How mobile is tritiated water through unsaturated cement-based materials? New insights from two complementary approaches

S Savoye; A Rajyaguru; N Macé; S Lefèvre; G Spir; J C Robinet

doi:10.1016/j.apradiso.2018.04.019

How mobile is tritiated water through unsaturated cement-based materials? New insights from two complementary approaches

Appl Radiat Isot. 2018 Sep:139:98-106. doi: 10.1016/j.apradiso.2018.04.019. Epub 2018 Apr 26.

Authors

S Savoye¹, A Rajyaguru¹, N Macé¹, S Lefèvre¹, G Spir¹, J C Robinet²

Affiliations

¹ Den-Service d'Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
² R&D Division, Transfert Unit, Andra, F-92298 Châtenay-Malabry, France.

PMID: 29734119
DOI: 10.1016/j.apradiso.2018.04.019

Abstract

This work presents two complementary approaches (for low and high desaturation) to study tritiated water (HTO) diffusion through unsaturated cement-based materials. The first approach was based on through-diffusion experiments where suction was controlled by osmosis. In the second approach, diffusion experiments were performed in humidity chambers controlled by under-saturated saline solutions. Results revealed a decrease of effective diffusion coefficient by a factor of 10 from 100% to 23% of saturation degree. Comparison with gaseous H₂ suggests that HTO diffuses through unsaturated cement-based materials at rates 4 orders of magnitude lower.

Keywords: Cement; Desaturation; Diffusion; Osmosis; Saline solution; Tritiated water (HTO).