Fuel for Fusion

The deuterium fuel for fusion reactions is present in a virtually inexhaustible supply in the world oceans. 

Lithium aluminates have a potentially important role in the development of new types of nuclear reactors [78-81], This role is a result of the nuclear reaction between the 6Li isotope and neutrons 6Li(n,a), which results in a tritium (3H) ion. The natural abundance of 6Li is 7.5%, so ceramics can be made without any need for isotopic enrichment. The 3H ions are the plasma fuel for fusion devices. The design of the... 

Although the isotopes of an element have very similar chemical properties, they behave as completely different substances in nuclear reactions. Consequently, the separation of isotopes of certain elements, notably from U and deuterium from hydrogen, is of great importance in nuclear technology. Table 1.5 lists isotopes important in nuclear power applications, together with their natural abundance and processes that have been used or proposed for their separation. In addition to applications mentioned earlier in this chapter. Table 1.5 includes the use of D and Li as fuel for fusion power, a topic treated briefly in Sec. 9, following. 

Moderator, fuel for fusion Distillation, electrolysis, chemical exchange... 

In stars with very heavy average masses, helium burning may last for only a few million years before it is replaced by carbon fusion. In time this leads to the production of elements such as calcium, titanium, chromium, iron, and nickel fusion partly by helium capture, partly by the direct fusion of heavy nuclides. For example, two Si can combine to form Ni that can decay to Co which then decays to stable Fe. These last steps of production may occur rather rapidly in a few thousand years. When the nuclear fuel for fusion is exhausted, the star collapses and a supernova results. 

The last steps of production of heavy elements (up to Fe/Ni) occurs rather r q>idly in a few thousand years. When the nuclear fuel for fusion is exhausted the star collapses and results in a supernova. Figure 17.6 illustrates the composition of a 20 Mq star just before a supernova explosion. 

Lithium hydride, Li H, is a potential fuel for fusion reactors because it is one of the few compounds of very small elements that exists as a solid, and is therefore more dense than gaseous fuels even under extreme conditions. LiH in the gas phase has a pure rotational spectrum consisting of lines spaced by 15.026 cm. Calculate the bond distance in LiH. 

The extremely high peak power densities available ia particle beams and lasers can heat the small amounts of matter ia the fuel capsules to the temperatures required for fusion. In order to attain such temperatures, however, the mass of the fuel capsules must be kept quite low. As a result, the capsules are quite small. Typical dimensions are less than 1 mm. Fuel capsules ia reactors could be larger (up to 1 cm) because of the iacreased driver energies available. 

Potential fusion appHcations other than electricity production have received some study. For example, radiation and high temperature heat from a fusion reactor could be used to produce hydrogen by the electrolysis or radiolysis of water, which could be employed in the synthesis of portable chemical fuels for transportation or industrial use. The transmutation of radioactive actinide wastes from fission reactors may also be feasible. This idea would utilize the neutrons from a fusion reactor to convert hazardous isotopes into more benign and easier-to-handle species. The practicaUty of these concepts requires further analysis. 

The development of a tritium fuel cycle for fusion reactors is likely to be the focus of tritium chemical research into the twenty-first century. 

It IS often stated that unclear fusion tvill produce no radioactive hazard, but this is not correct. The most likely fuels for a fusion reactor would be deuterium and radioactive tritium, which arc isotopes of hydrogen. Tritium is a gas, and in the event of a leak it could easily be released into the surrounding environment. The fusion of deuterium and tritium produces neutrons, which would also make the reactor building itself somewhat radioactive. However, the radioactivity produced in a fusion reactor would be much shorter-lived than that from a fission reactor. Although the thermonuclear weapons (that use nuclear fusion), first developed in the 1950s provided the impetus for tremendous worldwide research into nuclear fusion, the science and technology required to control a fusion reaction and develop a commercial fusion reactor are probably still decades away. 

The nuclear fuels were created in the cosmic event that created the universe and were deposited in the earth as it took form. There are two families of nuclear fuels, those for fission (uranium and thorium) and those for fusion (protium [[//], deuterium, helium-3, and lithium). Only uranium fission has been developed as a commercial source of nuclear energy. Although fusion has been developed as a military weapon, the hydrogen bomb, it is premature to include the fusion fuels in the world s inventory of capital energy. The technology for controlled fusion is not available, nor is development of a controlled fusion process expected in the next several decades. When available it would increase the capital supply to a level greater than that from all other sources combined.16... 

As the increase of the curve in Fig. 2.6 in the range of light nuclides is much steeper than the decrease in the range of heavy nuclides, the energy gained per mass unit of fuel is much higher for fusion than for fission. In the sun and in the stars the energy is produced mainly by nuclear fusion. 

An interesting application of catalytic membrane reactors [14,136] relates to the production of tritium which together with deuterium will be the fuel for the fusion reactors of the future. Tritium is produced by mearts of a nuclear reaction between neutrons and lithium atoms in a breeder reactor. The tritium thus produced must be further purified to reach the purity levels that are required in the fusion reactor. For the extraction and purification process Basile and... 

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