Minerals for encapsulation of high-level nuclear waste: simulating damage and durability

Lead Research Organisation: University of Cambridge
Department Name: Earth Sciences

Abstract

Radioactive waste disposal is the Achilles heel of nuclear power generation. The Eurobarometer poll of November 2001 revealed a majority of EU citizens would accept nuclear power if an assuredly safe and secure method of waste disposal was available. Yet concerns over the long-term aqueous durability of borosilicate glasses as hosts for high-level waste (HLW) have been noted since the 1970's. Learning from Nature, we have been using the fundamental insights provided by natural minerals to steer the search for synthetic materials that could far outperform the current glass technologies, especially in terms of how well they retain uranium and plutonium within their atomic scale structure when they are immersed in the potential groundwaters of a geological waste store. Our preliminary work has combined experimental work on the principles of crystalline architecture with computer simulations. These highlight the characteristics of damage to the surrounding crystal that occurs during radioactive decay, and show that the damaged regions form high-density shells around themselves. We propose to capitalise on our recent advances in understanding radiation damage accumulation in the mineral zircon, using accurate computer simulations, to test the hypothesis that zirconium and titanium oxides (with the pyrochlore structure) may be as impervious and robust in retaining radionuclides over geological time frames.

Publications

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Zhao P (2014) Phase Transitions in Zeolitic Imidazolate Framework 7: The Importance of Framework Flexibility and Guest-Induced Instability. in Chemistry of materials : a publication of the American Chemical Society

 
Description Understanding of iodine, one of the key bioactive radioactive elements present in waste from civil nuclear energy production, has been improved so that we have a better appreciation of how iodine is incorporated into solid substrates.
Exploitation Route development of a waste form for radioactive iodine
Sectors Energy

Environment

 
Description My work has led me to be being appointed to the Committee on Radioactive Waste Disposal (CoRWM) at BEIS and advising on current strategies for deep geological disposal and selection of a Geological Disposal Facility for radioactive waste.
First Year Of Impact 2016
Sector Communities and Social Services/Policy,Energy,Environment,Government, Democracy and Justice
Impact Types Societal

Policy & public services