Novel Portland cement matrices incorporating a γ-MnO2/Ag2O hydrogen/tritium getter -structure changes and trapping performance

•Novel Portland cement mortars are developed, which incorporate a hydrogen/tritium g-MnO2/Ag2O getter.•XRD, TGA and MAS NMR experiments are done on the cement pastes of these mortars.•The structure of the Portland cement solids is not impacted by the presence of getter.•Gamma ray irradiation tests a...

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Bibliographic Details
Published in:Journal of nuclear materials 2022-08, Vol.567, p.153819, Article 153819
Main Authors: Lanier, S., Davy, C.A., Albert-Mercier, C., Farcy, O., Cau-Dit-Coumes, C., Lambertin, D.
Format: Article
Language:English
Subjects:
Chemical Sciences
Getter
Hydrogen fires and explosions
Hydrogen suppression
Material chemistry
Portland cement
Radioactive waste
Trapping
Tritium
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Summary:•Novel Portland cement mortars are developed, which incorporate a hydrogen/tritium g-MnO2/Ag2O getter.•XRD, TGA and MAS NMR experiments are done on the cement pastes of these mortars.•The structure of the Portland cement solids is not impacted by the presence of getter.•Gamma ray irradiation tests are performed after 4 months maturation in endogenous conditions.•With this in situ H2 generation method, the getter-added mortars trap 77 - 96% of H2 produced. This study investigates novel Portland cement-based mortars, developed for hydrogen/tritium trapping and radioactive waste immobilization. They incorporate a γ-MnO2/Ag2O getter powder at 10% wt (i.e. 6.8 to 7.1% vol). Compared to former patented materials, no drying or heat treatment of the materials is needed. Complementarily to X Ray Diffractometry (XRD) and thermo-gravimetry analysis (TGA), 27Al and 29Si Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) evidences that the structure of the Portland cement solids (i.e. the C-A-S-H) is not impacted by the presence of getter, even after several month curing. Yet, Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy (SEM+EDS) shows that calcium is significantly present at the surface of the getter grains; this could affect trapping efficiency. However, after gamma irradiation with cumulated doses of 491 or 997 kGy (i.e. 23 to 46 days at 900 Gy.h−1), all mortars made with getter have a hydrogen trapping efficiency of between 77 and 96%, when compared to the irradiation of mortars made with a non-trapping γ-MnO2 powder, or to the irradiation of pure water considered alone. This means that the developed mortars display excellent hydrogen trapping efficiency, without any impact on their solid structure. [Display omitted]
ISSN:0022-3115
1873-4820
DOI:10.1016/j.jnucmat.2022.153819