Abstract
A flow-impingement facility has been developed at the AECL Chalk River Laboratories to study flow accelerated corrosion (FAC) and the electrochemical behaviour of reactor and steam generator (SG) materials. Tests can be done under conditions simulating a nuclear power plant heat transport system (HTS) and SG operation. High-temperature water is pumped through nozzles, impinging on the surface of test samples, and simulates turbulent flow conditions for accelerated corrosion tests. The flow-impingement stand was installed in a once-through autoclave system. Tests can be performed under impinging flow at temperatures up to 330°C. The maximum linear velocity of the impinging jet can be as high as 6 m/s at 300°C. Mass transfer coefficient calculations indicate that the hydrodynamic conditions under the impinging jet are equivalent to that in a 2.5-inch tube at free flow velocities between 12 to 18 m/s.
This facility can be used to verify the corrosion rate of material as a function of temperature and key water chemistry parameters, such as pH, oxygen concentration, etc., in flowing high-temperature water. Accelerated corrosion tests and a variety of electrochemical measurements can also be performed under well controlled hydrodynamic and chemistry conditions using this facility. An overview will be provided of some of these test results, and their application to operating plant issues.
