LFTR: A Long-Term Energy Solution?

Victor Stenger Physicist, PhD, bestselling author

Currently more than 80 percent of the world's energy is obtained from fossil fuels: petroleum, coal, and natural gas. Another 10 percent comes from biomass and waste, leaving only 10 percent from sources other than carbon burning.

According to the World Health Organization, urban outdoor air pollution is estimated to cause 1.3 million deaths worldwide per year, from respiratory infections, heat disease, and lung cancer. Indoor air pollution is estimated to cause approximately 2 million premature deaths mostly in developing countries. Almost half of these deaths are due to pneumonia in children under 5 years of age. The source in both cases is carbon combustion, from fossil fuels or biomass.

The overwhelming majority of climate scientists tell us that the greenhouse gases generated by human carbon combustion are likely to trigger disastrous global climate change in the decades ahead. Even those who deny this surely must admit that the world would be a better place if we could find an economically feasible and safe alternative to the use of carbon combustion as our primary source of energy.

And so, it came as a surprise to me to learn recently that such an alternative has been available to us since World War II, but not pursued because it lacked weapons applications. When the war ended and nuclear reactors were developed to generate electrical power, the designs adopted were based on the same technologies that were used in the nuclear bombs dropped on Japan. These relied on the fission of uranium-235 (U-235) and plutonium-239 (Pu-239).

U-235 constitutes only 0.72 percent of natural uranium, which is mostly U-238, so costly separation is required. Plutonium is not found in nature and must be "bred" by uranium reactors, also a costly process.

It was well known to physicists of the time that another uranium isotope, U-233, is also fissionable. This isotope also does not occur in nature, but can be bred from the element, thorium, which is very common. However, a reactor breeding U-233 also produces U-232, which has a decay chain that generates high-energy gamma rays. This makes U-233 fusion unusable as a weapon, since these gamma rays are very destructive to a bomb's instrumentation and dangerous to the personnel handling it. Furthermore, U-233 is not an efficient breeder of plutonium, since it contains two fewer neutrons than U-235.

Because of its lack of application to weapons, a promising project at the Oak Ridge National Laboratory that was leading toward a thorium reactor was cancelled by the Nixon administration in 1969 in favor of a more efficient plutonium breeder. The Oak Ridge program was advancing the technology of using molten salt as a reactor fuel rather than the solid rods found in existing naval and commercial reactors. It had successfully operated such a reactor for 22,000 hours before being terminated. Liquid fuel offers great advantages in cost and safety over the solid fuel design.

Currently the liquid fluoride thorium reactor (LFTR) is having a resurgence of interest worldwide. Let me list the advantages of an electrical power plant based on LFTR compared to conventional nuclear and fossil-fuel plants:

• Thorium is plentiful and inexpensive. One ton costing $300,000 can power a 1,000-megawatt plant for a year. One pound of thorium yields as much power as 300 pounds of uranium or 3.5 million tons of coal.
• Unlike conventional high-pressure water reactors, LTFR operates at atmospheric pressure, obviating the need for a large, expensive containment dome and having little danger of explosion.
• LFTRs cannot melt down since the normal operating state is already molten.
• LFTRs are stable to rising temperatures since salt expands slowing the reaction. A salt plug kept solid by cooling coils will automatically melt if external power is lost and the fluid drain out to a safe dump tank.
• Salts used are solid below 300 F or higher, so any spilled fuel solidifies instead of escaping into the environment.
• Liquid fuels use almost all the available energy is used, unlike solid fuels that must be removed before they have generated 1-3 percent of the available energy because of damage.
• The radiative waste is much less than from conventional plants and far more manageable.
• Air-cooling possible where water is scarce.
• Should be cheaper than coal, especially if CO2 is sequestered.
• Proliferation resistant. Can't use to build bombs.
• Smaller size and lower cost.
• Could provide the world's energy needs carbon-free for a thousand years.

The gamma rays from U-232 are not a problem for reactors since unlike nuclear weapons they are already sufficiently shielded.

Of course, the disasters at Three-Mile-Island, Chernobyl, and Fukushima has greatly chilled public acceptance of nuclear power. But if these plants had used LFTRs, no radiation would have escaped to the environment.

Although far less of a problem than U-235 and Pu-239, waste from U-233 still has to be stored someplace. Here a comparison can be made with carbon sequestration in which waste CO2 is pumped into the ground, which is being talked about as a solution to problem of coal pollution. The amount of underground space needed to store a year's CO2 output from a single coal power plant is equivalent to 600 football fields filled to a height of ten yards. By comparison, one football field filled to the same height is required for all the waste from the entire civilian nuclear program.

Work on LFTR is going on worldwide, with research being done in China, France, the Czech Republic, Japan, Russia, Canada, and the Netherlands. The only significant U.S. research is on molten salt reactors, but with no emphasis on thorium. The U.S. may end up buying LFTRs from China. Perhaps WalMart will sell them cheap.

Thanks to reactor physicist Bob Zannelli for bringing LFTR to my attention and helping me learn the science.

Further Reading:

World Health Organization, "Air Quality and Health: Fact Sheet No. 313".

Daniel Yergin, The Quest: Energy, Security and the Remaking of the Modern World, (New York: Penguin Press, 2011).

Robert Hargraves, and Ralph Moir, "Liquid Fluoride Thorium Reactors: An Old Idea in Nuclear Power Gets Reexamined," American Scientist 98, no. 4(2010): 304-13.

Robert Hargraves, and Ralph Moir, "Liquid Fuel Nuclear Reactors," Physics & Society 40, no. 1(2011): 6-10.

Also, see the online lecture by Robert Hargraves "Aim High: Using Thorium to Address Environmental Problems".

Allen West's (R) FL. Hummer, "It cost me $75. to fill it up."

By Steve Benen

 - 

Thu Feb 23, 2012 4:06 PM EST

Associated Press

President Obama was in South Florida this afternoon, discussing energy policy and increased oil production at the University of Miami. With rising gas prices, the president is, not surprisingly, eager to discuss his ideas about reducing energy costs.

And then there's Rep. Allen West (R) of Florida, who shared his own concerns about the same issue on his Facebook page today.

"This 'tax policy' is an example as well as today's speech on his 'energy policy' shall be. Here is the bottom line, last night it took 70 dollars to fill the tank of my 2008 H3 Hummer, what is it costing you? What does it cost the president to fill his gas tank?"

It's hard not to enjoy the realization that West doesn't see the humor in this.

The far-right lawmaker drives a monstrous, almost cartoonish, vehicle, which was discontinued several years ago, and which gets about 15 miles per gallon. What's more, I know West's congressional district well -- I was born and raised in there -- and I can say with certainty that there's no practical reason the unhinged congressman needs to drive an Urban Assault Vehicle there.

They paved paradise and put up a parking lot.

If West wants to whine about gas prices, fine; he can join the club. But he doesn't get to complain about sticker shock when he's driving a five-year-old H3.

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MY THOUGHTS:
First, The H3 is a fine bush country machine, even if its built on the Suburban platform, they improved the suspension, clearance, and many other features that out does the Suburban when off the paved and improved roads. But for urban use, it doesn't make sense, I admit I do like the tough look of the Hummers, but looks are not as important as fuel efficiency, safety, and reliability.

His statement indicates that the Republicans have no concept about depleting oil reserves and saving any for future generations. They are only interested in drilling and burning up as much as they can before they die. To hell will future generations... Give me mine now....

We must replace fossil fuel with renewable clean energy. The technology is there and improving yearly. But it needs a political will to keep the momentum going and the assist some of the struggling technologies come to market.

The Republicans point finger at some of the new technology companies that went bust. Much of that is the credit markets and investors are not there to carry them into the market and to develop the consumer base needed to sustain viability.

In other countries, mainly European, governments are subsidizing these new technologies and bringing them to market. They are starting to see the return on that investment by the government. Fossil fuel consumption is on a decline there, more and more power is being generated by wind and solar. America is so far behind these other countries in the conversion of our energy to renewable, that very soon, they will have much cheaper energy costs with will relate into much cheaper manufacturing costs, so even with wages higher, companies will move to these countries for the huge savings in their energy costs.

Wake up Republicans, we must invest in these technologies and bring them to market her in America and we need to educate our workforce so we can create the innovations that drive a healthy economy.

Water, Food, Shelter and Energy; what you need to live.

Modern life requires four major services to exist; water, food, shelter and energy. The problem is we have a radically expanding population on this planet, estimated to be 9 billion by 2050 and doubling that number in less than 10 years. However, the amount of clean water is finite and declining, irrigable land is limited and normal rain patterns have shifted causing more irrigable land into arid land, shelter is becoming more expensive for the common person, and fossil fuels are declining and are harmful to our environment. In order for a civilization to survive the next century, it must change from a fossil fuel based economy to renewable energy economy.

To this end China is spending billions of dollars annually, mostly acquired from manufacturing most of the products Americans purchase, to building alternative energy generating capacity. They are investing in hydroelectric, geothermal power generation, huge wind power generating all across the country. They are pushing auto manufacturers to produce all electric cars and investing heavily in battery research, development, engineering and manufacturing. They are building a smart power grid to more efficiently transport and use electricity.

America on the other hand is spending a nano amount of government money on alternative energy production. The Republicans want free enterprise to invest in renewable energy production. But why would energy companies want to when they are making billions of dollars in real PROFITS from fossil fuel production? It may be short sighted for a corporation to not invest in new energy sources, but the current management are only looking at the now and what the company can produce in dividends to its shareholders. By the time these fossil fuels run out, they will be dead and gone. To hell with coming generations that will not have the advantages of cheap fossil fuel that current and past generations have enjoyed.

Energy conservation is an immediate process to reduce energy demand, but as a practical matter its impossible in the USA because we have become comfortable with our huge energy consumption. Add to that the new growing middle class of China and India that want all the electronic and transportation products that Americans enjoy. Why shouldn't they? We have kept saying to the third world to become more like us, and when they do, we say slow down you are using too much of the world's energy resources. That will mean Americans will have less energy for their bulging need.

But with all that said, America is bankrupt and a cooperative government/business investment in renewable energy is not possible to the level that would make any real difference in our demand for oil. Oil is fungible, therefore we can't talk about eliminating just foreign oil. So we have to talk about reduction in overall oil consumption.

According to a program on the Science Channel, a botanists has created a way to funnel the exhaust from coal burning power plants through chambers filled with plants that have high capacity to convert the CO2 into oxygen, thus cleaning the exhaust to clean air. However, it takes large amount of acreage next to the plant to perform this task and there is a cost to maintaining all the plants.This is what is called clean coal power generation. The second problem is the plants will expel CO2 at night requiring it to be collected and pumped into underground wells. They have tested it on two power plants with some success, but the operating cost drives up the cost of power to near nuclear power production rates.

If the country did invest in renewable energy, we could reduce our coal, oil and natural gas consumption for power generation to less than 20% of total output in 20 years. We could reduce oil consumption for transportation by producing bio-fuels for trucks and cars. A recent study showed that Sweet Grass can produce higher octane at a lower cost per gallon than corn or other grains for bio-fuels. Sweet grass is a wild grass and requires very little cultivation to grow in abundance and it grows very quickly. It would be better to grow sweet grass in areas where it is difficult to produce our food sources.

We as the human race must address our over population of the planet and our method of generating the power we critically need, unless we move back into caves and burn wood as our energy source.