Prediction of layer thickness of corrosion product on fuel plate of RSG-GAS reactor

The prediction of layer thickness completes the analyses of reactor's performance and safety as the layer decreases the heat transfer across the tube wall. The prediction has been executed for average and realistic conditions using Y.S.-KIM corrosion model that takes into account the operation time (t), pH, coolant velocity (v), temperature (T) and heat flux (q). Corrosion layer computation has been performed for reactor cooled by demineralized water at pH=5, with a few operating variations. The simulation was conducted for 100 days divided into 4 cycles at constant temperature and flux, with each period of 100 h. Operation data and physical properties are flux q = 3.8 MW/m², coolant velocity v = 7.6 m/s, and thermal conductivity k(T) = 1.2538×105.exp(-5913/T). The prediction shows that the layer thickness increases with operation time, although the temperature and flux decrease with time. A fluctuation of about 10 K and 5% of the average flux does not have significant effect on the corrosion layer, while the increase of temperature of 25 °C increases the layer thickness. (author)