Legacy Ponds and Silo Wastes

The ion exchange material used in SIXEP to remove Sr and Cs from Sellafield effluent is the natural zeolite clinoptilolite. The changing nature of the effluent due to factors such as accelerating legacy pond clean-up and finite lifetime of the current supply of clinoptilolite justifies research for new and improved materials that might either replace or supplement the clinoptilolite in future operations. The focus of this project would be to investigate other families of porous silicates, for example some related to the CST in IONSIV, as new ion exchangers not only for Sr and Cs but other relevant cations that may require removal from effluent such as actinides or other metals. These materials could find use more widely, both in the UK and internationally. The project would be experimentally led (materials discovery and optimisation, characterisation and exchange testing with both non-active and then active solutions) but incorporate an element of computer modelling (atomistic simulation to predict ion exchange sites, framework response to exchange, and potential migration pathways during exchange) to assist mechanistic understanding and materials performance optimisation.