Constant stress irradiation-induced compressive creep of graphite at high fluences

Abstract

One needle coke graphite and two isotropic graphites were irradiated under compressive stresses of 1000, 2000, and 3000 psi at 550 and 800°C to 1·1 × 10 21 n/ cm 2. At 550°C, the creep is linear with fluence and occurs at approximately constant volume for all three graphites. At 800°C, the creep is linear with fluence initially, but at 2000 and 3000 psi for the two isotropic graphites, the creep decreases markedly and even becomes negative at the highest fluences. Creep occurs with a small volume decrease at 800°C for all three graphites.