Fusion reactors, tritium extraction

One of the key chemical problems associated with lithium in fusion reactors is extraction of the tritium that has been either generated in or trapped by lithium. A figure of merit for tritium extraction is the blanket tritium inventory. Very large inventories require excessive start-up inventory and are a potentially large radioactive effluent in the event of a catastrophic accident. 

Deuterium is present in ordinary sea water at a concentration of one atom per 3300 water molecules, and it can be inexpensively extracted. Tritium is radioactive with a 12.3 y half life, and there is no abundant natural source. However, tritium can be produced in a fusion reactor by absorbing the neutrons in lithium (Figure 1). Natural Li is 92.5% Li and 7.5% Li. 

The use of lithium in fusion reactor designs has been described with emphasis on materials compatibility, safety, and tritium extraction. Several chemical issues remain unresolved, including ... 

The production of fusion energy would begin, of course, with fuel. In a fusion reactor, the most promising fuels are deuterium and tritium, the heavy isotopes of hydrogen, both of which can be extracted from seawater. Deuterium s potential as a plentiful energy source is easily understood when one considers that a small amount can produce the equivalent of some 300 gallons of gasoline when it is burned off. 

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... 

A potential application of the WGS reaction carried out in an MR is represented by the tritium recovery process from tritiated water from breeder blanket fluids in fusion reactor systems. The hydrogen isotopes separation at low concentration in gaseous mixtures is a typical problem of the fusion reactor fuel cycle. In fact, the tritium produced in the breeder needs a proper extraction process to reach the required purity level. Yoshida et al. (1984) carried out experimental and theoretical studies of a catalytic reduction method which allows tritium recovery from tritiated water with a high conversion value (> 99.99%) at a relatively low temperature, while Hsu and Buxbaum (1986) studied a palladium-catalysed oxidative diffusion... 

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