Ceramics-non-metallic materials capable of service at elevated temperatures-have several actual and potential applications in nuclear energy service . In particular, such materials are of interest in reactors intended for high temperature operations . They also have potential application because of their nuclear properties and corrosion resistance .
Physical research is carried out on ceramic materials under the sponsorship of the Atomic Energy Commission at a number of research institutions and it is the purpose of this paper to review some recent developments in this field .
FUEL ELEMENTS
The bulk of the recent research and development efforts on ceramics and ceramic metal combinations (cermets) has been in the fuel element field because of the relative stability of ceramics at elevated temperatures and their resistance to corrosion in certain environments .
Uranium Oxide
Many of the compounds of uranium are of interest for reactor use because of their higher service temperatures compared with the metal . In particular, the dioxide of uranium has received considerable attention because of its refractory nature and resistance to aqueous corrosion . Data on the uranium oxides are shown diagramatically in Fig . .
Differential Thermal Analysis
DTA-weight gain measurements in the temperature range, 20Β° C . to 1000Β° C ., have been used at the Oak Ridge National Laboratory as a method for rapidly indicating the oxygen contents and the reactivities fo U0 2 powders prepared by various techniques . Figures and show some DTA weight-loss data for selected UO 2 powders . The DTA and weight-change curves indicate two oxidation steps UO 2 , U"O, U"OA . Both steps are exothermic . The initial oxides studied vary from U02 .005 to U0 2 . 15 , and in general the intermediate oxides vary from 1-02 .34 to 1-02 .3, . These oxygen ratios were calculated on the basis that