Paper VT-ThP19
Consideration for the Role of Surface Boundary Layer and the Mechanism of Hydrogen Desorption in Stainless Steel

Thursday, October 18, 2007, 5:30 pm, Room 4C

Tritium loaded stainless steel specimens of 0.5 mm thickness plate were prepared. When the specimen was chemically etched by about 70 µm in thickness,the amount of tritium trapped within the top surface was measured by β-ray induced X-ray spectroscopy technique. When the chemically etched specimen was immersed in argon gas flow in atmosphere at ambient temperature, more than 99% of tritium released from the specimen was tritiated water, HTO, and the amount of released tritium was measured as a function of time by counting technique. In this paper to evaluate quantitatively the above experimental results, a model for hydrogen transport is proposed, and results of numerical simulation for the tritium release are shown. It is demonstrated that the numerical simulation well predicts the amount of tritium released from the stainless steel specimen in the experiment. This work will be discussed as an issue of outgassing reduction in stainless steel materials.