Characterisation of Graphite Powders Tested for Use in HTR Fuel Compact Matrices

摘要

A range of needle, natural and other graphite powders has been characterised to aid the choice of a powder suitable for use in the fabrication of Mk 3 HTR fuel compact matrices. The following techniques were applied: chemical analyis, particle size analysis, specific surface area and density measurements, gas desorption analysis, X-ray diffraction analysis, neutron capture cross section measurements, optical microscopy, and scanning and transmission electron microscopy. The results are presented and their relative merits discussed. Although most of the techniques applied are able to show differences between the powders, they do not enable precise fabrication behaviour to be predicted. Surface area measurements and particle shape indicate the approximate levels of resin to be used, particle size and shape indicate, in general terms, the ease of over-coating, and the particle size distribution, particle shape, crystallite size and dry compaction characteristics give a rough guide to how well the powders will compact. (Atomindex citation 09:354537)