title: Interaction between nuclear graphite and molten fluoride salts: a synchrotron radiation study of the substitution of graphitic hydrogen by fluoride ion.
abstract: The interaction between nuclear graphite and molten fluoride salts (46.5 mol % LiF/11.5 mol % NaF/42 mol % KF) is investigated by synchrotron X-ray diffraction and C K-edge X-ray absorption near-edge structure (XANES). It is found that there are a large number of H atoms in IG-110 nuclear graphite, which is attributed to the residual C-H bond after the graphitization process of petroleum coke and pitch binder. The elastic recoil detection analysis indicates that H atoms are uniformly distributed in IG-110 nuclear graphite, in excellent agreement with the XANES results. The XANES results indicate that the immersion in molten fluoride salts at 500 °C led to H atoms in nuclear graphite partly substituted by the fluorine from fluoride salts to form C-F bond. The implications of these findings are discussed.
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai, China.
authors.forename: Xinmei
authors.initials: X
authors.lastname: Yang
authors.forename: Shanglei
authors.initials: S
authors.lastname: Feng
authors.forename: Xingtai
authors.initials: X
authors.lastname: Zhou
authors.forename: Hongjie
authors.initials: H
authors.lastname: Xu
authors.forename: T K
authors.initials: TK
authors.lastname: Sham
mesh_terms: D005459:Fluorides / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D018020:Lithium Compounds / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry*; D012492:Salts / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry*; D017356:Synchrotrons
chemical_list: D007477:Ions; D018020:Lithium Compounds; D017680:Potassium Compounds; D012492:Salts; C027651:lithium fluoride; D006108:Graphite; D006859:Hydrogen; D012969:Sodium Fluoride; C033320:potassium fluoride; D005459:Fluorides