Richard Morris wrote:
Have you calculated the number of cubic miles of seawater that would
have to be filtered to supply as much energy as we presently get from
fossil fuels? How much is it going to cost to build and maintain all
the undersea infrastructure to do it?

Fortunately, the Sun and ocean thermodynamics conspire to cause
ocean currents without our having to lift a finger, and thus
circulation of seawater is a solved problem for most purposes.

At 3.3 ppb in generic seawater, there should be 3.3 tons per
cubic kilometer of water. Even on a once-through, LWR enriched
and 50% tails enrichment process we're talking about something
like 400 kg of usable material per cubic kilometer of seawater.
If half the energy content comes out as usable energy, then
we're talking about 74 terajoules per kg U-235, or about
2 TJ/kg enriched U. Which is 555,000 KWh/kg, or 222 million
KHw per cubic kilometer of seawater.

100 million households in the US. Times 25 KWh/day x 365 days/yr
call it 10,000 KWh/household/year. Double that for work and
transportation maybe? 1 Trillion KWh/year in the US?
So roughly 5,000 cubic km of water effectively filtered,
or at 1% effective recovery 500,000 cu km.

At a current flow rate of 10 kph, 24x365 hrs/year,
that is 87,600 kilometers of flow per year on average.
So a collecting surface area of around 6 square km.
Of perhaps 1mm thick, density 2.0 plastic with the
uranium specific activated resin coating. 12,000 or
so tons of plastic.

Annual plastics production in the US is something
like 50 million tons.


-george william herbert