The Coalition Against Nukes (CAN) is a citizens group dedicated to ending nuclear power. Their mission statement includes the following ideas:

            They are working to phase out all nuclear weapons and nuclear reactors. They are concerned about the tons of nuclear waste being generated by reactors that cannot be safely stored and disposed of and will be dangerous to life for thousands of years. They believe that the fact that nuclear waste produced by reactors can be used to develop nuclear weapons is a threat to world peace and stability. They are promoting the development and use of alternate sources of energy such as wind, sun, geothermal sources and flowing water. Conservation and boosting efficiency are also on their agenda. The core tenant of the organization is that all nuclear issues from uranium mining and refining to power generation to weapons proliferation must be approached as a single issue. Their activities include networking with elected officials, creating a circulating petitions, organizing peaceful marches and rallies, and disseminating information about why the nuclear industry must be stopped. They have a Nonviolent Action Code of Conduct on the website.

         Their media outreach includes press releases on nuclear issues, press kits on nuclear issues, lists of speakers at their events, downloadable posters advertising their events, rally event guides with transportation advice. The website includes a membership section where you can sign up for a newsletter and event bulletins. They also have a listserve which people are invited to join.

            They encourage people to take direct actions by writing letters to congressmen. There is a sample letter that can be downloaded and fields that can be filled in with your specific information. They have a nuclear free community program that provides a downloadable resolution document of concern about the Indian Point nuclear power plant. They suggest using the resolution document, which has been signed by 80 communities, as a template for drafting your own resolution of concern about a particular nuclear power plant in your area. And they encourage people to volunteer for CAN.

            Their donation page has a section for direct donations of under $250 via check, credit card or PayPal and another section for indirect donations through another organization called the Nuclear Information and Resource Service.

            September 20,21 and 22, CAN held the Rally for A Nuclear-Free Future, a major event in Washington, D.C. that was an umbrella for a number of different events including a big public rally at the Capitol, a congressional briefing, an evening of speakers and live music at Busboys and Poets, a protest at the Nuclear Regulatory Commission national offices, a presentation of anti-nuclear films at the Letelier Theater, and a ceremony about nuclear impact on Native Americans at the Museum of the American Indian.

           Congressman Dennis Kucinich sponsored the Congressional Briefing for elected Representatives that was part of the CAN program to promote greater awareness about critical issues complicating the use of nuclear power for energy generation.

The CAN website is http://www.coalitionagainstnukes.org

The CAN logo:

          There has been research in developing small thorium engines for consumer products like cars. Interest in such engines has increase recently with the concern about the decline in the oil supply and global warming. It is estimated that one gram of thorium contains the equivalent energy found in 7,500 gallons of gasoline.

          Cadillac debuted the Thorium Fueled Concept car designed by Loren Kulesus at the 2009 Chicago Auto Show. The design called for redundancy in all the major systems so that if a part failed, a backup part would take over. The car was supposed to last 100 years without need for replacement of parts or refueling. The design concept called for a small thorium powered nuclear reactor but the vehicle did not contain a real thorium engine. The reactor was to be contained in a study housing to prevent accidental or intentional tampering and had multiple systems to kill the reaction in case of any problems.

          A MaxFelaser is an example of a next generation table top accelerator that can support electrical fields much stronger than the old accelerators required. The thorium is inserted into a cavity laser. The alpha and beta particles released by the thorium triggers the lasing process. Power generation has been explored by the heating of a plasma and the utilization of magneto-hydrodynamics. Such generators have the potential to be small and powerful.

          It was announced last year that Laser Power Systems in Massachusetts is working on a prototype of a thorium powered “MaxFelaser” generator that could be used to generate enough energy to power a car which would produce no emissions. They says that the thorium will be heated to fire the MaxFelaser beam which will turn water into pressurized steam. The steam will turn a turbine that produces electricity. The steam will be condensed back into water and recycled in a closed system. A 250 kilowatt thorium power system will weigh around 500 pounds and be small enough to drop into the engine well of a regular sized car. The car is would be powered by feeding the generated electricity to motors in the hubs of the wheels.

          If such a power generation system can be developed it could be used for a myriad of other purposes such as powering buildings, ships, airplanes, trains, factories, etc. The problem with the Laser Power Systems claims is that there is very little information available about how their system actually works. Their website contains a lot of positive descriptions of the possibilities but very little technical detail. What I have read there does not make a lot of sense. I will feel much better about the reality of a thorium MaxFelaser generator when LPS actual puts a commercial unit on the market. Until then, I am afraid that I remain skeptical about the claims being made by Laser Power Systems.

Cadillac Thorium Fueled Concept car from autoblog.com:

          Nuclear batteries have been developed that utilize radioactive elements to generate electrical energy.  The first such battery was demonstrated in 1913 by Henry Moseley. There has been ongoing research since then in perfecting the technology. There are two basic designs for such batteries.

            Thermal converters utilize the heat generated by radioactive decay to generate electricity. Thermionic converter has a hot electrode that emits electrons to a cooler electrode. Radioisotope thermoelectric generators use thermocouples. Thermocouples generated electricity by joining two dissimilar materials, heating one material and cooling the other material causes electrons flow. Thermophotovoltaic cells convert infrared light (heat) into electricity. Alkai-metal thermal to electric converter has a ceramic aluminum barrier between a high pressure zone of sodium vapor and a low pressure zone where the sodium condenses into a liquid.

           Non-thermal converters do not depend on the direct conversion of heat into electricity. Direct charging generators consist of a capacitor with a layer of radioactive material on side of the insulator layer or vacuum. Electrons, positrons, alpha particles or fission products can be the charged particles that created the electrical charge which is tapped for power. Betavoltaics utilize electrons to generate electricity through semiconductor junctions. Alphavoltaics produce power through the use of alpha particles. Optoelectric generators have been designed that would generate electricity from luminescent materials excited by radioisotopes. Reciprocating electromechanical atomic batteries build up a static electric charge that bends a flexible plate until it touches another plate and discharges the charge, producing electrical power.

           Most nuclear batteries make use of radioisotopes that generate either low energy beta particles or low energy alpha particles. High energy particles would generate dangerous radiation that would require heavy shielding and increase the weight and size of the battery. Plutonium-238, curium 242, curium 2-44 and strontium-90 have been used in nuclear batteries. Tritium nickel-63, promethium-147 and technetium-99 have all been tested for potential use in nuclear batteries.

            Nuclear batteries are expensive and potential dangerous because they contain radioactive materials. They are also very long-lived and have a high energy density when compared to other types of batteries. There is a tradeoff between using radioisotopes which have a short half-life and generates greater power and radioisotopes which have a longer half-life and therefore a longer life as a battery. Efficiency in nuclear batteries varies from .1% to 8%. Nuclear batteries can last up to 20 years depending on the radioisotope used. They are very useful in applications which require reliable long term operation without needing any maintenance or replacement. They are especially important in space probes, underwater instruments, remote sensor stations and implantable devices such as pacemakers.

          Nanotechnology research is yielding new materials and structures that could lead to advanced designs for nuclear batteries that would have a twenty five year lifespan and would be small enough to be useful in powering tiny electronic devices.

Nuclear battery from the University of Missouri:

           In previous posts we have discussed thorium reactors based on solid fuels. There is another approach to creating a reactor that will burn thorium. Thorium and uranium can be dissolved in liquid composed of molten salts. The liquid is then pumped between a core and a heat exchanger where the heat is transferred generate steam.

           In the single liquid design, the thorium and uranium dissolved in the molten salts sit in a big reaction vessel with graphite rods for moderation. If breeding U-233 is needed, the core must be large. Considerable reprocessing is required to recover U-233. If not breeding U-233, then uranium refueling is required.

           In a two liquid design, there is a high density core that burns the U-233. There is a separate shell of thorium salts which absorbs neutrons and produces protactinium-233 which eventually decays to U-233. It is relatively easy to remove the U-233 from the outer shell and put it in the core for fuel. Benefits are simplified fuel processing with the thorium kept separate from the core and the smaller amount of fissile material required to start the reactor. There are concerns with the complexity of the graphite plumbing and the effect of neutrons on the graphite.

           There is a third design that is a hybrid of the first two. Thorium is included in the fuel in the core. This results in a mixture of the advantages and disadvantages of the first two designs.

           Between 1965 and 1969, the Molten-Salt Reactor Experiment was conducted at Oak Ridge National Laboratory (ORNL) to model the concept of a liquid fluoride thorium reactor. The functional core was built but the expensive thorium breeding blanket in the design was not included. Pyrolytic graphite was used as a moderator with a fluorine – lithium – beryllium compound as a secondary coolant. The fuel was a combination of molten lithium, beryllium, zirconium, fluorine salts with U-233 dissolved in the salts. It was turned on in 1965 and was operated successfully for the equivalent of 1.5 years reaching temperatures of 650 °C.

        Research continued at ORNL between 1970 and 1976 resulting the Molten Salt Breeder Reactor design for a thorium reactor. Thorium would be added to the molten salt mix, the secondary coolant would be a sodium – fluorine – beryllium compound. The reactor would have a maximum operating temperature of 650 °C. The funding was cancelled because the technology was not well understood and the AEC was allocating available funds to a different breeder reactor programmed based on uranium.

         There are many potential advantages to a thorium molten salt reactor. There is a lot of thorium available for fuel. The waste given off has less of the actinide transuranic wastes of uranium reactors and more short lived radioactive materials. They can be used to burn some types of reactor waste products reducing need for waste disposal. They can react to changes in electrical load demand in less than one minute, far faster than conventional commercial reactors. They operate at lower temperatures and pressures than conventional reactors. They make economical use of neutrons when compared to uranium reactors. These last two factors make it possible to build small thorium reactors which could be used in ships or even airplanes.

Molten Salt Reactor graphite core:   

   

          Between 1967 and 1989, 27 different experimental thorium reactors were designed and built to research the potential of thorium for nuclear fuel. These test reactors were built in Canada, Germany, India, the Netherlands, Norway, Sweden, Switzerland, the United Kingdoms, the United States. Here are some examples of thorium reactors. 

          The Shippingport Atomic Power Station in Pennsylvania was the first commercial nuclear power plant in the world in 1957. Between 1977 and 1982, they conducted  a test of what was called a seed-and-blanket fuel cycle in a light water reactor. The test generated a total of 1.2 gigawatt-hours of electricity over 29,000 power-hours.

          Germany created the THTR-300 gas cooled thorium reactor and operated it between 1985 and 1989. The fuel elements were six centimeter diameter balls. Each of these was filled with thirty five thousand half centimeter balls filled withTh-232 U-235 in a ration of ten to one. Layers of graphite was inserted between the balls to act as a moderator. Hydrogen was injected into the top of the reactor at 250° C and removed from the bottom of the reactor at 750° C. Fifty one control rods could be inserted from the top into the space between the rods. Six heat exchangers surrounded the core and transferred the heat from the helium to water to create steam which drove turbines.

           The THTR-300 produced seven hundred and fifty megawatts of thermal power and three hundred and seven megawatts of electrical power. The efficiency was around forty percent as compared to the thirty percent efficiency of standard uranium light water reactors. Some of the thorium was converted to uranium so t he reactor actually produced some of its own fuel.

           India has large reserves of thorium and is working on the creation of thorium reactors to exploit this resource. Tests have been run which utilize CANDU reactors which can utilize thorium as a fuel. Construction of the ASWR pressurized heavy water reactor began in 2011. The start up process will utilize plutonium to convert Th-232 to U-233. After that, the only fuel used in the reactor will be thorium.

            The United States is working on the HT³R Project near Odessa, Texas. The main fuel of the reactor will be bead of thorium coated with ceramic material. The earliest date of operation for that reactor will be in 2015.

            For the most part, experiments with thorium as a reactor fuel have been unsuccessful. There have been fuel failures where fuel elements disintegrated, cladding melted, or fuel has exploded. The tests have not proven the viability of thorium as a fuel for a new generation of nuclear power reactors. The most successful tests have been run by Atomic Energy of Canada Limited with CANDU reactors. The availability of cheap uranium and the problems with thorium fuel tests have prevented the development of commercial thorium reactors. The potential benefits and the availability of thorium indicate that research on thorium fuel should continue.

 Germany’s THTR-300 thorium reactor:

 

          Between 1967 and 1989, 27 different experimental thorium reactors were designed and built to research the potential of thorium for nuclear fuel. These test reactors were built in Canada, Germany, India, the Netherlands, Norway, Sweden, Switzerland, the United Kingdoms, the United States. Here are some examples of thorium reactors.  

          The Shippingport Atomic Power Station in Pennsylvania was the first commercial nuclear power plant in the world in 1957. Between 1977 and 1982, they conducted  a test of what was called a seed-and-blanket fuel cycle in a light water reactor. The test generated a total of 1.2 gigawatt-hours of electricity over 29,000 power-hours.

          Germany created the THTR-300 gas cooled thorium reactor and operated it between 1985 and 1989. The fuel elements were six centimeter diameter balls. Each of these was filled with thirty five thousand half centimeter balls filled withTh-232 U-235 in a ration of ten to one. Layers of graphite was inserted between the balls to act as a moderator. Hydrogen was injected into the top of the reactor at 250° C and removed from the bottom of the reactor at 750° C. Fifty one control rods could be inserted from the top into the space between the rods. Six heat exchangers surrounded the core and transferred the heat from the helium to water to create steam which drove turbines.

           The THTR-300 produced seven hundred and fifty megawatts of thermal power and three hundred and seven megawatts of electrical power. The efficiency was around forty percent as compared to the thirty percent efficiency of standard uranium light water reactors. Some of the thorium was converted to uranium so t he reactor actually produced some of its own fuel.

           India has large reserves of thorium and is working on the creation of thorium reactors to exploit this resource. Tests have been run which utilize CANDU reactors which can utilize thorium as a fuel. Construction of the ASWR pressurized heavy water reactor began in 2011. The start up process will utilize plutonium to convert Th-232 to U-233. After that, the only fuel used in the reactor will be thorium.

            The United States is working on the HT³R Project near Odessa, Texas. The main fuel of the reactor will be bead of thorium coated with ceramic material. The earliest date of operation for that reactor will be in 2015.

            For the most part, experiments with thorium as a reactor fuel have been unsuccessful. There have been fuel failures where fuel elements disintegrated, cladding melted, or fuel has exploded. The tests have not proven the viability of thorium as a fuel for a new generation of nuclear power reactors. The most successful tests have been run by Atomic Energy of Canada Limited with CANDU reactors. The availability of cheap uranium and the problems with thorium fuel tests have prevented the development of commercial thorium reactors. The potential benefits and the availability of thorium indicate that research on thorium fuel should continue.

Germany’s THTR-300 thorium reactor:

          The thorium fuel cycle is based on the use of the common isotope Th-232 as what is called the fertile material in the reactor. Natural thorium is not fissile meaning that it cannot create self-sustaining reactor. The Th-232 must be transmuted into the fissile material, U-233, via neutron capture. The U-233 is the actual nuclear fuel for the reactor.

          When bombarded by slow neutrons, Th-232 atoms absorb a neutron and becomes Th-233. The Th-233 atom then emits an electron to become protactinium-233. The Pa-233 atom then emits an electron and becomes U-233.     

          Ninety two percent of the time, when a thermal neutron hits a U-233 atom, that atom will split into lighter fission produced atoms.  The other eight percent of the time, the atom absorbs the neutron and becomes U-234. At each stage of neutron collision, a small percent of collisions produce transmutation so diminishing at each stage from U-234 to U-235 to U-236 to Np-237 to Pu-238 to Pu239 and heavier isotopes of plutonium. The plutonium can be used as a fuel and the other elements produced can be extracted as waste or recycled into reactors be converted into lighter fission products.

          Protactinium-131 can interact with Th-232 yielding Th-231 which decays to Pa-231. Pa-231 is radioactive and has a half-life of 3,270 years. It is a major contributor to long term radioactive waste. This production of radioactive wastes from thorium reactors is much less than the production of radioactive wastes in reactors fueled by uranium or combinations of uranium and plutonium.

          Uranium-232 is also produced in the thorium fuel cycle. It has a half-life of about seventy years and its decay path through Th-228  produce high energy gamma radiation .The hard gamma radiation produced by the thorium fuel cycle can harm electronics and requires remote handling during reprocessing Chemical removal of the Th-228 from the uranium can remove the gamma radiation threat.

          Thorium is three times as efficient at absorbing thermal neutrons as U-238. The U-233 captures fewer neutrons than U-235 and Pu-239 meaning that thorium makes more economic use of neutrons. And, the U-233 emits more neutrons than it absorbs so thorium reactors can be used to breed more uranium fuel.

          Thorium oxide used in thorium reactors has a higher melting point, higher thermal conductivity, less thermal expansion and greater chemical stability than the uranium oxide used in conventional uranium reactors. The U-233 that a thorium reactor produces is contaminated with U-232 which makes it useless as a source of feed stock for nuclear weapons materials. Thorium reactors produces much less of the heavily radioactive transuranics produced by uranium reactors.

           Thorium fuel is harder to fabricate than uranium fuel. The Pa-233 that develops in thorium fuels reduces the neutron economy. Once-through thorium reactors produces long lived radioactive waste. Recycling thorium fuel requires special handling to deal with the high levels of gamma radiation.

          Thorium is the 36^th most abundant element on Earth. It is four times more abundant than uramium. There has been no concerted international effort to exlplore for deposits thorium ores. Accurate estimates of world reserves of thorium are not available.  Known thorium deposits could supply a major part of the Earth’s energy needs for hundreds of years. Some estimates are as high as 1000 years at current world energy use. There are deposits of thorium in Australia, Brazil, Canada, Greenland, India, South Africa and the United States.

            In the U.S., it is estimated that there are 300,000 tons of thorium ore, half of which is easily extractable. The 150,000 tons that are readily available are equivalent to about 1 trillion barrels of oil. This is over 5 times the estimated oil reserves of Saudi Arabia. Two companies currently have major thorium ore claims, one in the mountains on the border between Idaho and Montana and the other in the Pea Ridge area of Montana.

           The most common thorium ore is a phosphate ore called monazite which can contain up to 12% thorium. The known reserves of monazite are esimated to be up to 1.2 million tons. Two thirds of these reserves are in heavy mineral sands on the south and east coasts of Indian. Monazite ore also contains important strategic rare earth metals such as creium, lantahnum, neodymium, yttrium and iridium.

Currently thorium is considered a waste product of processing of rare earth metals. It is thrown away with the rare earth mine tailings. The U.S. has recently imported thorium from France that was produced as a by-product of rare earth ore processing.

          There currently over 3000 metric tons of processed thorium nitrate buried in the Nevada dessert at the Frenchman Flats area of the Department of Energy site. This material was generated by the U.S. nuclear program between the years of 1957 and 1964. It was contained in 21,000 drums which were buried in pits with twenty feet of soil over them. This thorium could conceiveablely recovered and used to create nuclear fuel to jump start a thorium reactor program.

           It is difficult to estimate the ultimate cost of thorium as a fuel supply for nuclear reactor. It is not currently being mined for fuel but there are known bodies of ore that could be easily exploited. Thorium would be much less difficult and expensive to process than uranium because the naturually occuring thorium is mainly one isotope and does not have to be enriched. This means that one ton of thorium can produce the energy of 200 tons of uranium. In addition, the rare earths that can be recoved during thorium mining and processing are valuable and would lower the cost further.

Thorite ore from Ontario: 

   

           I have already written about thorium under the general subject of nuclear reactors. I have decided to cover thorium in more depth because of its possible use as a nuclear fuel.

          Thorium is a radioactive element with the symbol Th and the atomic number 90. It was discovered in 1828 by the Swedish chemist Jons Jacob Berzelious. The element was named for Thor, the hammer wielding Norse god.

         Thorium is a silvery-white metal that is soft and ductile. It oxidizes slowly and the chemical properties are strongly affected by the degree of oxidation. Powdered thorium is pyrophoric which means that it can spontaneously burst into flame when exposed to open air. Thorium can form compounds with oxygen, hydrated nitrogen and fluoride, carbon, and phosphate.

         Thorium has 33 isotopes, all of them radioactive. They range in atomic weight from 209 to 238. Their half-lives vary from Th-220 at 9 millionths of a second to Th-232 at 14 billion years, about the current age of the universe. Six of the isotopes of thorium occur in nature, mostly Th-232. Traces of Th-230 occur as a result of the decay of U-238. Most isotopes of thorium emits positrons and decays to radium. In rare cases some isotopes emit alpha particles and decay to actinium.  Th-232 can decay to radium, uranium, ytterbium and neon. Isotopes above 232 emit electrons and decay to protactinium-233. When bombarded with a neutron source, Th-232 can absorb neutrons and then decay to protactinium. Protactinium in turn decays to uranium-233.  

          Natural thorium is found in most soil and rock on Earth. It about four times as abundant in the earth’s crust as uranium, three times as abundant as tin and about the same abundance as lead. It occurs in several minerals including thorite with oxygen and silicon, thorianite combined with oxygen and monazite which is a phosphate mineral containing rare earth metals. Rare earth metal mining and extraction produce thorium as a byproduct.

           A common use of thorium was as a component in alloys such as a magnesium alloy called Mag-Thor that was used in the aerospace industry for engines because of its stability at high temperatures. It has also been used in electronic applications and welding rods.  Thorium dioxide has a very high melting point and was used in the mantles of gas lamps and as an additive for high temperature ceramics and laboratory glassware Recent concerns over radioactivity have ultimately made thorium and thorium dioxide unattractive for these application.

          Breathing large amounts of thorium dust has been shown to lead to lung disease or lung cancer. Thorium in the bloodstream can cause liver cancer, pancreatic cancer, leukemia, bone cancer, kidney cancer, and cancer of the spleen. Being around mining and processing facilities for uranium, phosphate or tin ore or nuclear waste can result in thorium exposure. Injection of thorium compounds for contrast enhancement in x-rays has been shown to be a health threat.

Thorium crystal:

          Polonium is a chemical element with the symbol Po and an atomic number of 84. It was discovered in 1898 by Marie and Pierre Curie and named after Poland where Marie was born. They removed uranium and thorium from pitchblende ore and discovered that the ore became more radioactive. Polonium was the first new radioactive element they discovered in the processed ore.

          Polonium is metallic and related bismuth and tellurium in the periodic table of elements. All the compounds containing polonium have been created in laboratories. It can be combined with hydrogen, oxygen, the halides, carbon, nitrogen, sulfur and other elements.

          Polonium has no stable isotopes, all 33 of its isotopes are radioactive. They range in atomic weight from 188 to 220 with half-lives varying from 115 nanoseconds for Po-205m4 to Po-102 years for Po-209. Most of the isotopes decay to lead by emitting an alpha particle. Rarely, polonium isotopes decay to bismuth via beta particle (positron) emission.

          Polonium is very rare because of the rapid decay of most of its isotopes. Approximately one tenth of a milligram will be found in one metric ton uranium ore. Po-210 with a half-life of 138 days is the most common isotope.

          Polonium can be extracted from uranium ore but it is difficult and expensive. Commercial polonium is created by bombardment of other elements in nuclear reactor which then decay to polonium. One of the major uses of polonium is in static eliminators. Foils which contain polonium are used in production equipment for materials whose production is accompanied by the generation of static electricity. It is also used to remove particles in clean rooms for the production of computer chips. Polonium is combined with beryllium to make sources of neutrons. Polonium has been used in thermionic power generators for satellites.

          Polonium which is ingested or inhaled is eliminated from the human body via feces. A small amount of inhaled polonium remains in the lung. About half of the portion which remains in the body tends to accumulate in the spleen, kidneys and spleen. The rest is found in bone marrow and distributed throughout the body in the blood and lymphatic fluid. The alpha particles emitted from polonium can disrupt cell structures, tear DNA strands, damage DNA and cause the death of cells.  Ultimately it can injure major organs, the immune system and cause death.

         There is no real danger from naturally occurring polonium. Proper handling will minimize the danger associated with commercial use. But there is a unique danger from man-made polonium because it has been used as an assassin’s weapon for eliminating political enemies. A piece of polonium the size as a grain of salt can kill an adult human. By mass, polonium is about 250,000 times more poisonous than hydrogen cyanide, a well known poison. A lethal dose would never be tasted or smelled when ingested or inhaled. Since it is hard to diagnose if you are not looking for radiation poisoning and the illness takes time to develop, it may escape detection.

        Alexander Litvinenko was a officer in a Soviet security service who fled to England and received political asylum. He cooperated with the British intelligence services and wrote books about conditions in Russia. In 2006 he suddenly fell ill and eventually die. It was determined that he had been poisoned with polonium by Russian agents.

        The theory had been advanced that Yasser Arafat of the PLO was killed by polonium poisoning. Traces of this rare element have been found on his personal effects and there have been requests for an exhumation of his body so that an autopsy can be performed. If his death was murder, there are several suspect organizations which would have benefitted from his death.

          Alexander Litvinenko picture from codkaxorriyadda.net: