Neutron-irradiated reactor pressure vessel steels investigated by positron annihilation

Hardening and microstructural evolution in A533B steels under neutron irradiation and a direct comparison with electron irradiation

“…This was consistent with the reported results in commercial steels after neutron irradiation at 300°C [27][28][29]. There are some notable differences between KUR and electron irradiation (Figs.…”

Positron Annihilation Measurements on Nuclear Reactor Pressure Vessel Steels

“…At this moment this can only be attributed to inhomogeneity of the weld material. The comparison of isochronal annealing results on non-irradiated and irradiated steels (e.g., [2,3,8]) can yield valuable information about changes introduced in the steel by radiation damage.…”

“…Several ways to tackle this problem are described in the literature. The most obvious way is of course to reduce the size of the steel samples as much as possible, while making sure that all positrons are stopped in the samples (e.g., [2,31). In addition, one can perform two measurements for each pair of samples, one with the positron source and one without the source (e.g., [4]).…”

Characterization techniques for assessing irradiated and ageing materials in nuclear power plant systems, structures and components (SSC)

“…as they enter a metal and annihilate when interacting with electrons, they emit photons with energies, momenta and time of emission which can be accurately measured. Positron annihilation (Pa) was established in the 1970s as a reliable technique to characterize vacancies in thermal equilibrium and other radiation-induced defects (Gauster 1976, Gil, De Lima et al 1989 ¥ 0.5 mm are the only requirement. Since Pa techniques are sensitive to the identification of vacancy-type defects in metals, they are very effective to characterize microstructure evolution during irradiation.…”