article posted 2 Apr 2016
currently works within the immobilisation science laboratory at the University of Sheffield.
She hase been conducting PhD research under the supervision of Dr Claire Corkhill, Prof Neil Hyatt and Prof John Provis.
The aim of this research is to understand how the evolving geochemical conditions of an
engineered barrier affect the dissolution kinetics of intermediate level waste glass.
Interactions between simulant vitrified nuclear wastes and idealised cement leachates
Colleen Mann1*, John L. Provis1, Neil C. Hyatt1,
Antoni E. Milodowski2, Lorraine Field2,
Richard Shaw2 and Claire L. Corkhill1
The UK Government have stated their preference for the final disposal of radioactive
waste within a Geological Disposal Facility (GDF), at a depth of between 200 m and
1 km1. The GDF will incorporate Engineered Barrier Systems (EBS) that will be
optimised to physically and chemically retard the transport of radionuclides to the
biosphere. In the case of the proposed GDF for UK Intermediate Level Waste (ILW),
groundwater will interact with the cementitious components of the EBS, resulting
in a highly alkaline and calcium-rich groundwater composition that will evolve as a
function of time. In order to evaluate the merit of such an EBS system for vitrified
ILW materials, an assessment of glass durability in cementitious leachate solutions is
We present results from an investigation of the interaction of simulated ILW glasses
and the International simple glass2 with cement leachate solutions. Glass powders
were exposed to idealised cement leachates, of "intermediate" and "old" ages,
approximately representative of GDF conditions at ~1000 and ~10,000 years of
operation, according to the ASTM standard C1285-14 product consistency test B3.
Analysis of the normalised mass loss and normalised leaching rate of these glasses
as a function of cement leachate composition was achieved through analysis of
We present concurrent analysis of monolith sample alteration
layers by SEM / EDX and vertical scanning interferometry. Combined, these data
support a mechanistic understanding of glass dissolution in the context of a complex
geological disposal environment for vitrified UK ILW. These experiments are
complimented by a high pH natural analogue study at a historic lime kiln site in the
UK, where a range of glass compositions will be exposed to relevant conditions for
1, 2, 5 and 10 years.
1 Department of Energy & Climate Change, Implementing Geological Disposal, 2014.
2 S. Gin, A. Abdelouas, L. J. Criscenti, W. L. Ebert, K. Ferrand, T. Geisler, M. T. Harrison, Y. Inagaki, S. Mitsui, K. T. Mueller, J. C. Marra, C. G. Pantano, E. M. Pierce, J. V. Ryan, J. M. Schofield, C. I. Steefel and J. D. Vienna, An international initiative on long-term behavior of high-level nuclear waste glass, Materials Today, 2013, vol. 16.
3 Standard Test Methods for Determining Chemical Durability of Nuclear, Hazardous, and Mixed Waste Glasses and Multiphase Glass Ceramics : The Product Consistency Test (PCT) ASTM C1285-14, 2002, vol. 15.
1 Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
2 British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham, NG12 5GG, UK