EFFECTS OF HELIUM ON VOID SWELLING IN BORON-DOPED V-5FE ALLOYS

The effects of helium on void swelling in V-5Fe were investigated with natural boron-doping techniques during FFTF/MOTA (Fast Flux Test Faci lity/Materials Open Test Assembly) irradiation. Microstructural observ ation was carried out to understand the swelling behavior obtained fro m density measurements. The cavity size distribution in V-5Fe-xB (x = 0, 100, and 500 appm) irradiated at temperatures lower than 713 K indi cates a suppressant effect of helium on void growth, and an enhancing effect on cavity nucleation. Since the chemical effect of boron additi on is competitive with the transmutation effect, the results have been compared with that of the dual ion irradiation experiments to allow s eparation of the effect of helium from the effect of boron. (C) 1998 E lsevier Science B.V. All rights reserved.