Effect of spinel oxide composition on rate of carbon deposition

Abstract

The deposition of carbon on fuel cladding and other steels results in a reduction in heat-transfer efficiency. Methane and carbon monoxide are added to the gaseous coolant in power reactors to reduce the radiolytic oxidation of the graphite moderator and this is known to increase the rate of carbon deposition. However, the composition of oxides formed on steel surfaces within the reactor may also influence deposition. In this investigation carefully characterised spinel-type oxides of varying composition have been subjected to γ-irradiation under conditions of temperature, pressure and atmosphere similar to those experienced in the reactor. The rate of carbon deposition has been studied using scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX).