Legacy waste from the decommissioned A-1 nuclear power plant in the Slovak Republic is scheduled for immobilisation within a tailored alkali borosilicate glass formulation, as part of ongoing site cleanup. The aqueous durability and characterisation of a simulant glass wasteform for Chrompik III legacy waste, was investigated, including dissolution experiments up to 112 days (90°C, ASTM Type 1 water). The wasteform was an amorphous, light green glassy product, with no observed phase separation or crystalline inclusions. Aqueous leach testing revealed a suitably durable product over the timescale investigated, comparing positively to other simulant nuclear waste glasses and vitreous products tested under similar conditions. Iron and titanium rich precipitates were observed to form at the surface of monolithic samples during leaching, with the formation of an alkali deficient alteration layer behind these at later ages. Overall this glass appears to perform well, and in line with expectations for this chemistry, although longer-term testing would be required to predict overall durability. This work will contribute to developing confidence in the disposability of vitrified Chrompik legacy wastes.

1. Introduction
2. Experimental Methodology
    2.1 Materials
    2.2 Analysis Methods
3. Results
    3.1 Glass Characterisation
    3.2 Durability Assessment
    3.3 Post Dissolution Characterisation
4. Conclusions
REFERENCES

• Sam A. Walling(Immobilisation Science Laboratory, The University of Sheffield)
• Laura J. Gardner(Immobilisation Science Laboratory, The University of Sheffield)
• H.K. Celine Pang(Immobilisation Science Laboratory, The University of Sheffield)
• Colleen Mann(Immobilisation Science Laboratory, The University of Sheffield)
• Claire L. Corkhill(Immobilisation Science Laboratory, The University of Sheffield)
• Alexandra Mikusova(Vuje Inc.)
• Peter Lichvar(Vuje Inc.)
• Neil C. Hyatt(Immobilisation Science Laboratory, The University of Sheffield) Corresponding Author