Insights into the zinc effect on radio-cobalt deposition on stainless steel piping surfaces under BWR conditions from experiment guided 1st principles modelling
Journal article, 2020

The beneficial effect of zinc to mitigate radio-cobalt uptake on stainless steel piping surfaces under BWR conditions is revisited by means of 1st principles modelling. A viable generic hydroxylated grain boundary interface (HGBI) model for magnetite, i.e., an inverse spinel, is formulated and interrogated in order to unravel how Zn may cause exclusion of Co by competing for the same sites. While Co2+ as well as Ni2+ reside preferentially in the octahedral lattice sites of the inverse spinel lattice, Zn2+ prefers to reside at the HGBI. The difference is consolidated for M(II), M being Cr, Mn, Fe, Co, Ni, Cu, or Zn. Similar affinities as well as mobilities of Co2+ and Zn2+ in the HGBI are taken to explain how, upon Fe2+ dissolution, Zn2+ may compete with Co2+ for the Fe2+ sites in the inner layer of the duplex oxide film. Impacts of Zn2+ and Ni2+ on Co2+ uptake in the outer oxide layer is also addressed. Zn2+ guided precipitation is found to be less effective than the Ni2+ guided process. Reported beneficial effects on radio-cobalt uptake upon sealing off the stainless steel acting Ni2+ source by coating with magnetite as well as hematite are discussed.

Author

Valentina Cantatore

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Christine Geers

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Jiaxin Chen

Studsvik

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Itai Panas

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Journal of Nuclear Materials

0022-3115 (ISSN)

Vol. 540 152361

Subject Categories

Meteorology and Atmospheric Sciences

Metallurgy and Metallic Materials

Corrosion Engineering

DOI

10.1016/j.jnucmat.2020.152361

More information

Latest update

9/3/2020 9