Projects at Lancaster

These projects are run by Lancaster University. 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.

  • Photo detector based measurement of beta radiation in groundwater

    In this project we are planning to investigate the potential of using GaAs photo-detectors to detect beta particle emissions from strontium-90. Photo-diodes are used for soft x-ray detection, particularly in harsh terrestrial and space environments (for example photo-diodes such as GaAs diodes originally developed for X-ray spectroscopy applications). The potential of using GaAs diodes for beta particle detection and spectroscopy, particularly for nuclear decommissioning, has not yet been explored. Photo-detectors contain PIN photodiodes, where incident beta particles create electron-hole pairs in the diode’s depletion layer. This generates a current pulse, which can then be amplified and processed to investigate the presence and concentration of strontium-90 contamination in groundwater.

     

    The primary objectives of the project can be summarised as follows:

     

    • Investigation of GaAs photo-detectors for beta detection and develop a conceptual model for the complete device
    • Study strontium-90  contaminated various nuclear environments based on  Monte Carlo modeling and simulations
    • Design and manufacturing of the device and related data processing electronics and background filtering (also to distinguish other particle types)
    • Development of corresponding pattern recognition algorithms for spectroscopy analysis
    • Isotopic level identification and characterisation of contamination level
    • Validate real-time performance of the complete device experimentally for various source conditions by reference to ISO standard radiation fields available at the National Physical Laboratory (NPL), Teddington, UK.
    • Test real-time operation of the device in a radiologically contaminated land

     

     

    Contact: Dr Kelum Gamage

  • Accident tolerant? Preventing corrosion in uranium nitride fuels

    Accident Tolerant Fuels (ATFs) are the next generation of nuclear fuels, designed to maintain their integrity when exposed to the extreme conditions present during an incident, thereby preventing release of radioactive material to the environment. Uranium nitride is a leading ATF candidate due to its high thermal conductivity high specific heat capacity and low thermal expansion that suppress overheating and swelling in the event of a loss of coolant accident (LOCA). However, a significant obstacle to adoption of UN fuels in light water reactors (LWRs) is its extremely low oxidation resistance. Corrosion of fuel exposed to high-temperature pressurised water or steam, following a breach of the fuel cladding, would lead to release of fuel debris and fission products to the coolant system. Therefore, a strategy for increasing the oxidation resistance of UN, either through coating or doping is essential.
    The aim of this project is to develop a mechanistic understanding of the corrosion of UN under reactor conditions, enabling the establishment of doping strategies to reduce the reactivity of the fuel’s surface making it safe for operation in LWRs. The project will employ a combination of state-of-the-art quantum mechanical simulations, supported by electrochemical and Raman spectroscopic studies of UN thin films, to understand how water interacts with the surface and how the introduction of defects and dopants, such as Cr and Si, will modify the surface chemistry and whether this can inhibit oxidation.

    Originally discounted for use in light water reactors (LWRs) due to its unacceptably high oxidation rate when exposed to high temperature water and steam, uranium nitride is currently a leading candidate for use as an accident tolerant fuel (ATF). However, before UN can be employed in LWRs it is essential to develop a strategy to reduce the oxidation rate to acceptable levels and this forms the focus of this project.
    An attractive method of passivating the UN surface is to use an additive that is homogeneously dispersed in a solid solution with the fissile material. The additive must react preferentially with the water molecules at the surface and form a stable oxide that is insoluble in water, which can then act as an oxidation barrier. The choice of additive is further constrained as it must be able to substitutionally solve into the nitride, leaving Zr, Al, Si and Cr as the leading candidates.
    An important goal in the study of corrosion processes is to determine what is the rate determining step (i.e. the slowest process). This is often the transfer of oxide and hydroxyl ions through the protective oxide or the chemical reactions occurring at the surface. The objective of this work, therefore, is to determine the rate determining step in the oxidation process of UN and how this changes due to the incorporation of additives, thereby allowing the development of a doping strategy to improve the accident tolerance of UN fuel.

     

    Contact: Dr Samuel Murphy

  • Groundwater monitoring on Nuclear sites

    Monitoring of ground water quality on nuclear licensed sites is a regulatory requirement affecting NDA estates. Their primary objective is to characterise and assess water quality underlying the site through monitoring programmes and meet statutory reporting requirements. Monitoring of 99Tc is a statutory requirement on a number of sites.

    Secondary objectives include the provision of reassurance ground water monitoring of leak detection programmes and measurements to support site hydrogeological models. Technetium-99 is most commonly present in ground water as the pertechnetate ion (TcO4-) which is highly soluble and mobile in ground water systems. Thus, in a contamination event, 99Tc is one of the first isotopes to be detected and presents an opportunity for early contaminant tracking.

     

     

    Contact: Dr Fabrice Andrieux

  • The Electrochemical Treatment of Nuclear Wastes

    Legacy wastes, especially those whose condition is such that straightforward disposal is not a viable option, present an important challenge for the nuclear industry. These are hazardous and must be thoroughly decontaminated prior to further processing for disposal. Current decontamination techniques involve the use of significant amounts of costly reagents which can have limited efficiencies toward separation and require further treatment as part of a secondary waste stream.

    Electrochemical treatment of these wastes can yield a means to efficiently provide separation without the need for additional reagents.  This significantly reduces the mass, volume and cost associated with decontamination process and any further conventional techniques and treatments which may be required to treat the extracted small volumes of higher level waste. Reaction conditions and electrode potentials can also be adjusted to exploit the difference in thermodynamic stability of the waste components to produce high degrees of selective separation, leading to improved efficiencies.

     

    Contact: Dr Richard Dawson

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