Effect of copper and phosphorus on the radiation stability of CrNiMoV steel

The radiation damage of reactor pressure vessel steels is influenced by both the working condition (temperature, neutron fluence), and chemical composition. Because there is only a little possibility to change the working conditions of pressure reactors, the most effective means for radiation embrittlement reduction are changes of chemical composition of steels. Considerable influence of impurities, first of all copper, phosphorus, arsenic, tin and antimony on the radiation embrittlement was found. The outstanding synergic effect of both nickel and copper were proved in some RPV steels. Special attention is paid to copper and phosphorus at the CrNiMoV and CrMoV steels. The evaluation of the influence of these both elements on the radiation stability is object of this study. (orig.)