Projects at Leeds

These projects are run by the University of Leeds. Application information can be found in their how to apply section.  Please contact the relevant person below before applying. Click on the titles below to see contact details and more information.

  • Process optimisation of mediated electrochemical oxidation for the destruction of waste organics

    The use of polymeric flocculants to promote the sedimentation and rapid separation of suspensions and fines is ubiquitous in industrial areas such as water treatment and minerals separation. However, such techniques are not utilised to a large extent in the processing of UK nuclear legacy suspension wastes, due to the potential impact of the organic species on downstream processing (e.g. encapsulation). Nevertheless, the extremely low concentrations required with large molecular weight polymers (which can be down to a few parts per million) is often below levels of other organic species already present in pond sludges, such as algae, which would suggest that downstream risk can be minimised with appropriate selection of a highly efficiency flocculant.

     

    The advantage of flocculation is that is can promote rapid aggregation, increasing sedimentation and separation of even small micron sized fines. Additionally, the open networks of flocculated aggregates can lead to a much higher dewatering capacity with filtration or other downstream techniques (as they are less susceptible to filter blinding). Hence, this PhD proposal seeks to understand the interaction of flocculation agents on the behaviour of legacy waste sludge test materials, focusing in three key areas; the settling rate and segregation of suspensions; the surface chemistry interactions of the components; and the advantages of flocculation on filtration or flotation dewatering performance.

     

    Contact: Prof Bruce Hanson 

  • Solving the magnox problem: how to store fuel In dry conditions

    The aim of this project is to develop and test a process which will allow long term storage of Magnox Fuel in dry conditions, prior to disposal.

    It is possible that a small quantity of Magnox fuel may not be reprocessed. Experience from the First Generation Fuel Storage ponds at Sellafield site shows us that wet storage of Magnox fuels is not possible for long periods. Therefore, an alternative solution is required for storage of Magnox fuel between reactor discharge and final disposal.

    Wylfa has experience of storing fuel, freshly discharged from the reactor, in a purpose built dry store. Therefore technical feasibility for uncorroded fuel, with self heating, is proven; as long as the fuel remains dry. There are reports that if the fuel is accidentally wetted, then the cladding corrodes leading to the risk of activity release. If this is the case, then the sensitivity to even a short term exposure to water will greatly affect the possibility of long term storage. 

    The main question that this project will address is whether fuel that has already been stored and cooled in wet conditions can be dried and passivated sufficiently to allow long term storage without (further) degradation.

     

    The project will consist of the following tasks:

    1)     Identify the likely cladding chemistry of wet stored Magnox fuel.

    2)     Recreate this cladding to establish surrogate materials for testing.

    3)     Determine the optimum physical conditions (pressure, temperature and time) for drying.

    4)     Determine the effect of gas composition on cladding chemistry.

    5)     Determine the effect of irradiation.

    6)     Investigate cladding stability during long term storage.

     

    Output from the project will be fed into the NDA’s spent fuel forum

     

    Contact: Prof Bruce Hanson

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