Nuclear fast breeder reactors

Reviews of analytical methods for impurities in alkali metals are largely devoted to Na and K owing to their use as liquid coolants in fast-breeder nuclear reactors ". These methods may be extended to Rb and Cs except the analysis for oxygen. In analytical work with the alkali metals, care is necessary during sampling and handling to avoid contamination in transit. The impurities usually considered are O, C, N, H and metals. 

In a typical fast breeder nuclear reactor, most of the fuel is 238U (90 to 93%). The remainder of the fuel is in the form of fissile isotopes, which sustain the fission process. The majority of these fissile isotopes are in the form of 239Pu and 241Pu, although a small portion of 235U can also be present. Because the fast breeder converts die fertile isotope 238 U into the fissile isotope 239Pu, no enrichment plant is necessary. The fast breeder serves as its own enrichment plant. The need for electricity for supplemental uses in the fuel cycle process is thus reduced. Several of the early hquid-metal-cooled fast reactors used plutonium fuels. The reactor Clementine, first operated in the Unired States in 1949. utilized plutonium metal, as did the BR-1 and BR.-2 reactors in the former Soviet Union in 1955 and 1956, respectively. The BR-5 in the former Soviet Union, put into operation in 1959. utilized plutonium oxide and carbide. The reactor Rapsodie first operated in France in 1967 utilized uranium and plutonium oxides. 

Liquid sodium is used to cool liquid-metal fast-breeder nuclear reactors. 

Sodium is also used, especially in alloys with potassium, as a heat-exchange liquid in fast breeder nuclear reactors. Sodium alloys with calcium, lead, copper, silver, gold, zinc, cadmium, and mercury are also industrially formed and used. 

As it was mentioned, boron carbide containing enriched elemental boron ( B 65 at%) can serve as the control rod material in fast breeder nuclear reactors. Because boron carbide is fabricated by reacting elemental boron with carbon and the elemental boron in turn is produced by electro-winning process, Jain et al. (2011) have carried out studies to explore the viability of a high-temperature molten salt electro-winning process for the large-scale production of °B isotopically enriched elemental boron. It was established that elemental boron powder with a purity of better than 95 wt% could be produced. 

Industrial uses of sodium are based primarily on its strong reducing properties. A large part of the annual sodium production is needed to produce the gasoline antiknock agents tetramethyllead and tetraethyllead. It is also employed for the reduction of titanium and zirconium chlorides to produce titanium and zirconium metals. The remaining part of sodium is used to produce compounds such as sodium hydride, sodium alkoxides, and sodium peroxide. Sodium is also used, especially in alloys with potassium, as a heat exchange liquid in fast-breeder nuclear reactors. 

Sodium occurs widely as NaCl in seawater and as deposits of halite in dried-up lakes etc. (2.6% of the Earth s crust). The element is obtained commercially via the Downs process by electrolysis of NaCl melts in which the melting point is reduced by the addition of calcium chloride sodium is produced at the steel cathode. The metal is extremely reactive, vigorously so with the halogens and also with water, in the latter case to give hydrogen and sodium hydroxide. It is used as a coolant in fast-breeder nuclear reactors. The chemistry of sodium is very similar to that of the other members of group 1. 

The Dounreay site was established as the site of the UK Fast Breeder Nuclear programme in 1955 and became operational in 1958. It accommodated three reactors, the Materials Test Reactor, (DMTR, 1958-1969), the Dounreay Fast Reactor (DFR, 1959-1977) and the Prototype Fast Reactor (PFR, 1974-1994). With all reactor operations now finished and the reactors already de-fuelled the site is undergoing active decommissioning which is planned to be completed by 2032. The Dounreay site has been cited by UKAEA as being the second biggest nuclear decommissioning challenge in the UK with similar liabilities to those at Sellafield but with smaller waste volumes. 

Mitsubishi Heavy Industries computer code CHAMPAGNE is a multi-phase, multi-component thermodynamics model originally created for the assessment of severe accidents in fast breeder nuclear power reactors. It was recently modified to also treat the formation and spreading of hydrogen gas clouds. CHAMPAGNE has been successfully applied both as a 2D and 3D version to the NASA LH2 spill tests from 1980 (Fig. 8-9) [30]. 

Ganguly.C. et al - Development and fabrication of 70% PuC 30% UC fuel for Fast Breeder Test Reactor in India, Nuclear Technology, Vol 72, Jan 86. 

The fast breeder test reactor (FBTR) is a loop type reactor located at Kalpakkam, India. The reactor has been operated for 27 600 h till now at various power levels up to 17.4 MW(t). The peak bum up of 90 000 MW d/T was achieved in the 70% PuC + 30% UC Mark-I fuel. Turbo Generator was synchronized to the grid with the nuclear steam to check its performance. Continued operation of TG is planned at high power. The post irradiation examination of the... 

RAMALINGAM, P.V., et. al., Operating experience of fast breeder test reactor, Proc. 7 International Conference on Nuclear Engineering, 19-23 April 999, Tokyo, ICONE-7337 (1999). 

The difference between thermal (e.g., light-water reactors) and fast reactors (fast breeder, nuclear weapons) is in the energy of the neutrons inducing the fission reaction. The reason for the distinction is the reaction cross sections for fission in ( Pu) and for competing (n,y)-reactions mainly in the main component of the fuel elements. 

Fig. 11. Reactor core of MONJU, the Japanese fast-breeder reactor. Courtesy of Power Reactor and Nuclear Fuel Development Corp.

Fast Breeder Reactors" uader "Nuclear Reactors" ia ECT3rd ed., VoL 16, pp. 184—205, by P. Murray, Westiaghouse Electric Corp. 

P. V. Evans, ed.. Fast Breeder Reactors, Proceedings of the London Conference on Past Breeder Reactors of the British Nuclear Energy Society, May... 

Many of the fission products formed in a nuclear reactor are themselves strong neutron absorbers (i.e. poisons ) and so will stop the chain reaction before all the (and Pu which has also been formed) has been consumed. If this wastage is to be avoided the irradiated fuel elements must be removed periodically and the fission products separated from the remaining uranium and the plutonijjm. Such reprocessing is of course inherent in the operation of fast-breeder reactors, but whether or not it is used for thermal reactors depends on economic and political factors. Reprocessing is currently undertaken in the UK, France and Russia but is not considered to be economic in the USA. 

Several alternative technologies that were heavily supported failed to become commercially viable. The most obvious case was the fast breeder reactor. Such reactors are designed to produce more fissionable material from nonfissionable uranium than is consumed. The effort was justified by fears of uranium exhaustion made moot by massive discoveries in Australia and Canada. Prior to these discoveries extensive programs to develop breeder reactors were government-supported. In addition, several different conventional reactor technologies were aided. The main ongoing nuclear effort is research to develop a means to effect controlled fusion of atoms. 

The phrase "nuclear power" covers a number of technologies for producing electric power other than by burning a fossil fuel. Nuclear fission in pressurized water-moderated reactors—light water reactors— represents the enrrent teehnology for nuclear power. Down the line are fast breeder reactors. On the distant horizon is nnclear fusion. 

Y. S. Tang. Ph.D has more than 35 years of experience in the field of thermal and fluid flow. His research interests have covered aspects of thermal hydraulics that are related to conventional and nonconventional power generation systems, with an emphasis on nuclear reactor design and analysis that focuses on liquld-meta -cooled reactors. Dr. Tang is co-author of Radioactive Waste Management published by Taylor 8 Francis, and Thermal Analysis of Liquid Metal Fast Breeder Reactors, He received a B5. from National Central University In China and an MS. in mechanical engineering from the University of Wisconsin. He earned his Ph.D. 

With respect to the future availability of nuclear fuels, among the above concepts, fast breeder designs are of particular interest. In the following, their characteristics as compared with conventional reactor designs are described. For a better understanding, the nuclear fuel options are addressed first. 

Since plutonium is the actinide generating most concern at the moment this review will be concerned primarily with this element. However, in the event of the fast breeder reactors being introduced the behaviour of americium and curium will be emphasised. As neptunium is of no major concern in comparison to plutonium there has been little research conducted on its behaviour in the biosphere. This review will not discuss the behaviour of berkelium, californium, einsteinium, fermium, mendelevium, nobelium and lawrencium which are of no concern in the nuclear power programme although some of these actinides may be used in nuclear powered pacemakers. Occasionally other actinides, and some lanthanides, are referred to but merely to illustrate a particular fact of the actinides with greater clarity. 

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