Optical imaging of environmental Np speciation (LN)

PI: Louise Natrajan, University of Manchester.

Ascertaining and predicting the migratory behaviour of actinide fission products in natural and engineered environments is imperative for the long-term safety assessment of radionuclide contaminated sites and nuclear waste repositories, meaning understanding the long-term storage behaviour and mobility of radioactive elements is crucial to the UK’s nuclear problem. The problems associated with environmental release of actinide ions have stimulated numerous studies into the bioavailability, biotransformation and mobility of actinide species. However, almost all studies rely on X-ray absorption techniques, which are limited in concentration, spatial and temporal resolution. By contrast, one and two photon (confocal) fluorescence microscopy has the unique ability to attain much greater spatial and temporal resolution, including 3D image mapping. We have previously shown that uranyl(VI) biosorption, internalisation and reduction with metal reducing bacteria (Geobacter sulfurreducens) can be visualised in real time in the absence of probe dyes with the one and two photon luminescence imaging facility at LSF. We now wish to extend these studies to the more radioactive ion neptunium. However in order to achieve this, specialized triple containment housing for the microscope needs to be constructed.