[en] The convenient program for solving the unsteady heat conduction equations in arbitrary two-dimensional non-uniform field by composition area using the finite element method, is proposed

[en] Peculiar features of horizontal weld formation on vertical surfaces are considered for submerged arc welding. Regimes are selected to obtain welded joints of various thickness with high efficiency. One-side welds for plates 12 mm thick as well as for 16 mm in case of nonlevel welds were found to be obtained using two-pass welding. It is recommended to use a glass cloth cord or a copper rod during weld root pass for weld metal quality improvement and productivity increase

[en] The basic statements of express-method are formulated for estimation of high-temperature effect upon fatigue cracks growth rate in thermostable steels from data on specimens tests in the same environments at normal temperature and cathodic polarization

[en] A model for thermal-hydraulic calculation of spacing grids for rod fuel assemblies realized in the GRIDE numerical program, is proposed. Real physical channels formed by spacing grids are considered as calculational subchannels. A hydraulic analogue of geometric packing is introduced for calculation of channel local resistance factors. This allows one to determine the values of mean coolant flow rate in spacing grid channels

[en] The work is aimed at evaluating the effect of ammonium addition to the HTGR pebble bed reactor helium coolant on the dynamics of the absorbing rod displacement. The results obtained confirm the ammonium addition effect on the reduction of graphite friction coefficient in helium and allow one to make a conclusion about the advisability of ammonium introduction to the HTGR core in order to reduce efforts for compensating rod displacement and for reduction of the quantity of damaged fuel elements. It is desirable to change the rod structure in such a way that helium is supplied directly to the zone of contact with fuel elements

[en] Results of vibrostrength and acoustic fatigue tests of the fragments of thermal insulation for in-vessel equipment and pipelines of the VG-400 reactor are presented. The insulation structure is based on the insulation layer made of steel foil and carbon materials. Weak points in the insulation structure, namely - the welded joints of stiffening ribs - are detected in the course of testing. A conclusion is made on the possibility of vibrational test substitution for the acoustic ones

[en] A model allowing one to conduct an engineering calculation of diffusion deposition of various fission products on the walls of pipelines and equipment of high-temperature reactor plants with regard to physical and hydrodynamic coolant characteristics, wall properties, temperature conditions and other factors, is proposed. The model is used when developing the RADON program. The intensity of particle deposition on the wall surface is taken into account using a special empirical parameter

[en] The technique for calculating the efficiency of absorbing rods in the reactor with spherical fuel elements are proposed. The technique is based on the determination of the initial data for the homogeneous reactor and a heterogeneous rod

[en] Using the experimental investigations at the LIKA facility, a possibility of decontamination of a steam generator of the HTGR reactor facility using the thermal technique based on the equipment heating in the inert medium, is proved. The data obtained testify to the fact that the heating temperature increase leads to an increase of the rate of radioactive iodine removal from the experimental channel surface. Iodine removal from the surface of the 12Kh18N10T steel occurs better than from the 12Kh1MF steel surface. The presence of graphite dust on the channel surface spoils the conditions of radioactive iodine removal

[en] To develop a mathematical model of plastic deformation during explosion welding of plates a physical model was chosen that is convenient for mathematical model was developed for the conditions of dynamical collisions of plates under the action of a shock wave moving over the external surface. The model is organized according to a module principle for ensuring numerical solution with the help of computer. Analysis of the problem numerical solutions allowed on to obtain main regularities for welding parameter effect on geometry and properties of welded joints