Irradiation induced creep behavior of H-451 graphite

The application of a creep model previously applied to compressive creep data for H-451 irradiated at 900 °C (13.7 and 20.8 MPa) has been extended to compressive creep data for H-451 irradiated at 600 °C (13.7 and 20.8 MPa). The basis of the creep model is discussed and the experimental data required to evaluate the terms in the creep model are reported and discussed. The model, which corrects the true (crystal) creep strain for the effect of creep on the dimensional change component of the creep specimen, is shown to be a good fit to the data. Creep strain data for H-451 graphite irradiated at 900 °C under a tensile stress of 6 MPa are also reported, along with the required experimental data to evaluate the terms in the creep model. The model is shown to inadequately represent the high dose (post volume turn-around) H-451 tensile creep strain data. Reasons for the models limitation are discussed and an approach to a potentially improved graphite irradiation creep model is suggested.