Nuclear power solar cycles

The recently started EU FP7 project HycycleS (Roeb, 2009) builds up upon the results of HYTHEC and aims at the qualification and enhancement of materials and components for key steps of solar- and nuclear-powered thermochemical cycles. Emphasis is placed on materials and components for sulphuric acid evaporation, decomposition and sulphur dioxide separation. The suitability of materials and the reliability of the components will be shown in practice by decomposing sulphuric acid and separating its decomposition products in scalable prototypes. 

If possible comparisons are focused on energy systems, nuclear power safety is also estimated to be superior to all electricity generation methods except for natural gas (30). Figure 3 is a plot of that comparison in terms of estimated total deaths to workers and the pubHc and includes deaths associated with secondary processes in the entire fuel cycle. The poorer safety record of the alternatives to nuclear power can be attributed to fataUties in transportation, where comparatively enormous amounts of fossil fuel transport are involved. Continuous or daily refueling of fossil fuel plants is required as compared to refueling a nuclear plant from a few tmckloads only once over a period of one to two years. This disadvantage appHes to solar and wind as well because of the necessary assumption that their backup power in periods of no or Httie wind or sun is from fossil-fuel generation. Now death or serious injury has resulted from radiation exposure from commercial nuclear power plants in the United States (31). 

H2 production via thermochemical cycles powered by nuclear or solar heat... 

Fthenakis VM, Kim HC (2007) Greenhouse-gas emissions from solar electric- and nuclear power a life-cycle study. Energy Policy 35 2549-2557... 

Power Production. Steam cycles for generation of electric power use various types of boilers, steam generators, and nuclear reactors operate at subcritical or supercritical pressures and use makeup and often also condensate water purification systems as well as chemical additives for feedwater and boiler-water treatment. These cycles are designed to maximize cycle efficiency and reliability. The fuel distribution of sources installed in the United States from 1990—1995 are as follow coal, 45% combined cycle, 27% miscellaneous, 14% nuclear, 11% solar, oil, and geothermal, 1% each and natural gas, 0.3%. The 1995 summer peak generation in the United States was 620 GW (26). The combined cycle plants are predominantly fired by natural gas. The miscellaneous sources include bagasse, black liquor from paper mills, landfill gas, and refuse (see Fuels frombiomass Fuels fromwaste). 

Professor Nurnberg then referred to the speaker s remarks concerning the inefficiency of involving two Carnot cycles in the production and consumption of hydrogen. He remarked that this was a serious matter only if fossil fuels remained the primary power source. Where the primary source was solar power or nuclear power, then this consideration was less important. Apart from the attendant thermodynamic inefficiency, the involvement of fossil fuels perpetuates the problems of atmospheric pollution including that of carbon dioxide. These problems will only be solved by using the correct primary energy sources. 

Say we wish to convert a fossil-fuel, nuclear, or solar energy source into net electrical power. To accompftsh this task, we can use a Rankine cycle. The Rankine cycle is an idealized vapor power system that contains the major components foimd in more detailed, practical steam power plants. While hydroelectric and wind are possible alternative sources, the steam power plant is presently the dominant producer of electrical power. 

Optimize the use of existing renewable technologies wind waves hydroelectric geotheimal solar conversion solutions and solar-assisted, sustainable, clean fuel cycles (including advanced biofuels and partial artificial photosyntliesis). Development and use of Clean Coal technology, advanced geotheimal technology, clean(er) nuclear breeders, and more efficient power stations. 

Storability is another important attribute of the chemical fuel hydrogen. Hydrogen makes it possible to economically store over time—for the winter season, for example—energy derived from intermittent sources such as solar power. Hydrocarbons (natural gas, petroleum, coal) obviously are easy to store. But how do you store sunlight or the heat from a nuclear reactor Storage works very well in solar power tower plants, where heat is stored very efficiently in 24-hour, day-and-night cycles in molten salt storage tanks.2... 

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