“…The materials tested were Model Alloys provided by the Kurchatov Institute, covering a large spectrum of compositions typical of ferritic steel with parametric variation of copper, nickel and phosphorus, elements known to play a significant role in material sensitivity to irradiation [3] Typical composition ranges used are: Ni 0 -2%, P 0-0.04% and Cu up to 1%, Mn 0.4%, low S and balance content of Fe. Table 1 shows the Cu, Ni, P and other element contents.…”