Journal Article

FZJ-2014-01700

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Research reactor fuel element corrosion under repository relevant conditions: separation, identification, and quantification of secondary alteration phases of UAlx-Al in MgCl2-rich brine

Klinkenberg, M. (Corresponding author)FZJ* ; Neumann, A.FZJ* ; Curtius, H.FZJ* ; Kaiser, G.FZJ* ; Bosbach, D.FZJ*

2014
Oldenbourg München

This record in other databases:  

Please use a persistent id in citations: http://hdl.handle.net/2128/16371  doi:10.1515/ract-2013-2126

Abstract: The corrosion of the UAl𝑥-Al research reactorfuel type in synthetic MgCl2-rich brine (static batch-type experiments) was investigated with respect to the longtermsafety of directly disposed research reactor fuel elements in salt formations. During corrosion, crystalline secondary phases were formed, which may serve as a barrier against radionuclide migration. For an optimized identification and quantification of the secondary phases using Xray diffraction, a sample treatment to separate and enrich the secondary phases is necessary. A grain size fractionation was carried out in iso-propanol. A chemical composition and phase characterization of the secondary phases was accomplished. The results of the chemical investigations reveal that only traces of Al and U were dissolved. The separation and enrichment of secondary phases were carried out reproducible and successfully. Due to the phase characterization by scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray diffraction the following secondary phases were unambiguously identified: Mg-Al-Cl layered double hydroxide, lesukite, Fe layered double hydroxide (green rust), lawrencite, Fe (elemental), and traces of uncorroded fuel (UAl4). The quantitative analysis showed that LDH compounds and lesukite are the major crystalline phases. All other observed compounds were only present in trace amounts, i.e. constituting accessories. The Rietveld analysis also revealed the high content of amorphous phases of approximately 30% ,which are expected to include the uranium as U(OH)4.

---

Contributing Institute(s):

1. Nukleare Entsorgung und Reaktorsicherheit (IEK-6)

Research Program(s):

1. 142 - Safety Research for Nuclear Waste Disposal (POF2-142) (POF2-142)

Appears in the scientific report 2014

---

Database coverage:
; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection ; Zoological Record

---