Comments by "TheThirdMan" (@thethirdman225) on "Chernobyl Show vs Reality - Footage Comparison" video.
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@rezae342
"Dyatlov was not obliged to continue the test when he saw that it reached under 30 MW."
I agree. The point I was making was that he was under massive time pressure and I don't think anyone foresaw the possibility that the reactor might explode so catastrophically. While, with hindsight, I think everyone would say that he was wrong to continue with the test, I don't think he saw this as a likely outcome and thus - to him - it was worth the risk.
"clearly in the documents and also explained that in order to be on the safe side, a 24h period was needed to slowly augment the reactor power back to normal, not doing so in several minutes to a power of just 200 MW for the sake of doing the test."
Do you know what they were testing? Just asking.
"He put too much faith in the equipment and reactor not mentioning the heavy pressure all the night shift staff where in."
With the benefit of hindsight, that would be true, yes. Dyatalov knew the RBMK about as well as anyone and I suspect he knew a lot more about the safety margins that we don't know. I haven't seen any of the documents about the operating parameters of an RBMK1000.
The night shift staff were the wrong people and I think Dyatalov found himself under even more pressure to finish the test because he couldn't really rely on them. Some were party members on the way up (they both died), including the one who was working from reams of notes. Others just lacked enough experience.
On the explosions, which there were two, please allow me to correct you to the best of my knowledge."
Yes, I know. I just wanted to keep the discussion about Dyatalov, in part because there are a lot of crazy theories about the second one being a nuclear explosion (which was impossible with U238).
If you're interested, there's a really good book in English called "Chernobyl: History of a Tragedy" by Serhii Plokhii. I have been reading about Chernobyl for about 30 years and hope to visit one day.
Thanks for your remarks.
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Reza E Not true. Dyatlov was very competent. He had more experience with nuclear reactors - most of them of the RBMK type - than anyone else at Chernobyl. He had been there for fourteen years. His biggest flaw was that he was a hard task master and didn’t hesitate to berate people for incompetence, laziness or trying to hide things. His bosses thought very highly of him because he was very good at getting things done.
The sequence of events which led to the explosion is poorly explained in the series (I should add that I haven’t seen it but nobody who has can convince me they have much idea of what happened). Chernobyl 4 was a long way behind schedule and the staff were under extraordinary pressure to get this last test done so that the reactor could officially go online.
On the night of this final test, Dyatlov was uncharacteristically late. In the meantime there had been a shift change and the replacement crew was at a lower state of readiness to undertake the test than the one it replaced. The reactor had been running at about half power (1600 MW) for most of the day. Dyatlov ordered it taken down to 580 so the test could begin.
The RBMK was quite stable at its normal operating level of 3200 MW but not so stable at below about 700. Unfortunately there had been a large build up of an isotope called Xenon 135 in the system and because it is a reaction killer, putting the control rods in almost stalled the reactor. The output plummeted to about 30 MW. Dyatlov had a choice; shut down the reactor and cancel the test or try to get it going again. He chose to keep going.
All but a few control rods - the start rods - were withdrawn and the output buildup again over about four minutes to 200 MW. The test - which was supposed to prove that the water pumps could function off the turbine for the time between the simulated failure of the plant’s electrical supply and the start of the emergency generators - was completed in 36 seconds. Then the reactor surged. The lack of water in the reactor, due in part to the slowing of the water pumps, meant that there was not enough water to act as a moderator and also that some of it turned to steam, creating voids, which was nothing like as good a moderator as water. This was the main fault with the RBMK design - a positive void coefficient.
Dyatlov ordered the crew to scram the reactor and they duly pressed the AZ-5 button after removing the cover. The RBMK reactor was seven metres deep. Debate rages as to whether the continuing surge was the result of the fact that the rods could only go in at a rate of 40 cms per second - the whole process taking approximately 18 seconds to complete - or whether the control rods simply jammed due the rupturing of the fuel rods due to the fantastic amounts of heat.
Either way, the result was the same. The reactor suffered a massive steam explosion which blew the 200 tonne cap off the top and threw bits of highly radioactive abs highly toxic material through the roof of the reactor hall and into the compound. The graphite tips on the rods also did not act as a moderator but tended to increase the reaction.
So, once the process is understood, it’s easy to see how Dyatlov can be blamed for this. However, the lack of experience of the night crew, one of whom was working from pages of dictated notes, and the massive time pressure they were under, made Dyatlov decision to continue with the test easier to understand.
The inquiry was looking for a fall guy and at an operational level, Dyatlov was the one. Two others, Briukanov and Fomin, were also jailed. All three received ten year sentences. I don’t think any of them served more than four years.
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