The effect of neutron irradiation on beryllium performance

This paper considers the effect of neutron irradiation on the performance of six beryllium grades (DshG-200, TR-30, TshG-56, TRR, TE-30, TIP-30) fabricated by VNIINM, Russia, and one fabricated by Brush Wellman, USA, S-65. The average grain size of the beryllium grades investigated varied from 8 to 40 mum, beryllium oxide content was 0.7-3.2 wt.%, initial tensile strength 250-680 MPa. All the specimens were irradiated in the active zone of a SM-3 reactor at 650-700 degreesC up to the fast neutron fluence (5.5-6.2) x 10(21) cm(-2) (helium content up to 1150 appm), E > 0.1 MeV. Beryllium behaviour under tensile and compressive tests, swelling and microstructure examination before and after irradiation are presented. The effect of neutron-induced embrittlement on thermal shock resistance of beryllium and its role in the selection of the beryllium grade for HHF-components of ITER are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.