Study of Tritium Decontamination of Stainless Steel, Copper, Aluminum Metals by Tritium Dry Desorption

In order to study the decontamination efficiency of stainless steel, copper, aluminum metals contaminated by tritium, the metals were decontaminated by exposing to UV, ozone, heating, and the combination of heating, UV and ozone. The result indicates that the elevation of temperature can obviously improve decontamination. While irradiated by 172 nm UV, the decontamination efficiency is low, but it is better while heated and irradiated by 172 nm UV. If the stainless steel is irradiated by 172 nm UV and heated at 500 ℃ for 4 h, the decontamination efficiency is 99.2%. There is better decontamination efficiency of copper while exposed to ozone. While exposed to ozone and heated at 500 ℃, the decontamination efficiencies of stainless steel, copper and aluminum are higher than 99.2%. The decontamination efficiency can more obviously improve when metal is heated at high temperature (500 ℃) than low temperature (300 ℃). The surface tritium of metal placed at 30 d after decontamination increases because of diffusion and penetration of the tritium. Resolution spectra of tritium show that there are four kinds of contamination adsorbed tritium of stainless steel.