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Media Center>Chernobyl
neech 10:53 PM 07-01-2019
Originally Posted by Frazod:
Yep. It's pretty much all downhill from there.

Ease into it slowly by watching The Pacific and John Adams.
Have you read the book With the Old Breed by Eugene Sledge? That's the best soldier book of WW2 hands down. It took me a long time to read a book in the pacific theater mainly because it was just island hopping where Europe is much more interesting.

Anyway the book contains a lot of what went on in the series Pacific.
[Reply]
Frazod 08:29 AM 07-02-2019
Originally Posted by neech:
Have you read the book With the Old Breed by Eugene Sledge? That's the best soldier book of WW2 hands down. It took me a long time to read a book in the pacific theater mainly because it was just island hopping where Europe is much more interesting.

Anyway the book contains a lot of what went on in the series Pacific.
Yes, I have. Outstanding book. Reads like he's just sitting there talking to you. It's a real gut punch. I also read Leckie's book, and while I enjoyed it, Leckie's slick, polished style kind of gets in the way of the story.
[Reply]
Stryker 07:24 PM 06-30-2019
Originally Posted by Why Not?:
You’re not going to have a whole lot of other weekends, TV wise, that can compare with that one
TV wise, is Jack Ryan on Amazon Prime season 1
[Reply]
Stryker 07:40 PM 06-30-2019
Back to the OP. In the end, the cards were stacked against Valery, he became a martyr with the tape recordings for his colleagues and it took his deliberate hanging to get action and "the truth" out to provoke action. Damn good series and so glad I watched. Really incredible series!
[Reply]
DJ's left nut 10:48 AM 07-01-2019
I am reading Midnight in Chernobyl (sadly, I'm only about halfway through and it's an E-book so I'm about to lose it and end up back on a 2 month wait list; stupid auto-checkout, had no idea I even had it for about 10 of my 21 days).

It's incredible. The insight into the mechanics of went went wrong, especially when combined with how they did it visually in the show, is really fantastic. I finally understand exactly how the positive void coefficient works due to their use of graphite as a moderator instead of water or heavy water. The fast-reactor dynamic is also very good information to have (and frankly, from a pure policy perspective, I'm surprised we haven't made more of those to burn off 'exhausted' nuclear fuel in a cleaner manner).

The way the RBMK reactor works and it's scale is easier to understand now as well. The way the fuel channels essentially superheated and burst, releasing heat into the coolant which flash vaporized, etc... is all extremely useful as well.

And I FINALLY understand why they used graphite on the tips of those boron control rods. All I've ever read/heard is 'because it's cheaper' and I've always wondered if they were really doing this to save a few thousand bucks in boron. That's not actually why they did it.

So boron is a neutron absorber (slow neutrons are what create the fission reactions) and by inserting the boron control rods, you absorb those neutrons rather than allow them to continue and collide with other neutrons to create energy. The more of the rod you insert, the more neutrons you absorb and the more the reaction slows. Absorb them all through a SCRAM and the reaction just stops. Make sense? Well the Russians wanted their reactors to be as fuel efficient as possible so they wanted as many of those slow neutrons to impact other neutrons as possible. So obviously you don't want neutron absorbing material in the fuel chambers when you're just trying to run it open, right?

Well the control rods NEVER truly come out of the fuel chamber. They're always at least partially in because if you need to bring them down, you don't want there to be some scenario where one of them misaligns and jams the mechanism. You see where I'm going with this?

If the entire control rod is made of boron, you're going to have a section of boron in the fuel chamber at all times, even if the rods are retracted. And in so doing, those small sections of Boron are going to absorb neutrons and make the reactor marginally less efficient.

By having graphite tips on the ends of the rods for as far as they needed to be inserted to ensure that they're in the channels at all times, you have a moderating material in the fuel channels instead of a neutron absorber and so you get as many 'fissions' as possible. Makes the reactor just an Nth more fuel efficient. And also makes it 'splodey (a fact they already knew, just didn't tell anyone about).

And the positive void coefficient thing is fascinating as well. Getting back to the 'slow neutrons' thing - most neutrons spun off are high speed, they move too fast to reliably create any other fission event - they just fly out into the ether and don't collide with anything. So inside the reaction chambers you have to have a 'moderator' to capture those neutrons and release them more slowly (or just generally slow them down). This creates far more fission events and far more energy. It's something like 10-1 in a conventional reactor, IMO.

Well most western reactors use water as their moderator (regular or heavy). It's a good material for it. They also use water as a coolant. And lets say you have a situation where you lose your coolant - PANIC!!!! Right? Wrong, by losing your coolant, you've also lost your moderator. And with no moderator in place, your neutrons become more and more fast neutrons that are largely useless. As the coolant drops, so does reactivity. Also the case as the coolant converts to steam - the steam is much less efficient to cool, but also to moderate. So in steam voids (in the rare instance they even exist in western reactors) slow down the reaction.

But in a graphite moderated, water cooled reactor, you have the opposite problem for obvious reasons. If you lose coolant or create steam, then you create more heat and more energy. The moderators, meanwhile, are still there because it's just graphite and the graphite isn't impacted by the loss of coolant. So the graphite continues to create very 'fissionable' slow neutrons even in the absence of water or in the presence of these large steam pockets. The steam now does NOTHING to absorb neutrons (water will absorb a little, steam absorbs essentially none) and so you end up with a runaway reaction.

So the idea of positive void coefficient makes intuitive sense but it's nowhere near as cool as the concept of negative void coefficient that comes about as a result of having your coolant AND your moderator be the same substance. It's just fascinating as hell to me.
[Reply]
O.city 09:04 AM 07-02-2019
Originally Posted by DJ's left nut:
I am reading Midnight in Chernobyl (sadly, I'm only about halfway through and it's an E-book so I'm about to lose it and end up back on a 2 month wait list; stupid auto-checkout, had no idea I even had it for about 10 of my 21 days).

It's incredible. The insight into the mechanics of went went wrong, especially when combined with how they did it visually in the show, is really fantastic. I finally understand exactly how the positive void coefficient works due to their use of graphite as a moderator instead of water or heavy water. The fast-reactor dynamic is also very good information to have (and frankly, from a pure policy perspective, I'm surprised we haven't made more of those to burn off 'exhausted' nuclear fuel in a cleaner manner).

The way the RBMK reactor works and it's scale is easier to understand now as well. The way the fuel channels essentially superheated and burst, releasing heat into the coolant which flash vaporized, etc... is all extremely useful as well.

And I FINALLY understand why they used graphite on the tips of those boron control rods. All I've ever read/heard is 'because it's cheaper' and I've always wondered if they were really doing this to save a few thousand bucks in boron. That's not actually why they did it.

So boron is a neutron absorber (slow neutrons are what create the fission reactions) and by inserting the boron control rods, you absorb those neutrons rather than allow them to continue and collide with other neutrons to create energy. The more of the rod you insert, the more neutrons you absorb and the more the reaction slows. Absorb them all through a SCRAM and the reaction just stops. Make sense? Well the Russians wanted their reactors to be as fuel efficient as possible so they wanted as many of those slow neutrons to impact other neutrons as possible. So obviously you don't want neutron absorbing material in the fuel chambers when you're just trying to run it open, right?

Well the control rods NEVER truly come out of the fuel chamber. They're always at least partially in because if you need to bring them down, you don't want there to be some scenario where one of them misaligns and jams the mechanism. You see where I'm going with this?

If the entire control rod is made of boron, you're going to have a section of boron in the fuel chamber at all times, even if the rods are retracted. And in so doing, those small sections of Boron are going to absorb neutrons and make the reactor marginally less efficient.

By having graphite tips on the ends of the rods for as far as they needed to be inserted to ensure that they're in the channels at all times, you have a moderating material in the fuel channels instead of a neutron absorber and so you get as many 'fissions' as possible. Makes the reactor just an Nth more fuel efficient. And also makes it 'splodey (a fact they already knew, just didn't tell anyone about).

And the positive void coefficient thing is fascinating as well. Getting back to the 'slow neutrons' thing - most neutrons spun off are high speed, they move too fast to reliably create any other fission event - they just fly out into the ether and don't collide with anything. So inside the reaction chambers you have to have a 'moderator' to capture those neutrons and release them more slowly (or just generally slow them down). This creates far more fission events and far more energy. It's something like 10-1 in a conventional reactor, IMO.

Well most western reactors use water as their moderator (regular or heavy). It's a good material for it. They also use water as a coolant. And lets say you have a situation where you lose your coolant - PANIC!!!! Right? Wrong, by losing your coolant, you've also lost your moderator. And with no moderator in place, your neutrons become more and more fast neutrons that are largely useless. As the coolant drops, so does reactivity. Also the case as the coolant converts to steam - the steam is much less efficient to cool, but also to moderate. So in steam voids (in the rare instance they even exist in western reactors) slow down the reaction.

But in a graphite moderated, water cooled reactor, you have the opposite problem for obvious reasons. If you lose coolant or create steam, then you create more heat and more energy. The moderators, meanwhile, are still there because it's just graphite and the graphite isn't impacted by the loss of coolant. So the graphite continues to create very 'fissionable' slow neutrons even in the absence of water or in the presence of these large steam pockets. The steam now does NOTHING to absorb neutrons (water will absorb a little, steam absorbs essentially none) and so you end up with a runaway reaction.

So the idea of positive void coefficient makes intuitive sense but it's nowhere near as cool as the concept of negative void coefficient that comes about as a result of having your coolant AND your moderator be the same substance. It's just fascinating as hell to me.
I tried to focus and read this thing. I really did.

I think I'm just too scarred from all the undergrad chemistry and physics to do it.
[Reply]
bowener 07:32 AM 07-05-2019
Originally Posted by DJ's left nut:
I am reading Midnight in Chernobyl (sadly, I'm only about halfway through and it's an E-book so I'm about to lose it and end up back on a 2 month wait list; stupid auto-checkout, had no idea I even had it for about 10 of my 21 days).
Disconnect your e-reader from the internet until you've finished reading the book. It won't be removed if you do that.

You can also use sites like this one: https://ebook2pdf.com/

Or just open the file on your PC, then tell it to print as PDF.
[Reply]
DJ's left nut 09:08 AM 07-08-2019
Originally Posted by bowener:
Disconnect your e-reader from the internet until you've finished reading the book. It won't be removed if you do that.

You can also use sites like this one: https://ebook2pdf.com/

Or just open the file on your PC, then tell it to print as PDF.
I'll have to give those a shot.

The problem is that mine's all downloaded to my phone so I can't really disconnect it from the internet. I don't use an E-Reader. And I don't think I can get the file to my PC, but maybe there's a way to do that through just plugging it in and rooting around my phone downloads. I'm not sure if Overdrive will convert the format and print it still, but maybe it would.

The ebook2pdf seems promising though, I'll have to give it a shot. Thankya sir.
[Reply]
'Hamas' Jenkins 12:50 PM 07-03-2019
There are other ways to boost output beyond keeping your control rods to a minimum, or having the rods tipped with graphite. You can also use a neutron reflector, like beryllium, to substantially increase power.
[Reply]
Baby Lee 07:43 AM 07-04-2019
This week's Harmontown was off to a hilarious start.

ignore if you have no interest in Harmon-alia

Spoiler!

[Reply]
'Hamas' Jenkins 09:20 AM 07-09-2019
There are numerous aggregate sites that store thousands of ebooks. You can download the file and either strip the DRM or convert it to a PDF using a program like Calibre.
[Reply]
DeepPurple 07-09-2019, 09:41 AM
This message has been deleted by DeepPurple.
BigRedChief 10:41 PM 08-07-2019
Lots of Emmy nominations
Skasguard
Harris
Director
Series etc.
[Reply]
Buehler445 10:42 PM 08-07-2019
Originally Posted by BigRedChief:
Lots of Emmy nominations
Skasguard
Harris
Director
Series etc.
Deservedly so.
[Reply]
Demonpenz 09:35 AM 08-08-2019
I saw at Hollywood Casino yesterday they got the new Cherobyl progressive slot. I got two bonus rounds. The first I made 10 dollars not great not terrible but the second I got 3 smoke stacks to release an explosion and a chance at the increasing jackpot. I ran into the KGB though and only won 25 dollars.
[Reply]
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