Reductive precipitation of neptunium on iron surfaces under anaerobic conditions
Küçük Resim Yok
Tarih
2017
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Bv
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Reductive precipitation of the radiotoxic nuclide Np-237 from nuclear waste on the surface of iron canister material at simulated deep repository conditions was investigated. Pristine polished as well as pre corroded iron specimens were interacted in a deoxygenated solution containing 10-100 mu M Np(V), with 10 mM NaCl and 2 mM NaHCO3 as background electrolytes. The reactivity of each of the two different systems was investigated by analyzing the temporal evolution of the Np concentration in the reservoir. It was observed that pre-oxidized iron specimen with a 40 tm Fe3O4 corrosion layer are considerably more reactive regarding the reduction and immobilization of aqueous Np(V) as compared to pristine polished FeM surfaces. Np-237 immobilized by the reactive iron surfaces was characterized by scanning electron microscopy as well as synchrotron-based micro-X-ray fluorescence and X-ray absorption spectroscopy. At the end of experiments, a 5-8 tm thick Np-rich layer was observed to be formed ontop of the Fe3O4 corrosion layer on the iron specimen. The findings from this work are significant in the context of performance assessments of deep geologic repositories using iron as high level radioactive waste (HLW) canister material and are of relevance regarding removing pollutants from contaminated soil or groundwater aquifer systems. (C) 2017 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Nuclear waste, Neptunium, Iron canister materials, Disposal, Reductive precipitation
Kaynak
Journal of Nuclear Materials
WoS Q Değeri
Q1
Scopus Q Değeri
Cilt
496
