Anyone out there have a good knowledge of nuclear energy?

[Brian W. Foster]

I've spent a couple of hours researching the topic, and I'm not getting anywhere fast. I'm not sure that this is an appropriate place to post this, but I need help. My epic fantasy novel (sorry that it's not scifi, but I figured I'd stand a better chance of getting science help here) character has the ability to manipulate nuclear energy.

Here are the abilities I need him to possess:

- Detect harmful nuclear radiation and remove energy from it so as to make it harmless
- Find fissionable material
- Make said fissionable material explode. (How much does he need to destroy a good sized medieval city?)

So if you were this guy, what would radiation look like to you? Does removing energy from radiation make sense? If you're going to make fissionable material explode, how exactly would adding energy make this happen?

I don't have to use a ton of technical details, but I do want the world to make some kind of sense.

Thanks a bunch!

Brian

 

[Phyrebrat]

@Venusian Broon - your arena...

pH

 

[Ray McCarthy]

All the info you need is on Wikipedia.

However ... As I first studied Nuclear bombs in 1972 ...

- Detect harmful nuclear radiation and remove energy from it so as to make it harmless

You can make photographic plates (see Wikipedia), silver nitrate is later version. keep in dark. Radiation will expose the plate, as if light was on it (black / solid, dark or radiation free is transparent). You can't "remove energy from it so as to make it harmless", it decays naturally see half life. Unless you have magic that bypasses entropy, quantum mechanics and nuclear physics, somehow, you can't remove the radiation.

- Find fissionable material

You want Uranium containing ore.
List of uranium projects - Wikipedia, the free encyclopedia

There is a snag! Only element in Nature that goes "bang" at critical mass is 235 U isotope. You need a good lot more than critical mass (suddenly) or it just gets very hot and burns a hole in the ground.

Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight. 235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons.

It took combined expertise of UK & USA and Refugee German scientists to enrich uranium during 1940s.
Plutonium was created in a "breeder reactor" from Uranium. Then had to be refined.

It's not easy to enrich Uranium or make plutonium or local terrorists would be making atomic bombs. The North Koreans only recently made some and the Iranians are still trying.

The minimum for an atomic bomb is three disks each a bit under the critical mass in a tube. Ideally mostly evacuated. One in middle and one at each end. You have explosives (I'm not sure if gunpowder is good enough, you may need nitroglycerine (for quarry blasting, Nobel came up with idea of soaking it in diatom type earth, kiesgur (SP)) or use TNT.
It would just about fit in a milk churn, I think.
The conventional explosives have to slap the three or four chunks of Uranium (each just under critical mass) together really quickly. The smallest weapon made during cold war could be carried in a back pack (just). Though a second person had to carry the weapon that fired it. I suspect it used plutonium, but I don't know.

You may die from radiation poisoning making it. If you stole Plutonium (the only way to get it unless you are equivalent to France, USA, UK, India, Israel, Pakistan, Russia), you will die making the bomb. Plutonium is more reliable for a bomb, but doesn't exist at all in nature.

Making an atomic bomb isn't that hard, it's getting 235U isotope that is REALLY hard. Plutonium bombs are even easier, but Plutonium is harder to make / get and very poisonous.

A hydrogen bomb / thermonuclear bomb is REALLY hard to make. It uses an atomic bomb as detonator. Apart from the detonator and the design, the actual Lithium Hydride (using heavy hydrogen) is easier to make than U235.


Your only hope is lots of magic and explain nothing. Possibly some other fantasy apocalyptic weapon.

 

[The Judge]

I know absolutely nothing about nuclear energy so I'm less than helpful in that respect, but I just thought I'd reassure you that it's fine to pose the question here, since it's a problem you need solving for your writing. And there's no need to apologise for it being a fantasy not SF world! We cover both here, but we'd try and help anyone with any kind of writing issue, regardless of genre.

Good luck in the quest for answers! I see Phyrebrat has tagged Venusian Broon -- sometimes the tagging doesn't work properly, though, so if he doesn't show up in the next couple of days, one or other of us will give him a nudge.

 

[Brian W. Foster]

You can make photographic plates (see Wikipedia), silver nitrate is later version. keep in dark. Radiation will expose the plate, as if light was on it (black / solid, dark or radiation free is transparent). You can't "remove energy from it so as to make it harmless", it decays naturally see half life. Unless you have magic that bypasses entropy, quantum mechanics and nuclear physics, somehow.

Logically, you can't do anything that my mages do as they are using magic that does betray physics to a degree. My problem is to make sure that all the unrealistic stuff they can do stays consistent.

For example, a kinetic mage approaches a rock that lying on the ground. The mage decides, "Hey, I want that rock to fly up and hit the guy with a sword that's running at me." Instead of kicking the rock or applying some kind of action that obeys physics, the mage applies magic to the rock. The magic instantly changes the state of energy of the rock (what I'm calling "adding energy"), making it move in the desired speed and direction. Or he could stop a sword that's coming at him by "removing its kinetic energy."

I'm looking to wrap my head around doing kind of the same thing with nuclear energy. It's my understanding that radiation is a form of energy. If something is radioactive, it kind of make sense to me that a mage could simply make that energy disappear, rendering the object no longer radioactive. But I'm really iffy on all this stuff. I'm sure there's a way to do this so that I can keep my internal logic, I'm just at a loss as to the specifics.

Thanks for the reply!

Brian

 

[Ray McCarthy]

It's my understanding that radiation is a form of energy.

Due to the decay of one element into another. The energy is a mix of energetic particles and gamma radiation.
look up radioactivity on wikipedia.

I write fantasy and SF. I have the concept that there are two kinds of "magic". Catalytic, which allows speeding or hindering chemical reactions (quite different to radiation or nuclear reactions). The other kind is to speed or slow entropy (affects nuclear reactions). You'd still need enriched uranium for fission, or heavy hydrogen and Lithium for fusion. I don't explain it at all.

Elements beyond Iron can release energy by fission into simpler elements. (Uranium to Lead)
Element before Iron can release energy by fusion becoming more complex. (Hydrogen to Helium)

Getting energy from nowhere or making energy vanish breaks the most fundamental laws of the universe (Thermodynamics), so often with Magic the Energy is deemed to be taken from somewhere or moved to somewhere. Though you can simply have fairy tale magic where it makes no sense.

Half and half is bad. Either you make it fit with known "laws" even if there is magic, or you just have magic and don't explain at all (LE Modsitt Chaos / Order Wars)

 

[Brian G Turner]

Fantasy readers are already familiar with wizards doing the impossible by manipulating energy. If you have someone who can specifically manipulate nuclear energy, I'd just leave it as that - keep it generic and avoid specifics.

Otherwise you will end up trying to describe a scientific process behaving in an unscientific manner - or else flooding your story with scientific terms that are not relevant or even undermine your story.

 

[Brian W. Foster]

Getting energy from nowhere or making energy vanish breaks the most fundamental laws of the universe (Thermodynamics), so often with Magic the Energy is deemed to be taken from somewhere or moved to somewhere.

Energy is added to a system magically by converting a flow of magic into energy. The reverse occurs in the same manner.

I tend to think that a magic system can do anything you want as long as you stay consistent with the rules you establish.

 

[Brian W. Foster]

Fantasy readers are already familiar with wizards doing the impossible by manipulating energy. If you have someone who can specifically manipulate nuclear energy, I'd just leave it as that - keep it generic and avoid specifics.

Otherwise you will end up trying to describe a scientific process behaving in an unscientific manner - or else flooding your story with scientific terms that are not relevant or even undermine your story.

I really have no idea how much or any description of this process will make it into the book. In order to stay consistent with my internal logic, however, I really need to have some kind of internal logic. At this point, I don't know what makes sense for my mage to be able to accomplish.

Thanks.

Brian

 

[Ray McCarthy]

Exploding mages!
xkcd: Log Scale

Petrol / Gasoline is 46 MJ/kg energy density.
Uranium is 76,000,000 MJ/kg energy density.
Randell Monroe is ex Nasa, a good researcher and a mathematician.

Also mining and transporting the uranium ore (which has very little uranium in it) is non-trivial.

Why not just have unexplained fireballs and maybe some sort of artefact that can be charged up for some days by a team of mages?

You don't need to have an idea of what megajoules are. A 1 gallon can of petrol / gas might be about 4.5kg. The same amount of Uranium* is about 1.7 million times more destructive than a fuel / air bomb of gasoline.



[*Probably U235)

 

[Brian W. Foster]

Petrol / Gasoline is 46 MJ/kg energy density.
Uranium is 76,000,000 MJ/kg energy density.

Cool. That helps a bunch!

Why not just have unexplained fireballs and maybe some sort of artefact that can be charged up for some days by a team of mages?

The first book in the series is already published, and I included "blighted" areas that were obviously hit with nuclear explosion and the existence, long ago, of blighters who accomplished this. Now, I'm kinda stuck figuring out details that work within the confines of my world.

Your answer in the previous post answered how much I need. I think it also makes sense that he'd be able to "see" radiation when he wanted to, since most mage types can see or somehow sense whichever form of energy they can manipulate. I don't need to be too specific at this point on what that looks like.

The issue now, apparently, is how he obtains a fissionable material as it seems like a process is required to make it. It shouldn't be too hard from him to find instructions that, given his magic abilities, will allow him to do it. I'll do a bit more research on that.

Thanks!

 

[Ray McCarthy]

Or
8 kWh of heat can be generated from 1 kg of coal, approx. 12 kWh from 1 kg of mineral oil and around 24,000,000 kWh from 1 kg of uranium-235.

is how he obtains a fissionable material as it seems like a process is required to make it.

Loads of slaves in the far Asian or South African mines. About 2000 tonnes of ore are needed. Then a vast chemical processing factory and hundreds of centrifuges to refine the ore and separate the U235. Or maybe magic sorting on the 2000 tonnes of ore.

First, a simple problem that looks at how much uranium we get out of a metric
ton of uranium ore. A metric ton (or sometimes called a tonne) is 1,000 kilograms of
material. So here we want to calculate the mass of U-235 per metric ton (t) of uranium
ore assuming the total uranium is 1 wt% of the ore. (Note: U has 0.711wt % U-235)
[So 1 tonne of ore gives 10 kg of actual uranium]
Now the U-235 is only 0.711 weight % of uranium, so 0.00711 times 10 kg is 0.0711 kg
or 71.1 grams of U-235.

from https://s3.amazonaws.com/accredible...35765/original/open-uri20140316-19925-1izfwtd
( A PDF possibly, but I cheated and used HTML cached version)

Now Critical mass of U235 is 52kg, so you want maybe three pieces about 45kg, that means you need to refine about 633 tonnes of medium grade Uranium ore (poorest stuff has 1/10th and best is twice as good) per piece or 1900 tonnes of good ore for your 135 kg bomb.
Note that critical mass of Plutonium is maybe about 10kg, so it's handier.
Critical mass - Wikipedia, the free encyclopedia
see also
Uranium - Wikipedia, the free encyclopedia

135kg is about twice the weight of an average person. However it doesn't take up much space. Denser than lead. Actually 19 times denser than water and more than 20 times gasoline. Note that "real" bombs don't use 100 pure U235, They might use half a tonne of mixed U238 and U235!
Hence France, UK, USA and USSR built Nuclear power stations that created Plutonium for bombs. That takes a few years.

Have to go... I hear sirens and helicopters.