Characterising nuclear fuel pond materials using µX-ray absorption spectroscopy

A core of radioactive, coated concrete, from the decommissioned spent nuclear fuel cooling pond at the Hunterston-A nuclear site (Ayrshire, UK) has provided a unique opportunity to study radionuclides within a real-world system.

Researchers from The University of Manchester, National Nuclear Laboratory (NNL) and Diamond Light Source (DLS) have undertaken a detailed analysis of the concrete surface, it’s coating, and their interaction with radionuclides using microfocus spectroscopy on the I18 Beamline at DLS. 

Mapping of Sr across the surface coatings using microfocus X-Ray Fluorescence (XRF) combined with discrete area X-ray absorption spectroscopy showed that Sr was bound to TiO2 particles in the paint layers. Stable Sr and Cs sorption experiments using concrete coupons were also undertaken to assess the interaction of these elements with the bulk concrete in the event of a breach in the coating layers. XRF and scanning electron microscopy showed that Sr was efficiently immobilized by the cement phases, while at elevated experimental concentrations, Cs was associated with clay minerals in the aggregates.

Studies of challenging real world samples such as this are crucial to ensure the safe management of nuclear wastes and limit the uncertainties associated with post-operational clean out and decommissioning, thereby reducing overall costs. The information on Sr–Ti interactions and on Sr and Cs fate in concrete from the core provides wholly new insight to the likely fate of 90Sr and 137Cs, highlighting both the effectiveness and limitations of the techniques applied.

 

Left: Image showing a section through the core coating to the underlying concrete. Right: Elemental maps from I18 (Ti, Cr, Rb, Zr, Sr & Zn) along the same cross section.

 

Bower, W. R., Morris, K., Mosselmans, J. F., Thompson, O. R., Banford, A. W., Law, K., Pattrick, R. A. Characterising legacy spent nuclear fuel pond materials using microfocus X-ray absorption spectroscopy. J. Hazard. Mater., 2015, 5, 97-107. DOI:10.1016/j.jhazmat.2016.05.037.

 

 

Funding opportunities & events

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The network can provide funding for up to 10 projects £20-£30k+ for pump priming projects linked to STFC

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We will be running dedicated training courses and support for attendance of central training course (e.g. XAS data analysis courses). Training strategy will be based on small projects funded.

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Actinide XAS 2017.