The influence of metal substrate on CRUD build-up under simulated PWR conditions

摘要

CRUD deposition tests were carried out on several microorificespecimens in a Hastelloy C-276 and a SS 316Lflow loop. The results showed that irrespective of thematerial used for the construction of the discs (SS 304L,Titanium, Alloy 690, Zirlo and Magnesia stabilisedZirconia) no significant differences in term of radialCRUD build-up were observed. The effect of the Ni andFe cations dissolved in the water was also investigated;the results revealed that CRUD build-up rate increasedwith the ferrous ions concentration and decreased withnickel ions. Finally, SEM and Energy Dispersive X-RaySpectroscopy were used to characterise the oxidemorphology showing higher particulate build-up for thespecimens tested in the Hastelloy autoclave.