[en] Radiation effect on the behaviour of mechanical properties and structure of chromium low alloys such as VKh-2K, KhP-3, VKhM in the wide range of temperatures and neutron fluences is studied. Radiation stability of the alloys is shown to be limited by low-temperature radiation embrittlement (LTRE), caused by radiation hardening as a result of formation of radiation-induced defects such as dislocation loops and vacancy voids in the structure. The methods for prevention LTRE of chromium alloys are suggested. 8 refs.; 8 figs

[en] Methods and results of control of reactivity arising and development of steam-gas volume in the WWER-1000 reactor at the Rovno NPP third unit based on measurement and analysis of noise spectra of neutron flux density, coolant temperature and pressure are discussed. The information and measurement system and software used for measuring and processing the reactor plant parameter noises are described. 7 refs., 5 figs

[en] The problem of efficiency increase of NPP_s with WWER type reactors is discussed. Possible ways for modernization of NPP_s with WWER-100 and WWER-440 reactors are considered. Critical analysis on the improvement of fabrication technology and the increase in NPP main equipment service life is made. The design-technological measures for increase of control rod drive service life for the pilot plant with WWER-1000 reactor at the Novo-Voronezh NPP 5th unit are realized. Owing to the increase in wqear resistance of kinematic units and details of the WWER-440 control rod drives, structure optimization and increase in servise life of complete set of details it is planned to increase the service life from 8 to 15-20 years. Calculational research on the increase in vessel component service from 10 to 50 years, these of heat-exchanger equipment from 30 to 40 years are conducted

[en] Investigated was the effect of a neutron irradiation in the CM-2 type reactor at 150 deg C in the range of doses from 1.5x10¹⁹ to 5.1x10²¹ neutron/cm² (E > 0.1 MeV) upon the mechanical properties and the structure of vanadium and of the V-Zr-C alloy. It was shown that a strong irradiation strengthening is accompanied by a plastic instability which in vanadium appears at an exposure dose 10 times smaller than that causing a similar effect in the alloy. The correlation is examined between the plastic instability and the size, the density and the type of radiation defects. A comparison of the calculated and the experimental values of the radiation strengthening has been made. The suggestion is substantiated that carbon atom accumulations on annealing of irradiated specimens are produced by the decomposition of ''impurity-defect'' type complexes

[en] Short communication

[en] The influence of neutron irradiation in a SM-2 reactor at temperatures of 780-1080 deg C in doses of (1.3-1.8)x10²¹ neutr./cm² (E > 0.1 MeV) upon the mechanical properties of the Mo-0.11 Zr-0.002 B alloy has been investigated. Studied was the effect of the size and of the density of radiation defects upon the strengthening of the alloy in a wide range of test temperatures. A relationship was found between the decrease in uniform elongation in the range of test temperatures Tsub(t)=400-900 deg C and the porosity parameters. Examined is the part of impurities in suppressing the effect of high-temperature embrittlement in the course of irradiation

[en] The effect of neutron irradiation on mechanical properties and the structure of the V-2.5, Zr-0.35C, Nb-I Zr-0.1C and Mo-0.11 Zr-0.002B alloys has been investigated at 730-1070 deg C and (1.3-1.8) 10² n/cm² (> 0.1 MeV). It is shown that under these conditions the irradiation results in intense softening of the V-Zr-C alloy and hardening of the Nb-Zr-B and Mo-Zr-B alloys, whereas a minimum yield strength increase of two latter alloys is observed in the radiation temperature range 0.43-0.45 Tsub(m). Reasons for appreciable irradiation-induced enhancement of V-Zr-C softening are established. It is shown that the minimum softening of the Mo-Zr-B alloy at temperature of 0.43-0.45 Tsub(m) is due to suppressing void formation at these temperatures. Properties of vanadium, niobium and molybdenum alloys exposed to neutron irradiation are discussed

[en] Generalized are the experimental results from the investigations of neutron irradiation effects on the mechanical properties and structure of some vanadium-, niobium-, molybdenum-base alloys. The specimens of the materials studied were irradiated within various cells of both SM-2 and BOR-60 reactors at the temperature between 150 and 1100 deg C by fluences from 1.5x10²³ to 2.2x10²⁶ n/m²(>0.1 MeV). The most important experiment results are discussed

[en] A generalization of the model of dynamically triangulated random surfaces is suggested which makes it possible to investigate numerically the two-dimensional quantum gravity with matter fields having the central charge C being varied continuously in the region C≥1. The Monte-Carlo simulation is carried out for a number of values of C. According to our results the susceptibility to cosmological constant with respect to the cosmological constant remains finite for C≥1 in a wide region of C

[en] Short communication