Deposition of CRUD (Corrosion Residual Unidentified Deposit) in BWR (Boiling-Water Reactor) Water on Various Steels Exposed in the Dodewaard Nuclear Power Plant

摘要

A rack composed of different materials and surface treatments was exposed in the reactor vessel of the GKN boiling-water reactor in Dodewaard for one reactor cycle in order to study the CRUD (Corrosion Residual Unidentified Deposit) deposition. Ferritic, austenitic and ferritic-austenitic steels and Inconel 600 were mounted in the rack. The Co-60 and Mn-54 activity of the CRUD and of the adherent oxide layer were measured. The more CRUD was deposited on the samples, the higher the Co-60 and Mn-54 activities of the adherent oxide layer appeared to be. The Co-60 activity of the adherent oxide layer increased greatly with higher CRUD deposition for the high-chromium austenitic steels. The effect of CRUD deposition on Co-60 activity of the adherent oxide layer was slight for the ferritic low-chromium steels and for Inconel 600. The influence of CRUD deposition on the Mn-54 activity of the adherent oxide layer was greater for the ferritic steels than it was for the austenitic steels.