... when it comes to writing, especially since I haven't produced anything in a while for the current projects, but a new idea has been insisting on elbowing its way to the front of my consciousness.  And I'm posting about it here because it's COH-related:

Evangelia, immediately post-2012-shutdown, wakes up in Aincrad from Sword Art Online.

No solid plot yet, but some interesting ontological issues to explore, particularly with her as a player character with no player behind her... and of course all her incarnate abilities come along...

What's bothering me is that I really want to finish up the current chapters of DW8 and DW-S first, but this is building the kind of inertia in my mind that DW-S did when it first demanded that I start writing it some years back.

So, recently I've been reading Lazy Dungeon Master as translated by "Ziru's musings," and it's fairly decent... well, at least once you get about a dozen chapters in. The MC is a much bigger asshole at the beginning, and collaborates with a bandit gang who are in no way Robin Hood like "outlaws with a heart of gold."

They bring prisoners in to be murdered because it makes the dungeon grow, and in 10 maybe the chief buys a dog-girl "whose age is not even double digits" as a sex slave and is non-explicitly described making use of her... until getting horribly slaughtered by some knights from the capital, while the girl hides and is later rescued from the fire they set to dispose of the bandits' remains by MC convincing himself she's an object so the dungeon can absorb her. Yeeeaaah. If you think that'll be a show-stopper for you, skip the chapter(s?) from the bandit chief's viewpoint, because while it's still not explicit and I don't remember anything that would trip a word filter it's distinctly unpleasant even so. He dies far too kindly, is all I will say about that.

It takes all of two paragraphs once she's been rescued to snap out of that bit of self-hypnosis, though, and while I still feel she springs back unrealistically fast to become a non-sexualized little sister figure the rest has been largely clear of that particular flavor of squickiness. Asked what he thinks of young girls while under the effect of a truth-detecting magic, MC answers, "Eh? They're cute I guess..." and restates his internal narration of tastes reserved for well grown legs and feet, directly shutting down a few shows of affection from the girl that could be taken in questionable ways on other occasions.

Slavery as such is still a thing though, enforced by magical contract and unremoveable collars, and the MC takes advantage of the security of the contract to make sure she and the second "employee" he acquires will keep his secrets, even if they are also treated as well as a normal standard fantasy setting issekai party member otherwise.

Honestly, the only way it really stands out in its genre is that the MC mostly gets over being an asshole so quickly even if the only thing he wants to do most of the time is sleep, but if you enjoy the genre it's a solid example, and the food porn once the group gets an inn going in the area above their dungeon can lead to some tasty sounding recipes if you search for the dishes.I've only gotten into the low 40s out of... er... not quite 400 I think? current chapters, but the tone has kept quite constant since getting rid of the bandits.

Note that the site as a whole is NOT work safe - some of the other translation projects are R18, and their titles at least are directly on the page below as links to other TOC pages and also recently posted chapters.

https://zirusmusings.com/ldm-toc/

So, the Alberta (Conservative) Government has decided it doesn't want to have to explain about public schools and funding, so it has changed the name of every public school and public school board to eliminate the word public. They even managed to do it without using the word public.

Hard to have a difference between public and private if you can't name it after all.

https://albertapolitics.ca/2019/09/alber...cI56K_e3o4

Hey, guys. I ran into a common bug in the Sutter TF last night that ended up causing the PUG I was in to hang around for 30 minutes, waiting for a GM, and then to restart a mission, before figuring out the workaround. This added about an hour to the TF, so I thought I'd share.

After Part 2, "Defend Paragon City," which takes you into the sewers to fight Riptide and Harbinger, you should exit the mission into the Skyway City sewers. An exit will take you to Part 3, "Defend Skyway City," which is the final confrontation with Fusion and Temblor, and then the Durays. Upon clicking on the mission entrance, you may get the message that you have to complete your current mission to enter the next mission, even though you have already gotten the message that Part 2 has been finished. The GM that finallly got back to us reported that this is a common bug. The workaround is to have the entire team log out of CoX, wait one minute, then log back in. You should then be able to progress on to Part 3.

Hope that helps.

So, a couple of weeks back I found this channel on YouTube where the guy does a possible build of a fictional character for a D&D game. Today it was Usagi’s turn:


Enjoy.

Okay, bit of background info here, so just bear with me.

My sweet little laptop, a 15" HP Envy x360, is not without its deficiencies.  It had a mere 250GB SSD - which is pretty pathetic these days if we're being brutally honest.  And it only has 8GB of DDR2400 RAM.

However, it's not like this can't be fixed.

The RAM only occupies one of the two slots on the mainboard.  And the mainboard, interestingly enough, has provisions for both an M.2 SSD (those are the funky little PCIe SSD sticks), as well as a SATA drive.

I was able to score the laptop in the first place because I purchased it on a leasing program.  Recently, that lease has been paid off and now I can go ahead and take out another lease.

My goal?  Upgrades, and a dash cam setup for my Jetta.  And an iPad.  I have dearly missed the one I used to have, and the price point isn't all that bad if you're getting the ones that don't have cellular service.  (I'm perfectly happy with tethering my iPad to my iPhone for Internet on the go.)

So, to resolve the storage issue, I got two SSDs: a 1TB Samsung 970 EVO Plus M.2 SSD, and a 2TB Samsung 860 QVO SATA SSD.

Yeah, one of my online friends went "GOOD LORD!" at that.  What can I say?  I hate having insufficient storage.  The real drive hogs is the anime.  Most of what I watch I tend to get on Crunchyroll, but for the few they don't have, I still torrent that stuff.  And let me tell you, fansub groups don't like to skimp on the quality - they see themselves (perhaps even rightfully so) as providing a product that is superior to any offerings by American distributors.

It is rare for me to find a 720p DVD rip for new anime these days.

So yeah.  1TB for the OS, applications, and other sundries.  And a 2TB for all my media.  I should be good to go for a while here, though I still have an eye towards building my own little workstation, because I will be tailoring my education with an emphasis on designing mechanical systems.

SO....  Now to the fun part.

I'd been eagerly anticipating this upgrade, and I had an added advantage in that HP is good enough to make the service technician's guide free to download form their site.  This way there was little chance of me screwing something up because I missed it.

There were a few unexpected surprises, such as the metal housing that covers the RAM and the M.2 SSD.  It really threw me because there was no mention of it at all in the manual.  Eventually, I figured out that it was just held on by some clips soldered to the main board.  Some careful work using a prying tool for servicing smart phones got it off nice and neatly.

But the biggest issue....

The SATA cable for the SATA drive was missing.  Or rather, it wasn't included because why would you?  The port is there on the main board, so I just had to find the cable online (unfortunately, HP had already discontinued my laptop and, as such, no longer made spare parts for it) and order it up through eBay.

But it left me with an issue.

For whatever reason, the only place in town that sells an external USB enclosure for M.2 SSDs was Altex.  Nobody else.  And unfortunately, they were closed because of Labor Day weekend.  Argh.

When I came up short on the enclosure, I figured in that case I could just use the SATA drive - clone the current 250GB SSD into the SATA without changing the partition sizes, and then once the drives were installed in my laptop, clone it from the SATA drive into the M.2 SSD.

But the absence of the internal SATA cable complicated things.

In order to get this done, I would have to start out as I would have before, cloning the old drive to the SATA drive, and then boot up from the SATA while it was connected through the USB port.

This should work, right?  Especially since I'm cloning to partition, right?

Wrong.

UEFI and Secure Boot fucked me over.

See, UEFI is what they've replaced BIOS with.  It has a lot of nice features for things that BIOS wouldn't support without a whole lot of ugly kludging.  But what manufactures love the most is Secure Boot.  I forget exactly how it works - something about a security hash shared between the OS and UEFI to ensure no one tampers with the precious machine.

Basically, it makes it virtually impossible to boot from USB or anything other than a hard drive mounted directly into your computer.

What follows is the process I had to come up with in order to finally get my drive properly migrated into the new M.2 SSD.  Keep in mind, this was a VERY iterative process (EDIT: At least, it was after Step 8), where each step below was only figured out after a couple of hours of research and trial and error.  Wash, rinse, and repeat ad nauseum.

1. Use cloning software the USB 3.0-to-SATA cable you bought came with to clone the contents of the currently residing SSD into the SATA SSD.
   
2. Completely power down your laptop.
   
3. Open up your laptop
   
4. Remove the battery which is secured with six tiny little screws
   
5. Carefully pry off the protective cover over the RAM and M.2 SSD
   
6. Swap the old M.2 SSD for the new one
   
7. Put everything else back the way it was
   
8. Boot up machine
   
9. Wait for error message to show up with the options to go to recovery tools, special boot options (safe mode, etc.), or the UEFI settings.  Since it's being a poison fucking pill about it, it's not letting you into Recovery Options or Special Boot Options.
   
10. Go into UEFI settings and disable Secure Boot and enable Legacy Boot
    
11. Save and Reboot
    
12. Wait for error message to show up again
    
13. This time, you can now enter special boot options
    
14. Choose safe mode - safe mode with networking is fucking useless because Windows doesn't like to use WiFi in any sort of safe mode.
    
    Now that you're in the OS, you can actually do THINGS.  Except...  the cloning software you used the first go around doesn't work in safe mode.
    
    
15. Fight the urge to start breaking shit because now you have to open the laptop again and put the 250GB M.2 SSD back in because you need to download cloning software that WILL work in safe mode.
    
16. Clone the drive to the SATA drive again, and then repeat steps 2 through 14.
    
17. After several false starts, one OH SHIT moment, and two errors that necessitated reboots, FINALLY get the contents of the original drive cloned onto the new M.2 drive.
    
18. Cross your fingers and reboot.
    

With a few days to mull over the whole thing, I'm rather concerned that being associated with Trump will poison the idea of space exploration in general for a while, especially with the always-present struggle between things that will get votes now and things that will pay off more than an election or two in the future and with the lion's share of the funding being redirected from "organizations already conducting space operations," which I expect can pretty much be read as "those pinko hippies at NASA who keep contradicting the party line."

https://www.nytimes.com/2019/08/29/us/po...force.html
https://www.politico.com/story/2019/08/2...nd-1693825
https://www.npr.org/2019/08/29/755383671...osed-space-
https://www.npr.org/2019/08/11/743612373...-to-launch

Also, aren't there supposed to be treaties preventing the militarization of space? Not that I ever expected them to last or that Trump has shown any hesitation about ignoring inconvenient treaties, but still. I'd like to be able to tell myself that America is still the good guys without having a laugh-or-cry moment.

Also, on the gripping hand, when the US can put a man into space again without begging a seat on a rocket launched from Russia or China or buying a ticket from Virgin Galactic, maybe that's the time to talk about having a new arm of the military to protect US interests against Russia and China? Just sayin.'

AP: A Catholic school in Tennessee has removed the Harry Potter books from its library after the school's priest decided they could cause a reader to conjure evil spirits.

Quote:In an email obtained by The Tennessean, the Rev. Dan Reehil of Nashville's St. Edward Catholic School said he consulted exorcists in the U.S. and Rome who recommended removing the books.

Reehil wrote, "The curses and spells used in the books are actual curses and spells; which when read by a human being risk conjuring evil spirits into the presence of the person reading the text."

Or the weird things that you come across when doing your research for a fic exactly thirty people have read.

----Pt 1---------

Everybody knows about Chernobyl. Everybody knows either one of two things. The accident was caused by gross incompetence. Or the accident was caused by a gross design error. Or the accident was caused by both. Yes, that's three things - but this isn't the Spanish Inquisition.

Anyway, to figure out why an RBMK reactor can explode, first we have to understand how a nuclear fission reactor works in the first place. It's not actually that complicated. A uranium atom splits - small particles called neutrons fly out from the atomic shrapnel and they each find another uranium atom, collide with it and break it apart too, letting more neutrons find more Uranium atoms in a chain reaction. And out of each split we get energy - once split, the fragments snap apart as the energy holding them together is released - like cutting an elastic band. These fragments explode away, run into the atoms next to them at high speed and all that speed is turned into heat. Heat is used to boil water. This steam turns a turbine. This turbine turns an electric generator and, eventually you get electric power out of it.

Now, it's not quite that simple. Because big, heavy atoms like Uranium come in multiple different versions - called Isotopes - sort of like different models of the same car. They're all Uranium, but they're all slightly different at the same time. The most well known, are Uranium 235, and Uranium 238. U238 is by far and way the most common - on the order of 99% or more of Uranium on Earth is U238. It's a big, heavy fat atom that doesn't really like to split - it takes more energy to break it apart than it gives up when it breaks. On the other hand, U235 is much happier to break apart - unfortunately, it's about as rare as common sense. So, out of a large block of Uranium, only a small amount can actually split. Only the U-235 is actually fissile.

Out of the ground, less than 1% of your Uranium fuel is actually fuel.

More than that, in order to have a chain reaction, the neutrons released by one atom splitting have to be able to cause further atoms to split. Otherwise everything just runs down. It turns out, that the neutrons released by fission are extremely fast - too fast in fact to actually find their way to the next atom and split it. For a fast neutron, the probability that it will cause another fission is really low. Either you need a lot more U-235 around it to get the probability up, or you need to find someway of slowing it down. If you slow it down - the probability of fission goes way up. This is called a Moderator. 

For most reactors, this moderator is water. Ordinary - albeit extremely pure - water. Water is a good moderator, but it has one slight drawback - it absorbs neutrons. Absorbed neutrons do not get to go and make another fission happen - they just turn the water radioactive. Using water to moderate a reactor absorbs so many neutrons, that the quantity of U235 in the reactor fuel has to be increased. This process is called enrichment. It's expensive and energy intensive - and it turns out if you enrich Uranium to about 80% U235 it can be used to make an atomic bomb.

Which, naturally, is why Isreal got so pissy about Iran having the ability to enrich Uranium. The difference between safe reactor fuel and weapons-grade bomb fuel, is time in the centrifugal oven to bake.

Now, doesn't it seem eminently sensible to find a way to build a reactor that will be happy on regular, non-enriched Uranium?

Canada did it with the CANDU reactor. Instead of regular water, a CANDU reactor uses 'heavy' water. 'Heavy' water is like ordinary 'Light' water, except the Hydrogen atom that's the H in H2O is a little different. It has one neutron and one proton, rather than just a single proton. It absorbs less neutrons, which means more neutrons are free to cause more fission. In fact, Heavy Water is so effective that CANDU reactor doesn't need enriched fuel. The Nazis appearred to have tried a similar appoach, and the destruction of their Norwegian Heavy Water factories stalled their weapons program.  On the other hand, heavy water - while common - is still fairly expensive.

What if you could build a reactor that ran on natural uranium, that didn't need heavy water?

The first Hanford Reactors, built in the United States for the Manhattan project used Graphite - pencil 'lead' - as a moderator. They also used regular, light water as a coolant to keep the reactor from melting down with its own heat. This hot water was dumped merrily into the local river. Of course, somebody had worked out that if the reactor lost cooling water, it would very quickly begin to run out of control so the Hanford reactors were built miles from anywhere inhabited. They never generated a watt of electricity-  but they did create the Plutonium for your nuclear weapons.

The British Government, aware of this risk, built the Windscale Piles to be Air cooled - with giant fans blowing air over hot graphite and metal. These then went and caught fire. In the end, the solution was to use graphite and an inert gas, like carbon dioxide, to cool the core.

This was still extremely expensive.

So, the Soviet Union looked at this and though; We can build a graphite moderated reactor, cool it with regular light water and so long as we don't fuck up, we'll have a shitton of free energy.

We know the result already. But that's being a little bit churlish. These people weren't fools.

This why an RBMK reactor is different to every other reactor built anywhere else in the world. The majority of modern nuclear reactors are basically big pressurised kettles, filled mostly with pressurised water. This water either boils in the kettle-  or it is under such a high pressure that it remains liquid and is used to boil water in a second circuit. In an RBMK reactor, the fuel is contained in more than 1600 vertical channels cut through the graphite moderator. Inside these channels, light water flows as coolant. It enters a pair of drums high above the reactor where any steam bubbles in the water seperate and are drawn off to the turbine to generate power - while the liquid water is recirculated, being mixed with cooler water coming back from the turbine. Interspersed within these channels are more than 200 others - each contaning a control rod. These control rods are also cooled by liquid water - but at a much lower temperature.

The main steam circuit on an RBMK reactor operates at somewhere around 270 degrees and 60-odd Bar of pressure. The control rod circuit operated at 70 degrees.

The light water in the channels still absorbs neutrons sure - but because there's so much less of it, the reactor will still run on natural unenriched Uranium. It also means that, since each fuel assembly has its own individual channel, it can be removed, moved and replaced without shutting down the reactor. This is a feature few other reactors have - most reguire a shutdown to open the reactor vessels to refuel. This is goof for fuel economy, good for efficiency, and good for creating weapons grade plutonium on the sly if you were that way inclined.

The people who designed the Chernobyl reactor weren't fools. There were compelling reasons for making the decisions they did. It made a big, powerful reactor cheap and easy to build, while improving the reactor's fuel economy and general uptime. And you could potentially fuel a weapons program with it.

The one clear drawback with this should be obvious. When the cooling water boils, its replaced by a bubble of steam. This steam absorbs far fewer neutrons than liquid water - meaning more neutrons availably for fission, which means more fission, more heat, more steam, more neutrons, more fission.

This is called a Positive Void Coeeficient. It is an example of positive feedback - an action creates a stronger action in the same direction - like setting a ball rolling at the top of a hill, it's only going to start rolling faster as it gets further down. Engineers love positive feedback. It usually results in entertaining explosions.

This is potentially problem for an RBMK reactor specifically because the water does not act as a moderator - more correctly, it provides little to no moderation. On a conventional reactor, the water also provides moderation - so if it is boiled away by heat, the moderation in the reactor reduces, neutrons get faster, the probability of fissions gets lower, less fission happens and the problem self-corrects. On an RBMK reactor - even if all the water in the core somehow is removed, the moderator is still present in the form of the graphite to keep the reactor going.

It would be dangerous to have a reactor which behaved like this. The engineers who designed Chernobyl were, of course, aware of this. But real physics is not that simple. As the fuel heats up and gets more energetic, it responds to neutrons differently. The hotter it gets, the harder it is for a neutron to cause a fission. Hotter fuel is less likely to fission - so an increase in power will actually reduce the ability of the fuel to fission and create power - in effect an automatic brake provided free by simple physics. This is called Negative feedback, and is basically the same as you feeling a tug in the steering wheel of your car, and steering the other direction to compensate.

Positive feedback acts to destabilise. Negative feedback acts to stabilise.

But - if the negative feedback from the fuel heating is stronger than the positive feedback from the steam boiling, the reactor's power level will self stabilise and everything will be fine.

For a large part of the reactor's life this was true. But this changed as the reactor got older, and more and more fuel was used up. the negative reactivity from the fuel heating up, no longer counterbalanced the positive reactivity from the steam boiling.

This balance changed with old fuel. Where a reactor had been running for several years- the fuel gets more and more depleted. In addition, more and more poisons are added, each of which absorbs neutrons differently or introduces additional hazards into the reactor. The reactor in Chernobyl had been running for about three years. After this time, changes in the fuel meant that the negative feedback from the fuel heating was no longer enough to counterbalance the effect of the void coefficient. The reactor operated in a positive feedback loop.

An increase in power, left unchecked would create a further increase in power. Only the reactors control rods kept the reactor under control, The majority of these control rods inserted from the top of the reactor. Some inserted from the bottom. They served to absorb any excess neutrons in the core and act as the final brake on the reactor to keep it in control, to keep the reactor critical.

Fission reactors are at their happiest when they're critical. A critical reactor is a reactor running in a balanced steady state at a constant power. It's the desired state of being. Every fission is creating one further fission and that's it. A reactor that is supercritical, is a reactor that's accelerating - each fission creates more than one further fission. A reactor that is subcritical, is a reactor that's decelerating - each fission creates less than one further fission.

The reactor is moved from state to state by adding or removing reactivity. Reactivity is like the throttle and brake on the reactor. It's not really the current power level - it's sort of the potential change in power level. Positive reactivty means fission is more likely to happen than it is now - which will cause an increase in power. Negative reactivity, means making fission less likely to happen - which will cause a decrease in power.

In theory, there is no limit to the amount of negative reactivity you can add - all it does is stop the reactor faster. But there is a limit to the positive reactivity.

When an atom fissions, the vast majority of neutrons are released instantaneously - at the moment of fission. The neutrons fly away, get themselves moderated, and in the space of microseconds find more atoms to collide with and split. The scientists of the Manhattan project called this a 'Shake' and it is an extremely short interval of time - from nanoseconds to microseconds. These are called Prompt neutrons.

Fission with prompt neutrons happens so quickly, that there is little to no mechanical process capable of controlling and regulating it. If the universe had been created in such a way that there were only prompt neutrons - controllable fission power would likely be impossible.

But, luckily, a very small fraction of the neutrons released by a fission event are delayed - they happens seconds, to minutes later. It is this small fraction of delayed neutrons which enables every nuclear fission reactor to be controlled. It is possible therefore, to have a reactor which is critical on the combination of the Prompt, and the Delayed neutrons. In fact, this is how things normally are. Even a supercritical reactor, will take seconds to minutes, to change power output. There's time there for the process machinery of the reactor to respond to changes and stabilise.

But, if the reactor is pushed to the point that it is capable of achieving criticality on the Prompt neutrons alone - before any of delayed neutrons are emitted - then things get interesting. Instead of a power increase that happens on the order of seconds to minutes - now the only limiting factor the the reactor's power increase is the time it takes for a neutron to find an atom to fission, and however long the reactor manages to stay together in a critical assembly against the energies that are being very rapidly liberated. A reactor which has going prompt critical, has become, in effect, a really, really shit nuclear bomb. The big difference being that bombs take advantage of physics, inertia and a dozen other things to keep the reaction going that few nanoseconds longer it takes to go from 5 tons of TNT, to 15 Kilotons of TNT.

Scientists at the Manhattan project, for whatever reason, called this interval a 'Dollar' of reactivity. Once you get a reactor past that point - unless it's a type specifically designed to go there and self recover - the reactor will be destroyed. Importantly, this does not have to happen within the entire reactor - it can be limited to a very small part of the core where conditions align like the stars.

At the Chernobyl reactor, Reactivity was added by fresh fuel, by removing control rods and by boiling water to make steam. Reactivity was removed by increasing water flow, adding control rods, and by another factor.

The shrapnel left over from fission creates what's known as 'fission products'. Most of these are hideously radioactive. Many of these are effective at absorbing neutrons. Absorbed neutrons reduce reactivity, which has to be compensated for either by withdrawing control rods, or by removing the used fuel and replacing it with fresh fuel. One of the most effective neutron absorbers is an isotope of Xenon, called Xenon-135.

It starts to appearr about 6 hours after the fission events that effectively 'created' it. The amount of it that's created, is in direct proportion to the quantity of fission that happened six hours ago. So if a reactor is run at full power for a long time, and then throttled down, Xenon will continue to appearr according to that fuel burned six hours previously. It's a bit like the exhaust from your cars engine magically taking longer to form after the combustion in the cylinders. Normally, with the reactor in a steady-state, Xenon is created as quickly as it is consumed - the physics balances out. It can make it very difficult to increase or reduce power - if power is reduced too quickly, and the Xenon continues to build, the reactor might even be stalled by it.

It can also mean that, if the fuel in the reactor has been burned for a long time - there may not be sufficient reactivity in the remaining fuel to overcome this Xenon pit - the reactor is stalled and effectively impossible to start.

This is important. Because after a few hours more, the Xenon goes away. More than that, Xenon which absorbs a neutron also 'goes away' - it's no longer Xenon-135 and it's massive ability ot hoover up neutrons is suddenly gone.

Keeping all of these positive and negative reactivities in balance is the job of the Senior Reactor Engineer, who manipulates the reactor core's systems and control rods to achieve the required stable power output. The Engineer has only so much control as the rods will give them.

Finally, there is the concept of the Reactivity Margin. And that's basically the count of control rods left inside the reactor, which are required to maintain criticality. The higher the reactivity margin, the more control rods remain in the core and the more reactivity can be added to the core. A reactor with fresh fuel will have a very high reactivity margin. A reactor with old fuel, or with xenon poisoning, will have a low reactivity margin. Other factors like Xenon can push the reactivity margin down. It may seem that a low reactivity margin might be 'safer', because now there's less reactivity that can be added by the control rods (which are already out of the reactor at low margin). At a high reactivity margin, the control rods are inside the reactor. More of them can be withdrawn, to push the reactor  further into the supercritical - more positive reactivity can be added to the reactor.

the Chernobyl reactor was happy around about 30 Rods of reactivity. At this point, fresh fuel was being added frequenctly enough to keep the reactor stable, but not so frequently as to be uneconomical. The official limit, was somewhere around 15 Rods of reactivity. This wasn't thought to be a safety limit - it was simply economic. The reactor was far more likely to stall at low reactivity margins, resulting in downtime and lost energy production - or surprise blackouts.

But, below 30 rods of reactivity, another insidious effect began to occur.

The Control rods of an RBMK reactor are manufactured from boron. Boron absorbes neutrons, which reduces power. The deeper they go into the reactor - the more neutrons are absorbed - the slower the reactor goes. They can also be moved independently of each other - which changes where and how power is produced throughout the reactor, to compensate and balance for old and fresh fuels and how they're distributed through the reactor.

But, at the tip of the control rod on a telescoping extension, is a single slug of graphite and the end of a telescopic rod. The graphite tip of the control rod acted as a displacer. Its purpose was to push water out of the control rod channel, to remove it and its neutron absorbtion effect after the rod was withdrawn. In effect, instead of giving the control rod an action of -1,0 - they are something like -1,+1. They graphite displacer gives the control rod a stronger control action. It makes it more powerful by adding reactivity after the rod is withdrawn.

This led to an interesting effect.

If a number of rods in the same area of the reactor were inserted at the same time, and were in the same vertical position as they moved, a small amount of postivie reactivity could be momentarily added to the bottom of the reactor. This would cause an uptick in power for a few seconds before the boron control rod travelled the entire height of the core and finally quenched the reaction.

This was not thought to be much of a concern - power changes in the reactor after all, take longer than it takes for the rod to travel. It was just something the RBMK reactor did. Methods to mitigate it had been known and discussed for a decade prior Chernobyl Disaster, but were not seen as too much of a big deal. An RBMK reactor cannot explode, after all.

It would also reflect badly on the director of the Kurchatov institude if the reactor he had overseen were found to have a potentially fatal flaw. It was quietly buried in the documentation.

We do not yet know how an RBMK reactor explodes. But we know what we need to know

So I haven't been around in game much due to Fire Emblem: Three Houses devouring my spare time, but I ran across this on the forums and thought people would find it interesting:

https://forums.homecomingservers.com/top...-in-stats/