Dissolution of glass in cementitious solutions: An analogue study for vitrified waste disposal. (27th February 2018)

• Record Type: Journal Article
• Authors: Mann, Colleen; Le Hoh, Tjin; Thorpe, Clare L.; Corkhill, Claire L.
• Is Part Of: MRS advances. Volume 3:Number 21(2018)
• Page Start: 1147
• Page End: 1154
• Publication Date: 2018-02-27
• Subjects: glass, -- cement & amp, -- concrete, -- nuclear materials; Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/adv.2018.227
• Languages: English
• ISSNs: 2059-8521

Abstract

Abstract : The dissolution of a soda-lime silicate glass in two cement leachate compositions, Young Cement Water (YCW) and Ca(OH)2, was investigated, as an analogue for dissolution of vitrified nuclear waste in a cementitious geological disposal facility. Dissolution was performed at repository temperatures (50°C) and under CO2 -exclusion. Dissolution rates were observed to be a factor of 20 times higher in YCW than in Ca(OH)2, as result of the high potassium content of YCW solutions. The precipitation of the zeolite phase, K-phillipsite (K(Si, Al)8 O16 ·6H2 O), is thought to be responsible for elevated dissolution rates. Conversely, in Ca(OH)2 solutions, the precipitation of calcium- and silica-containing phases, such as tobermorite (Ca5 Si6 O16 (OH)·4H2 O), acted to reduce rates of dissolution by forming a barrier to diffusion. These results show that dissolution of vitrified nuclear waste materials in a cementitous repository may be significant during the early stages of cement leaching in groundwater.