Positron Study of Radiation Embrittlement of Steels Used in Water Cooled, Water Moderated Energy Reactors

Positron annihilation spectroscopy (PAS) and Moessbauer spectroscopy (MS) were applied in the evaluation of the microstructure parameters and degratdation processes of nuclear reactor pressure vessel (RPV) steel surveillance specimens. Study was oriented to the material investigation of Russian WWER-1000 steels (15Kh2MNFAA and 12Kh2N2MAA) with highter Ni content (1,26 wt.% in base metal and 1,7 wt.% in weld). For comparison, the WWER-440 weld metal (Sv10KhMFT) without Ni wasw measured, too. Specimens were studied in as received stage, after irradiation in LVR-15 experimental reactor to the neutron fluence F(E>0.5 MeV)=4x10 23m-2s-1 and after annealing in vaccuum at 475 oC/2h. Changes due to different chemical composition and due to irradiation were registered using MS. Post-irradiation thermal treatment and annealing of defects was well detected by different PAS techniques. It was observed that the sensitivity of PAS and MS parameters to defined irradiation treatment decreases with Ni-content increase. Results confirm the hypothesis that Ni affects size (decrease) and distribution (more homogeneous) of the Cu- and P-rich clusters and MxCx carbides.

ZEMAN Andrej;  PETRISKA Martin;  KRSJAK Vladimir; 

SLUGEN Vladimir; 

2006-05-19

ELSEVIER SCIENCE BV

JRC30141

http://www.sciencedirect.com/science/article/pii/S0169433205012365,    https://publications.jrc.ec.europa.eu/repository/handle/JRC30141,   

10.1016/j.apsusc.2005.08.076,