INFLUENCE OF FLUX-SPECTRA DIFFERENCES ON TRANSMUTATION, DIMENSIONAL CHANGES AND FRACTURE OF VANADIUM ALLOYS

Density and dimensional changes can arise in vanadium alloys from radi ation-induced segregation and precipitation of chromium, titanium and other elements, Transmutation of vanadium to chromium can also lead to significant changes in density, either directly or indirectly, via it s effect on precipitation. Furthermore, the swelling of vanadium and i ts alloys is known to be very sensitive to the chromium level. Since t he transmutation rate to produce chromium is very sensitive to neutron spectra, an apparent flux-dependence of void swelling may occur that actually arises from the spectral differences that accompany changes i n displacement rate within most reactors, Transmutation and segregatio n can also severely impact the fracture behavior in some alloys.