Uranium Seawater Extraction Makes Nuclear Power Completely Renewable

America, Japan and China are racing to be the first nation to make nuclear energy completely renewable.

The hurdle is making it economic to extract uranium from seawater, because the amount of uranium in seawater is truly inexhaustible.

And it seems America is in the lead. New technological breakthroughs from DOE’s Pacific Northwest (PNNL) and Oak Ridge (ORNL) national laboratories have made removing uranium from seawater within economic reach and the only question is – when will the source of uranium for our nuclear power plants change from mined ore to seawater extraction?

Nuclear fuel made with uranium extracted from seawater makes nuclear power completely renewable.

It’s not just that the 4 billion tons of uranium in seawater now would fuel a thousand 1,000-MW nuclear power plants for a 100,000 years.

It’s that uranium extracted from seawater is replenished continuously, so nuclear becomes as endless as solar, hydro and wind.

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 

Specifically, this latest technology builds on work by researchers in Japan and uses polyethylene fibers coated with amidoxime to pull in and bind uranium dioxide from seawater (see figure above).

In seawater, amidoxime attracts and binds uranium dioxide to the surface of the fiber braids, which can be on the order of 15 centimeters in diameter and run multiple meters in length depending on where they are deployed (see figure below).

After a month or so in seawater, the lengths are remotely released to the surface and collected.

An acid treatment recovers the uranium in the form of a uranyl complex, regenerating the fibers that can be reused many times.

The concentrated uranyl complex then can be enriched to become nuclear fuel.

This procedure, along with the global effort, was described in a special report in Industrial & Engineering Chemistry Research.

The scientists from PNNL and ORNL led more than half of the 30 papers in the special issue, involving synthesizing and characterizing uranium adsorbents and marine testing of these adsorbents at facilities like PNNL’s Marine Sciences Laboratory in Sequim, Washington.

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

Gary Gill, deputy director of PNNL’s Coastal Sciences Division who coordinated the marine testing, noted,

“Understanding how the adsorbents perform under natural seawater conditions is critical to reliably assessing how well the uranium adsorbent materials work.”

In addition to marine testing, PNNL assessed how well the adsorbent attracted uranium versus other elements, how durable the adsorbent was, how buildup of marine organisms might impact performance, and which adsorbent materials are not toxic.

This marine testing shows that these new fibers had the capacity to hold 6 grams of uranium per kilogram of adsorbent in only about 50 days in natural seawater.

A nice video of U extraction from seawater can be seen on the University of Tennessee Knoxville website.

And later this month, July 19 to 22, global experts in uranium extraction from seawater will convene at the University of Maryland-College Park for the First International Conference on Seawater Uranium Recovery.

Stephen Kung, in DOE’s Office of Nuclear Energy, says that “Finding alternatives to uranium ore mining is a necessary step in planning for the future of nuclear energy.”

And these advances by PNNL and ORNL have reduced the cost by a factor of four in just five years. But it’s still over $200/lb of U3O8, twice as much as it needs to be to replace mining uranium ore.

Fortunately, the cost of uranium is a small percentage of the cost of nuclear fuel, which is itself a small percentage of the cost of nuclear power.

Over the last twenty years, uranium spot prices have varied between $10 and $120/lb of U3O8, mainly from changes in the availability of weapons-grade uranium to blend down to make reactor fuel.

So as the cost of extracting U from seawater falls to below $100/lb, it will become a commercially viable alternative to mining new uranium ore. But even at $200/lb of U3O8, it doesn’t add more than a small fraction of a cent per kWh to the cost of nuclear power.

However, the big deal about extracting uranium from seawater is that it makes nuclear power completely renewable.

Uranium is dissolved in seawater at very low concentrations, only about 3 parts per billion (3 micrograms/liter or 0.00000045 ounces per gallon). But there is a lot of ocean water – 300 million cubic miles or about 350 million trillion gallons (350 quintillion gallons). So there’s about 4 billion tons of uranium in the ocean at any one time.

However, seawater concentrations of uranium are controlled by steady-state, or pseudo-equilibrium, chemical reactions between waters and rocks on the Earth, both in the ocean and on land. And those rocks contain 100 trillion tons of uranium.

So whenever uranium is extracted from seawater, more is leached from rocks to replace it, to the same concentration.

It is impossible for humans to extract enough uranium over the next billion years to lower the overall seawater concentrations of uranium, even if nuclear provided 100% of our energy and our species lasted a billion years.

In other words, uranium in seawater is actually completely renewable.

As renewable as solar energy. Yes, uranium in the crust is, strictly speaking, finite. But so is the Sun, which will eventually burn out. But that won’t begin to happen for another 5 billion years. Even the wind on Earth will stop at about that time as our atmosphere boils off during the Sun’s initial death throes as a Red Giant.

According to Professor Jason Donev from the University of Calgary, “Renewable literally means ‘to make new again’.

Any resource that naturally replenishes with time, like the creation of wind or the growth of biological organisms for biomass or biofuels, is certainly renewable.

Renewable energy means that the energy humans extract from nature will generally replace itself.

And now uranium as fuel meets this definition.”

So by any definition, solar, wind, hydro and nuclear are all renewable. It’s about time society recognized this and added nuclear to the renewable portfolio.

Dr. James Conca is a geochemist, an energy expert, an authority on dirty bombs, a planetary geologist and professional speaker.

Follow him on Twitter @jimconca and see his book at Amazon.com

forbes.com

inngeniar

Researchers Claim Nuclear Power Has Saved 1.8 Million Lives

Nuclear power. When things go wrong as they have in places like Fukushima and Chernobyl, they get really scary, really fast. 

People die. They get radiation poisoning. 

The damage it wreaks is so unnatural-seeming, it’s the stuff of fantastic sci-fi visions—where irradiated ants grow to size of tanks and hijack Los Angeles; irradiated dead people rise from their graves and eat our entrails.

But as Motherboard’s own Brian Merchant argued last summer, our fears about nuclear fall-out, though grounded in some pretty grizzly reality, want a bit of perspective. 

“Compared to the toll of other energy sources (namely coal),” he writes, "nuclear power’s impact has been relatively benign—with regards to human life, anyways.”

A study published recently in Environmental Science and Technology by scientists at the NASA Goddard Institute for Space Studies and the Columbia University Earth Institute adds heft to that argument, indicating just how much human life nuclear power may have saved over the years. 

To wit, researchers estimate nuclear power has prevented more than 1.8 million deaths due to air pollution between 1971 and 2009.

Given our fears, the findings are counterintuitive. But they're persuasive. 

Those lives were spared, researchers say, because nuclear power spared the earth’s atmosphere 64 gigatons of CO2-equivalent greenhouse gas emissions. 

What’s more, they argue, an additional 80 to 240 gigatons and up to 7 million deaths could be prevented by around 2050 if we replace some of our fossil fuels with nuclear power over time.

There’s a big difference between the estimated 1.8 million from the last 40 years and as many as 7 million in the next 40 years. 

Some of that is attributable to the world’s growing population. 

But some is because the world is industrializing in places like China, where fossil-fuel pollution is a major problem. 

As the graph above indicates, estimated rates of annual lives saved by nuclear power has grown steadily for decades.

As Ben Schiller at Co.Exist explains:

[Study authors] Pushker Kharecha and James Hansen estimate that 4,900 people died as a result of nuclear power between 1971 and 2009, mostly from workplace accidents and radiation fallout, but, they said, 370 times more people (1.84 million) would have died, had we generated the same power from fossil fuels.

The scientists’ figures are based on estimates of mortality caused by particulate pollution, which killed 1.2 million people in China in 2010, according to a recent report. And it gets worse. They say burning natural gas to replace nuclear power will result in at least 420,000 deaths by 2050, and 7 million more if we replace it solely with coal.

Nuclear doesn’t have to be the solution. 

There are plenty of green tech alternatives under development. 

The researchers make it clear, however, that they believe “large-scale expansion of unconstrained natural gas use” would not solve the problem and would “cause far more deaths than expansion of nuclear power.”

Lead image by mbeo via photopin

By Austin Considine 

otherboard.vice.com

Can Small Reactors Ignite a Nuclear Renaissance?

Nuclear option:Babcock & Wilcox’s proposed power plant is based on two small modular nuclear reactors.

Small reactors have some benefits, but they won’t make nuclear as cheap as natural gas.

Small, modular nuclear reactor designs could be relatively cheap to build and safe to operate, and there’s plenty of corporate and government momentum behind a push to develop and license them. But will they be able to offer power cheap enough to compete with natural gas? 

And will they really help revive the moribund nuclear industry in the United States?

Last year, the U.S. Department of Energy announced that it would provide $452 million in grants to companies developing small modular reactors, provided the companies matched the funds (bringing the total to $900 million). In November it announced the first grant winner—Babcock & Wilcox, a maker of reactors for nuclear ships and submarines—and this month it requested applications for a second round of funding. The program funding is expected to be enough to certify two or three designs.

The new funding is on top of the hundreds of millions of dollars Babcock & Wilcox has already spent on developing its 180-megawatt reactor design, along with a test facility to confirm its computer models of the reactor. Several other companies have also invested in small modular reactors, including Holtec, Westinghouse Electric, and the startup NuScale, which is supported by the engineering firm Fluor (see “Small Nukes Get a Boost,” “Small Nuclear Reactors Get a Customer,” and “Giant Holes in the Ground”).

The companies are investing in the technology partly in response to requests from power providers. One utility, Ameren Missouri, the biggest electricity supplier in that state, is working with Westinghouse to help in the certification process for that company’s small reactor design. 

Ameren is particularly worried about potential emissions regulations, because it relies on carbon-intensive coal plants for about 80 percent of its electricity production.

As Ameren anticipates shutting down coal plants, it needs reliable power to replace the baseload electricity they produce. Solar and wind power are intermittent, requiring fossil-fuel backup, notes Pat Cryderman, the manager for nuclear generation development at Ameren. “You’re really building out twice,” he says. That adds to the costs. And burning the backup fuel, natural gas, emits carbon dioxide.

Nuclear reactors that generate over 1,000 megawatts each can cost more than $10 billion to build, an investment that’s extremely risky for a company whose total assets are only $23 billion. 

Power plants based on small modular reactors, which produce roughly 200 to 300 megawatts, are expected to cost only a few billion dollars, a more manageable investment. 

“They’re simply more affordable,” says Robert Rosner, coauthor of a University of Chicago study of potential costs that the DOE has drawn on in evaluating the potential of small reactors.

The smaller size has other potential advantages. Siting a large nuclear power plant can be difficult—it requires, for example, an emergency planning zone extending 10 miles around the plant, Cryderman says. 

That zone could be as small as half a mile for a small modular reactor—in part because of its size and in part because the reactors have added design features. 

For example, while the newest reactors—such as the Westinghouse AP1000—are designed to keep the fuel cool for three days without power, small modular reactors can be designed to go without any power for weeks. He says that if the Nuclear Regulatory Commission approves a smaller emergency planning zone, that could allow Ameren to build nuclear power plants at old coal plant sites, simplifying grid connections and other siting issues.

The smaller size is also an advantage in the United States, where power demand is growing slowly and many utilities don’t want to add multiple gigawatts at a time. 

The modular reactors are expected to take much less time to build as well, so utilities need to forecast demand only a few years out rather than more than a decade, Cryderman says.

Yet questions remain about the viability of small nuclear reactors. While their up-front cost is lower than that of larger reactors, they might prove to cost more per kilowatt of capacity—and per kilowatt-hour of power generated.

Nuclear power plants are built large to achieve economies of scale. 

“Designers could make the reactors put out more power, but they didn’t have to increase the capital costs proportionally,” says John Kelly, deputy assistant secretary for nuclear reactor technologies at the Department of Energy. 

The hope, he says, is that building the reactors in factories will provide an alternative way to reduce costs—through mass production. The small reactors are also simpler in some ways, which can also reduce costs.

But whether those savings will be realized is uncertain. It’s not clear how many reactors need to be built before the potential savings from factory production kick in, and whether there will be enough orders for reactors to hit those numbers. 

For that to happen, Rosner suggests, the government may have to be the first customer, buying the reactors for military bases or government labs.

Even once the final design is approved by the NRC, costs could prove higher than expected once the plants are actually built. 

“Part of the problem when you start in on these things, especially with a new technology, is that all the news after you begin is bad,” says Michael Golay, a professor of nuclear science and engineering at MIT. “Things never behave in an optimized fashion.”

Even if small reactors can compete with conventional nuclear power, they still might not be able to compete with natural-gas power plants, especially in the United States, where natural gas is cheap (see “Safer Nuclear Power, at Half the Price”). 

Their success will depend on how much utilities think they need to hedge against a possible rise in natural-gas prices over the lifetime of a plant—and how much they believe they’ll be required to reduce carbon dioxide emissions.

“At the end of the day, we’ll build the lowest-cost option for ratepayers,” Cryderman says. 

“If it’s too expensive, we won’t build it.” The challenge, he says, is predicting what the lowest-cost options will be over the decades new plants will operate.

Image by The Babcock & Wilcox Company

By Kevin Bullis on March 28, 2013

technologyreview.com