Chlorine speciation in nuclear graphite studied by X-ray Absorption Near Edge Structure

In this paper, we present an X-ray Absorption Near Edge Structure (XANES) study of chlorine speciation in virgin nuclear graphite of the French UNGG reactors of St. Laurent (SLA2) and Marcoule (G2). Comparable Cl K-edge XANES spectra are obtained for both kinds of virgin nuclear graphite. Spectral analysis shows that chlorine is covalently bound to carbon atom, with a formal valence equal to (−I). Annealing of the samples in the temperature range 200–1000 °C induces a release of chlorine but does not change its speciation and valence.

► A first XANES study of chlorine speciation in virgin nuclear graphite.
► Chlorine is covalently bound to carbon atom, with a valence equal to (−I).
► Annealings induce a chlorine release but does not change its speciation and valence.