Production of H2 by water radiolysis in cement paste under electron irradiation: A joint experimental and theoretical study

Sophie A Le Caër (1) , Lucile Dezerald (2, 3) , Khaoula A Boukari (4) , Maxime A Lainé (1) , Sébastien A Taupin (1, 3, 5) , Ryan M. Kavanagh (6, 7) , Conrad S.N. Johnston (6) , Eddy A Foy (8, 9) , Thibault Charpentier (7) , Konrad J. Krakowiak (3, 10) , Roland J.-M Pellenq (3, 5, 4) , Franz J. Ulm (3, 5) , Gareth A. Tribello (6) , Jorge A Kohanoff (6) , Andres A Saúl (4)

1 LIONS - Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire
2 IJL - Institut Jean Lamour
3 CEE - Department of Civil and Environmental Engineering [Cambridge]
4 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
5 MSE 2 - Multiscale Material Science for Energy and Environment
6 QUB - Queen's University [Belfast]
7 LSDRM - Laboratoire Structure et Dynamique par Résonance Magnétique (LCF)
8 LAPA - UMR 3685 - Laboratoire Archéomatériaux et Prévision de l'Altération
9 IRAMAT - LMC - IRAMAT - Laboratoire Métallurgies et Cultures
10 Cullen college of Engineering

Long-term confinement of nuclear waste is one of the main challenges faced by the nuclear industry. Fission products such as 90 Sr and 137 Cs, both β − emitters known to induce serious health hazards, represent the largest fraction of nuclear waste. Cement is a good candidate to store them, provided it can resist the effects of irradiation over time. Here, we have investigated the effects of β − decay on cement by performing electron irradiation experiments on different samples. We show that H 2 production in cement, the main effect of water radiolysis, depends strongly on composition and relative humidity. First-principles calculations indicate that the water-rich interlayer regions with Ca 2+ ions act as electron traps that promote the formation of H 2. They also show that holes localize in water-rich regions in low Ca content samples and are then able to participate in H 2 production. This work provides new understanding of radiolysis effects in cements.

Mots clés: Reaction mechanisms; First-principles calculations; H 2 production; Radiolysis; Cement paste

Domaines: Matériaux

Sophie A Le Caër, Lucile Dezerald, Khaoula A Boukari, Maxime A Lainé, Sébastien A Taupin, et al.. Production of H2 by water radiolysis in cement paste under electron irradiation: A joint experimental and theoretical study. Cement and Concrete Research, 2017, 100, pp.110 - 118. ⟨10.1016/j.cemconres.2017.05.022⟩. ⟨cea-01543011⟩