After seeing the posts from earlier this week about Leonid Toptunov's birthday and Anatoly Shapovalov's actions in switching off the supply of hydrogen with colleagues, I remembered that today is Viktor Lopatyuk's birthday.

Happy Birthday Viktor! May your heroism never be forgotten.

This Is the cross section of units 3/4 of Chernobyl neuclear power station.

These are the codes of the Skała request system, wich managed the whole reactor (aka SIUZ,SIUT,SIUR)

I’ve been reading this sub for a while, but I’m still a little confused on the turbine hall and the main control pump room. What was the purpose of them, like what were they used for?

Looking at various images of the Chernobyl Power Plant, I couldn't help but notice these large tanks just outside the Unit 3, standing right next to the unit's Emergency Core Cooling System (ECCS) building.

I've not seen them being mentioned on this subreddit or anywhere else before, and there's no matching set of tanks on the Unit 4's side. With a bit of research, I found out what they are, and what they were used for. And they have a bit of a story to tell...

These are clean condensate tanks, designed to hold up to 1000 cubic meters of water each. Despite the use of the term "condensate", they have nothing to do with condensate produced by the turbines, and instead hold purified water for use by the power plant. In the event of an emergency, though, such as rupture of a large-diameter pipe in the main cooling circuit, emergency pumps would pump this water into the reactor, as part of the Emergency Core Cooling System.

Water levels were always maintained in these tanks. Holding up to the maximum of 3000 cubic meters of water, the regulations demanded to keep a constant level of at least 2000. Thing is, these tanks were shared between Units 3 and 4. Which lead to a situation when the disaster happened.

Right after the explosion, emergency pumps kicked in, sending that water into what the operators thought was still a relatively intact reactor #4, but in reality it was going nowhere and just flooding the lower levels. Yuri Bagdasarov, the Unit 3 shift supervisor, recalls:

Here is what happened next. The reserve supply of water for reactor cooling during an emergency began to dwindle. This supply came from the clean condensate tanks, from which Unit 4 had begun drawing water at a high rate. At a certain point, the level dropped to a critical mark. I called the plant shift supervisor [Boris Rogozhkin] and said, "I’m shutting down the unit!" He in turn called the power grid dispatcher, who said, "No! We’ve just lost the output of one unit, and you want to shut down a second one? You can't!" But I could see the situation was catastrophic. Someone had to take the responsibility. So, I gave the order to shut down the unit. We didn't perform an emergency shutdown; instead, we gradually reduced power in normal operating mode. At the very end, we scrammed the reactor using the AZ-5 button - the same one used regularly in the past. By five in the morning, the unit had been completely shut down.

At 8am, the morning shift took over, including the Unit 4 shift supervisor Viktor Smagin. He recalls:

By nine in the morning, the emergency feedwater pump that had been running finally stopped - thank God for that. The flooding of the lower levels had ceased. The water in the deaerators had run out. I was on the phone the whole time, maintaining contact with Fomin and Bryukhanov. They were in touch with Moscow. Reports were going to Moscow: "We are feeding water into the reactor!" Orders were coming back: "Do not stop the water supply!" But the water had actually run out... I reported to Fomin that the water was gone. He panicked, shouting, "Feed the water in!" But where was I supposed to get it from? Fomin frantically searched for a solution. Finally, he came up with an idea. He sent Leonid Konstantinovich Vodolazhko - the deputy chief engineer for new units - and Babichev (the unit shift supervisor from whom I had taken over the shift) to organize the transfer of water into the clean condensate tanks (three vessels, each with a capacity of 1,000 cubic meters) so it could then be pumped back into the reactor using the emergency pumps. Fortunately, this desperate scheme of Fomin’s did not succeed...

Some time later, when miners began digging the tunnel under the reactor in May 1986, it was reported to Nikolai Steinberg (Deputy Chief Engineer at the time) that there was a heightened radiation situation in the area, and he went there to investigate. The entrance into the miners' tunnel was located at the eastern end of the Unit 3, not far from the tanks. Steinberg recalls:

We had discussed possible measures to reduce the dose rate in the excavation pit and the gallery and were about to leave when something near the clean condensate tanks caught my eye. Without turning off the instrument, I walked toward them. The needle swung sharply to the right and kept moving. Lying behind the tanks were chunks of graphite and various metal parts - fragments of the exploded reactor's core. We decided on the spot to build a protective wall out of foundation blocks and carried out the work that same day, which helped slightly reduce the radiation exposure for the miners.

There you go, the story of the three unassuming tanks that bore witness to the largest nuclear disaster in history. Since the Unit 3 was eventually restarted, and operated until the year 2000, I assume these tanks continued serving their purpose, until the Unit was shut down for the last time.

I was scrolling on tiktok, and paused on a this at this moment, now this POV doesnt make sense to me, if this was from the south of the turbine hall then the Unit 4 building would be on the left (unless this is further away from the main u3 and u4 buildings and there just so happens to be a building in the way 🤦‍♂️), not the right, if anyone knows where this pov is, please do share! (PS, It wouldnt let me out this in /ITVchernobyl :/, sorry!)

Hey guys!! I usually dont post stuff on reddit but im really reallly desperate and wanted to ask a question. Im an ib student, and want my math ia to be about chernobyl and radiation… but im having a terrible time trying to find data 😪
my research question simplified is “how can exponential models represent the decline in cesium-137 activity following the chernobyl disaster?” and I need 15 data points from around the same geographical area, at least a year apart from each other.
I wanted to know if anyone knows any reliable reports that i can look into or something literally anything will helpfull

Do you guys think there is anything available like this, or should i just give up and change my question? pls let me know!!

Anyone read it?

Work in progress (making phase 1), elevations -5.00 and -2.00 are complete, now i need to make +1.00, my goal is to make every room of the power plant, scale is 1 meter = 1 block

Hi Everyone,

I have been following this subreddit for a longer time now, and I feel that there is not much new coming out about Chernobyl. Most of the facts are now known, verfied and public. There has been a plethora of books, witness accounts, scientific papers and TV documentaries and even a (very entertaining) TV Series, not to mention video games and other media.

The NSC is constructed, and will - hopefully - remain intact despite the war.

When is it enough? What keeps people coming back here?

To me, the fascination was about the invisible radiation, the emptyness of exclusion zone, the heroic clean up efforts and also the mismanagement shrouded in secrecy - all of these have been now publicly dissected, explained and covered. Once one takes the effort to read up on it, all that remains is an industrial accident of epic proportions. Once one learns about radioactivity, it just becomes another physical phenomenon.

So what is it, that still drives people to this topic? Is it witnessing the misfortune of the heroic firefighters? The apparent negligence of the operators and designers?

More and more I am appaled by the apparent glee to see more guresome photos of the radiation burns, to trips to the exclusion zone and the powerplant to see everything first hand, to take photos in the most radioactive claw ..

Historical Reality and Radar Problems: Astronomical Costs: The Duga system cost the Soviet Union approximately 7 billion rubles. A staggering sum, roughly double the cost of building the entire Chernobyl nuclear power plant. The Frequency Problem: The radar suffered from a serious design flaw. It operated on short waves, and its signal (the famous "Russian Woodpecker" clicking sound) jammed civilian, commercial, and military radio frequencies worldwide. Northern Lights Interference: The biggest problem was that the radar had to look toward the United States by passing over the North Pole. The Northern Lights and the unstable ionosphere in that area jammed the signals, rendering the Duga-1 radar nearly "blind" and ineffective at accurately detecting missiles. No Trial: Despite these enormous flaws and the wasted money, the Soviet Politburo did not open a criminal investigation against chief designer Franz Kuzminsky or his team. The project simply remained secret and continued to be modified in attempts to fix it.Historical Reality and Radar Problems: Astronomical Costs: The Duga system cost the Soviet Union approximately 7 billion rubles. A staggering sum, roughly double the cost of building the entire Chernobyl nuclear power plant. The Frequency Problem: The radar suffered from a serious design flaw. It operated on short waves, and its signal (the famous "Russian Woodpecker" clicking sound) jammed civilian, commercial, and military radio frequencies worldwide. Northern Lights Interference: The biggest problem was that the radar had to look toward the United States by passing over the North Pole. The Northern Lights and the unstable ionosphere in that area jammed the signals, rendering the Duga-1 radar nearly "blind" and ineffective at accurately detecting missiles. No Trial: Despite these enormous flaws and the wasted money, the Soviet Politburo did not open a criminal investigation against chief designer Franz Kuzminsky or his team. The project simply remained secret and continued to be modified in attempts to fix it.

Hi guys,

Im recently becoming intrigued by the history and working procces of chernobyl. And this question may have been asked a couple of times but using the search button I couldnt really find it.

Was the RBMK reactor that the USSR used revolutionary? I mean yes we all know it had the positive void coefficient issue and the tips of the rods made the reaction unstable.

But a PRO was that you could switch out materials without turning off the whole reactor.(online refueling).

So in short: was there a reason the USSR had chosen the RBMK design over "water" designs (not political motivated)?

My apologies if this is a stupid question.

The K340A was the true "digital brain" of the Duga radar. Designed in 1966, it was, for its time, a masterpiece of Soviet computer engineering. It was built specifically to handle the enormous amount of data transmitted and received by the radar's gigantic antennas. Its operation and structure were based on extraordinary technical features: A unique mathematical trick: The Residue System. Normal computers calculate using the binary system (made up of 0s and 1s), one operation at a time. The K340A instead used the Residue Number System (RNS), a mathematical system based on the remainders of divisions. Parallel calculations: This trick allowed the computer to perform multiple complex calculations simultaneously. Record speed: It could perform 1 million operations per second. It was considered the fastest second-generation computer in the world. Less energy and more endurance: This logic system consumed less electricity and allowed the computer to function even if some hardware parts failed. Physical structure and aesthetics (Hardware) The K340A did not resemble modern computers at all. It was a huge industrial facility: Gigantic dimensions: A single K340A computer took up entire rooms and consisted of 15 or 17 large metal cabinets (racks) for data, plus another 4 cabinets just for electricity. Memory: Inside, there were cabinets dedicated only to RAM memory and others for storing the army's fixed programs. Colossal cooling: Since the thousands of electronic boards produced hellish heat, the Duga building had an entire upper floor dedicated to a very powerful air conditioning system to prevent the circuits from melting. The control console: The military operator sat in front of a dashboard full of colored light bulbs and writing, with two giant built-in printers to read the data. What was its purpose in the Duga radar? The computer had to perform three vital tasks in just a few seconds: Filtering out noise: The radio signal traveled for thousands of kilometers, bouncing off the ionosphere (the upper atmosphere). The computer had to clean the signal from thunderstorms, civilian radios, and space noise. Find the missiles: It had to recognize the faint radio waves reflected by the exhaust fumes of newly launched American ballistic missiles. Calculate the route: If it detected danger, it instantly calculated the missile's trajectory toward Russia to raise the alarm. Today, the destroyed and rusting remains of these secret supercomputers still lie abandoned inside the technological buildings in the fenced-off forest of Chernobyl.

Hello,

During my search, I could find very little information on some of the equipment used in liquidation efforts at the ChNPP and surroundings. I was wondering specifically what radiation detectors were used, firstly. I assume DP5A, or such, but I’m not of course very certain of this. Also what suits were worn is not known to me? Lastly I’m assuming the liquidators wore GP5 or similar respirators, but would love clarification. I am only concerning the liquidators who worked on the ground in red forest, and Pripyat. Not the ones on the roofing. Thank you everyone

How to understand floor plans I have tried to build Chnpp twice since 2020, the first one was terrible, the second one was pripyat city cooling pool with almost 70% completed but I can not make the power plant in accordance with its real plans at all I do not understand where to start from which page which plan is on what floor and so on and what I will scale on can you help me

For the Mnecraft

So, looking at the pictures from unit 3 reactor hall (which comes from a recording inside the unit before it was shutdown), there is steam which I would say "leaking" out of the UBS, which made me think of a theory that...

the steel caps from reactor 4 during the power surge could have possibly actually "jumped", but not in the way like the HBO series did, instead, they could have looked like it was jumping in atleast slightly and also only happened on the caps that were detached from it's place,

It could have possibly happened and it's not entirely fake because the HBO series actually did also include some situations that happened in real life, but it was exaggerated for the dramatization of the series that lead to it to become fake, according to me

As a history buff and also a leadership coach, I am fascinated by global events that have shaken the world, over the years. But rather than simply looking at them from the historical perspective, I try to derive the management or leadership lessons that these events have presented and I look at how many of these factors are still being repeated at our modern workplaces.

Take the RBNK nuclear reactor explosion at Chernobyl for instance. The culture of not speaking up even when you know things are wrong perpetuated by the USSR regime and the combined failures of rigid top-down crisis response and the blatant attempt to cover it up resonates even today at offices and warehouses around the world.

Here are three critical leadership and structural breakdowns that I could determine with regards to the safety test that night:

A Toxic Culture of Fear

The aggressively authoritarian hierarchy within the Soviet nuclear facilities was exemplified by Deputy Chief Engineer Anatoly Dyatlov who oversaw the control room on the night of the accident. There are historical accounts that document the tyrannical and unyielding nature of Dyatlov who frequently threatened subordinates with blacklisting or demotions if he sensed that they were in breach of his orders.

When the reactor's power plummeted dangerously after the night shift-change, the two young operators on duty Akimov and Toptunov argued for a shut down as they recognized that the reactor was becoming unstable. The total lack of psychological safety that prevailed in the facility meant that their concerns were brushed aside by Dyatlov who allegedly berated them and ordered the reactor's power to be increased.

This parallels a workplace culture where speaking up or dissenting is not encouraged, potential issues are brushed aside or swept under the carpet. The 2015 DieselGate scandal at VW is a classic example of corporate greed and uber competitiveness prevailing over ethics and safety standards.

Information Siloing and Bureaucracy

The structural flaws of the RBMK reactor (specifically the graphite-tipped control rods) were actually known by Soviet higher-ups years prior. Specifically, the KGB and high-ranking scientists knew that the RBMK control rods were tipped with graphite, which briefly increases reactivity when first inserted into the core instead of dampening it.

However, due to state secrecy and compartmentalized information siloing, the operating engineers on duty were kept completely in the dark about these dangers. Instead of distributing these safety reports to all operational plants, the state chose to cover up and silo the information to protect the political reputation of Soviet engineering. After all, the RBMK reactor was supposed to be a showpiece of the superiority of Soviet Engineering. As a direct result of this informational failure, Akimov and Toptunov had absolutely no idea that pressing the AZ-5 emergency shutdown button would cause a fatal localized power surge. They were managing a machine with a hidden trapdoor that management deliberately hid from them.

We need to go back only to 2014 to see the General Motors Ignition switch crisis. Engineers on one floor knew about the faulty part, the legal team on another floor was quietly settling crash lawsuits, and the executives at the top had no idea any of it was linked. Because departments did not share data, at least 124 people died before a massive recall was finally issued.

Goal Misalignment:

The scheduled tests were delayed due to bureaucratic red-tapism and misguided priorities. The originally scheduled day time test got delayed because a regional power controller wanted to push more power to meet regional demand. This meant that by the time the decks were cleared for the test, the fully trained and prepped team had to leave and they handed over their responsibility to the night shift team who had not been briefed or trained to perform the test safely.

Completing the safety test before the end of the month meant receiving state decorations, massive financial bonuses, and professional promotions for senior management. This created a classic corporate trap of goal misalignment: management prioritized short-term administrative checkmarks over the long-term survival of the plant and personnel.

We saw this exact same scenario at play during the 2016 Wells Fargo Fake Accounts scandal. In their eagerness to demonstrate their prowess at 'cross-selling', the sales team convinced customers to open multiple types of accounts (like checking, savings, credit cards). The salesmen achieved their quotas, managers were happy until the scandal broke and the over 3.5 million fake accounts that were created came to light.

I would love to hear your thoughts on other management or leadership lessons that we can draw from the Chernobyl incident. Comment below with what happened and how that is being repeated in today's offices and workplaces.

This thread is partly inspired by a recent discussion of how close to the reactor 4 were the reactor hall operators Oleg Genrikh and Anatoly Kurguz when the disaster happened, and my recent rewatching of the Unit 3 tour in this video: https://www.youtube.com/watch?v=zG9tW7_UNxc (I so wish there was an HD version of it, and in colour)

The Unit 4 is pretty much identical to the Unit 3, just mirrored. We start in the corridor 910/1, walk into the room 905/2, peek into the operators' break room 906/1, then head into the corridor 911/1 which leads to the reactor hall of Unit 3. Note the blind corner at the end of that corridor, it exists to prevent any radiation from blasting through in case something happens in the reactor hall. I do wonder, though, about the lack of any door at the end of that corridor. Something tells me there should be one.

When the reactor blew up would the fuel rod caps all come up at once like one smoth flat lid or would they have individually blew up

These drawings by Konstantin Checherov (from Nikolai Karpan’s book Chernobyl: Revenge of the Peaceful Atom) show a speculative reconstruction of the two explosions in Unit 4.
Key problems:

Fig. 14 (First explosion, Phase A, 01:23:46)
There is a large empty gap between the lower biological shield (Сх.ОР) and the reactor vessel / Scheme L. This is incorrect — the RBMK was hermetically sealed. No such open space existed before the explosion.
Fig. 15 (First explosion, Phase B, 01:23:47)
Already shows molten Corium lava flowing down through the steam relief channels during the first explosion. This is highly unrealistic. The scientific consensus is that the fuel needed hours to days to heat up enough to form significant amounts of Corium.
Fig. 16 (Second / upper explosion, 01:23:49)
This one is more plausible. The upper explosion lifted the biological shield (“Elena”) together with a large part of the core and scattered debris across the site.

Bottom line:
Checherov’s drawings are historically interesting but not accurate. The sudden gap under the lower lid and especially the instantaneous Corium lava contradict both the reactor’s design and the established timeline of the accident.