Limitless Nuclear Fuel from Ocean Could Provide Thousands of Years Worth of Energy

Image Source : David Cannon/Getty Images
NUCLEAR FUEL FROM SEA WATER

Attention! Next time when you go to the beach, look at the horizon and think about this:
You are swimming in nuclear fuel!

According to a recent scientific research, our oceans contain an estimated 4.5 billion metric tons of Uranium. This Uranium is diluted down to a minuscule 3.3 parts per billion.

This amount of nuclear fuel is enough to supply energy for thousands of years. During the past 2-3 decades extracting Uranium from seawater has been quite in news. However, the materials and processes to do this has become economically viable only now.

HOW URANIUM EXTRACTION WORKS

A polymer substrate—basically, plastic—is irradiated, and then chemicals with an affinity for Uranium are grafted onto it. The material is woven into 60-meter-long braids, and these are then brought out by boat to waters that are at least 100 meters deep.

The braids are chained to the ocean floor and allowed to float passively in the water, like an artificial kelp forest. After about 60 days, the boat returns and pulls in the adsorbent materials—now sporting a healthy yellow tint from the Uranium.

The plastic is then brought back to shore, and the Uranium is eluted off.

You get between 2 and 4 grams of Uranium sticking to this stuff per kilogram of plastic,” says Erich Schneider, a nuclear engineer at the University of Texas at Austin. “That doesn’t sound like a lot, but it all adds up.

Nuclear Fuel:Researchers around the world have been working frantically to develop an array of materials and fibers able to economically extract uranium from seawater. They have succeeded, as discussed at a conference devoted to the topic. Researchers at the Pacific Northwest National Laboratory exposed this special uranium-sorbing fiber developed at ORNL to Pseudomonas fluorescens and used the Advanced Photon Source at Argonne National Laboratory to create a 3-D X-ray microtomograph to determine microstructure and the effects of interactions with organisms and seawater. Courtesy of Pacific Northwest National Laboratory 
Researchers around the world have been working frantically to develop an array of materials and fibers able to economically extract uranium from seawater. They have succeeded, as discussed at a conference devoted to the topic. Researchers at the Pacific Northwest National Laboratory exposed this special uranium-sorbing fiber developed at ORNL to Pseudomonas fluorescens and used the Advanced Photon Source at Argonne National Laboratory to create a 3-D X-ray microtomograph to determine microstructure and the effects of interactions with organisms and seawater. Image Courtesy of Pacific Northwest National Laboratory
URANIUM IS PRECIOUS!

Extracting Uranium out of seawater is certainly a cost-effective way to source nuclear fuel. Now that the extraction technique is in place, this could pave the way for coastal countries to switch to nuclear power.

A team of researchers from Stanford University in California reported in Nature and demonstrated that they have found a way to more efficiently extract the Uranium dissolved in our oceans.

Uranium is in the form of the isotope U-235. It is currently the radioactive element of choice when it comes to using nuclear energy to produce electricity. Across 30 countries about 450 nuclear power plants are spread and can chew through more than 60,000 tons of the stuff each year.

Concentrations are tiny, on the order of a single grain of salt dissolved in a litre of water,” said team researcher Yi Cui from Stanford University. “But the oceans are so vast that if we can extract these trace amounts cost effectively, the supply would be endless.

4.5 billion tons of Uranium dissolved in our planet’s waters would supply us “endless” amount of energy, with any we remove being replenished as Uranium in the surrounding rocks dissolves.

Indeed, in our oceans there a lot of water to sift through – about 1.37 billion cubic kilometers, in fact, (that’s more than 332 million cubic miles), with only about 3 particles of uranium per billion particles of seawater.

“We have a lot of work to do still but these are big steps toward practicality.” Cui said.

IMPROVED EXTRACTION

Scientists would need to dip plastic fibers into the seawater coated in a chemical called amidoxime. The uranyl ions then stick to the plastic fibers allowing for extraction and then eventually refinement.

What the Stanford team have done is taken this method and improved it threefold.

Nuclear Fuel:Researcher Chong Liu examines a carbon-amidoxime electrode as part of research to improve extraction of uranium from seawater. Image Credits: L.A. Cicero
Researcher Chong Liu examines a carbon-amidoxime electrode as part of research to improve extraction of uranium from seawater. Image Credits: L.A. Cicero

This approach depends on three main variables: how much uranyl sticks to the fibers; how quickly ions can be captured; and how many times the fibers can be reused.

At Stanford, researchers improved on all three variables: capacity, rate, and reuse.

KEY ADVANCES
  1. The team developed a conductive hybrid fiber incorporating carbon and amidoxime.
  2. By creating a carbon and amidoxime fiber prototype they were able to pass electricity through the fibers with the resulting effect being a 3x increase in the amount of uranium collected and a 3x increase in the lifespan of the fibers.
  3. By sending pulses of electricity down the fiber, they altered the properties of the hybrid fiber so that more uranyl ions could be collected.
Nuclear Fuel:Scientists envision anchoring hundreds of lengths of U-extracting fibers in the sea for a month or so until they fill with uranium. Then a wireless signal would release them to float to the surface where the uranium could be recovered and the fibers reused. It doesn’t matter where in the world the fibers are floating. Source: Andy Sproles at ORNL
Scientists envision anchoring hundreds of lengths of U-extracting fibers in the sea for a month or so until they fill with Uranium. Then a wireless signal would release them to float to the surface where the Uranium could be recovered and the fibers reused. It doesn’t matter where in the world the fibers are floating. Image Source: Andy Sproles at ORNL
NUCLEAR VIABILITY FOR FASTER AND BETTER SUPPLY

This report emphasizes how feasible uranium collecting can be. But much research still needs to be conducted in order for these methods to be simplified for extraction. Looking at the numbers it is currently much easier to gather Uranium from the ground compared to the ocean.

Professor Steven Chu, a Nobel Prize-winning physicist and co-author of the Nature Energy article believes that as long as research on extraction is carried out in parallel with work on reactor safety and waste disposal challenges, this could offer new countries a homegrown opportunity for nuclear fuel.

Chu emphasized, “We need nuclear power as a bridge toward a post-fossil-fuel future. Seawater extraction gives countries that don’t have land-based uranium the security that comes from knowing they’ll have the raw material to meet their energy needs.

“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 added.

The paper was published in the journal, Nature Energy.

Source Forbes Stanford

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2 Comments

  1. Hans Hoolmans says

    Wouldn’t a Molton Salt Reactor be more feasible than expensive fishing?

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