I don’t know about you guys, but I am fascinated by the Demon Core.

This mini series looks interesting.  Different subject but interesting.

Really enjoyed the first episode.

Graphite moderation was part of it but the delay in the turbine trip test and extended run at "low" power was the major factor.   Xenon..etc.

All stuff they knew not to do and they knew why.  They just about popped an RBMK a few years earlier and they changed the rules for operating them...then dyatlov and chernobyl's  leadership ignored them due to local party pressure to complete the trip test after some recent upgrades.  Symptom of the broken Soviet system? Sure, the aftermath certainly was.  Dyatlov was the smartest man in that room..more than enough blame to go around but he owns a bunch of it.

I can forgive the denial immediately after the explosion. It would be tough to cope with the reality that you just opened Pandora's box and killed an entire country.  A run away half destroyed burning pile of transuranics venting to the atmosphere.

There are a number of things you don't want to do with a commercial reactor, and choosing not to scram on a turbine trip is one of them.  But, that doesn't necessarily go towards the kinetic severity of the reactor breach.  Powering through the turbine trip is how they got there; and the xenon transient set them up for disaster; but the graphite moderator, void coefficient and control rod bite is what put this one into a class of its own.

How could the elephants foot weigh hundreds of tons, yet only measure 6 feet wide?
Osmium has the most density and naturally occurring is plutonium. It looks like it contains a lot of silicate in the colored photos.

The text on the photo is wrong. Not that the elephants foot isn't bad mind you, but whats on there is hyperbolic to say the least.

in this thread I leaned that there are arfcomers that paid attention in sci.

Good first episode. It really illustrates how unprepared they were to deal with a nuclear disaster and how f-ed up it would be to deal with it. Things aren’t much better now for any country dependent on nuclear power. Think Fukushima. Other than being upfront and honest with the public, dealing with a nuclear disaster is still going to be a horrifying lethal shit show. With all the nuclear facilities located in vulnerable areas in this country near high population areas, it’s very possible we could experience our own nuclear disaster at some point.

Get out of here, Stalker!  

There ought to be a movie or series based on the S.T.A.L.K.E.R. series.  Or at least a remake / reboot of the 1979 movie.

There was nothing unique about it, it was a plutonium "Christy" core the same as the Trinity and Fat Man cores. It was just used for some incredibly dangerous tabletop lab experiments. If you think the demon core was crazy, read up on "tickling the dragons tail" experiments. Yikes.

Well it's a British production (at least the credits said Sky), so....

I'm ok with not listening to Russian accents.

Graphite isn't nearly as bad as some other stuff that was lying around, and what was going up in the smoke plume. But the presence of the graphite would mean that other stuff is happening.

Those are proper British actors. Having a bunch of hollywood types running around speaking broken english with stereotypical Russian bad guy accents is stupid, especially when you want to convey the complexity and the technical aspects of this show's subject matter.

That would have been a multiple kiloton event that would have removed far more than the roof.

Playing fast and loose with the term nuclear explosion?

With all the factors involved, there were essentially hot spots of high neutron flux in the reactor that the operators couldn't see.  When they started to notice the instability in power output they knew something was wrong and they SCRAMed. The control rods were graphite tipped...I assume for some reliability reasons.  The graphite tips increased the moderation in the reactor, this allowed more neutrons to slow down enough to react with uranium fuel and cause fissions.

So basically they setup a scenario where the reactor or at least parts of it went prompt critical.  Conceptually similar to the demon core just 10000x bigger.   While not a nuclear detonation like a bomb..it is a rapid release of energy.   I think it took a few seconds to flash the cooling water to steam, I think the steam did most of the damage but it's pretty well documented that various amounts of damage occurred over the last several minutes of the reactors life.

No US nuclear reactors have positive void coefficients and lack containment domes like the Soviet RBMK did.

The control rod movement was likely too slow for this, and "mundane" fuel channel failure would outpace/outfail the prompt ramp; ie: it would just tear itself apart before reaching prompt criticality/supercriticality of any sort of weapon.

Thought it was really well done. The director did a great job of showing us the profound horrors that we can associate with the disaster, combined with with the sheer ignorance of the locals, firefighters, etc. The children playing in the fallout was horrifying.

And the old commie expertly displayed the hard line, insane, Soviet belief in the State.

Just watch this. Probably more accurate / less dramatized and you can find out how it ends today.

They caused a nuclear meltdown to cover up for a radar system?

The Soviets weren't unprepared, they were utterly incapable of dealing with a nuclear disaster.

As the statement by the Party hack shows, how the facts fit into (or don't) the Leninist model is the beginning. middle, and end of the discussion.

Facts that don't fit the Leninist model must be disposed of.

Leninist theory unsupported by facts must see those "facts" manufactured to support the theory.

In the end, all is there to support the glorious revolution and to make Comrade Lenin look good.

The Ukraine, and perhaps the world, owes a great deal to the workers who simply said "Oh, fuck Lenin. We gotta fix this."

RBMK is a shit design.

Nightmare scenario though would be a sodium fast reactor melting down.... I really don't know why people keep trying to bring that shit design back from the dead.

Huh..good point. So slower than a prompt..still "slower" is relative.   Definitely not the speed of a nuclear detonation.

What's the mechanism of fuel channel failure?  Rods go in..moderation increases initially...reactivity spikes...then what?

I seem to recall reading in one of the reports...IAEA maybe..that prior to the scram the control rod channels had already been damaged by the instability in the core. So the rods couldn't even enter all the way. Given that the first section of the rods were graphite it was thought that at least some of the rods only entered far enough to expose the graphite and not the actual neutron absorbing portion.  So they just increased thermal neutron flux and did nothing to absorb neutrons.    The pin that popped the balloon.

Purses will not swing themselves, will they?

I read a book about Chernobyl a few years ago and it haunts me to this day. It affected me in ways I could never hope to fully articulate. I humiliated myself by sitting in the lobby of a doctor's office, awaiting my turn, trying to not cry. You know how bad it is when you try not to cry. You wind up making it worse. The lump in your throat becomes painful. The constant throat clearing and sniffling draw attention. It was so bad that the nurse brought me a face mask because she thought I was so ill it made me cry, cough, and sputter and sniffle. People actually moved AWAY from me like I was contagious.

I think this book should be mandatory reading.

Voices From Chernobyl

Any good/recommended books on Chernobyl?

Yeah yeah, book forum is that way but this is on topic and gets way more traffic.

There are still a bunch of them keeping the lights on in various parts of the former Soviet union.  Certainly not a great design but the people running it did just about everything they could have to kill Chernobyl 4.  The west uses containment buildings and pwr/bwr designs but even our reactors aren't stupid proof.

I know it’s not your first day here

As well as those who did not, like me.

Fascinating explanations to read here even understanding only the verbs and some of the nouns.

With mundane steam dryout, you'll get cladding failure from insufficient heat transfer, fuel rod disintegration; with severe dryout and coolant disruption disintegrated fuel will reorient somewhere and possibly assume a geometry that resumes/maintains criticality.

With RBMKs, since the water flow through the assembly is contained in a pressurized channel (the channels in a BWR aren't pressurized, but sit inside a huge pressurized vessel) if thermal power rise is fast enough, superheated steam can blow the individual channels apart.

Because reactor power levels looks something like water ripples (3D Bessel function), certain groups of peak assemblies would have had violently catastrophic overpressures, while other channels would probably have had sympathetic failures resulting from peak channel failures.

Certainly some supremely brave people sacrificed everything to save a big swath of europe.   After a day or so everyone was up to speed about how bad it was.

The core burned it's way into the basement, it shielded itself more or less.  All the dumping of sand/lead/boron didn't really do much. The 1000T lid that got blown out like a man hole cover blocked a lot of the attempts to dump material on the exposed core. The guys that drained the water out of the basement..and then promptly died,  prevented another steam explosion and a potential doubling of the disaster.  Some of the corium ended up in the drained bubbler pools..those guys knew it was suicide and not just death but a horrible death.  Did it anyway.  Not sure how they swam in that contaminated water with those giant brass balls.

Thank you for that.  GD isn't all jackassery

They're still alive mate.

Yeah, and fake Russian accents aren't authentic anyway.

Either have the actors speak normally or speak Russian with subtitles.

What in the world is going on?  First you have Hotel Mumbai that paints Islamic terrorists the way they actually are, and now Communism as it actually is.

I am sure Hollywood has seen the light and will now portray evil in a correct light.

Really? I thought they only lasted a few days.   Shit good for them.

ETA: I'm talking about these guys

Alexei Ananenko (who knew where the valves were), Valeri Bezpalov, and, Boris Baranov

I see claims that they died of radiation sickness shortly after draining the pools..

This.  That shit is scarier to me than any horror movie you can watch.  Wife and I are hooked so far from the first episode!

Watch The Death of Stalin.  It has a mix of American, British, Irish actors all just speaking their parts in their normal voices.

I don’t understand about 80% of this thread but I liked the first episode.

It's been more than a decade since I've looked at this event, so I'm fuzzy on the details, and even a decade ago, I was anything but an SME.  My background is in thermal-hydraulics, so reactor kinetics is an interface or academic interest, rather than a competency.

After giving it some thought overnight, watching Episode 1 probably requires about 40 hours of prep time - time spent learning the who's who; time spent re-learning the main physical configuration of the RBMK; time spent re-learning the best estimate reactor kinetics of the accident; time spent looking at low power operating limits and turbine trip restrictions.  And, on top of all of that, maybe especially with that last part, there still seems to be a fair amount of confusion about what they were allowed to do and what they were prohibited from doing, and the what and whys of it all.  So, let's call it 40 hours, plus.

And, on top of that, because of language and plant-specific features, what I'd expect something to be called may not be how they've chosen to call it.  And on top of that, maybe the show directors just decided to take complete liberty and omit or invent things.

Maybe the show never actually goes in and backfills the accident through the investigative details.  Maybe it takes a more top level, character level, character experience approach to it all.  Maybe all of the above is for naught because the directors decided to skip past some stuff to focus on other stuff.  There's just no a priori way to know how to take in what I'm seeing in the show right now.  Based upon some of the trailers, their description, or their trailer soundbite description, of which radionuclides are of greatest human threat was way off the mark.

The stuff in the trailer already biased me to doubt the technical accuracy of the show.

Unfortunately, that bias carried over into Episode 1 when I was listening to the steps the operators were taking in response to the emergency.  The mention of "feedwater" seemed completely out of place - that's balance of plant stuff, and since I'm a PWR guy it seems incongruent in responding to a reactor accident.  Turns out, though, I had forgotten that RBMKs, unlike CANDU reactors, are boiling water reactors - with no physical separation between the fluids of the reactor coolant and turbine legs.  So, feedwater was something that was very much in play during the disaster.  Which leads me to ponder what they meant by "control tank".  That just seemed out of place at the time.  One, I don't know what they are referencing, maybe it's a language issue, maybe it's completely invented, maybe it's a reference to a hydrogen accumulator, who knows.  With all of their pressure, power and steam separator level excursions, that's where I expected the conversation.  So, with my misunderstanding of the whole feedwater thing, maybe I'm also misunderstanding the context around this "control tank" they're talking about … or the "control tank" is just an invention.  With these shows, it's just hard to know.

They were the lead for the shutting off valves. Members of their team died IIRC.
The wiki article is very poorly worded.

Chernobyl Power Plant was still making electricity until 2000.

Yep, I don't really expect the show to be accurate to a level that an actual SME wouldn't be able to identify errors.  To most, reactors contain invisible death and when it get loose its 10k years of invisible death...period.  HBO made a techno-drama...but it's still about the drama. There is a compelling story to be told so I'll forgive them for not satisfying the nuclear engineers of the world.

The safety control tank..or control safety tank..it seemed to matter.  I don't know..you wouldn't use hydrogen in a pressurizer would you?   I read somewhere that hydrogen was used as a coolant of some sort..in the turbine?   Given that the entire steam loop was exposed to the core would hydrogen provide some benefit over other types of coolant...less susceptible to activation/contamination or something.  Yeah...you got me.

I think dyatlov just couldn't grapple with the fact that he blew it up.  I think he knew he did..but couldn't understand how so the hydrogen tank was a semi-logical conclusion that his mind would except.

Yeah

The photo caption says that it was only able to be photographed via mirror. It was photographed in person, there is even a photograph of the person taking that photograph.

What's disturbing is that the graininess of the photo isn't due to poor film or development or even JPEG compression of this image (though it doesn't help). It's due to radiation bombardment of the film.

My wife worked at the main Kiev hospital at that time and helped work on the injured as they were brought in. Yeah, she's got thyroid issues today.
She said that there was 1 - 2.5 cm of gray powder over everything outside for a week; not knowing what it was. Imagine standing in an inch of fallout while waiting for the bus to show up.

Curious if they showed the scene of the 2 engineers that dove into the blue glowing pool of water, knowing it was going to kill them in days, to close the valves to keep the water from causing a larger steam explosion. The book I read about this disaster said that those two men saved western Europe from being covered in the 'Dead Zone' levels of radiations.

God awful movie, I can't understand the recommendations to watch it. I gave it about a half hour and simply turned it off.

Like watching a B movie director's attempt to make a historical documentary in the style of Mel Brooks, but without any actual humor.

https://www.businessinsider.com/chernobyl-volunteers-divers-nuclear-mission-2016-4

"Definitively, Leatherbarrow said, none of the men died of ARS. The shift supervisor died of a heart attack in 2005.
(Leatherbarrow attributes this to a mix-up with an employee with the same surname who did succumb to ARS.)"

because it's a brave new world of entitlement

only black actors can play black parts...and you have to be the right kind of black....not too light....according to black people
only handicapped actors can play handicap roles, according to handicap people

where will it end.  only dead people can play dead people?