Quickly: What are the advantages to mining uranium from seawater and what are the disadvantages?
According to researchers at the University of Stanford, including former U.S. Secretary of Energy and Nobel Prize recipient Steven Chu, the advantages include a vast potential source that contains 4.5 billion metric tons of uranium and the possibilities that offers to nations that might not have their own uranium supply in their own backyards – speaking figuratively and literally.
With nuclear power viewed as a critical component to the world's future energy mix, one that can furnish power when the wind isn't blowing or the sun isn't shining, many nations may end up with imported reactor technology and imported uranium. But extraction from seawater, while avoiding the mess of land-based mining, opens up new potential, says Chu.
The primary disadvantage is that extraction from seawater has not been viable so far given the returns. Researchers, at Stanford, however, say they have made great progress in mining uranium from seawater that could fuel future reactors.Another researcher working on the uranium extraction project, Yi Cui, said that “concentrations (of uranium) are tiny, on the order of a single grain of salt dissolved in a liter of water. But oceans are so vast that if we can extract these trade amounts cost effectively, the supply would be endless.”
The extraction process exploits the chemical makeup of uranium in seawater. Uranium in the ocean combines with oxygen to form uranyl ions that have a positive charge. Extraction involves dipping plastic fibers into the water that contain a compound called amidoxime. This process sets up three pertinent questions: What is the saturation level of the fibers? How often can they be used? How quickly will they work?
Stanford has made progress on all three counts, the university's news service announced.
The first step was creating a hybrid fiber material that involved the use of amidoxime-carbon instead of simple amidoxime. Secondly, researchers found they could amp up the saturation level greatly by the use of electricity pulsing through the fibers. During recent studies, “Stanford's amidoxime-carbon hybrid fibers had already absorbed nine times as much uranyl and were still not saturated. What's more, the electrified fiber captured three times as much uranyl” during an 11 hour test. In addition, the hybrid fiber lasts three times as long as traditional amidoxime fiber.
Cui says research is far from done.
“We have a lot of work to do still, but these are big steps towards practicality,” Cui said.
“For much of this century, some fraction of our electricity will need to come from sources that we can turn on and off. I believe nuclear power should be part of that mix, and assuring access to uranium is part of the solution to carbon-free energy,” Chu said.
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This is interesting. Not sure it's necessary since Ux prices are quite low, but of course that can change.
Fully agree with this quote from Chu: “For much of this century, some fraction of our electricity will need to come from sources that we can turn on and off. I believe nuclear power should be part of that mix"