This paper presents the results of experimental studies of the interaction of helium plasma with a near-surface tungsten carbide layer. The experiments were implemented at the plasma-beam installation. The helium plasma loading conditions were close to those expected in the ITER divertor. The technology of the plasma irradiation was applied in a stationary type linear accelerator. The impact of the helium plasma was realized in the course of the experiment with the temperatures of ~905 °C and ~1750 °C, which were calculated by simulating heat loading on a tungsten monoblock of the ITER divertor under the plasma irradiation at the load of 10 MW/m² and 20 MW/m², respectively. The structure was investigated with scanning microscopy, transmitting electron microscopy and X-ray analysis. The data were obtained showing that the surface morphology changed due to the erosion. It was found that the carbidization extremely impacted the plasma–tungsten interaction, as the plasma–tungsten interaction with the carbide layer led to the carbon sputtering and partial diffusion towards to the depth of the sample. According to these results, WC-based tungsten carbide is less protected against fracture by helium than W and W₂C. An increase in temperature leads to much more extensive surface damage accompanied by the formation of molten and recrystallized flanges.

The BN-350 is the first industrial fast neutron reactor in the history of nuclear energy. It is currently undergoing decommissioning. One of the key challenges of decommissioning is managing the solid radioactive waste that has accumulated throughout the reactor’s operational life. At the moment, the accumulated solid radioactive waste is stored in a storage facility within the BN-350 reactor complex. An analysis showed that more than ~7262 tons with 5.17 × 10¹⁴ Bq activity of various types of solid radioactive waste have been accumulated over the reactor operation. They are mainly represented by materials with low activity. At the same time, the main share of activity is comprised of highly active waste with a total mass of ~170 tons and an activity of 4.73 × 10¹⁴ Bq. A solid radioactive waste management strategy has been developed. It includes all stages from collection and classification to transportation and long-term storage. Modern technologies now offer new possibilities. Some radioactive waste can be processed and reused in other economic sectors. In particular, recycling metals and alloys can reduce the volume of solid radioactive waste. It can also return valuable materials to industrial use.

This paper presents the results of computational and physical studies on the production of corium and its retention in an MR’s melt trap of the Lava-B facility. A feature of the Lava-B facility used in the IAE NNC RK to study the processes occurring during a severe accident at a nuclear reactor, is the separation of the stages of the reactor core corium formation and its interaction with structural materials. The melting of materials takes place in an induction furnace with a hot crucible, after which it moves to a melt receiver (MR) in which the test object is located. In the case of studies of processes occurring outside the reactor vessel, this is a special trap, which is placed in the inductor to simulate decay heat. However, based on the conservative computational estimates, it was found that the inductor power in the MR can be sufficient to directly produce, melt, and, subsequently, maintain the corium in the liquid phase. In this regard, in order to optimize the experiments under controlled conditions, the authors came up with the idea to experimentally test the possibility of producing corium by induction heating directly in the MR’s melt trap. In addition, according to the authors, this method would obviate the problem of corium contact with the carbon environment of the melting furnace of the Lava-B facility. Previously, burden heating simulating corium was modeled on the computer using available parameters of the MR’s induction heater. Based on the numerical experiment, the conditions for physical modeling of the corium production in the MR’s melt trap were established. An analysis of the physical modeling showed that during the burden heating in the melt trap, its metal components became liquid, thus, forming a melt pool. However, in terms of this design of the trap, there were problems associated with the complete melting of all corium components, as well as with the integrity of the experimental device when forming the corium pool and during the actual physical modeling.

In this work, effect of spark plasma sintering (SPS) temperature on structure and phase composition (SPC) of Ti-Al-Nb-based alloys produced by SPS technique at 1000 to 1550 °C has been investigated. X-ray phase analysis, raster electron microscopy and energy dispersive X-ray spectroscopy with determination of element distribution were applied to study sintered alloys. It was found that microstructure of alloys sintered at 1000 °C and 1200 °C is heterogeneous. These alloys consist of Ti₃Al grains and Nb₂Al phase as well as dispersed separations of Ti₂AlNb phase and unreacted particles of niobium and titanium. Results of structure and phase analyses showed that these alloys become homogeneous and laminar with increasing sintering temperature.

The paper addresses findings regarding the influence of electrolytic plasma treatment on the mechanical properties as well as structural and phase states of × 12 CrNi 18 10 Ti steel. Electrolytic plasma treatment is based on carburizing of stainless steel heated in electrolytes. Treatment of steel samples has been performed as follows: the samples were heated up to a temperature between 850 and 950 °C and then they were cured for 7 minutes in an electrolyte of an aqueous solution containing 10 % glycerol (C3H8O3) and 15 % sodium carbonate (Na2CO3). It is found that, after plasma electrolytic treatment, the surface of × 12 CrNi 18 10 Ti steel had a modified structure and high hardness. Increasing wear resistance of × 12 CrNi 18 10 Ti steel has been observed after carburizing and the coefficient of friction has been reduced. X-ray analysis showed that retained austenite γ-Fe is a main phase, and there are some diffraction lines of orthorhombic Fe3C phase as well as Fe3O4 cubic phase. It has been de... Kurzfassung Der vorliegende Beitrag stellt Ergebnisse bezüglich des Einflusses einer Elektrolyt-Plasma-Behandlung auf die mechanischen Eigenschaften sowie auf die Struktur- und Phasenzustände des Stahls × 12 CrNi 18 10 Ti dar. Die Elektrolyt-Plasma-Behandlung basiert auf der Aufkohlung von hochlegierten Stählen während der Erwärmung in Elektrolyten. Die Wärmebehandlung der Stahlproben wurde folgendermaßen durchgeführt: Die Proben wurden auf eine Temperatur zwischen 850 und 950 °C erwärmt und dann für sieben Minuten in einem Elektrolyt behandelt, der aus einer wässrigen Lösung und 10 % Glycerol (C3H8O3) sowie 15 % Natriumcarbonat (Na2CO3) enthielt. Es zeigte sich, dass nach Elektrolyt-Plasma-Behandlung die Oberfläche des Stahls × 12 CrNi 18 10 Ti eine modifizierte Struktur und eine hohe Härte aufwies. Es wurde ein zunehmender Verschleißwiderstand nach dem Aufkohlen beobachtet und der Reibkoeffizient wurde reduziert. Die Röntgenanalyse ergab, dass die Hauptphase aus Restaustenit besteht, und sich einige Dif...