Dr Frank Lewis

Nuclear power is becoming an increasingly key part of the energy mix in many countries as it offers a clean, low-carbon source of energy. However, a major disadvantage of nuclear power is the long-lived and highly radioactive nature of the waste that it produces, which is due to the presence of the actinides uranium, plutonium, americium and curium in spent nuclear fuel. In the currently-used PUREX (Plutonium and Uranium Reduction Extraction) process, uranium and plutonium are removed from the aqueous spent nuclear fuel liquor by solvent extraction and recycled as mixed-oxide (MOX) fuel, but no process is currently used to remove and recycle the minor actinides americium and curium. If these elements were removed, the time taken for the radioactivity of the remaining waste to decay to the levels of natural uranium would decrease from approx. 10,000 years to a much more manageable few hundred years.

In order to recycle the minor actinides, they must first be separated from the chemically similar lanthanides that are also present in spent nuclear fuel. Thus, future processes for recycling the minor actinides require highly selective organic ligands that can discriminate between the minor actinides and lanthanides. Of the many ligands screened for carrying out this challenging separation, ligands containing 1,2,4-triazine rings (BTPs, BTBPs, BTPhens) have emerged as some of the most selective.

Research in the Lewis group is focused on fine-tuning the structures and hence extraction properties of these ligands to maximise the efficiency of any future industrial recycling process using these ligands. Current projects include the evaluation of novel hydrophobic ligands with improved solubilities and rates of metal extraction (funded by EPSRC), as well as novel hydrophilic ligands that can be used as actinide-selective aqueous complexing agents (funded by National Nuclear Laboratory under the Advanced Fuel Cycle Programme).

• Please visit the Pure Research Information Portal for further information
• Evaluation of Multidentate Ligands Derived from Ethyl 1,2,4-triazine-3-carboxylate Building Blocks as Potential An(III)-Selective Extractants for Nuclear Reprocessing, Zaytsev, A., Distler, P., John, J., Wilden, A., Modolo, G., Sims, M., Lewis, F. 24 Oct 2024, In: ChemistryOpen
• New Route to Amide-Functionalized N-Donor Ligands Enables Improved Selective Solvent Extraction of Trivalent Actinides, Bulmer, R., Spencer, T., Wilden, A., Modolo, G., Vu, T., Simonin, J., Lewis, F. 28 Sep 2022, In: Chemical Communications
• Synthesis, physicochemical characterization and neuroprotective evaluation of novel 1-hydroxypyrazin-2(1H)-one iron chelators in an in vitro cell model of Parkinson's disease, Lewis, F., Bird, K., Navarro, J., El Fallah, R., Brandel, J., Hubscher-Bruder, V., Tsatsanis, A., Duce, J., Tetard, D., Bourne, S., Maina, M., Pienaar, I. 1 Mar 2022, In: Dalton Transactions
• Design and evaluation of bi-functional iron chelators for protection of dopaminergic neurons from toxicants, Gutbier, S., Kyriakou, S., Schildknecht, S., Ückert, A., Brüll, M., Lewis, F., Dickens, D., Pearson, L., Elson, J., Michel, S., Hubscher-Bruder, V., Brandel, J., Tetard, D., Leist, M., Pienaar, I. 1 Sep 2020, In: Archives of Toxicology
• Exploring the Subtle Effect of Aliphatic Ring Size on Minor Actinide Extraction Properties and Metal Ion Speciation in Bis‐1,2,4‐Triazine Ligands, Zaytsev, A., Bulmer, R., Kozhevnikov, V., Sims, M., Modolo, G., Wilden, A., Waddell, P., Geist, A., Panak, P., Wessling, P., Lewis, F. 7 Jan 2020, In: Chemistry - A European Journal
• Novel 1‑hydroxypyridin‑2‑one metal chelators prevent and rescue ubiquitin proteasomal‑related neuronal injury in an in vitro model of Parkinson’s disease, Lewis, F., Farooz, S., Elson, J., Hubscher-Bruder, V., Brandel, J., Soundararajan, M., Smith, D., Dexter, D., Tetard, D., Pienaar, I. 1 Mar 2020, In: Archives of Toxicology
• Thermodynamic parameters of Am(III), Cm(III) and Eu(III) extraction by CyMe4-BTPhen in cyclohexanone from HNO3 solutions, Distler, P., Stamberg, K., John, J., Harwood, L., Lewis, F. 1 Feb 2020, In: Journal of Chemical Thermodynamics
• 1,2,4-Triazines in the Synthesis of Bipyridine Bisphenolate ONNO Ligands and Their Highly Luminescent Tetradentate Pt(II) Complexes for Solution-Processable OLEDs, Pander, P., Bulmer, R., Martinscroft, R., Thompson, S., Lewis, F., Penfold, T., Dias, F., Kozhevnikov, V. 2 Apr 2018, In: Inorganic Chemistry
• Modelling of the Am(III) - Cm(III) kinetic separation effect observed during metal ion extraction by bis-(1,2,4)-triazine ligands, Distler, P., Stamberg, K., John, J., Harwood, L., Lewis, F. 2018, In: Separation Science and Technology
• Plutonium coordination and redox chemistry with the CyMe4-BTPhen polydentate N-donor extractant ligand, Reilly, S., Su, J., Keith, J., Yang, P., Batista, E., Gaunt, A., Harwood, L., Hudson, M., Lewis, F., Scott, B., Sharrad, C., Whittaker, D. 18 Nov 2018, In: Chemical Communications

Rachel Bulmer Design and Synthesis of Novel Actinide Selective Ligands for Future Spent Nuclear Fuel Reprocessing Start Date: 01/10/2015 End Date: 10/05/2019

• Chemistry PhD July 03 2008
• Member American Chemical Society 2014
• Member (MRSC) Royal Society of Chemistry (RSC) 2014