Investigations of the Dual Benefits of Zinc Injection on Cobalt-60 Uptake and Oxide Film Formation Under Boiling Water Reactor Conditions
Zinc injection in reactor feed water is a well-known mitigation strategy for prevention of radioactive 60Co deposition in both Boiling and Pressurised water reactors. Furthermore, zinc leads to the formation of a thinner, more stable oxides arising from the thermodynamically driven replacement of Ni and Fe in the characteristic spinel type oxide formed on stainless steel. However, the interaction of zinc with the oxide formation under different water chemistries is not fully understood. Oxidation tests on type 316 stainless steel were performed under two hydrogen water chemistry conditions (HWC), with and without zinc injection and the resultant oxides analysed using analytical electron microscopy (AEM), field emission gun scanning electron microscopy (FEG-SEM), and energy dispersive X-ray spectroscopy (EDXS). The present work identifies and quantifies the positive microstructural changes that Zn has on the oxide formation on a #600 grit surface and an OPS polished 316 SS surface under boiling water reactor (BWR) conditions.
KeywordsHydrogen water chemistry Normal water chemistry Analytical electron microscopy Scanning electron microscopy Energy dispersive X-ray Zinc injection Oxide characterisation
- 7.S.E.E. Ziemniak, M. Hanson, Zinc treatment effects on corrosion behavior of 304 stainless steel in high temperature, hydrogenated water. Corros. Sci. 48(10), 2525–2546 (2002)Google Scholar
- 8.J. Henshaw, S. Bowskill, S. Dickinson, M. Redmond, J. Glover, Material and Activity Transport Modelling in BWRs Paper. Nucl. Plant Chem. Conf. (2016)Google Scholar