In the world(not Earth, but eath-like), I am building there was a nuclear exchange recently. Recently, I mean 25(subject to change) years into the past. I am describing a small clump of cities near the coast, they were protected enough that they were unharmed by nuclear impacts.
After surviving initial difficulties they now need power. Among those cities, there is one big city, like New York or Shanghai and there are some nuclear power stations.
Nobody knows if any more parts of the world maintained the pre-war level of technology.
Speaking of the level of technology.
It is similar to Saraksh from Prisoners of Power of Noon Universe. There is nuclear power, but there are no personal computers and no internet, there is some advanced crop designing, but everything is controlled via buttons and sliders. Computers are big, slow, and expensive.
The question is if no uranium or thorium mines are present and provided that significantly large quantities of depleted uranium are stored. How feasible it is to recollect enriched uranium particles from nuclear explosion sites to power a nuclear reactor?
The type of nuclear reactor is subject to change, there may be even different reactors in different blocks for pre-war research reasons. The same applies to the design of nuclear warheads, what is inside them is a degree of freedom to play with.
I know it is probably insanely inefficient, but if no other options are present, how much can be recovered?
I would really appreciate some upper bounds relative to the nuclear explosion center. My google-fu is not strong enough.
My thoughts so far:
- One can find unexploded warheads. That's a win, but one needs to have a special reactor if the warhead has plutonium in it.
- Found uranium is already highly enriched, so one can use it almost immediately after decreasing enrichment to the desired level. So only chemical extraction is required, no need for power-hungry centrifuges.
- Maybe it is a good idea to use something like a lunar harvester concept for harvesting helium-3 or spice harvester from Dune. Several things are the same: the dust, the preciousness, and the need for a mobile factory for the initial processing.
Edit1 with some numbers:
- according to this only 4% of uranium is used in nuclear fuel
- according to this(188.8.131.52) only 25% of uranium is used in a nuclear explosion
This is not Earth, but an Earth-like planet with one big continent that was nuked to hell, and many islands that were not, but are controlled by a very closed society with Japan-like culture. They have big naval forces(post-WWI-like vessels with a lot of big cannons). Their tech level is lower than on the pre-war continent and they probably do not know how to make energy via fission.
I am dropping the hard-science tag because the idea of spice or helium harvester seems appropriate as a solution, but not appropriate in a hard-science setting.
As I understood from the answers below there are some problems with the idea of collecting uranium in desired way:
- Airborn explosion lifts everything too high up. All unreacted fissile material will be effectively scattered uniformly around the globe. No gathering will be possible here.
- Pure fissile bombs were produced only in a very short window of our history. And most of them were plutonium ones.
- It is far more productive to go to other cities and collect natural uranium or unused fuel rods.
The third one is easy: I know it is far more feasible to do. I just think that it is might be interesting to explore another possibility.
The solution to the first problem is provided by
Starfish Prime in his answer below. Bunker busters and nuclear mines explode on the surface and leave very radioactive areas. If they are made from uranium it is possible to recollect some from them. Not much is needed if it is highly enriched uranium.
The solution for the second problem is the most complex one. As only one bomb design is feasible for all this to work, I need to create an environment where only one design is possible. A good way to do it is when such design is stolen, given, or captured.
Initial idea is that somewhere among the islands there was a former empire. With technology ahead of everybody else for about 35-50 years. A good way to set up this is to make the continent into a prolonged everybody-for-themselves-styled war.
After the war on a continent is settled there is tension between the former empire and the new upper dog of the continent. After some time another war bursts out. Due to superior numbers, the continent's armies are able to win. Not without paying a heavy price. The first nuclear explosion in this world appears on the outskirts of the capital city. It does not save it from capture, though. The former empire fell, but the effort is made not to let new destructive technology to fell into the wrong hands. Much of it is destroyed.
The winners are trying to replicate the technology, with a 35-50 year technology gap it is possible to replicate the existing technology, but not to improve it.
So the first bomb was made from uranium, resembling Little Boy. The enrichment process was likely the same as for early nuclear devices. Thus, no centrifuges are involved.
After the end of the second war in a row and many dead from the use of a new weapon, civil unrest is splitting territories of the former upper dog of the continent while newly acquired technology is leaked.
Each independent state is trying to replicate new technology and many eventually succeed. As design can not be improved, only stockpiled in large quantities while borders are mined with nuclear devices.
After some local conflicts, it is recognized that nuclear weapons are not very usage-friendly and many major countries agree to ban the usage and production of such weapons, while research continues.
After some time the situation is as follows:
- Each independent country has a stockpile of old nuclear warheads made from the same initial design. With some low quantity of illegal new ones.
- Each of them implemented some kind of dead hand protocol.
- Research is approaching the post-WWII level. Civil reactors are built and computers are invented.
Then some event triggers dead hand protocols and nuclear exchange happens. Making the world in a state it was before this post was made.
P.S. I know there are a lot of details to figure out for this scenario to be realistic. I just tried to come up with an initial painting to satisfy all constraints. I would like to hear suggestions though.
How hard it is to fuel a nuclear power station using fuel from unexploded Little-Boy-type bombs?
Assuming these facts hold:
- Reactor is 1GW PWR
- Reactor eats 27 tonnes of 1% enriched uranium per year
- Little Boy contains 64 kg of 80% enriched uranium
Little boy Fissile uranium mass = 64 * 0.8 = 50 kg
Fissile uranium needed for PWR = 27'000 * 0.01 = 270 kg per year per GW
Total GW-year per Little boy = 50 / 270 = 0.18
To summarize: It is hard to power a full-scale power station with unexploded little-boy-styled bombs. It is not impossible though.
P.S. If one has heavy water figured out then it is possible just to use a CANDU reactor and never think about fuel enrichment ever again :)