Chalk river unidentified deposit (CRUD) is an acronym used to describe the corrosion deposits that form in nuclear power plants. Such deposits are often associated to reduction of heat transfer in fuel rods and to blockage of channels in regions of fast hydrodynamic flow. Given the significance of the operational consequences associated to CRUD deposition, the development of methodologies to remove it is of scientific and technical interest. In this study, a microscale flow loop setup, replicating conditions relevant to plant operations, was used to explore the potential of exploiting hydrodynamic cavitation for CRUD removal. Tests were performed on discs with micro-orifices that were previously exposed to high temperature water flow to induce CRUD deposition. CRUD removal from within the micro-orifices was performed by inducing cavitation, and monitored via periodic microstructural examinations. The results indicate that a cavitating regime can reduce the volume of CRUD deposit by 80–90% within minutes, with no detectable damage to the metal surface.
- CRUD removal
- Hydrodynamic cavitation