Simulation of the Thermal Conditions of Cask with Fuel Assemblies of BN-350 Reactor for Dry Storage

The analysis of the thermal condition of spent FA (fuel assembly) of BN-350 reactor in a six-place cask for dry storage is presented. Simulation of the thermal condition of the cask is conducted with finite elements method using ANSYS software. Calculations of fuel temperature, fuel cladding, and assembly structural elements are the part of the safety analysis for storage of spent FA. In conclusion, the results of the thermal calculations in the cases of filling cask with argon and atmospheric air are given when the thickness of the insulation cask with concrete is 0.5 and 1 m. As a result of the calculated studies, the parameters of SNF (spent nuclear fuel) storage are determined, under which the fuel temperatures will have minimum and maximum values

Interaction between nitrogen plasma and tungsten

The set of experiments using a glow discharge of direct current in the mixture of working gases (nitrogen-hydrogen) was carried out in order to choose optimal method of tungsten nitriding. In the result of experiments it was chosen nitriding mode which leads to formation of tungsten nitrides on the surface of irradiated sample. Analysis methods SEM, EDS, X-ray diffraction were used to determine parameters such as the structure, microhardness, phase and element composition of the irradiated tungsten surface, and also the depth of nitrogen penetration into tungsten. The mode of tungsten nitriding, which can be used for studying the effect of plasma and thermal influence on nitrided surface of tungsten (forming of tungsten “fuzz” at nitrided tungsten, sputtering of nitrided tungsten) was determined