Breeder reactors could, in principle, extract almost all of the energy contained in uranium or thorium, decreasing fuel requirements by a factor of 100 compared to traditional once-through light water reactors.
The uranium-235 isotope is the nuclear fuel used for energy generation via nuclear fission of in a typical power reactor. Each kilogram of uranium-235 fissioned releases the energy equivalent of millions of times its mass in chemical reactants, as much energy as 2700 tons of coal, but uranium-235 is only 0.7% of the mass of natural uranium.
The 235U consumption (linked to various factors as electricity generated by nuclear power plants, population growth, oil and coal consumption, etc) will lead to vanishing of U enriched ores in the near future.
It is generally recognized that long-term development of nuclear power as a part of the world's future energy mix will require the use of a new technology that produce a minimum amount of nuclear waste. This new technology is the so-called “fast reactor technology” with closed fuel cycle. The fast neutron spectrum allows fast reactors to increase the energy yield from natural uranium by a factor of sixty to seventy compared to thermal reactors, granting therefore realization of nuclear power programmes for thousands of years, as well as a significant improvement of nuclear waste management. It is for these reasons that fast reactors have been under development for decades in several countries, primarily as breeders and, in recent years, also as High-Level Waste burners.
The necessary condition for successful deployment in the near and mid-term is the understanding and assessment of technological and design options, based on both past knowledge and experience, as well as on scientific and technological research efforts.
With regard to the first, the design and operation of several sodium-cooled fast reactors, such as the Fast Flux Test Facility (FFTF) in USA, the small size Prototype Fast Reactor in the United Kingdom, the prototype Phénix in France, the BN-350 in Kazakhstan, the demonstration plant BN-600 in Russia, Monju in Japan, the commercial size Superphénix in France, etc. have provided an operational experience base of about 400 reactor-years. In addition, there is a considerable base of experience with lead-bismuth (eutectic) cooled propulsion (submarine) reactors operated in Russia.
According to IAEA sources, examples of current sodium-cooled fast reactors are the China Experimental Fast Reactor (CEFR), which has been connected to the grid in July 2011, the Russian BN-800 and the Prototype Fast Breeder Reactor (PFBR) in India, both under construction.
Besides current fast reactors construction projects, several countries are engaged in intense research and development programmes for the development of fast reactors innovative (GENIV) concepts. In order to establish multilateral international cooperative frameworks to carry out R&D in support to the next generation nuclear reactors, the following initiatives have been launched:
the Generation IV International forum (GIF)
the IAEA - International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO)
European Sustainable Nuclear Industrial Initiative (ESNII)
Fast Reactors Data (as of December 2011)
Fast Reactors in the World (experimental, demonstration and power reactors)
Number of units in operation/non-permanent shutdown 6
Number of units under construction 2
Number of countries with/constructing fast reactors 4
It is generally recognized that long-term development of nuclear power as a part of the world's future energy mix will require the use of a new technology that produce a minimum amount of nuclear waste. This new technology is the so-called “fast reactor technology” with closed fuel cycle. The fast neutron spectrum allows fast reactors to increase the energy yield from natural uranium by a factor of sixty to seventy compared to thermal reactors, granting therefore realization of nuclear power programmes for thousands of years, as well as a significant improvement of nuclear waste management. It is for these reasons that fast reactors have been under development for decades in several countries, primarily as breeders and, in recent years, also as High-Level Waste burners.
The necessary condition for successful deployment in the near and mid-term is the understanding and assessment of technological and design options, based on both past knowledge and experience, as well as on scientific and technological research efforts.
With regard to the first, the design and operation of several sodium-cooled fast reactors, such as the Fast Flux Test Facility (FFTF) in USA, the small size Prototype Fast Reactor in the United Kingdom, the prototype Phénix in France, the BN-350 in Kazakhstan, the demonstration plant BN-600 in Russia, Monju in Japan, the commercial size Superphénix in France, etc. have provided an operational experience base of about 400 reactor-years. In addition, there is a considerable base of experience with lead-bismuth (eutectic) cooled propulsion (submarine) reactors operated in Russia.
According to IAEA sources, examples of current sodium-cooled fast reactors are the China Experimental Fast Reactor (CEFR), which has been connected to the grid in July 2011, the Russian BN-800 and the Prototype Fast Breeder Reactor (PFBR) in India, both under construction.
Besides current fast reactors construction projects, several countries are engaged in intense research and development programmes for the development of fast reactors innovative (GENIV) concepts. In order to establish multilateral international cooperative frameworks to carry out R&D in support to the next generation nuclear reactors, the following initiatives have been launched:
the Generation IV International forum (GIF)
the IAEA - International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO)
European Sustainable Nuclear Industrial Initiative (ESNII)
Fast Reactors Data (as of December 2011)
Fast Reactors in the World (experimental, demonstration and power reactors)
Number of units in operation/non-permanent shutdown 6
Number of units under construction 2
Number of countries with/constructing fast reactors 4
I read that sodium cooled reactors are unstable because if there is a leak, it could get fire and radioactive releases to the atmosphere. It is impossible to use water to cool it down as it was done at Fukushima after the disaster by the firemen.
If sodium is used, use as lass as possible and take in account that all the sodium could gets in contact with water when designing the reactor containment (or wait until the next accident to stop this kind of reactors)
It is possible using fast reactors to recycle actual used fuel? I read it is stored enough fuel for 100 years operation
Generally speaking, GenIV reactor should be able more "flexible" concerning their fuel. This is due to the fast neutron spectrum, making more or less all nuclides to look the same (fission at 1 barn, capture very low).
The use of one fuel or the other is more due to waste and breeding considerations.
"....vanishing of U enriched ores in the near future" is not a real problem.
Uranium is a relatively common element in the crust of the Earth (very much more than in the mantle). It is a metal approximately as common as tin or zinc, and it is a constituent of most rocks and even of the sea.
An ore body is, by definition, an occurrence of mineralisation from which the metal is economically recoverable. It is therefore relative to both costs of extraction and market prices. At present neither the oceans nor any granites are ore bodies, but conceivably either could become so if prices were to rise sufficiently.
At ten times the current price, seawater might become a potential source of vast amounts of uranium. Thus, any predictions of the future availability of any mineral, including uranium, which are based on current cost and price data and current geological knowledge, are likely to be extremely conservative.
Today uranium is the only fuel used for nuclear reactors. However, thorium can also be utilised as a fuel for reactors specially designed for this purpose. Neutron efficient reactors, such as CANDU, are capable of operating on a thorium fuel cycle, once they are started using a fissile material such as U-235 or Pu-239. Then the thorium (Th-232) atom captures a neutron in the reactor to become fissile uranium (U-233), which continues the reaction. Some advanced reactor designs are likely to be able to make use of thorium on a substantial scale.
The thorium fuel cycle has some attractive features, though it is not yet in commercial use. Thorium is reported to be about three times as abundant in the earth's crust as uranium.
Was the original question "can U238 be used as a fuel and fissioned by the fast neutrons (not using conversion to Pu239)"?
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