Tritium Transfer in Porous Concrete Materials Coated with Hydrophobic Paints

Abstract

An experimental study on tritium transfer in porous concrete materials for the tertiary tritium safety containment is performed to investigate; (i) how fast tritium is transferred through porous concrete walls coated with or without a hydrophobic paint, and (ii) how well the hydrophobic paint coating works as a film protecting against tritium migrating through concrete. The experiment is comparatively carried out using two types of cement-paste and mortar disks with or without two kinds of paints. The results obtained here are summarized as follows: (1) Tritium transfer can be correlated in terms of the effective tritium diffusivity of DT=1.2x10-11 m2/s in porous cement. (2) Adsorbed or condensed liquid HTO itself is transferred only through pores in cement, and no tritium transfer path is present in non-porous sand. (3) Rates of tritium sorption and dissolution in cement and mortar coated with an epoxy-resin paint is correlated in terms of the diffusivity through the paint film of DT=1.0x10-16 m2/s. (4) The epoxy paint works more effectively as an anti-tritium diffusion coating than the acrylic-silicon resin paint. (5) The hydrophobic property of the silicon resin paint is deteriorated with elongating the contact time with H2O.