CO₂corrosion of IG-110 nuclear graphite studied by gas chromatography

Abstract

The CO 2 corrosion behavior of IG-110 nuclear graphite has been investigated using the gas chromatography method which allows the continuous analysis of the CO 2 /CO gas mixture at the outlet of the corrosion chamber. The effects of temperature and initial CO 2 concentration are studied based on the Arrhenius-type reaction model. From 745 to 995• C, the Arrhenius curve shows a linear behavior. For higher temperatures, a non-linear behavior is observed. The activation energy is calculated as 210 kJ/mole and is independent of the initial CO 2 inlet concentrations of 10%, 14% and 17%. The corrosion behavior at 1145• C, in the diffusion-controlled regime, has also been investigated. At this temperature, the interior of IG-110 graphite is severely attacked by CO 2 , and the material's surface morphology is changed drastically. A measurement of the corrosion rate against corrosion time shows that the corrosion rate initially increases to a maximum value at a weight loss degree of 30%-35%, after which it begins to decline.

Characterizing thermal-oxidation behaviors of nuclear graphite by combining O2 supply and micro surface area of graphite

“…Consequently, the oxidation/corrosion of graphite arises to be a crucial issue to assess the economy and safety of a HTGR among which O 2 oxidation is usually the fastest reaction. There are two main concerned reactions related with O 2 oxidation of graphite when temperature is less than 900 °C 14 : The reaction ( 1 ) is considered as the intrinsic oxidation reaction between O 2 and graphite. Reaction ( 2 ) (CO combustion) may influence the reaction ( 1 ) (oxidation reaction) by varying O 2 supply and energy balance of reaction ( 1 ).…”

Improved Interpretation of Mercury Intrusion and Soil Water Retention Percolation Characteristics by Inverse Modelling and Void Cluster Analysis

“…Samples of IG-110 and IG-430 graphite, also referred to as IG-11 and IG-43, were supplied by Toyo Tanso Ltd., Japan. IG-110 is a fine-grained, isotropic graphite which exhibits high thermal durability and strength, currently utilised in the Japanese high-temperature test reactor (HTTR) (Yan et al 2013) and the Chinese high-temperature reactor-pebble bed modules (HTR-10) (Zhen et al 2014). IG-430 is a comparable graphite, developed to display higher density, strength and thermal conductivity when compared with IG-110.…”