Review and evaluation on the surface area of HLLW vitrified products; Surface area increase factors due to fracturing and their bases for performance assessment of geological isolation

Igarashi, Hiroshi

The literature overseas was reviewed on the increase in the surface area of HLLW vitrified products due to cooling during glass pouring process and mechanical impact, from the perspective of a parameter of modeling the radionuclide release rate from glass in performance assessment of geological isolation. The investigation was focused on the experimental work to evaluate an increase in surface area, and how the parameters on surface area were set based on those experimental results. The surface area obtained from the experiments executed in Japan were also discussed in comparison with the overseas studies. While surface area increase factor and the management on its uncertainty in the modeling varied according to the country, the factor set in the modeling reported from Japan was within the range from overseas. The surface area increase factors from the experiment in Japan which were evaluated in the same manner as overseas, were comparable with those overseas.