Study of the microstructure of irradiated beryllium for the validation of the ANFIBE code
The behaviour of beryllium under fast neutron irradiation is a key issue of the Helium Cooled Pebble Bed Tritium Breeding Blanket, due to the production of large quantities of helium and of a non-negligible amount of tritium. To optimise the design, a reliable prediction of swelling due to helium bubbles and of tritium inventory during normal and off-normal operation of a fusion power reactor is needed. The ANFIBE code is being developed to meet this need. The code has to be applied in a range of irradiation conditions where no experimental data are available, therefore a detailed gas kinetics model, as well as a specific and particularly careful validation strategy is needed. The validation procedure of the first version of the code was based on macroscopic data of swelling and tritium release. This approach is, however, incomplete, since a verification of the microscopic behaviour of the gas in the metal is necessary to obtain a reliable description of the swelling. This paper discusses a general strategy for a thorough validation of the gas kinetics models in ANFIBE. The microstructure characterisation of weakly irradiated beryllium pebbles, with different visual examination techniques, is then presented as an example of the application of this strategy. In particular, the advantage of developing 3D techniques, such as X-ray microtomography, is demonstrated.
Bibliographic Reference: An oral report given at: 6th International Symposium on Fusion Nuclear Technology Organised by: University of California, San Diego Virtual Laboratory for Technology and Center for Energy Research Held at: San Diego (US), 7-12 April 2002
Record Number: 200214572 / Last updated on: 2002-04-04
Original language: en
Available languages: en