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Properties of reactor fuel rod materials at high temperatures: Final summary report: Severe Core Damage Property Tests Program

Description: This report summarizes work sponsored by the US Nuclear Regulatory Commission Division of Accident Evaluation to investigate those physical properties that are needed to predict the behavior of fuel-rod assemblies during a loss-of-coolant accident. The results include a determination of the oxidation kinetics of Zircaloy and Zircaloy-uranium oxide mixtures in steam and steam-hydrogen gas mixtures at 1300 to 2400C, viscosity measurements of zirconium-oxide mixtures at 1800 to 2100C, an estimate of the heat of reaction for the dissolution of uranium oxide by molten zirconium at 2000C, and thermal diffusivity measurements on prereacted Zircaloy-uranium oxide mixtures at 800 to 1500C.
Date: July 1, 1987
Creator: Prater, J.T. & Courtright, E.L.
Partner: UNT Libraries Government Documents Department

Oxygen permeability of several ceramic oxides above 1200 degrees C

Description: Oxygen permeability as a function of temperature was measured for several ceramic oxides over the range 1200 to 1700{degrees}C. Of the oxides testbed, alumina, beryllia, yttria, lanthanum halfnate, and calcium zironcate exhibited the lowest permeabilities in order of decreasing resistance to oxygen transport. None of the permeability constants were less than the 10{sup {minus}10} to 10{sup {minus}12} g O{sub 2}/cm {center dot} s needed for a useful protective coating system above 1500{degrees}C. In some of the mixed oxide compounds, cation segregation was observed to occur with the more rapidly diffusing species segregating to the side of highest oxygen potential. Thus, segregation must be considered when selecting mixed oxides for high temperature applications.
Date: January 1, 1992
Creator: Courtright, E.L. & Prater, J.T.
Partner: UNT Libraries Government Documents Department

Oxygen permeability of several ceramic oxides above 1200{degrees}C

Description: Oxygen permeability as a function of temperature was measured for several ceramic oxides over the range 1200 to 1700{degrees}C. Of the oxides testbed, alumina, beryllia, yttria, lanthanum halfnate, and calcium zironcate exhibited the lowest permeabilities in order of decreasing resistance to oxygen transport. None of the permeability constants were less than the 10{sup {minus}10} to 10{sup {minus}12} g O{sub 2}/cm {center_dot} s needed for a useful protective coating system above 1500{degrees}C. In some of the mixed oxide compounds, cation segregation was observed to occur with the more rapidly diffusing species segregating to the side of highest oxygen potential. Thus, segregation must be considered when selecting mixed oxides for high temperature applications.
Date: January 1, 1992
Creator: Courtright, E. L. & Prater, J. T.
Partner: UNT Libraries Government Documents Department

Fabric space radiators

Description: Future Air Force space missions will require thermal radiators that both survive in the hostile space environment and stow away for minimal bulk during launch. Advances in all aspects of radiator design, construction, and analysis will be necessary to enable such future missions. Currently, the best means for obtaining high strength along with flexibility is through structures known as fabrics. The development of new materials and bonding techniques has extended the application range of fabrics into areas traditionally dominated by monolithic and/or metallic structures. Given that even current spacecraft heat rejection considerations tend to dominate spacecraft design and mass, the larger and more complex designs of the future face daunting challenges in thermal control. Ceramic fabrics bonded to ultra-thin metal liners (foils) have the potential of achieving radiator performance levels heretofore unattainable, and of readily matching the advances made in other branches of spacecraft design. The research effort documented here indicates that both pumped loops and heat pipes constructed in ceramic fabrics stand to benefit in multiple ways. Flexibility and low mass are the main advantages exhibited by fabric radiators over conventional metal ones. We feel that fabric radiators have intrinsic merits not possessed by any other radiator design and need to be researched further. 26 refs., 16 figs., 17 tabs.
Date: January 1, 1988
Creator: Antoniak, Z.I.; Krotiuk, W.J.; Webb, B.J.; Prater, J.T. & Bates, J.M.
Partner: UNT Libraries Government Documents Department