Characterising legacy spent nuclear fuel pond materials using microfocus X-ray absorption spectroscopy

DOI: 10.1016/j.jhazmat.2016.05.037

Authors: William Bower (University of Manchester) , Katherine Morris (University of Manchester) , Fred Mosselmans (Diamond Light Source) , Olivia Thompson (NNL) , Anthony Banford (NNL) , K. Law (The University of Manchester) , Richard Pattrick (University of Manchester)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Journal Of Hazardous Materials

State: Published (Approved)
Published: May 2016
Diamond Proposal Number(s): 9045

Abstract: Analysis of a radioactive, coated concrete core from the decommissioned, spent nuclear fuel cooling pond at the Hunterston-A nuclear site (UK) has provided a unique opportunity to study radionuclides within a real-world system. The core, obtained from a dividing wall and sampled at the fill level of the pond, exhibited radioactivity (dominantly 137Cs and 90Sr) heterogeneously distributed across both painted faces. Chemical analysis of the core was undertaken using microfocus spectroscopy at Diamond Light Source, UK. Mapping of Sr across the surface coatings using microfocus X-ray fluorescence (μXRF) combined with X-ray absorption spectroscopy showed that Sr was bound to TiO2 particles in paint layers, suggesting an association between TiO2 and radiostrontium. Stable Sr and Cs sorption experiments using concrete coupons were also undertaken to assess their interactions with the bulk concrete in case of a breach in the coating layers. μXRF and scanning electron microscopy showed that Sr was immobilized by the cement phases, whilst at the elevated experimental concentrations, Cs was associated with clay minerals in aggregate. This study provides a crucial insight into poorly understood infrastructural contamination in complex systems and is directly applicable to the UK’s decommissioning efforts.

Journal Keywords: concrete; decommissioning; legacy materials; spent fuel pond; contamination; microfocus spectroscopy; X-ray absorption

Subject Areas: Environment, Materials, Energy


Instruments: I18-Microfocus Spectroscopy