatchernobylguy2915 that was not very bright

  • @icarus_is_tired544
    @icarus_is_tired544 Před 2 měsíci

    Things I didn't know I needed: A KEO-11 button
    Where can I get one-?
    Edit: I just realized most of your content is about Chernobyl- the disaster is one of my special interests- I love this channel already

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci

      I got mine on EBay, but I did also get 6 of them, so...
      Also, I'm happy you enjoy the content :)

    • @icarus_is_tired544
      @icarus_is_tired544 Před 2 měsíci

      @@thatchernobylguy2915 Thanks! I'll keep it in mind for later. ^^ Have a good day/afternoon/night!

  • @otrab1080
    @otrab1080 Před 23 dny

    So RBMK reactor cores don't explode anymore?

  • @rojobou
    @rojobou Před 2 měsíci +3

    Excellent video as usual - the SCRAM design of Chernobyl was so awful, it’s like it was intentionally designed to fail horribly - like the exhaust port on the Death Star

    • @markusw7833
      @markusw7833 Před 2 měsíci +1

      lol...

    • @kirgan1000
      @kirgan1000 Před 2 měsíci +1

      The exhaust port on the Death Star, is a masterful piece of engineering, it allow to discharge all exhaust from the reactor, who power a planet killing laser, and only be 1 m in diameter. To have a starfighter drop a bomb into the exhaust port, is almost impossible, and demand a pilot with supernatural aiming skill.
      How will a enemy know there to bomb? Its not like we will give them the blueprint, but just to be sure, the Death Star will carry 5000 TIE fighter, so all enemy starfighter can be shoot down before they can start there attack run. Only a totally stupid overconfident Grand Morf will not send out a overwhelming number of TIE fighter then the Death Star is under attack.

    • @ThunderClawShocktrix
      @ThunderClawShocktrix Před 2 měsíci

      the biggest flaw of the deathstar was the same one that all weapons have, its wielder@@kirgan1000

  • @RtCmdr
    @RtCmdr Před 2 měsíci

    It makes little sense that releasing the button would halt the control rods. Despite the inherent design flaws in that reactor, I doubt that the AZ-5 button was intended to ‘jog’ the rods downward. The post-accident change from button to rotary switch was probably to provide positive feedback to the operator that they’d engaged the system, and to avoid the consequences of a ‘light touch’ or ‘brief bounce of the button’.
    I’ve had to do something similar where the switch used to command a move from a primary to a backup system was physically small, difficult to operate and provided basically no visual or tactile feedback to the operator. I ended up replacing the original switch with a large and expensive 90° cam switch simply to address the issues we encountered when operators failed to use the original (poorly designed and implemented) switch correctly.
    If the AZ-5 button was pressed twice, why? Why do people feel the need to press an elevator call button or crosswalk button or any other momentary switch two or more times? If you think your first button press didn’t go, or there was no immediate feedback, you’d be inclined to press the button again. If the computer was slow, maybe pressing the button took a moment before it registered, so it got pressed again.
    As for why the AZ-5 button was pressed AT ALL, my thinking is that it was to simply turn the reactor off at the conclusion of the test, and perhaps not pressed in response to noticing an emergency developing. The test had been underway for 30-40 seconds at this point. The turbine and pumps were coasting down, and if the automatic ‘scram’ signals or other automatic controls had been inhibited for the purposes of the run-down test, then it would stand to reason that the operator would need to shut down the reactor manually.
    The reactor was going into scheduled maintenance anyway, so one would think that ‘turning it off’ would be a normal step taken.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +4

      1) The purpose of replacing the button with a switch was confirmed to be for post-locking reasons in the book "Chernobyl: Revenge of the Peaceful Atom," by Nikolai Karpan, Deputy Chief Engineer of the Chernobyl NPP Nuclear Safety Department at the time of the accident, on pages 357-358. Before then, you would have to hold it down for the duration of the shut down.
      2) That is another reason Toptunov may have double pressed, if it is eventually proven that it was indeed such the case.
      3) This is not disputed. The reason why it was pressed at that specific time was probably because it should have been at the beginning of the test, and Toptunov was waiting for a signal to do so. Not that it would have made a difference, as the reactor would have just exploded 35 seconds earlier.

  • @eviladm1n
    @eviladm1n Před 2 měsíci +1

    So it sounds like you must push and hold AZ5 to trigger the scram, not just a single push. This sounds like a terrible design. It should electronically latch once pushed.

  • @keith_5584
    @keith_5584 Před 2 měsíci

    6:47 It is possible that a seismic event or fissure from the reactor shook his finger loose.

  • @dianaholwerda8850
    @dianaholwerda8850 Před 2 měsíci

    When Ignalina video?

  • @virt1one
    @virt1one Před 2 měsíci

    "NO chance of another explosion"... well, back in those days, they ALSO thought there was NO chance of an explosion.

  • @saumyacow4435
    @saumyacow4435 Před 2 měsíci +2

    Wasn't the signal latched by a relay or a computer?

  • @tydiablo
    @tydiablo Před 26 dny

    Wasn't the AZ-5 a switch?

  • @TheTransporter007
    @TheTransporter007 Před 2 měsíci +4

    It's not like pressing A3(Z)-5 a second time halts or reverses the rod insertion, right?
    *R I G H T ?* 😳

    • @GlutenEruption
      @GlutenEruption Před 2 měsíci

      It doesn't. The rods wouldn't stop if you accidentally slipped off the button or pressed it again. It's an emergency scram - any signal whatsoever no matter how brief and the scram will run to completion. The button doesn't need to be held.

  • @AiOinc1
    @AiOinc1 Před 2 měsíci

    Better have a good debounce on that

  • @oscarr.g.509
    @oscarr.g.509 Před 2 měsíci +1

    Maybe that's the true hidden secret of Chernobyl, the AZ-10 command ! And you did it once more, great video, thanks !

  • @Yourmomproductionsofficial
    @Yourmomproductionsofficial Před 2 měsíci +5

    Oh no I press AZ-5

    • @crf80fdarkdays
      @crf80fdarkdays Před 2 měsíci

      Now listen here ya ⚙️ sucker, ya better unpress that button right now

  • @electronash
    @electronash Před 2 měsíci

    And that... is how an RBMK reactor core explodes.

  • @bobcousins4810
    @bobcousins4810 Před 2 měsíci

    "Just look at all these buttons! I wonder what happens if I press this one?"
    "I wouldn't do that"
    "Oh!"
    "What happened?"
    "A sign lit up saying 'Please do not press this button again'"

  • @andreascarlsson6579
    @andreascarlsson6579 Před 2 měsíci +1

    Famous last words.. 😅

  • @user-oc6jr9mb9g
    @user-oc6jr9mb9g Před 2 měsíci +1

    unlock the volume of the game you recorded

  • @Name-ot3xw
    @Name-ot3xw Před 2 měsíci +2

    I habitually press buttons twice, that was my bad. Sorry guys.

  • @Gerhard57NL
    @Gerhard57NL Před 17 dny

    The exact behavior of the AZ-5 button (and other buttons) should be described accurately in manuals and in operating instructions. Is a single short push and therefore a single pulse enough to get the process going? Or does the process go on for as long as the button is pushed and stops upon release? Should the button be held down for some time? And if so, for how long? Does a second push halt the process? Or does another button need to be pushed for the process to stop? In which case a second push of the AZ-5 wouldn't have mattered? All this should be clearly explained in a manual and instruction. So what do these papers say?
    Furthermore, there is a lot of AZ-5 scenarios circulating on the web. Like this one: czcams.com/video/eIoJ_cHRTI8/video.htmlsi=ioyT1pEe3aa_qWEd
    In this video, the button/switch looks different.

  • @Boop__Doop
    @Boop__Doop Před 2 měsíci

    "there is no chance of an rbmk exploding"
    famous last words

  • @markusw7833
    @markusw7833 Před 2 měsíci

    Interesting.

  • @markobajt9261
    @markobajt9261 Před 2 měsíci

    Only problem is that the A/-5 was a switch which you had to turn not a button

    • @fralex5014
      @fralex5014 Před 2 měsíci +2

      No. The switch (which is presented by all the NPP tour guides) was installed after the accident for the remaining reactors.

    • @richardmillhousenixon
      @richardmillhousenixon Před 2 měsíci

      The switch was retrofitted in RBMK reactors after the incident. It was a momentary button at that time.

  • @johnkern7075
    @johnkern7075 Před 2 měsíci

    Sounds like me trying to print something out on my printer from my computer. I sit there and click print print print print print print print. 😆

  • @Yazovheimer
    @Yazovheimer Před 2 měsíci

    Nice

  • @cosmicgreen
    @cosmicgreen Před 2 měsíci +1

    AZ-5 was a switch back then, no?

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +2

      In 1986, AZ-5 was a button. They replaced it in 1987 alongside other modifications to the RBMK reactor :)

    • @thing_under_the_stairs
      @thing_under_the_stairs Před 2 měsíci

      @@thatchernobylguy2915Where did you find that button? I'd pay a lot for a replica of that big red button! (And I'd probably have way too much fun with it...)

  • @French20cent
    @French20cent Před 2 měsíci

    They just pressed the AZ5 like you press the elevator button that's all.

  • @XErox7X
    @XErox7X Před 2 měsíci +1

    so the reactor could have been saved? If it was not for the weak grip of a man who was not strong? The ussr could still be standing today. The incident with that hunk of metal was thew reason the union fell. All because of one weak wristed man.

    • @markusw7833
      @markusw7833 Před 2 měsíci +2

      Apparently calculations/analysis done after Chernobyl assumed there was no interruption in control rod descent and they didn't come to a different conclusion regarding the reactor's fate. I think there's another reason mentioned but I forgot.

    • @crf80fdarkdays
      @crf80fdarkdays Před 2 měsíci

      Leonid Toptunov was no weak wristed ⚙️ sucker mate, I think you've got it all wrong.
      You are the reason the ussr isn't standing today.

  • @Based_transition_Clocker
    @Based_transition_Clocker Před měsícem

    No, Chernobyl was doomed on the drawing board. It was designed to be unstable.

  • @whirledpeas3477
    @whirledpeas3477 Před 2 měsíci +1

    He accurately pressed Z, not Zed. The English blew up the plant

  • @bearg936
    @bearg936 Před 17 dny

    Какой бред, думаете там не было защиты от дребезга контактов?

  • @ThomasHaberkorn
    @ThomasHaberkorn Před 2 měsíci

    It's Dyatlov

  • @rogervanbommel1086
    @rogervanbommel1086 Před 2 měsíci

    Video on my birthday;), and the 2 year anniversary of the Russia war

  • @KrolKaz
    @KrolKaz Před 2 měsíci

    Wait that was real??
    I saw that show on Netflix, thought it was bullshit

    • @su-25frogfoot74
      @su-25frogfoot74 Před 2 měsíci

      It's highly exaggerated, but It was a real incident.

  • @venator5
    @venator5 Před 2 měsíci

    The push and hold type of button for such an important safety feature sounds like a very horrible idea.
    Fortunatelly this guy had a switch which is turn and forgett, He ruined his stuff delayless :)
    czcams.com/video/tr3LEdQoGlk/video.htmlsi=-mW1eT-gWc4Zm9zz&t=260

  • @BB-qp1ir
    @BB-qp1ir Před 24 dny

    There is no core

  • @SmidFilip
    @SmidFilip Před 2 měsíci

    No.

  • @octavianova1300
    @octavianova1300 Před 2 měsíci

    Do you have another channel perhaps? You're voice sounds so familiar but I can't place it and it's driving me nuts cuz it feels on the tip of my tongue lmao

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +1

      While I was compared to a crime channel a long time ago, I don't have any other channels of my own :)

    • @michaelmichael2382
      @michaelmichael2382 Před 2 měsíci +1

      Plainly Difficult has a similar speech pattern
      youtube.com/@PlainlyDifficult?si=4q0cin3t_1JhRwle

    • @markusw7833
      @markusw7833 Před 2 měsíci

      UK Man.

  • @mikefochtman7164
    @mikefochtman7164 Před 2 měsíci +1

    Well there's always a question about the signal-processing equipment. We had a LOT of small pilot/ signal-repeater relays for our process computer's inputs (BWR-4 built circa 1970's). So even if the AZ5 button was held fully and properly, if there was a serious electrical transient might cause computer input to 'glitch'?? But then, there would probably have been other 'doubled' signals if a whole 'rack' of signal relays were affected.
    Having watched operators in training simulators for many years, I think your explanation of a momentary 'slippage' of the operators 'thumb' on the button is ENTIRELY PLAUSIBLE. A bit surprised there was no 'AZ5 removed' or other signal recorded showing the loss of signal at some point. But that may be a design detail of the computer event recording system.

  • @kjamison5951
    @kjamison5951 Před 2 měsíci +1

    When your regime is so cheap it builds nuclear power plants with off the shelf parts instead of bespoke for maximum safety.

  • @tyrell519
    @tyrell519 Před 2 měsíci +63

    Thank you for serving the Soviet Union, comrade.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +15

      You're welcome!

    • @rogervanbommel1086
      @rogervanbommel1086 Před 2 měsíci

      Video on my birthday;), and the 2 year anniversary of the Russia war

    • @richersonkate
      @richersonkate Před 2 měsíci +1

      Soviet Union?

    • @SunBear69420
      @SunBear69420 Před 2 měsíci +1

      How about a short video where you tell us more about yourself?​@@thatchernobylguy2915

    • @Rasmus2210
      @Rasmus2210 Před 2 měsíci +2

      @@rogervanbommel1086happy birthday 🎉

  • @TikhonT.
    @TikhonT. Před 2 měsíci +1

    Had the Chornobyl incident not happend on that day it would have just happend on another, maybe closer to our times or in the future, maybe at Kursk or Ignalina. It was always going to happen, Murphy's law.

  • @karstendoerr5378
    @karstendoerr5378 Před 2 měsíci

    AZ-5 was just one cause of the explosion. A postponement of the experiment by about half a day contributed significantly to the occurrence of the accident. The resulting long holding time at partial load led to an enrichment of the reactor with neutron absorbing xenon-135. The so-called xenon poisoning made the neutron physics behaviour of the reactor much more complex and less predictable.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +1

      Actually, studies such as INSAG-7 (the IAEA's official report on the accident) have shown that when the test was performed on the 26th, xenon concentrations were much much higher than when the test was supposed to be performed on April 25th. The drop from 3100MW to 1500MW of thermal output had a much greater xenon impact than anything in the morning, but it also had several hours to burn off at the 1500MW output.
      This is shown as the control rod insertion was initially very low after the power drop on April 25th (to compensate for xenon poisoning), and returned to normal when the xenon had burned off. This is a classic HBO mistake.
      You can view more about this in one of my earlier videos: czcams.com/video/HmpY6GAA6pA/video.htmlsi=UUhYFCeqCoxl-ct5

    • @karstendoerr5378
      @karstendoerr5378 Před 2 měsíci

      @@thatchernobylguy2915 135Xe played an important role in the Chernobyl nuclear disaster. During the preparation of an experiment, the power of the reactor was severely reduced for a long time, contrary to the provisions of the operating manual, resulting in xenon poisoning. In order to increase the output again, the control rods were pulled out very far, which, however, remained ineffective due to xenon poisoning. When, after the steam supply of the turbine was closed, the neutron flux temporarily increased due to the positive steam bubble coefficient, 135Xe was reduced, which increased the reactor output and thus the further reduction of 135Xe. This rapid increase in power was one of the reasons that led to the explosion of the reactor core.

    • @markusw7833
      @markusw7833 Před 2 měsíci

      @@karstendoerr5378 The reactor was depoisoned over the Kiev delay. Watch some other videos, like "Why power decreased under 700 MW?" Watch the following Unanswered Questions video while you are at it too. You're repeating nonsense.

  • @roygunnargranmo4641
    @roygunnargranmo4641 Před 2 měsíci

    Wtf. Since fiction has shown me the kind of button used now. I didn't think it was a push button. You had to keep pushing. Fiction is so annoying. I want the truth

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci

      The button is plainly visible in photos and videos of the Control Room before the disaster.

  • @bayo_yayo4317
    @bayo_yayo4317 Před 2 měsíci +1

    is this roblox?

  • @lexinexi-hj7zo
    @lexinexi-hj7zo Před 2 měsíci +3

    IF they pressed CTRL ALT DEL that would have fixed it, or if their mom/NRC was coming they could have pressed ALT TAB, and switched to a less "HOT ...and 'dirty' lolz" screen so their supervisors wouldn't have seen what was happening. MSDOS rulez!!!

    • @669karlos
      @669karlos Před 2 měsíci

      Very true! And if CTRL ALT DEL did not produce satisfactory conditions they always had ALT F4 as an emergency back up. 👍🏻

    • @davidbaca7853
      @davidbaca7853 Před 2 měsíci

      Or they could have just unplugged the panel and plugged it back in…reboot 😜

  • @namelesske
    @namelesske Před 2 měsíci +1

    I think if an a Emergency stop button gives a signal for the control system it should activate. No matter the length of the input.
    Pressing and holding on the AZ 5 is a stupid design. Absolute trash. Why the hell somebody would cancel such an event. Just imagine and earthquake middle of a similar test. Operator pushes the button but a lamp drops on its head from the sealing and the process stops 😂 what a soviet bullshit design. I think the analysis Is not correct RBMK cant be that stupid.

    • @thatchernobylguy2915
      @thatchernobylguy2915  Před 2 měsíci +2

      Unfortunately, RBMKs were that stupid. AZ-5 would not become self locking until it was replaced with a switch in 1987.

    • @namelesske
      @namelesske Před 2 měsíci

      @@thatchernobylguy2915 That button type opeartion / feature is dangerous on its own, allows the operator to use emgergency features as normal function... Without internal locking / safety relay what keeps the operator to turn back to normal the AZ5 switch? .... Just fixing the ergonimics not the root cause.

  • @fixitalex
    @fixitalex Před 2 měsíci +1

    I'd say irresponsible actions of crew far before pressing АЗ-5 - that's what actually doom Chernobyl

  • @garywillis7253
    @garywillis7253 Před 2 měsíci +1

    Another crap theory...It dont matter if they pressed it once ir 11x...The temp of the water was already boiling,steam blew apart the fuel rod channels which froze some in position where the graphite endlessly made reactivity spike that causes the explosion.

    • @MinSredMash
      @MinSredMash Před 2 měsíci

      There was no spike in reactivity or temperature until AFTER AZ-5 was pressed. You seem to be repeating the fictional HBO version, or the version the Soviets tried to peddle to cover their own asses.

    • @markusw7833
      @markusw7833 Před 2 měsíci

      Given the scram is what's identified as the pivotal factor for the reactor's destruction then anything potentially affecting the positive reactivity it introduced is considerable.

  • @garethde-witt6433
    @garethde-witt6433 Před 2 měsíci +1

    No one vares

    • @valerija.legasov548
      @valerija.legasov548 Před 2 měsíci

      Hi, I highly appreciate Your work! One reason for upgrading SCRAM emergency protection system was right this situation! AZ 5 button has been changed by the "key" switcher! I have few footages focused on this topic, but they are only in Russian.