Question:

I read with interest the article by Mr. Thierry Dujardin entitled “Are uranium reserves adequate?”, and was surprised he did not mention seawater reserves, though others bring it up regularly. Could this expert provide us with exact data on this potential resource? Thank you and bravo for your very interesting magazine.

Answer:

The concentration of uranium in seawater is very low, in the parts-per-billion (ppb) range, but the oceans do indeed represent the world’s largest uranium reserve, at some 4 billion metric tons, or 100 times more than all estimated land-based resources as of this date. Laboratory tests and economic studies, particularly in Japan, put the estimated cost to extract the uranium from seawater at around $350 per kg, or almost triple the current spot price for uranium. So it’s not economically attractive today to extract uranium from seawater. If demand and prices were to continue to rise, other non-conventional resources, particularly phosphates, might be brought into play before seawater is considered. Nonetheless, insofar as the cost of natural uranium is only a few percentage points of the cost of the nuclear-generated kWh, the existence of this gigantic theoretical reserve is another argument in favor of using nuclear power for sustainable development.