PRESSURE-VESSEL STEELS - INFLUENCE OF CHEMICAL-COMPOSITION ON IRRADIATION SENSITIVITY

Neutron irradiation of steels used in the construction of nuclear reac tor pressure vessels can lead to the embrittlement of these materials, i.e. increasing the ductile-to-brittle transition temperature and dec reasing the fracture energy, which can limit the plant life. The knowl edge of irradiation embrittlement and the means for minimizing such de gradation is therefore important in the field of assuring the safety o f nuclear power plants. Irradiation embrittlement is quite a complex p rocess. It involves many variables. The most important of these are ir radiation temperature, neutron fluence (neutron dose), neutron flux (n eutron dose rate) and chemical composition of the irradiated material. This paper is concerned with the effect of chemical composition, i.e. the role of residual and alloying elements in the irradiation embritt lement of nuclear reactor pressure vessel steels in light water reacto rs. It presents a critical review for the published work in this held over the last 25 years. (C) 1998 Elsevier Science Limited. All rights reserved.