Stabilities of dimension and thermal-resistance of ASR-ORB carbon for thermal barrier materials of HTTR

Dimensional stability as well as thermal-resistivity is one of the important properties for thermal barrier materials to be used in the High-Temperature Engineering Test Reactor (HTTR). Changes in these properties under the reactor operation condition were estimated on ASR-ORB carbon selected as the thermal barrier material. Stabilities of these properties were evaluated from the experimental results and graphitization behavior of the carbon crystallite by heat-treatment. It is indicated that during the reactor operation the dimension shrinkage of the material will be less than 0.1 per cent and that change in the thermal-resistance will remain within the sample-to-sample variation. (author)