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The development of remote controlled methods for manufacturing EBR-II fuel elements was influenced by many interacting factors. Radiation levels within the process cell have been predicted to range from 10³ to 10⁷ rad per hour. Radiation damage to organic lubricant, electrical insulations, elastic seals, and protective coatings precludes the use of many standard machine components. Heat generated in the fuel by absorbed radiation makes forced cooling necessary in many operations. Oxygen must be exluded from all operations where the fuel is exposed. Equipment must be designed for remote maintenance and component replacement within the limitation of available manipulators. The EBR-IImore » fuel consisted of fissium alloy pins sodium bonded in stainless steel tubes. Precision casting was chosen as the basis for refabricating the fuel pins. Remote controlled equipment was developed to cast, assemble, and inspect the EBR-II fuel elements. Radiation resistant, plug-in machine components were developed to give reasonable life expectancy and to allow remote maintenance and replacement.« less

Here, the influence of plutonium as a fuel constituent on burner reactor behavior is examined. Both the SM-1 and the Shippingport seed lattices are investigated. It is found that the decrease in the effective absorption cross section of Pu²⁴⁰ with fuel burnup gives the plutonium the characteristic of a self-compensating fuel, thereby leading to the extension of core life with minimum shim control requirements. The illustrated behavior is similar to that which was previously shown to be possible for converter-type reactors.

The solid solution of (U1-yFPy)O-_2±x, has the same fluorite structure as UO_2±x lambda, and the lattice parameter is affected by dissolved fission product and oxygen concentrations. We investigated the relation between the lattice parameter and the concentrations of neodymium and oxygen in the fluorite structure of (U_1-yNd_y)O_2±x using X-ray diffraction. Moreover, the lattice parameter behavior in the (U_1-yNd_y)O_2±x, solid solution shows a linear change as a function of the oxygen-to-metal ratio and solubility of neodymium. The lattice parameter depends on the radii of ions forming the fluorite structure and also can be expressed by a particular rule (modified Vegard's law).more » Furthermore, the numerical analyses of the lattice parameters for the stoichiometric and nonstoichionietric solid solutions were conducted, and the lattice parameter model for the (U1-yNdy)O_2±x, solid solution was assessed. There is a very linear relationship between the lattice parameter and the Nd and O concentration for the stoichiometry and nonstoichiometry of the (U_1-yNd_y)O_2±x solid solution was verified.« less

Advanced optical diagnostic techniques and instruments are being developed to operate successfully in the high-temperature coal combustion environments of large scale facilities. The success of these instruments depends heavily on maintaining a clear optical path into and out of the gas stream for long periods of time. The buildup of slag at the access port and contaminate fouling of the optical window require special systems to maintain the optical path. The rationale for, and design of, two such systems are presented in this article. The first system, a remotely operated window changer, provides for exchanging fouled windows for clean windows.more » The second system, a remotely operated slagbuster, provides for removing slag buildup in the access port. The design and operation of both systems are discussed. Parts lists, drawings, and schematics are presented also.« less

It must be conceded that great uncertainty pervades the estimates of the effect of increased CO₂ concentration in the atmosphere. It is of the highest importance that these uncertainties be resolved as expeditiously as possible, say by 1985. This will require a worldwide commitment of considerable scale. Only such aggressive effort is likely to lead to an estimate of the effect of CO₂ sufficiently robust to warrant the political, social, and economic measures that might be required to deal with unprecedented changes in the world's climate. Increases in the atmospheric concentration of CO₂ cause concern only when the quantities becomemore » large--i.e., several hundred billion tons of additional carbon. The direct contribution from emphasis on coal use through 1985, as called for in the U.S. National Energy Plan, is of minor consequence. On the other hand, if such a policy continues into the next century, or if it serves as a model for major segments of the world, then the quantity of resulting CO₂ could have serious consequences early in the next century. Further, if coal is used on a large scale as the base for liquid and/or gaseous synthetic fuels as the oil and natural gas reserves are depleted, the inefficiencies of conversion would serve to increase the CO/sub 2/ produced per unit of delivered energy and further aggravate the problem.« less