Deposition of corrosion products under pressurised water nuclear reactor conditions: The effect of flow velocity and dissolved hydrogen

摘要

The effect of water flow velocity and dissolved hydrogen on the deposition rate of Corrosion-Related Unidentified Deposit (CRUD) was investigated under conditions relevant to pressurised water nuclear reactors using type 3041 stainless steel micro-orifices. The results indicate that the CRUD build-up rate increases with hydrogen concentration because the amount of iron in solution also increases. At the same time, the fluid shear forces induce a mechanical removal of the oxide for flow velocities above 15 m/s. This suggests that the CRUD deposition process occurs under mass transport control, but the overall build-up rate is also affected by flow-induced mechanical removal.