Okay, I guess the method is good, and after checking the proportions of Ura in seawater, I guess it could be industrialized at a very high cost (ressources + EU/way of crafting maybe ?) But ... I guess if it should be implemented, others things should come before (ex way of getting Ura from Basalt/Lava/other mineral)
the main advantage of my suggestion is the fact that it can be extended to provide more than just the uranium. irl it can be industrialized to produce uranium at a very low cost relative to other fuels (uranium is absurdly cheap as it is, so 10 times really cheap is still cheap http://en.wikipedia.org/wiki/U…ng#Recovery_from_seawater $240/kg is about $530/lb, current price is about $40 or so, to be comparable to oil would need to be $240 000/lb or so, for coal about $40 000/lb or so). This sea water idea could be used as a way to provide multiple different needed materials, such as lithium, iridium, etc, and only when using the right fiber to exctract, that fiber is where you can stick the expense for getting certain materials you want to keep rare.
Edit 1: sorta, i was suggesting a special pump like thing that only works in ocean biomes and rather than giving water, turns fiber into a full fiber that you can then extract ore from. modeled after the current methods of uranium extraction from sea water.
Edit 2: The main inspiration for this idea is the currently existing Scrap boxes. They allow Cobblestone to be turned into most materials in the game. Also, using the right setup will produce materials fairly quickly. This water extraction method would allow for a more realistic way to obtain the materials, in a way where you can more easily choose what you get (rather than current systems of determining the probability of getting what you want and dumping the rest of the useless junk)
Edit 3: On the composition of these Fibers. From my understanding of basic principles involved, they would probably consist of a nanofiber polymer to maximize surface area which has been coated in the absorbent material. This indicates that a reasonable recipe would be to make carbon nanofiber from charcoal or coal dust, then to craft that with several dusts to represent the coating, then possibly cook that in a furnace to finalize the fiber. This would give a place to add an EU cost (the cooking of the fiber) as well as a way to make it as expensive as you want (you would have 8 types of dust to use, and up to 64 of each if you want)
Edit 4: for the material to coat the nanofiber with: http://en.wikipedia.org/wiki/Amidoxime_group#Amidoximes There is a set of basic structures used by the system the Japanese designed. the ORNL version will probably still be a similar organic compound, so you could even make a second intermediate involving carbon, nitrogen, water and then craft that with the various modifying dusts, then craft the result with the nanofiber, then possibly smelt it.
Edit 5: What i am trying to show here is that this method could be made arbitrarily expensive by just modifying the recipe for the fiber used. You could even make some of the fibers non consumed, but horribly expensive, so they are still "end game" due to the initial cost, but result in a renewable energy source.
Edit 6: on the mechanics of the extractor, you could have it act similar to the miner but in more than 1 dimension, where it places the fibers similar to the mining pipes. It can only place them inside water in the right biome, and the yield is based on the number placed. when the blocks are retracted they can replace themselved with water source blocks, but can only extend into a source block. This would make it easier to make the system need a large area of ocean to work in, rather than using 1 block bits of source water. Related idea: allow it to go upwards as well, then you can have some interesting looking ocean floor collectors
