AN EXPERIMENTAL STAND FOR RESEARCHING THE PROPERTIES OF SPENT FUEL ASSEMBLY DRY STORAGE

Abstract

The paper analyzes the modern methods of storing spent nuclear fuel and its processing, taking into account the finding of fuel in spent fuel assemblies. Currently, the most common methods involve storage in containers for fuel assemblies filled with a substance that has a high thermal conductivity. Therefore, experimental methods of researching the storage properties of spent fuel assemblies in containers are promising. In the work, research was carried out in the indicated directions with the help of the created experimental stand. A description of the stand itself and the sequence of conducting the experiment are given, as a result of which the necessary experimental data should be obtained. Namely, the heating regimes in the experimental heater were determined, which are close to the real processes of heating spent fuel assemblies loaded into the container. For this purpose, a laboratory autotransformer with a capacity of 4.6 kW was used. The next task was to determine the time required for the heater to go into constant operation. For this purpose, the concept of constant time of the heating process was introduced. FLIR ONE thermal imager was used to determine this parameter, as well as devices that allowed to determine the voltage on the laboratory autotransformer. This made it possible to determine the dependence of the change in the temperature of the heater on time and voltage, as well as the voltage of the heater, which simulates real heating modes. The paper presents the thermographic results of thermal imager measurement of the main areas of the stand. Taking into account that the power of the heater should be about 1.5 kW, the stand was made airtight with pressure control and taking into account the real conditions of storage of spent fuel assemblies, where there may be damage and cracks in the container. As a result of the conducted experimental studies, the optimal heating modes of the heater were determined.