Controlled fission-fusion process

Figure 2.11 Principle of co-miniemulsion where both components must be dispersed independently in water and mixed afterwards. The controlled fission/fusion process in the miniemulsification realized by high-...

In the third step of the synthesis route, a monomer miniemulsion with 20 wt.% dispersed phase is prepared and added to the water-based ferrofluid containing the magnetite aggregates, as obtained above. This mixture is then cosonicated, and the controlled fission/fusion process which is characteristic for miniemulsification is expected to destroy all aggregates and liquid droplets. As a consequence, only hybrid particles composed of magnetite and monomer should remain, presumably since this species shows the highest stability. Polymerization of the monomer is then started for all the samples presented here by adding an initiator. 

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... 

This chapter gives a brief account of the nuclear fission reaction and the most important fissile fuels. It continues with a short description of a typical nuclear power plant and outlines the characteristics of the principal reactor types proposed for nuclear power generation. It sketches the principal fuel cycles for nuclear power plants and points out the chemical engineering processes needed to make these fuel cycles feasible and economical. The chapter concludes with an outline of another process that may some day become of practical importance for the production of power the controlled fusion of light elements. The fusion process makes use of rare isotopes of hydrogen and lithium, which may be produced by isotop>e separation methods analogous to those used for materials for fission reactors. As isotope separation processes are of such importance in nuclear chemical engineering, they are discussed briefly in this chapter and in some detail in the last three chapters of this book. 

Nuclear fusion is the process of combining two light nuclei to form a heavier, more stable nucleus. Nuclear fission involves the splitting of a heavy nucleus into two (more stable) lighter nuclei. Current nuclear reactors employ controlled fission. 

In nuclear fission, big atoms break apart into smaller atoms. In nuclear fusion, the opposite occurs—small atoms combine together to make larger atoms. In both processes, however, a very large amount of energy is released. Thus, both processes can be used to make atomic bombs. Controlled fission has been used for over fifty years in the commercial production of electricity. There are serious technological difficulties that must be overcome. 

The droplet size and size distribution seems to be controlled by a Fokker-Planck type dynamic rate equilibrium of droplet fusion and fission processes, i.e., the primary droplets are much smaller directly after sonication, but colloidally unstable, whereas larger droplets are broken up with higher probability. This also means that miniemulsions reach the minimal droplet sizes under the applied conditions (surfactant load, volume fraction, temperature, salinity, etc.), and therefore the resulting nanodroplets are at the critical borderline between stability and instability. This is why miniemulsions directly after homogenization are called critically stabilized [19,20]. Practically speaking, miniemulsions potentially make use of the surfactant in the most efficient way possible. 

One nuclear reaction seems to fill the bill fusion. The awesome process that powers the sun and the stars, and the hydrogen bomb, fusion occurs when the nuclei of smaller, lighter atoms are squeezed together—fused—under intense heat to form larger, heavier, and more stable nuclei. The reaction produces enormous bursts of energy which, if controlled and made self-sustaining, could provide a virtually unlimited supply of power from so innocuous and plentiful a source as seawater, and do it far more safely than the fission process. 

Nuclear energy, which is obtained when nucleons (protons and neutrons) are allowed to adopt lower energy arrangements and to release the excess energy as heat, does not contribute to the carbon dioxide load of the atmosphere, but it does present pollution problems of a different land radioactive waste. Optimists presume that this waste can be contained, in contrast to the burden of carbon dioxide, which spreads globally. Pessimists doubt that the waste can be contained—for thousands of years. Nuclear power depends directly on the discipline of chemistry in so far as chemical processes are used to extract and prepare the uranium fuel, to process spent fuel, and to encapsulate waste material in stable glass blocks prior to burial. Nuclear fusion, in contrast to nuclear fission, does not present such serious disposal-related problems, but it has not yet been carried out in an economic, controlled manner. 

During spontaneous nuclear fission reactions, heavy nuclei split when bombarded by neutrons, and release large amounts of energy. This process was used to produce two atomic bombs whose use ended World War II. A second energy-releasing nuclear process, fusion, is the basis for today s hydrogen bombs. Nuclear fission is in limited use as a source of electrical power however, this use is controversial. Nuclear fusion has not yet proved feasible as a controlled source of power, but research toward this end continues. 

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