Title :
TEM Study of Radiation Induced Defects in Baffle-Former-Barrel Assembly From Decommissioned NPP Greifswald
Author :
Srba, O. ; Michalicka, J. ; Keilova, E. ; Kocik, J.
Author_Institution :
Struct. & Syst. Diagnostics, Centrum vyzkumu Rez, Rez, Czech Republic
Abstract :
A complex transmission electron microscopy (TEM) study of reactor vessel internal (RVI) materials from the baffle-former-barrel assembly from NPP Greifswald (VVER 440), Unit 1 decommissioned after 15 service cycles has been undertaken. All parts of the baffle-former-barrel assembly are made from Ti-stabilized austenitic stainless steel 08Ch18N10T. The materials were exposed to different dose of neutron radiation (2.4-11.4 dpa) at temperatures 267-398°C depending on position in the core. Three types of radiation induced defects were identified and quantified, namely: dislocations, cavities (voids) and fine-scaled precipitated particles of Ni-Si rich phases. Black-dot type defects were observed too. Operation conditions are around ≈ 300°C that is why we have observed defect typical for both low and high regions of irradiation temperatures.
Keywords :
dosimetry; fission reactor decommissioning; fission reactor materials; fission reactor safety; light water reactors; Ni-Si rich phases; TEM Study; Ti-stabilized austenitic stainless steel; VVER 440; baffle-former-barrel assembly; black-dot type defects; cavities; complex transmission electron microscopy; decommissioned NPP Greifswald; dislocations; fine-scaled precipitated particles; irradiation temperatures; neutron radiation dose; radiation induced defects; reactor vessel internal materials; temperature 267 degC to 398 degC; Cavity resonators; Inductors; Materials; Microstructure; Neutrons; Steel; Temperature; Neutron radiation; TEM; reactor vessel internal (RVI);
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2014.2306976
