Insights into the zinc effect on radio-cobalt deposition on stainless steel piping surfaces under BWR conditions from experiment guided 1st principles modelling
Artikel i vetenskaplig tidskrift, 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.

Författare

Valentina Cantatore

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Christine Geers

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Jiaxin Chen

Studsvik

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Itai Panas

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Journal of Nuclear Materials

0022-3115 (ISSN)

Vol. 540 152361

Ämneskategorier

Meteorologi och atmosfärforskning

Metallurgi och metalliska material

Korrosionsteknik

DOI

10.1016/j.jnucmat.2020.152361

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Senast uppdaterat

2020-09-03