Modelldatensatz für den Reflektorgraphit der Kugelhaufenreaktoren

A model data set covering the temperature range 300 - 800 °C and irradiation dose range 0 - 4$\cdot$10$^{2}$ n/cm$^{2}$ EDN has been compiled for the reflector graphite of the OTTO-type pebble-bed high temperature reactor. The stipulated irradiation-induced changes in the properties of the model graphite are based mainly, but not exclusively, on experimental data from an extruded pitchcoke graphite of british manufacture, which had been irradiated to a dose of 2.8$\cdot$10$^{22}$ n/cm$^{2}$EDN. Since the initial properties of the unirradiated graphite were not known in detail, the properties of the German extruded pitch coke graphite ATR-2E from the SIGRI company were substantially used in the definition of the pre-irradiation properties of the model graphite. The main philosophy behind the compilation of the model data set was to predict as well as possible at this point in time the irradiation behaviourof the reference graphite for the reflector of the OTTO-type pebble-bed reactor and thus provide material data for stress analysis calculations. In order to allow a comparison of these stress calculations, it is recommended to use this data set which has been agreed upon among the partners in the HTB programme