r/chernobyl

Was the RBMK-reactor revolutionary?

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.

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u/No_Chef6653 — 3 hours ago
▲ 192 r/chernobyl

A Colourised image of Unit 4 being covered by the completed Sarcophagus next to the Liquidators taken in late November 1986

u/TheTardisMan2 — 12 hours ago
▲ 265 r/chernobyl

This is also Chernobyl.

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.

u/gioangi — 15 hours ago

I Dont understand floor plans

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

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u/DonEscobarSalamanca — 15 hours ago

the K34OA supercomputer of radar Duga

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.

u/gioangi — 15 hours ago
▲ 0 r/chernobyl+1 crossposts

The spectacular management and communication failures behind the Chernobyl disaster

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.

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u/theworkplacetoolkit — 18 hours ago
▲ 202 r/chernobyl

A theory that I thought of before and would like to be debunked

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

u/500cigarettes_1 — 2 days ago

These drawings by Konstantin Checherov (from Nikolai Karpan’s book Chernobyl: Revenge of the Peaceful Atom)

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.

u/gioangi — 3 days ago

Let's walk through some rooms and corridors to the reactor hall of Unit 3

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.

u/maksimkak — 2 days ago
▲ 171 r/chernobyl

the first color film of the Lava (corium) of the time acquired by Raiplay Italy

u/gioangi — 4 days ago

Reactor 4 explosion

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

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u/Amg_gaming — 2 days ago
▲ 663 r/chernobyl

Alexander Akimov

Aleksandr Fyodorovich Akimov (6 May 1953 – 11 May 1986) was the Unit 4 shift leader.

He was at the reactor control panel at the moment of the explosion. Believing the reactor was still intact, he and Leonid Toptunov stayed for hours trying to restore cooling water flow, receiving a fatal dose estimated at over 15 Gy (≈1,500 rad).

He died of acute radiation syndrome in Moscow Hospital No. 6 and was posthumously awarded the Order For Courage.

u/gioangi — 4 days ago
▲ 608 r/chernobyl

Helicopter

Almost 40 years ago, on October 2, 1986,

Alexander Yungkind, Leonid Khristich, Nikolai Ganzhuk, and Vladimir Vorobyov were involved in an accident in which all of them lost their lives.

The pilot struck a crane cable and consequently crashed.

In 2017, during preparatory work for the dismantling of Block 4, the tail rotor of the helicopter that crashed in 1986 was discovered.

The propeller had crashed onto the roof of the turbine hall of Block 4, but it was so heavily contaminated that it was immediately walled up with a large amount of concrete.

Rest in peace, heroes.

u/gioangi — 4 days ago

Happy Birthday Lenya

So sorry I'm a day late, but Happy Heavenly Birthday to Leonid Toptunov.

u/titaniac79 — 3 days ago
▲ 347 r/chernobyl

first photo in flight April 27, 1986

The destroyed Reactor Unit 4 – April 27, 1986. Photo by V. Yevtushenko.

u/gioangi — 4 days ago

What’s all the evidence pointing towards a nuclear blast in Chernobyl?

hello everyone!

whenever I do research regarding the last moments of the reactor before the explosion, I always see the same 3 theories. The hydrogen theory (been disproved many times). The second steam explosion theory (the sudden influx of water that surged into the bottom of the core caused a second much larger explosion, my personal favourite). And the nuclear theory, that the excursion somehow had enough energy to cause a nuclear “fissile” and that obliterated the core. My question is, why do so many people (and experts alike) believe this one over the steam one? Is there any evidence suggesting one over the other? Thanks!

(also I apologize for any grammatical errors, English is not my first language so any recommendations are appreciated!)

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u/FluffyAd6520 — 4 days ago