ADSORPTION AND DESORPTION BEHAVIOR OF TRITIATED-WATER ON THE PIPING MATERIALS

The behavior of tritium on the surface of various piping materials mus t be investigated for establishment of the safety confinement technolo gy of tritium or for development of the effective fuel handling techno logy in a D-T fusion reactor, because tritiated water or gaseous triti um is captured on the piping surface through adsorption or isotope exc hange reaction. The present authors carried out the water adsorption a nd desorption experiments on 304 stainless steel, copper, and aluminum in the temperature range from 5 to 100 degrees C and in the partial p ressure range of water vapor between 11.8 and 198 Pa using a breakthro ugh method and quantified the amount of water adsorbed and the overall mass transfer coefficients in adsorption and desorption of water. It was observed in this study that aluminum adsorbed more water than stai nless steel or copper. It was also observed that the adsorption and de sorption rates of water for three materials showed almost the same val ues. The breakthrough behavior of tritiated water in a 100m pipe of st ainless steel was also evaluated applying the results of this work. It is concluded that water adsorption and desorption reactions influence the behavior of tritiated water in the piping system under the condit ion where the partial pressure of tritiated water vapor is lower than several pascals.