Disposal procedure for contaminated surface of tritium handling facility in the decommissioning operation

For the decommissioning operation of tritium handling facility, surveillance of contamination with tritium on floor, wall and roof was performed. Significant amount of tritium contamination was detected in approximately 86% of total surface measurement points and maximally 70 mm of scraping was required to eliminate tritium contamination. In some samples for measurement of tritium depth profile, the highest tritium concentration was observed at the inside but not the surface. This measurement result of depth profile is also discussed with our previous calculation results considering diffusion, adsorption, desorption of tritium in the concrete and isotope exchange reaction between tritiated water vapor in the concrete bulk and atmospheric water vapor.