An analysis of the effects of graphitization temperature on the irradiation dimensional change behavior of graphite

Graphitizations at temperatures greater than 2700 degrees C are generally preferable for nuclear graphite manufacture in order to obtain higher order of graphitization and lattice density. In 1993, Brocklehurst and Kelly published data showing graphitization temperature played a significant role on the dimensional change behavior (DCB) of pile grade A (PGA) graphite, irradiated at 600 degrees C with fast neutrons. These data were analyzed using a recently developed regression analysis method to generate derived figure of merits (DFOM). DFOMs are useful tools, which can be used to enable professional engineering judgement (PEJ). The resulting DFOMs reinforce the general premise of ASTM International nuclear graphite specifications, which require graphitization to be performed at a temperature of at least equal to 2700 degrees C.