Nuclear power plants breeder reactor

The most common use of uranium is to convert the rare isotope U-235, which is naturally fissionable, into plutonium through neutron capture. Plutonium, through controlled fission, is used in nuclear reactors to produce energy, heat, and electricity. Breeder reactors convert the more abundant, but nonfissionable, uranium-238 into the more useful and fissionable plutonium-239, which can be used for the generation of electricity in nuclear power plants or to make nuclear weapons. 

One can consider other energy options. For example, to supply 40 to 60 Terawatts of energy via nuclear fission is possible, it could be done. However it necessitates increasing by almost a factor of x500 the number of nuclear power plants ever built. The consequence of such demand is that we would soon deplete earth s uranium supplies. Breeder reactors are an un-stable possibility, like mixing matches, children, and gasoline. Depending upon ones viewpoint fusion remains either a to be hoped for miracle, or an expensive civil-works project. 

One of the many problems of nuclear power is the availability of fuel uranium-235 reserves are only about 0.7% those of the nonfissile uranium-238, and the separation of the isotopes is costly (Section 17.12). One solution is to synthesize fissile nuclides from other elements. In a breeder reactor, a reactor that is used to create nuclear fuel, the neutrons are not moderated. Their high speeds result in the formation of not only uranium-235 but also some fissile plutonium-239, which can be used as fuel (or for warheads). However, breeder reactors are more hazardous to operate than nuclear power plants. They run very hot, and the fast reactions require more careful control than a reactor used for nuclear power generation. Because of safety concerns, their use is still controversial. 

The Experimental Breeder Reactor EBR-1 was the first power reactor and the first fast neutron reactor. It was put in service in 1951 on the site of Idaho in the United-States and it became the world s first electricity-generating nuclear power plant when it produced sufficient electricity to illuminate four 200-watt light bulbs. 

By 2040-2050, natural gas reserves will be in very short supply, and the production of coal will quite likely be approaching peak production levels.19. While nuclear power plants are a source of large scale electricity generation, there exist major concerns regarding uranium supply (without breeder reactors), safety, waste disposal, and nuclear weapon proliferation. Therefore, it is prudent to explore the economic feasibility of other fuel sources such as PV electrolytic H2 for centralized, electricity generating plants. 

A breeder reactor at a nuclear power plant in St. Laurent-Des Eaux, France. 

The source of energy in a nuclear reactor is a fission reaction in which neutrons collide with nuelei of uranium-235 or plutonium-239 (the fuel), causing them to split apart. The products of a fission reaction include not only energy but also new elements (known as fission products) and free neutrons. A constant and reliable flow of neutrons is insured in the reactor by a moderator, which slows down the speed of neutrons, and by control rods, which limit the number of neutrons available in the reactor and, hence, the rate at which fission can occur. In a nuclear weapon, the fission chain reaction, once triggered, proceeds at an exponentially increasing rate, resulting in an explosion in a nuclear reactor, it proceeds at a steady, controlled rate. Most commercial nuclear power plants are incapable of undergoing an explosive nuclear chain reaction, even should their safety systems fail this is not true of all research reactors (e.g., some breeder reactors). 

O How is a typical nuclear power plant in the United States different from a breeder reactor commonly used in Europe ... 

The fission of U-235 is used exclusively in nuclear power plants located in the United States. There are many different fission reactions of U-235, but all the fission reactions are self-sustaining chain reactions. Explain. Differentiate between the terms critical, subcritical, and supercritical. What is the critical mass How does a nuclear power plant produce electricity What are the purposes of the moderator and the control rods in a fission reactor What are some problems associated with nuclear reactors What are breeder reactors What are some problems associated with breeder reactors ... 

The Compact Sodium-cooled Nuclear Reactor Facility (KNK) was an experimental nuclear power plant of 20 MW electric power erected on the premises of the Karlsruhe Research Center. The plant was initially run as KNK I with a thermal core between 1971 and 1974 and then, between 1977 and 1991, with a fast core as the KNK II fast breeder plant. 

The more familiar sodium-cooled reactor is the liquid metal-cooled fast-breeder reactor (LMFBR). The Enrico Fermi nuclear power plant was built in Lagoona Beach, Michigan, in 1966. The reactor operated at 61 MWe unhl 1972. Reactors of this type have the advantage of operating at relatively low pressure. 

Uraniuin-235 is capable of sustaining a chain reaction, but it makes up only 0.7% of all naturally occurring uranium. Therefore, it is not a very satisfactory source of nuclear fuel (Fig. 20.16). An alternative is the plutonium isotope, Pu, produced from the most abundant uranium isotope (Equations 20.4 to 20.6). Pu has a long half-life (24,360 years) and is fissionable. It has been used in the production of atomic bombs and is also used in some nuclear power plants to generate electrical energy. It is made in a breeder reactor, the name given to a device whose purpose is to produce fissionable fuel from nonfissionable isotopes. 

Z = 92—can be produced via nuclear bombardment in a particle accelerator. 6. Nuclear fission is a nuclear reaction in which a large nucleus splits into two smaller nuclei. A nuclear power plant uses the energy released in a fission reaction to generate electricity. Nuclear fusion is a nuclear reaction in which two small nuclei combine to form a larger nucleus. Solar energy is an example of a fusion reaction. 7. A chain reaction has one of its own reactants as a product, allowing the original reaction to continue. The minimum quantity of matter necessary for a chain reaction to continue is its critical mass. A breeder reactor is a nuclear reactor in which fissionable fuel is produced from nonfissionable isotopes. 

This appendix provides additional materials (schematics, layouts, T—s diagrams, basic parameters, and photos) on advanced thermal (combined cycle and supercritical pressure Rankine steam turbine cycle) power plants and nuclear power plants with modern nuclear power reactors [pressurized water reactors (PWRs), boiling water reactors (BWRs), pressurized heavy water reactors (PHWRs), advanced gas-cooled reactors (AGRs), gas-cooled reactors (OCRs), light water-cooled graphitemoderated reactors (LGRs) (RBMKs and EGPs), and liquid metal fast-breeder reactors (LMFBRs) (BN-600 and BN-800)]. 

Along with these power plants, the U.S. could build up a fuel reprocessing capability to allow spent nuclear fuel to be reused which would lower fuel cost and eliminate the storage of high-level nuclear waste. Fuel for the reactors has been estimated to be available for 1,000 years using standard reactors with high breeding ratios and breeder reactors where more fuel is produced than consumed. 

Nuclear fission power plants were at one time thought to be the answer to diminishing fossil fuels. Although the enriched uranium fuel was also limited, an advanced nuclear reactor called breeders would be able to produce more radioactive fuel, in the form of plutonium, than consumed. This would make plutonium fuel renewable. Although plutonium has been called one of the most toxic elements known, it is similar to other radioactive materials and requires careful handling since it can remain radioactive for thousands of years. 

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