There are many so-called "Generation IV" nuclear reactor designs being studied to replace the world's aging fleet of light water nuclear power plants. Light water nuclear reactors use ordinary H2O to moderate nuclear fission, for cooling, and to create steam for running turbines. All of the newer reactor designs have clear advantages over the old light water standard. China and South Africa are rapidly perusing meltdown proof pebble bed reactor technology, and the Idaho National Laboratory is experimenting with prismatic block reactors, reported to be even more efficient and stable. Most of the proposed new designs represent evolutionary improvements, but the LFT (liquid fluoride thorium) reactor design is truly revolutionary. LFT reactors are an earth friendly power source that solves all of the major problems associated with nuclear power.
LFT reactors transform thorium into fissionable uranium-233, which then produces heat through controlled nuclear fission. The reactor only requires input of uranium to kick-start the initial nuclear reaction, and as the uranium can come from spent nuclear fuel rods, LFT reactors will inevitably be used as janitors to clean up nuclear waste. Once started, the controlled nuclear reactions are self-perpetuating as long as the reactor is fed thorium. As the fuel is a molten liquid salt, it can be cleansed of impurities and refortified with thorium through elaborate plumbing, even while the reactor maintains full power operation. This reduces reactor downtime and increases total yearly energy output.
LFT reactors produce electric power via a waterless gas turbine system that can use helium, carbon dioxide, or nitrogen gas. The reactors are small and air cooled, so they can be installed anywhere, even in a desert. Robert Hargraves, an LFT advocate, states that "Liquid fluoride thorium reactors operate at high temperature for 50% thermal/electrical conversion efficiency, thus they need only half of the cooling required by today's coal or nuclear plant cooling towers." LFT reactors will be manufactured on an assembly line, dramatically lowering costs and enabling electricity generation at a projected rate of about 3 cents per kilowatt hour. It has been estimated that a physically small 100 megawatt LFT reactor would cost less than 200 million dollars to build, which is a bargain. Multiple reactors can be installed at one location and connected to a single control room. With convenient modular design, LFT reactors can be transported in pieces by truck or barge for easy assembly on site. This allows for swift construction with reliable results, avoiding delays and cost overruns. Rapid assembly line construction also allows for easy updating of the design, which will get better and better, like the evolution of automobiles, airplanes, and computer chips.
LFT reactors are much more fuel efficient than other designs, because they burn up 100% of the thorium fed them. Light water reactors typically burn only about 3% of their loaded fuel, or about .7% of the fundamental raw uranium, which must be enriched to become fissionable. Because of their high energy conversion efficiency, LFT reactors produce less than 1% of the long lasting radioactive waste of light water reactors, making the controversial Yucca Mountain Repository for nuclear waste unnecessary.
A LFT reactor can never meltdown, because its fuel is already in a molten state by design. Any terrorists who obtained forceful entry into the reactor complex could not realistically remove any of the hot molten fissionable fuel. Coolant in LFT reactors is not pressurized as in light water reactors, and the fuel arrives at the plant pre-burned with fluorine, a powerful oxidizer. This makes a reactor fire or a coolant explosion impossible. LFT reactors do not require large, cavernous pressure vessels designed to contain an internal explosion of superheated steam, so LFT enclosures are tightly fitting and compact, which makes them less expensive to build. The reactors will be installed underground with a thick reinforced concrete cap, making an attack by a kamikaze airplane pilot ineffective. Overheating of a LFT reactor expands the molten salt fuel past its criticality point, making the design intrinsically safe due to the unchangeable laws of physics. Even a total loss of operational reactor control would not cause disaster. In addition to the fuel's natural safety, any excess heat in the reactor core would automatically melt a built-in freeze-plug, causing the liquid fuel to drain via gravity into underground storage compartments, where the fuel would then cool into a harmless, noncritical mass.
We have enormous amounts of low cost thorium fuel available, with estimates of efficiently recoverable reserves ranging from a supply lasting thousands of years, to a supply lasting over 2 million years. LFT reactors can be used to manufacture synthetic gasoline made from atmospheric CO2 and water, or can produce high energy methanol fuel. The French Reactor Physics Group is leading in LFT research, and there are LFT experiments being conducted in Japan, the Netherlands, Russia, and in the Czech Republic. If the U.S. Government committed a relatively modest amount of money to LFT research in cooperation with France, a fully operational TOTAL ENERGY SOLUTION might be possible within as little as 5 years, because most of the basic research has already been accomplished and is well proven. LFT research at Oak Ridge National Laboratory was ended in 1976, because the reactor's design cannot practically produce weapons grade plutonium. LFT reactors will not lead to the proliferation of nuclear weapons.
LFT technology will have a very small footprint on planet earth, unlike renewable energy schemes that use up impossibly large amounts of land and vital resources. Scientist Jesse H. Ausubel, Director of the Program for the Human Environment, found that to meet U.S. electricity demand for 2005 with wind power would require about four million megawatt hours of electricity. Even with impossible around-the-clock-winds, he calculated this would require a wind farm covering over 301,159 square miles, which is about the size of Texas and Louisiana combined. It has been proven by real-world experience that solar and wind power schemes are far more costly than a simple price per kilowatt hour comparison would suggest. Their unreliable on-again, off-again nature requires huge backup power reserves from other energy sources, which greatly increases costs.
The Energy Information Administration, which provides official energy statistics from the U.S. Government, has projected the estimated cost of electricity from U.S. power plants of different varieties that will come into service in the year 2016. These average levelized costs, expressed in 2007 valued dollars, includes all costs of construction, financing, fuel, and all other operating costs. The EIA also listed the expected Capacity Factor (CF) for each power plant type. A power plant with a CF of 85 generates energy at its rated capacity an average of 85% of the time during a given year. The ideal power plant would have a CF of 100, meaning it could output energy at full power 100% of the time. As capacity factor drops, economic efficiency drops, usefulness drops, and real-world costs increase. In the comparison below I have inflated the projected cost of electricity produced by LFT reactors from the projected 3 cents per kilowatt hour (kWh) to 6 cents per kWh in order to allow for unexpected cost overruns.
Natural Gas in Conventional Combined Cycle @ 8.34 cents per kWh (87 CF) - Not carbon free; small footprint; cost effective and cleanest fossil fuel available.
Conventional Coal @ 9.3 per cents per kWh (85 CF) - Not carbon free; medium footprint; causes approximately 24,000 U.S. deaths per year due to air pollution, which also damages buildings. Judged in total, coal is not cost effective due to the environmental damage it creates.
3rd Generation Light Water Reactor Nuclear Power @ 10.48 cents per kWh (90 CF) - Carbon free; small footprint and cost effective.
Geothermal @ 11.67 cents per kWh (90 CF) - Carbon free; small footprint and cost effective.
Wind @ 11.55 cents per kWh (35.1 CF) - Carbon free; extremely large footprint; not cost effective due to unreliability and very low CF.
Solar Thermal Mirror Oven @ 25.75 cents per kWh (31.2 CF) - Carbon free; extremely large footprint; not cost effective due to unreliability, high construction cost, and very low CF.
Solar Photovoltaic Panel Power Plant @ 38.54 cents per kWh (21.7 CF) - Carbon free; extremely large footprint; very high construction cost; cannot be updated after manufacture; relatively short lifespan; solar panels are not cost effective for large scale power production.
LFT Nuclear Reactor @ 6.0 cents per kWh (over 90 CF) - Carbon free; small footprint; highest CF available; highest cost effectiveness. If things go well, the actual eventual cost per kWh may be at or close to the original 3 cents per kWh projection, which would be wonderful. LFT technology's tiny ecological footprint on planet earth makes it the most environmentally harmless energy source available.
Christopher Calder is an advocate for world food supply security with no financial interest in any energy related business.