Chernobyl Part 5 Comments Review
Вставка
- Опубліковано 25 чер 2024
- Key for Mark I BWR Containment image:
DW - Drywell
WW - Wetwell
SF - Spent fuel pool
Timestamps:
00:00 Intro
00:16 Nuclear explosion or nuclear bomb?
03:12 Safety Changes to RBMK After Chernobyl
04:47 What Exploded at Fukushima?
Images Used:
Mark I BWR Containment: en.wikipedia.org/wiki/File:BW...
Fukushima Unit 4 After Explosion: en.wikipedia.org/wiki/Fukushi...
Thank you, thank you, thank you. I failed all my high school science courses and never understood any of this topic. You explain it in such depth and with great analogies. It's like a fog has been lifted and I can see and understand this subject now.
What a lovely comment, this means a lot to me. I'm so very glad you were able to get some new understanding out of my videos.
Big yes to the reactor series!
I think that you have misinterpreted the statement. The writers didn’t mean that an actual nuclear weapon or its equivalent had detonated. They only wanted the character to emphasize the extent of the disaster to the judges at the trial. An out of control nuclear reactor had resulted in a pressure explosion and fire that had strewn radioactive debris over a large area making the whole vicinity uninhabitable.
Can't wait for the next set of videos. I have watched the Chernobyl mini-series 3 or 4 times and those review videos you did really got me into what you are doing. As somebody who has made a career in rad protection and worked both DoD and DoE, I really enjoy your content.
Thanks, Brian! I really appreciate it.
@@TheAtomicAgeCM have you spoken about Small Modular Reactor Technology?
The Philippine Government recently acquired one to innovate in.
No one is talking about it nor giving a proper explanation on it's merits and the positives of that technology.
Great to see another upload
Looking forward to videos about reactors coming up! Will you be going over each reactor type in one video per type style? Anyway, will be very interesting! Hope you can also go into things like design changes and generational development for some reactor types, but I get that might be too much to ask for :)
I feel your pain with the "nuclear bomb" phrasing. I got into it one time with this girl who clearly didn't know anything about nuclear power and kept insisting that it was a nuclear explosion simply because it blew up. Even after using the analogy of a pressure cooker and an overinflated balloon, she still didn't get it. Just goes to show how difficult it can be for some to understand basic nuclear physics. Kinda ran into this same problem with, what was it, episode 2 or 3 where they were concerned with the corium melting down into the flooded basement and that if they didn't get the water out in time it would be like a 20 megaton "thermonuclear explsion" and all of Europe would be decimated or whatever they said. Some of my coworkers were talking about it at the time and I had to reassure them that, no, that's not how that works; there's a reason they need to enrich uranium. Makes me wish the general public would have a better understanding of nuclear power so that they wouldn't be so worried about it all time.
Indeed.
And your concern is true for many concepts in many important fields in Physics
well i greatly appreciate your empathy haha. good to see ya again.
We as humans will dramatize things that we don't understand. There are/were some concerns and mistakes that lead to disaster whether we all understand is not necessarily needed but making things up and spreading it as truth is even worse. We continue to get more knowledgeable, and we can learn from our mistakes. It takes smart people like yourselves to teach the teachable and stay unwavering on the others. You can't change any one's mind in the moment, plant the seed and you may be surprised how fast it grows.
Think of it the other way, the ones that don't understand may pay the ultimate price for ignorance. I think about all those people, the innocent bystanders that died because the "smart ones" chose to be silent about what was happening.
However, in this case I understand why the analogy is poorly used, as insinuation can stop growth. But let's face it we have our scars because of the ignorance of intelligent people as well.
I learn something new every day and it makes me feel good that I still can, good stuff and thanks.
@@titanmanification I really like what you wrote about planting seeds cause sometimes people just need to gestate for awhile on difficult concepts before they figure it out. Ever since the Chernobyl series first came out I've thought about making a few videos going over basic nuclear physics. I'm learning how to do animation in photoshop for another channel I'm working on so that could come in handy. Oy! I'd have to clear out some major cobwebs in my head to make sure I got it right though. I haven't hardly looked at this stuff since I got out of the Navy in 09. Hell, before that actually. The last time I did anything nuclear-related was in 05. Still, it'd be interesting to relearn some of the stuff I've forgotten and maybe even fill in some of the gaps that I never learned to begin with. At the very least, if I ever get into a conversation like that again, I can point them to one of those videos instead of relying on UA-cam's search function to try and find a good video that covers what I'm trying to explain. I don't know. We'll see.
yeah the videos, i've learned, take as much work and time as you want them to. i need to try and simplify/shorten my editing process a bit.
Yes, another excellent video! And I cannot wait to see what you're going to do with your Reactor Series videos. Be sure to include the wonky-looking, but incredibly awesome CANDU reactor design. These can actually help us close the nuclear fuel cycle as they can run on the "waste" from PWRs via the DUPIC (Direct Use of spent PWR fuel in CANDU) process.
Here is some additional info on the safety improvements they gave the RBMK reactors after the Chernobyl accident:
- Reducing the positive steam (void) coefficient of reactivity and the effect on
reactivity of complete voiding of the core;
They raised the enrichment to 2.4% like you already mentioned. And they loaded additional absorbers. The number of
additional absorbers varies from 85 to 103, depending on the reactor. Technical specifications now require at least 81 additional absorbers. There is to be no deviation from this at any time.
- Improving the speed of the scram system;
Not only did they improve the overall speed of the scram system to 12 seconds from the skeletal 18, they also added an additional fast-acting EPS. This system can fully insert 24 control rods in less than 2.5 seconds, or in 7 seconds depending on the emergency signal activated. The FAEP is meant to ensure that on demand, a negative reactivity of more than 2 ß will be inserted in less than 2.5 s. The actuator in this system cools the channel wall with a thin film of water and moves the rod in a gas medium. In 1987-1988, this new system was put through full scale testing at the Ignalina and Leningrad plants. The tests confirmed the design characteristics of the system, i.e. 24 fast acting EPS rods in less than 2.5 s cause an insertion of negative reactivity of over 2 ß. All RBMK reactors are now equipped with these systems.
- Introducing new computational codes for the ORM, with numeric indication
of the ORM in the control room;
- Precluding the possibility of bypassing the emergency protection system while
the reactor is at power through an operating limit requirement, and the introduction of a two key system for the bypass action;
Ergo, the staff can no longer willy-nilly shut off safety systems like they did in 1986.
- Avoiding modes of operation leading to reduction of the departure from
nuclear boiling (DNB) margin for the coolant at reactor inlet (this addresses the question of adequate sub-cooling at the core inlet).
(Sources: INSAG-7 and Safety of RBMK reactors: Setting the technical framework)
The Netflix series about TMI is horrible. I couldn't even finish it, I quit after two episodes. Not only do they get a lot of things wrong (yes, I did a lot of in-depth reading about TMI), they include conspiracy theories as fact. Including the statement that TMI caused ARS in people comparable to the levels of Chernobyl directly after the accident, and that it was all covered up. My biggest disappoint was Michio Kaku who went along with all the fear mongering. The whole series is decidedly anti-nuclear. Every other minute there was a "Nuclear Bad!" punchline with some accompanying ominous music to drive the point home to the unsuspecting viewer. So, be aware of this before you start watching. But it would be great to hear your take on the Netflix series.
Check out Moltex's SSR that Canada are building to go with their CANDU
EXTREMELY long comment
@@st3phan321
What, you don't like reading long nerdy reactor-y YT comments?
It's strange, I don't think I have ever really been all that interested in physics, let alone nuclear physics (maybe astrophysics?), but after watching your videos and listening to you talk about it and explain all these concepts, I am suddenly very intrigued. Like the thought had never crossed my mind before, but I recently found myself thinking, "huh, it would actually be pretty cool to be a nuclear engineer!" So, thank you for very suddenly opening up that door for me haha!
that's amazing, glad to hear it!
Thanks!
You're welcome, and thank you so much!
I wonder if it would make sense as part of reactor design to include a sort of “waffle maker” shaped slab of copper on the floor, possibly with horizontal holes bored through to arrest a meltdown?
Copper is very conductive (and somewhat neutron absorbing?), and with coolant flowing through the holes, could remove heat very quickly from anything that came into contact with it. The “waffle maker” shape could serve to increase the surface area and help separate the molten core into more manageable bits?
sounds like a good idea! look up the French EPR, I believe it has some kind of feature like this
Their was one aspect of Acute Radiation Sickness that “Chernobyl” briefly discussed but didn’t explain why. The Latent phase of ARS, where the exposed will seem to get better, before the symptoms come back even worse. What causes this temporary recovery? Is it caused because of the immune system is fighting of the poisoning, and then once the immune system is destroyed that’s when the symptoms start to reappear, or is it caused by something else?
The latent phase has to do with the DNA damage that was done to the cells in the body. The cells weren't killed, but the DNA was damaged to the point the cells lose the ability to divide and replace themselves or lose the ability to function correctly. Different cells have variable lifecycles. Skin cells for example have a lifespan of two to four weeks. So, if suddenly large portions of your skin lose the ability to divide and be replaced, on the outside you look fine for a while, but in two to four weeks as those cells die, your skin starts to deteriorate. Same thing is going on internally. Your immune system keeps on working, but no new white blood cells are being made so their numbers drop and opportunistic infections can start to take over.
Hi there. I've thoroughly enjoyed your series of videos and share your opinion that the Chernobyl miniseries was generally pretty good but slightly spoiled by being overly dramatised. I'm looking forward to seeing where you go with reactor designs, but if you are going to look at the issues at Fukushima Daiichi I'd like to see specific comparisons to Onagawa Nuclear Power Plant - the reactor complex closest to the earthquake epicentre that was hit by the biggest tsunami anywhere along the Honshu coast but didn't experience disaster. A little feature on the role of Yanosuke Hirai likewise wouldn't go a miss.
Thank you for reading.
Thank you! I do want to cover accidents, likely as a different series. I'm a technical person so I will likely stick to the technical and I don't plan on doing any exposé on humans involved.
Onagawa is also a BWR, with 3 reactors. It survived the earthquake and tsunami thanks to Hirai's determination.
@@spidrespidre because they built the wall up higher for one
At Daiichi they actually lowered the sea wall to reduce pumping costs, but there's more to it than that. At Onagawa, they were prepared for the earthquake and tsunami - and the difference is one of culture. Tohuku Electric were focused on safety while Tokyo Electric were yes men.
Restrictions on hundreds of Welsh and Cumbrian sheep farms dating back to the Chernobyl nuclear disaster have finally been lifted - 26 years on. See BBC Article
Look at footage of what many are calling a tactical nuke explosion in Yemen in 2015. Notice the intensity of heat in the mushroom cloud. Notice how the camera sensors are impacted. Thoughts?
Please do a video on Santa Susana Field Lab!
2:00 I prefer to think Legasov was speaking hyperbolically. You could say it was nuclear, and it was a bomb, so it was a "nuclear bomb." Bad choice of words, but not necessarily wrong.
The nuclear bomb analogy may be more accurate than you realize. It has actually been hypothesized that rather than a delayed supercritical increase, one of the explosions may have been caused by a runaway prompt criticality resulting in an explosion somewhat similar to that of a fizzled nuclear weapon.
There is evidence for this, as xenon-135 was found 1,000 km northeast of Chernobyl only 4 days after the explosion. This would’ve required short-lived fission products to be ejected to heights much higher than should be otherwise possible, whereas the main debris from the core drifted northwest towards Scandinavia and contained equilibrium isotopes of xenon.
Additionally, observations of the destroyed reactor tank indicated that the initial explosion created temperatures high enough to melt through the 2 meter bottom plate in part of the core, which is consistent with a nuclear explosion. The bottom plate in the rest of the core didn’t melt but was pushed down 4 meters, which is more consistent with a steam explosion.
So it’s possible that there actually was an initial nuclear explosion in only a few channels, followed by the larger steam explosion less than three seconds later. Swedish nuclear physicist Lars-Erik De Geer did a full paper on this in 2017, although he did still mention that the nuclear explosion concept is still not to be confused with an actual nuclear bomb. There was a prior hypothesis from a different scientist in 2009 that the second explosion was nuclear and the first was not, but it’s so incredibly unlikely for a nuclear explosion that powerful (estimated at 40 billion joules, equivalent to 10 tons of tnt) to occur by accident, and the evidence is more consistent with a smaller explosion.
But of course Legasov would also not have known any of this, so given the information he actually had at the time, saying it was a nuclear bomb was still wrong.
Do the LFTR. I love that design as it addresses some of the nastier drawbacks of a PWR/BWR or even a liquid metal cooled fast reactor. Also I would love a series that goes over the reactors in subs, aircraft carriers and places like mcmurdo. I would also love videos on the canyons used at Hanford and SRS to extract the Plutonium.
LFTR's interesting, but have a look at Moltex's SSR. So many of the problems of fission power solved in a single elegant design.
@@MostlyPennyCat To be honest any of these gen 4 designs would be a blessing for our baseload.
Quick question here. What are the chances of Zaporizhzhia nuclear power having a meltdown as a result of the war?
Can it accidentally become an _ineffective_ nuclear bomb?
Like a "fizzled" one.
With a positive void coefficient the maximum "void" factor is all void, no water.
If the first explosion vented all the water, could the second not have been a runaway event?
Two modes, the delayed-critical core used in reactor cores and the supercritical lump used in bombs.
We use delayed criticality because each generation of neutrons take minutes to, er, make-reactor-go.
It's slow enough that you can move rods about to control it.
But a bomb is a supercritical assembly.
Each generation of neutrons creates the next in nanoseconds.
Great for bombs, crap for reactors.
So here's the point:
You have 200 tons of 1.8% LEU
But you have it riddled with moderator and surrounded by reflectors.
And your absorbers are all gone.
Part of the core may have experienced a prompt-critical excursion, just like a bomb.
Which tore the core apart, ending the fission.
I guess the real question is _what defines a nuclear bomb?_
Obviously it's not a steam explosion.
It's probably prompt criticality
But if your assembly is sub-critical and it fizzles, is that NOT a nuclear bomb?
Or is it a _failed_ Nuclear bomb?
I just find this fascinating, the definition of the thing.
First, let me say thank you for opening this line of questioning without insulting me first lol (we've exchanged comments before, so I wasn't expecting anything less from you just to be clear). Others who have tried to pose this question have been very crass about it. The first major issue is enrichment (we're going to stick with uranium here but it's quite similar with plutonium). You want bombs to be highly enriched because Uranium-238 tends to suck up neutrons and not give you any fissions. Another benefit of high enrichment is a lighter bomb. The RMBK reactor is very low enriched. There have been fission bombs made with somewhat low enriched uranium (20% enrichment seems to be the cutoff point), but the enrichment in the RBMK is too low. The second major issue is all that moderator. Nuclear bombs use fast neutrons - all the neutrons in an RBMK are being moderated and being slowed down greatly (thermalized) - too slow for a nuclear bomb to happen before it blows itself apart. Even if it's prompt supercritical. I work to prevent criticality safety accidents and all of those that have happened are prompt supercritical. But, they don't explode like nuclear bombs. Many criticality safety accidents were moderated but not all - like demon core and such. I suppose in theory, an unmoderated criticality safety accident could get to nuclear bomb levels of power if other parts of physics were put on hold, but something in the real world always interferes - like blowing itself apart or decreasing density via thermal expansion from heat. The main thing is it's always too slow before something changes, neutrons are too slow, it blows itself apart, some liquid splashes out in the case of a fissile solution criticality accident, etc. That's why all nuclear bombs start with a conventional explosion - trying to squeeze the shit out of that fissile material very very quickly - usually by imploding it, and letting a nuclear bomb level of chain reaction happen before it blows itself apart.
@@TheAtomicAgeCM
Thanks and you're welcome.
I find the whole concept fascinating, as it is fairly obvious.
If it looks like bomb, sounds like a bomb and booms like a bomb, is it a bomb?
That's your philosophical side.
I mean, no mistake, it very much was a Nuclear _powered_ bomb with the steam explosion.
Then there's the technical side, indeed there is no way to make a supercritical assembly that goes prompt kaboom or even fizzle, certainly not by modelling the core as is.
But there's one question I still can't answer and that's that _one_ published paper describing proof of uncontrolled prompt criticality, from isotopes found in the Arctic circle (I think)
The only thing I've got for that is in such a massive core, well, maybe they didn't mix the uranium correctly? (This is broken soviet Ukraine at this point, they don't even have Geiger counters, not proper ones)
Maybe there was a pocket of concentrated U²³⁵ by dumb luck?
Then, well, this core was already exploded, the paper claims the first was rupture followed by steam loss and the second was the prompt excursion. It's another five roll thing but, if it did go supercritical on the second blast, it _did_ start with a conventional explosion
The idea in the paper is just a small part of this massive core that went critical. And if that explosion lifted the, what, 6000 ton bio shield?
Will, everything for crushed downwards and outwards.
And that, that's as far as I can speculate.
Does the SCALA data stop at the first or second explosion? If it's the second I think it would be interesting to calculate its exponent and compare it to that of prompt criticality.
@@TheAtomicAgeCM
Hey, Atom Age.
I got an idea for you, a short one so you can put it in a UA-cam short!!
OK, there's a game called Half-Life 2.
And it had a continuation chapter called, Half Life 2 Chapter 1.
At the conclusion of Ep1 the "power unit" of the alien tower in the center of the city explodes, with the force of what appears to be in the multi-megaton range.
Your challenge, should you choose to accept it, is to guesstimate what the Megatonage is.
I recommend you play the game and the chapter, or maybe the final chapter of the game followed by the expansion chapter.
Clues:
Tower height is mentioned.
Location of the power core in the tower expressed as height relative to ground level.
Video of the explosion as you run away, fireball height it seems.
Various bits of exposition.
How long they traveled away and possible even speed can be guessed.
They survived the over pressure wave, you can time how long the over pressure took to arrive.
Sounds fun, eh? 😁😁😁
@@MostlyPennyCat i love half life! my favorite game series. this could be a fun concept, something to look into. i do plan on addressing how the series portrays nuclear science too
Hey can I ask do you think nuclear power is the way to go for future energy? People being in the politics of this. That isnt what I am asking. What I am asking is would nuclear power be a good source of energy for the future?
I think it's good, yes. In a perfect world, all nuclear fuel would be reprocessed after leaving the reactor to greatly minimize the waste. Even without reprocessing, it's still a very small amount compared to carbon dioxide emissions. I think fusion would be better but who knows when that will come.
Really enjoyed the Chernobyl series. In my humble opinion moving onto the Fukushima disaster would result in many returning eyes. With that being said I think it will be very difficult as much of the most current information has been completely scrubbed from the internet in my opinion. Even to find a recent documentary or discussion regarding the current status of the cleanup is impossible, the most recent things you can find are from the first year or two following the disaster. I'm admittedly under the possibly false assumption that the disaster is ongoing and TepCo and the Japanese government has gone to great lengths to hide this information. I'm no expert by any means but I try my best to understand what actually happen and it just seems extremely odd to not have any recent information being released what so ever.
Close the block valve???
Oh wait, Chernobyl.
I’d like an episode discussing the Thorium cycle.
yes, fuel cycles will be fun
I'd like to see your reaction Red Alert (1977), could be fun and will be completely inaccurate haha
thanks! added to the list. I need to do more silly movies haha
The hydrogen creation at Chernobyl and Fukushima.
Is the process chemical or nuclear?
It seems to be chemical,
Zircalloy + water + heat
=> Zirc Oxide + Hydrogen
But there's still a load of low level neutron flux in the area I guess, can any of that hydrogen come out as Deuterium or Tritium?
Burning that in oxygen would create heavy water, are any of those free isotope gasses or heavy water created dangerous?
The sea is full of heavy water and uranium anyway, always has been so I'm guessing it's not dangerous.
What are the half lives anyway?
I know Tritium is short, hence the Lithium Deuteride.
You'd think a flair system would be included, like in an oil rig.
In an emergency, you flare off the hydrogen as it gets created.
Hell, even get a drainage system to route it back into where it came from in the spent pool or into the reactor core!
Can a Nuclear Fission EXPLOSION happen in nature? I understand that they have now found that fission happens naturally in the earth but what about a naturally occurring fission explosion?
Good question. No, not on earth at least. I don't want to misspeak for some hypothetical condition somewhere in the far reaches of the universe. Nuclear fission explosions are very hard to do, not that fusion explosions aren't hard either but they happen all the time in stars (I'm assuming you knew that and that's why you quantified a fission explosion). A nuclear fission bomb needs a bunch of different things to happen at once: highly enriched uranium or weapons grade plutonium (both of which take a lot of money and technical prowess to acquire) has to be exploded in such a precise way so as to allow an amazingly powerful chain reaction to happen in the order of microseconds.
So called natural reactors happened in the past on Earth but the abundance of fissile U-235 in natural uranium is too low now for them to happen in present day (U-235 has a shorter half life than U-238, which is the isotope of the vast remainder of uranium). Accidental chain reactions caused by humans, however, are a serious concern and must be actively worked against, which is part of my job - preventing criticality accidents. But these do not get anywhere near approaching bomb levels of energy. So what is theorized to have happened at Chernobyl is a criticality accident.
Has part 5 been deleted?
no, it's still public
@@TheAtomicAgeCM I can't find it on your channel, there's Chernobyl Episode 1-4, then "Ask your Chernobyl Part 5 Questions", and then "Chernobyl Part 5 Comments Review", other than that there's no other Chernobyl related content...
@@H3LLGHA5T here you go! ua-cam.com/video/tsB0FJYekmM/v-deo.html
@@TheAtomicAgeCM thank you for the link! For some reason I can't view the video on desktop, but it works on mobile.
Not going to lie, I wish you mentioned the fact the "caps" didn't jump up and down, I've done my research on this and everyone I know agrees that it wasn't possible for them to jump, at least not in the way it was portrayed, at most the "caps" would've been shaking and potentially risen, but they wouldn't of been jumping.
probably done for dramatic effect then. to the viewer, the caps jumping up communicates immediately that something is wrong, whereas just rattling or rising could be confusing to the average viewer as to what's happening.
@@TheAtomicAgeCM I understand dramatisation, however I think it would of worked if instead of them jumping, a lot of steam was released from between the so called caps, and then they began pushing upwards, not jumping but the being pushed up as a whole. I think that there would signal something is wrong in the same way.
@@TheAtomicAgeCM and the main reason I brought it up is that it’s becoming an actual misconception in several people, for instance ask like 10 people what they think happened leading up to the explosion, 9 out of 10 will probably say the rods jumped. I know it’s not exactly a harmful misconception, however it kinda annoys me for some reason.
I think his use of the phrase denoting it’s a bomb is likely targeting Soviet complacency and suppression of knowledge of the design flaws, less so than technically identifying what was happening in the reactor. Perhaps the “outlandish” claim he makes is actually MORE credible because of his past work and reliability. For a man of pure logic and science to say something of this nature goes to show that it had clearly rattled his soul. He goes on very shortly to directly challenge the Soviet leadership, this line may have been his attempt to grab their utmost attention. Food for thought. I know it’s sensational writing but still. Anyways, great video!
You should really go check out a channel called The Chernobyl Guy, it has a lot of fact filled information.
Maybe you have covered this but isn’t this series a historical representation? If that’s what the real Legasov is quoted to have said, the producers/writers are more accurate.
Hello there
Can this guy watch Farman and little boy and talk and react to the demon core incident lol…I mean talk about crazy when a dude handles a core with a screwdriver lol
If you can hear it from 20 miles away it is a bomb
Many explosions aren't bombs.
Whale song can be heard more than 20 miles away
Your bone picking about "Nuclear bomb" as a phrase in the movie is poorly chosen on your part. 1. All of this happened in the Soviet Union (more than likely before you were even born) and it was a very different time, and a very different culture involved. Legasov was speaking to some seriously dumb politicians and generals of the USSR and he used language to get his point across to those less intelligent people, the movie more than likely got this right . ALSO many people with more experience than you have argued it was a nuclear "Fizzle" which would classify as a small or failed nuclear detonation. In the end Chernobyl was a pretty large dirty bomb, considering how much of Europe saw fallout and contamination.
care to give a reference?
React to Homer Simpsons/Simpsons