Computer simulation of tritium retention and release in irradiated beryllium

The helium produced by the 9Be(n,2n)2 4He and the oxygen impurities present in the material appear to be the main cause of tritium retention in irradiated beryllium. Because of the strong relation between the helium bubbles distribution and tritium release, it was decided to extend the code ANFIBE (ANalysis of Fusion Irradiated BEryllium), initially used to describe the helium induced swelling in beryllium, by including a new model describing the trapping effects on tritium due to chemical reactions with beryllium oxyde and capture in helium bubbles. The resulting modified code allows the calculation of tritium distribution and release from beryllium. Good agreement between calculated and experimental data was found. (orig.)