[jacquesm]

> Uranium in seawater is replenished by erosion through streams at a rate faster than we could ever burn it.

Isn't there a substantial energy cost associated with collecting that Uranium?

The same goes for gold, there is a huge amount of gold in seawater and yet, nobody has been able to extract it in a way that left money on the table after the process had run.

[acidburnNSA]

Great question, and one that I don't have a quantitative reply to on hand. The thing with uranium is that it is so unimaginably energy dense that with the success we've seen so far in seawater extraction technology, it's hard to imagine the energy required for extraction being anything but minuscule in comparison. Obviously there's a limit of concentration where this becomes not true but my understanding is that we are not near that limit.

Here's a summary of some recent work on seawater uranium extraction: https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s...

And here's a special edition of Industrial and Chemical Engineering dedicated to the topic: http://pubs.acs.org/toc/iecred/55/15#UraniuminSeawater

[jacquesm]

Thank you for the links and the answer.

[mseebach]

This article suggests a total cost of $1000-$1500 which is ~20x the cost of mined uranium (and 40x less the cost of gold). It does not mention energy as a significant driver of this cost.

http://scienceandglobalsecurity.org/archive/2013/06/the_cost...