Role of Surface Chemistry in Crud Deposition on Heat Transfer Surface^★

Crud deposition on fuel cladding in light water reactors is the source of induced radioactivity which contaminates the reactor coolant system when released. The deposition behavior of hematite particles (crud) on heat transfer surfaces was studied experimentally at atmospheric pressure. The role of surface chemistry in crud deposition on heat transfer surfaces was studied. Crud particles are hydrophobic and thus are trapped on water-bubble interfaces and collect preferentially at the boundary between a bubble and heat transfer surface during boiling. Crud deposition on heat transfer surfaces can be attributed more to the interaction between particles than to the electrostatic force between the particles and the heat transfer surface.