1. Department of Materials Science and Engineering, Immobilisation Science Laboratory, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, U.K.
2. GeoRoc International (GRI) Ltd, Whitehaven, Cumbria CA28 8PF, U.K.
3. School of Materials Science and Energy Engineering, Foshan University, Foshan 528000, China
4. National Nuclear Laboratory, Workington, Cumbria CA20 1PJ, U.K.