Status of works on radiation stability examination of SAV-1 alloy at the Petersburg nuclear physics institute N.A.B.P. Konstantinov (Russian academy of science)

Full text: Having a unique combination of nuclear, chemical, mechanical characteristics and low cost, aluminum alloys are widely used in nuclear reactor industry as constructional materials. In particular, aluminum alloy SAV-1 is used as constructional material for a reactor core (a reactor vessel, a support grid) in WWR-M reactor. For validation of the reactor life-time extension the radiation stability examination was started in 1976 and is continued up to date. The report presents overview of investigations carried out at PNPI. These investigations include calculated validations of the stress-strain state of reactor equipment elements fabricated from SAV-1 alloy, study of the samples cut from these elements and examinations of the samples after irradiations in the SM and WWR-M reactors. Basing on the performed investigations of SAV-1 alloy, the data are presented on mechanical characteristic changes depending on neutron fluency and test temperature. The brittle state of SAV-1 alloy has been estimated by the crack resistance criterion KC up to the fluency of 2.4x1022n/cm2 (E>0.8 MeV). Perspective works on SAV-1 alloy radiation stability examination were considered. They include first of all investigations of crack resistance and short-term mechanical characteristics of the samples after irradiation during 2009 -2010 up to the fluency of 3 1022n/cm2 (E>0.8 MeV), and also study of the samples after irradiation in the WWR-M reactor since 1984. Performing of these works will allow one to obtain the data validating further life-time extension of the WWR-M reactor operating since 1959. (authors)