This paper describes the facilities of the Institute of Atomic Energy of the National Nuclear Centre of the Republic of Kazakhstan (IAE NNC RK) (Kurchatov, Kazakhstan) designed to conduct studies on the interaction of hydrogen isotopes with materials of nuclear and fusion reactors with and without neutron irradiation. Experiments with sample irradiation are carried out at the LIANA facility, which is located at the IVG.1M reactor. The VIKA and TiGrA installations are designed to conduct experiments with materials before or after irradiation using the temperature-programmed desorption spectroscopy (VIKA), thermogravimetry, and differential scanning calorimetry (TiGrA) methods. The main results of some experimental studies are also presented.

The behavior of structural materials of nuclear and fusion reactors during operation largely determines their safe and economical work. Structural materials of nuclear and fusion reactors are operating under conditions of interaction with various chemical active elements (gases, vapor-gas mixtures, fission products, etc.) in a wide temperature range; they are subject to high requirements in terms of their thermal and corrosion resistance. This paper presents the new methodology of complex studies on structural materials corrosion resistance of nuclear and fusion reactors with different gases and vapor-gas mixtures by thermal-gravimetric analysis (TGA), differential-scanning calorimetry (DSC) and mass spectrometry (MS) methods simultaneously.

Radiation-induced attenuation (RIA) at wavelength λ=1.55 μm as well as the RIA spectra were investigated in optical fibers during and after irradiation at the IVG.1M nuclear reactor (Republic of Kazakhstan). The fibers studied were single-mode at λ=1.55 μm, had an undoped-silica-core and an-F-doped-silica cladding (”pure-silica fibers, PSFs”), and were provided by different manufacturers. In addition to five PSFs, a single-mode revolver hollow-core fiber was also studied. The PSFs had different coating materials: polyimide, copper, or aluminum. All fibers were exposed to three runs of reactor irradiation at enhanced temperature (155-355 °C) so that by the end of the 3rd run, the fast-neutron fluence amounted to Φ=4.46∙1017n/cm2 and γ-dose to D=2.91∙107 Gy. The total induced loss at λ=1.55 μm was found to be composed of 1) RIA, 2) bending loss (BL), caused by thermal expansion of the copper cylinder the PSFs were wound on, and 3) thermo-induced microbending loss (ML) in Cu-coated PSFs. At the end of the irradiation campaign, the net RIA in PSFs proved to lie in the interval of 0.12-0.16 dB/m, which appears to be admissible to intrareactor transport fibers. It was confirmed that long-wavelength RIA tail is the only RIA origin at λ=1.55 μm in PSFs in such strong radiation fields. The hollow-core fiber was found to feature zeroth RIA throughout the campaign.