Nuclear fusion energy production from

Inevitably, the final goal of nuclear fusion research is to create such conditions that Pout > f in> that is, the power necessary to run a fusion-based power station, must be smaller than the power output OUt of the station. From a global perspective, this inequality is the necessary condition for efficient fusion energy production. However, it is clear that in the everyday work, this inequality is too general and so practically meaningless. More practical necessary conditions are needed (see later on), which can serve as reachable targets during the developments. 

The sun and all other stars produce energy at a huge rate from sustained nuclear fusion. Over time, stars evolve through several stages, including stellar explosions. The products of a stellar explosion can form stars of more complex composition. Three distinct generations of stars have been identified, each fueled by a different set of fusion reactions. 

Energy from nuclear fusion might also be used for propelling jets and rockets. Formidable difficulties would be encountered, however. For reactions occurring at ca 10 °K, such as those between the hydrogen isotopes, chamber pressures of around 100 atm could give rates of energy production comparable to those from the familiar chemical fuels. 

Cold fusion has been reported to result from electrolyzing heavy water using palladium [7440-05-3], Pd, cathodes (59,60). Experimental verification of the significant excess heat output and various nuclear products are still under active investigation (61,62) (see Fusion energy). 

These workers observed the generation of neutrons and tritium from electrochemically compressed D+ in a Pd cathode. Their study has stimulated a variety of calorimetric and nuclear measurements. However, the occurrence of the phenomena is sporadic and appears unreproducible on a consistent basis. Therefore a pessimistic view of cold fusion must be taken with respect to the possibility of future energy production. 

A scheme has been proposed for using the neutrons from the fusion reaction to convert uranium 238 to plutonium 239 or thorium 232 to uranium 233 for the manufacture of bombs. While in theory this may be possible, it does not appear to offer an easier route to the produetion of bombs than the current methods of separation of uranium 235, or the production of plutonium in a conventional reactor. As a result of these factors, use of a fusion energy system will in no way add to the potential for further nuclear weapons or provide a source for the unauthorized procurement of materials that might be used to produce weapons. 

The variety and con lexity or nuclear reactions make this a fascinating area of research quite apart from the practical value of understanding fusion and fission. From studies of such properties as the relative amounts of formation of various conq)eting products, the variation of the yields of these with bombarding energy, the directional characteristics and kinetic energies of the products, etc., we may formulate models of nuclear reaction mechanisms. Such models lead to systematics for nuclear reactions and make possible predictions of reactions not yet investigated. 

Although all current power reactors use the fission process to generate electricity, research is being conducted on nuclear fusion. In this process, hydrogen (or deuterium and lithium) atoms are fused, which creates energy and a helium atom. This process has the advantage of more readily available fuel, such as hydrogen from water, and less radioactive waste because fission products are not created. However, tritium would be a by-product, and marty materials used in the reactor would be activated to create additional radioactivity. 

Table V summarizes estimatesL39,42J for the fuel production-ability of two types of producing hybrids, with various fuel cycles for the fusion drivers. One of the Hybrid Fuel Factories (HFFs) uses a fission-suppressed blanket having beryllium for neutron multiplication and moderation, while the other uses a fast-fission blanket. The figure-of-merit used for measuring the fuel production-ability of the HFFs is F/W - the net number of fissile atoms they can produce per unit thermal energy (resulting from fusion, fission and other nuclear reactions) that must be removed from the plant. The fusion devices driving these HFFs are assumed to be ignited.

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