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I've seen a number of posts for nuclear setups already, but they all seemed quite complex, using combinators and whatnot. So I thought it must be possible to do it more simply.

The goal is to only consume nuclear fuel when needed. I'm assuming that the base runs off 100% nuke power, but I think it should work fine with solar in the mix as well as that goes first in the energy mix. I don't think it will use coal before nuclear or the other way around, but who burns coal these days?

Note: It's entirely possible that someone posted this exact configuration already. I read a number of posts but didn't read them all (I'm here to play, not to catch up on the reactor design literature ). If you have, let me know and I will give proper credit .

The setup:



Fuel is only inserted when needed, which is if (a) there is no fuel in the reactor and (b) steam is low. (a) is achieved by using the presence of spent fuel in the steel chest as 'memory': after a cycle the spent fuel is inserted in the chest, signalling that the reactor is in standby. The inserter from the steel chest to the provider chest is set to enable on steam < 5k (read from the green wire connected to a steam tank) and read pulse:
The pulse is transferred over the red line to the fuel inserter, which is set to stack size one, enabled if spent fuel > 0:
To activate a new reactor, insert 1 fuel cell, starting off the process.

I've tested this with a 2 reactor, 16 exchanger, 32 turbine, 16 steam tank setup. Under no load it goes up to just about 25k steam, under medium load it fluctuates between 5k and 10-15k steam, under full load it operates continuously with no steam.
Edit: I've removed the combined turbine/exchanger setup as that was mosly invalidated by the heat pipe change, see viewtopic.php?f=208&t=47895 for separate blueprints for exchangers and turbines.

I've only built and tested this in creative mode, not in "the wild", so it's entirely possible that there are some conditions under which it won't work or will not function optimally... please let me know if you see something wrong with the design!

Edit: I've now used it a number of hours in production and haven't seen any real problems. I increased the steam threshold to 10k as a tradeoff of robustness to efficiency with the new slower cooldown/heatup of the heat pipes. Increasing the ratios of steam storage to steam turbines might (currently 1:2 in my setup) also work.

Striking simple and clever idea - the Gordian knot cut right in the middle

thanks

I also pasted some .15.11-safe blueprints for a reactor setup here - viewtopic.php?f=208&t=47895

Thanks for the information.

Does this setup work for v0.15.12?

Meant to comment on this earlier - I had to smack myself for not thinking of that combination of trigger conditions! But they work beautifully, and can even be adapted for belt-only use as well. This just made my reactor designing a whole lot simpler.

Mehve wrote:Meant to comment on this earlier - I had to smack myself for not thinking of that combination of trigger conditions! But they work beautifully, and can even be adapted for belt-only use as well. This just made my reactor designing a whole lot simpler.

Thanks! I saw the depleted fuel cell as trigger and memory somewhere else, so I didn't do more than combine ideas from other places into a single setup...

Very nice concept, thank you.

I improved it a bit:
I removed the steel chest and instead have ONE of the inserter that removes the empty fuel cell "read hand content" in Hold mode. The condition is also "steam>5k". All other inserters insert use "empty cell >0" and remove and add fuel cells synchronously. Works very well.
I also added a belt system that makes sure there is exactly one fuel cell at every inserter.
This is quite useful when you have limited supply of fuel cells and do not have requester chests.

That does not work if you are late on delivering new fuel. You only have a limited amount of time where the spend fuel cell is in the hand while a chest keeps the signal as long as needed.

I did a similar setup (posted in another nuclear thread) where I used 4 chests with a token for a multi reactor setup. The 4 chest signal 4 states:

1) steam is low
2) all reactors have at least one fuel ready
3) insert fuel (kind of a dummy state but 4 chests form a circle)
4) spend fuel removed from all reactors

4 inserters move a token item (e.g. a fish) between those 4 chests, each enabled only when the next condition is met.
Each reactor also has a buffer chest for the next fuel cell (checked for state 2, insert fuel cell if empty) and spend fuel cells (checked in state 4, remove spend fuel cell s in state 4)

Yes, I am assuming fuel is plentiful, which for me it has always been by the time I build a serious reactor. If you ever run out of fuel you need to manually restart (or make a more sophisticated setup..)

vanatteveldt wrote:Yes, I am assuming fuel is plentiful, which for me it has always been by the time I build a serious reactor. If you ever run out of fuel you need to manually restart (or make a more sophisticated setup..)

Which I think is not the case for such a simple reactor. You would build that when you first get nuclear power researched. And then you have no enrichment process. Mining fuel without enrichment takes a long time. The ratio between U235 and U238 is too heavy on one side to give much fuel.

That is a good point. In my setup it is more or less solved by having one fuel cell on the belt in front of each inserter.
The easiest way to prevent the system from restarting the reactors is to add virtual steam to the storage.
When I am happy with my solution I will post an overview. Currently it uses 1 combinator per reactor to stop the belts. It could be replace it with a chest, which might be easier to understand. One combinator counts the fuel cells that get released into the system. I will probably add one combinator to add 10k steam if the system is not ready for the next cycle.

mrvn wrote:That does not work if you are late on delivering new fuel. You only have a limited amount of time where the spend fuel cell is in the hand while a chest keeps the signal as long as needed.

In my setup I solved this by attaching simple latch which holds empty fuel cell signal until new fuel cell is inserted.