报告摘要：
Irradiated nuclear fuel has been reprocessed at Sellafield since the early 1950s to separate plutonium. In the course of these operations, low level effluents have been discharged to the Irish Sea under authorisation, and the sediments now contain elevated concentrations of plutonium and a range of other nuclides. This area provides an opportunity to explore the behaviour of plutonium in the natural environment over a period of decades, and follow environmental transport pathways.

There are also historic fuel storage facilities at Sellafield in which plutonium-containing sludges have accumulated, and these are now being emptied. There is a concern that remobilising the sludge will release plutonium in a form which is not effectively trapped by the site’s effluent treatment plants, and hence lead to excessive plutonium discharges to sea. By understanding the chemistry of different components of the effluents, and their interactions, it is possible to control plutonium discharges.

Ultimately, the sludges retrieved from the storage ponds will be immobilised in cement, and directed to geological disposal. However, the nature of the plutonium in these wastes is not well understood. Model samples show significant redistribution of plutonium, and synchrotron techniques (X-ray fluorescence mapping and X-ray absorption spectroscopy) illustrate the underlying plutonium chemistry. 
报告人简介：

Prof Francis Livens has held a radiochemistry position at The University of Manchester since 1991. He worked for over 30 years in environmental radioactivity and actinide chemistry, starting his career with the Natural Environment Research Council, where he was involved in the response to the Chernobyl accident.

At The University of Manchester, he has worked in many aspects of nuclear fuel cycle research, including effluent treatment, waste immobilisation and actinide chemistry. He was the founding Director of the Centre for Radiochemistry Research, established in Manchester in 1999 and is now interim Director of the Dalton Nuclear Institute and Director of the EPSRC-funded Next Generation Nuclear Centre for Doctoral Training. He has acted as an advisor to the nuclear industry both in the UK and overseas.