Did Pressing AZ-5 Twice Doom Chernobyl?

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.

[duffmcbaine]

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

[LeCharles]

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

[srenkoch]

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.

[SatanHimself]

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

[Yazovheimer]

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

[StoneyK]

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.

[proskub]

Toptunov any% 0.5xAZ-5 press Chernobyl wr confirmed

[saschakrause]

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

[XXXXLance]

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.

[cpt.rogers]

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

[karlos]

At 0:58 seconds you said the reactor exploded. RBMK reactors don’t explode comrade you must be mistaken.

No you’re drunk.

[djscottdog]

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

[GelloMania]

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

[YukariAkiyamaTanks]

My personal theory is that someone pressed it again in panic. Its interesting to look into this. Great video!

[Sypaka]

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

[SteelSmoker]

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

[KurisuYamato]

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.

[davidbaca]

GREAT I always look forward to your videos.

[Cragified]

Considering the operating culture of the RMBK reactors and the number of incidents said reactor type had it was inevitable that there would be a disaster like Chernobyl eventually with them.

[maximusflightymus]

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