We study the relationships between the thermal emissivity of nuclear graphites (IG-110, PCEA, IG-430 and NBG-18) and their surface structural change by oxidation using scanning electron microscope and X-ray diffraction (XRD). The nonoxidized (0% weight loss) specimen had the surface covered with glassy materials and the 5% and 10% oxidized specimens, however, showed high roughness of the surface without glassy materials. During oxidation the binder materials were oxidized first and then graphitic filler particles were subsequently oxidized. The 002 interlayer spacings of the non-oxidized and the oxidized specimens were about 3.38~3.39a. There was a slight change in crystallite size after oxidation compared to the nonoxidized specimens. It was difficult to find a relationship between the thermal emissivity and the structural parameters obtained from the XRD analysis.

• Seung-Kuk Seo(School of Advanced Materials and System Engineering, Kumoh National Institute of Technology)
• Jae-Seung Roh(School of Advanced Materials and System Engineering, Kumoh National Institute of Technology)
• Suk-Hwan Kim(School of Advanced Materials and System Engineering, Kumoh National Institute of Technology)
• Se-Hwan Chi(Korea Atomic Energy Research Institute)
• Eung-Seon Kim(Korea Atomic Energy Research Institute)