As the era of fossil fuel dwindles to an end, new research published by Researchers at Pacific Northwest National Laboratory (PNNL) suggests resupplying the grid with electricity produced from nuclear fuel extracted from the ocean.
In a recent study, the team of researchers created five grams of yellowcake - a powdered form of Uranium used in the production of nuclear fuel.
"This is a significant milestone," said Gary Gill, a researcher at PNNL, a Department of Energy national laboratory. "It indicates that this approach can eventually provide commercially attractive nuclear fuel derived from the oceans — the largest source of Uranium on earth."
New Method of Extracting Uranium from Seawater
The new material, built in part by LCW Supercritical Technologies, is made from yarn processed into an acrylic fiber which attracts and captures dissolved Uranium naturally found in ocean water.
"We have chemically modified regular, inexpensive yarn, to convert it into an adsorbent which is selective for Uranium, efficient and reusable," said Chien Wai, president of LCW Supercritical Technologies. "PNNL's capabilities in evaluating and testing the material, have been invaluable in moving this technology forward”
Extracting the Uranium from the seawater involved submerging the fiber in a tub constantly circulated by large volumes of seawater pumped from Sequim Bay on the coast West coast of Washington.
"For each test, we put about two pounds of the fiber into the tank for about one month and pumped the seawater through quickly, to mimic conditions in the open ocean," said Gill. "LCW then extracted the Uranium from the adsorbent and, from these first three tests, we got about five grams — about what a nickel weighs. It might not sound like much, but it can really add up."
According to Wai, the Uranium-absorbent material is relatively inexpensive to manufacture. Impressively, the material is also reusable.
Five grams of yellowcake sounds measly, but considering enriched Uranium contains three million times the energy equivalent of oil or coal, the small amount of material collected can still produce impressive amounts of power.
While yellowcake is not an enriched form of Uranium in and of itself, it is part of an intermediary step in the process of manufacturing nuclear fuel.
Trace amounts of Uranium naturally exist in seawater in low concentrations of about 3 parts per billion or about 3 milligrams of Uranium per cubic meter. In all, it is estimated that the oceans contain about four billion tons of Uranium in seawater - 500 times the amount of Uranium in land-based ores, according to PNNL.
Researchers have considered extracting the abundance of Uranium from the oceans since World War II. However, with land-based nuclear mining operations already well underway, scientists dismissed the idea to focus on exploring the already proven methods of mining Uranium.
But the process of extracting Uranium from the ocean is not met by the same environmental challenges facing land-based Uranium mines. Ocean mining does not require digging or destroying the land. Rather, strips of the absorbent material will simply be installed along the floors of the ocean. The natural flow of the water is sufficient enough to saturate the fiber in Uranium.
The technology is new, but the early results are promising. Further development is required to decrease production costs and finally allow the world to harvest nuclear fuel from the ocean and fuel humanity’s power demand.