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A study of the porosity of nuclear graphite using small-angle neutron scattering

Mileeva, Z; Ross, DK; King, SM

A study of the porosity of nuclear graphite using small-angle neutron scattering Thumbnail


Authors

Z Mileeva

DK Ross

SM King



Abstract

Small angle neutron scattering (SANS) measures porosity in nuclear graphites, including both open pores, caused by escaping decomposition gases, and internal cracks (in coke particles) generated by anisotropic thermal contraction along the c-direction (Mrozowski Cracks). Porosity changes on the length scale observable by SANS must control the development of internal stresses and hence of cracking in AGR graphite due to irradiation (both fast neutron displacements of carbon atoms and radiolytic corrosion by CO2). Such cracking may cause premature reactor shutdown. SANS measurements show that porosity is fractal on a length scale between ~0.2-300 nm, presumably due to Mrozowski cracks – because the fractal index of the SANS signal depends only on the porosity of the graphitic filler. We report here two novel uses of the SANS technique as applied to reactor graphite – contrast matching with D-toluene (to measure the fraction of the porosity open to the surface) and the temperature dependence of the scattering (to measure pore width changes up to 2000 °C). These results provide important new information on AGR graphite porosity and its evolution during irradiation.

Citation

Mileeva, Z., Ross, D., & King, S. (2013). A study of the porosity of nuclear graphite using small-angle neutron scattering. Carbon, 64, 20-26. https://doi.org/10.1016/j.carbon.2013.06.030

Journal Article Type Article
Publication Date Nov 1, 2013
Deposit Date Jun 20, 2013
Publicly Available Date Apr 5, 2016
Journal Carbon
Print ISSN 0008-6223
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 64
Pages 20-26
DOI https://doi.org/10.1016/j.carbon.2013.06.030
Keywords nuclear graphite, irradiation damage, small angle neutron scattering
Publisher URL http://dx.doi.org/10.1016/j.carbon.2013.06.030
Related Public URLs http://www.sciencedirect.com/science/journal/00086223
Additional Information Corporate Creators : University of Salford, ISIS Facility
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Funders : Engineering and Physical Sciences Research Council (EPSRC)
Projects : Fundamentals of current and future uses of nuclear graphite

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