Professor Ian Farnan

Earth and nuclear materials at an atomistic scale - interaction with radiation and water

The successful disposal of radioactive waste arising from civilian nuclear power production or weapons programmes requires an understanding of processes taking place over timescales ranging from picoseconds to millennia and distance scales of nm to km.  

We concentrate on the small distance and long lime scale which can provide a more deterministic understanding of the behaviour of nuclear waste than large scale repository models. We apply fundamental, atomistic approaches to reveal underlying physical and chemical processes. Confidence in our knowledge of the underlying mechanisms is the only way to ensure the safety of disposed materials over the timescales mandated by regulators. We use nuclearised analytical techniques to examine the atomic scale effects arising from the irradiation of materials with highly energetic light and heavy ions, neutrons and high-energy electrons to accelerate how radiation damage accumulates over time.  We also compare radiation damage occurring in natural analogue materials such as zircon with materials doped with 238Pu to accelerate actinide radiation damage effects directly. Our group has spent time developing protocols and techniques to handle irradiated and actinide containing materials, which includes the development of 'active' facilities at nuclear licensed sites such as EC JRC Karlsruhe and Pacific Northwest National Laboratory with whom we collaborate. We combine an applied approach related to systematic durability testing with fundamental atomic scale methods using isotope specific methods such as ICP-MS and NMR to understand the production and durability of the primary barriers to radionuclide release from nuclear waste forms (glass, spent nuclear fuel, ceramic waste-forms) and methods of waste minimization through re-processing using molten salts and production of appropriate halide tolerant waste forms. The techniques we have developed can be readily applied to other situations where an understanding of the combined effect of radiation and water on materials is required. We are actively involved with the development of new nuclear fuel cladding that is more tolerant of severe accidents (station blackout) and the exploration of ab initio methods of materials discovery applied to produce more accident tolerant fuels.

Collaborations

• The effect of radiation damage on molybdate solution in radioactive waste glass

Karishma Patel,  Cambridge International Doctoral Scholar and in collaboration with Commissariat à L'Energie Atomiques et Alternatives, Marcoule, France

• Dissolution-precipitation versus in situ alteration in radioactive waste glass durability

Rui Guo,  Cambridge International Doctoral Scholar

• Understanding the relationship between the durability of complex and simplified UK HLW glasses

Tom Goût, PhD studentship  in collaboration with Radioactive Waste Management Ltd

• Coupling source term, mineral reactivity and flow in radionuclide transport

Taj Iwalewa,  Cambridge-IDB Doctoral Scholar

• Uranium oxide dissolution mechanisms in oxic, anoxic and reducing environments

Beng-Thye Tan, Government Singapore Doctoral Scholar

• Chemical and radiolytic ageing of actinide oxides by MASNMR

Giles Rought Witta, PhD studentship EPSRC ICO-CDT In Nuclear Energy, AWE

• The effect of radiation damage on the properties of zirconium carbide based layered ceramics

Dhan-sham Rana,  PhD studentship EPSRC ICO-CDT In Nuclear Energy, Westinghouse Electric

• Layered carbide materials for reactor cores

Dr Aleksej Popel, Post-doctoral Fellowship, Frazer-Nash

• New materials for nuclear applications

Dr John Trail, Post-doctoral Fellowship (with Chris Pickard MSM) Frazer-Nash

Research Consortia

EPSRC Advance Materials for Fission: Carbides for Future Fission Environments (CaFFE)

EU H2020 Implementing Geological Disposal Technology Platform: Dissolution of spent nuclear fuel, in container effects  (DISCO)