Б» [2]. Способом компьютерного моделирования получены основные параметры системы кориумнагреватель для каждого из выбранных методов и определены границы их применимости для имитации остаточного энерговыделения при проведении эксперимента на установке.

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This paper is devoted to the creation of an information and analytical system (IAS) which is under development to manage the data obtained in experiments and investigations to justify the safety of atomic energy, which the National Nuclear Center of the Republic of Kazakhstan (RSE NNC RK) has been conducting for over 30 years. The main components of the IAS determining its consumer capabilities is an analytical unit that will allow the creation of programs for planned experiments in view of the technical requirements for them and based on the results of previous experiments, generalized and consolidated by processing and comparison tools provided by the IAS. An important component of the IAS is a set of tools for the predictive calculation of the temperature of materials of test sections depending on a given change in the power of energy release in them, predictive calculation of the required power of energy release in materials depending on a given change in their temperature, formation of arrays of experimental information in digital format and graphical form, comparison of experiments and their data among themselves, and the formation of protocols of experiments with the possibility of choosing specific data and methods for their processing. It should be noted that the created IAS greatly simplifies the preparation for experiments.

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 order to obtain experimental knowledge on fragmentation and cooling behavior of molten core material discharged into regions where the depth and volume of sodium are limited, a series of out-of-pile experiments using alumina (Al2O3) as a simulated molten core material was conducted at an experimental facility of National Nuclear Center of the Republic of Kazakhstan (NNC/RK). In this experimental series, approximately 9 kg of molten alumina was discharged through a duct of 40 mm in inner diameter into a test vessel (200 mm in depth and 300 mm in inner diameter) installed in an outer large vessel filled with sodium. The discharge mass of molten alumina and the dimension of the inner test vessel were determined so that the bulk temperature of sodium inside the test vessel could exceed its saturation temperature. Flow holes were provided in the top lid of the inner test vessel to allow sodium flow between the inner and outer vessels. The shape of solidified alumina recovered from the inner test vessel after this experiment was not ingot-like but fragmented debris. As a possible mechanism for such a debris shape, Fuel-Coolant Interaction (FCI) at the molten alumina jet impingement on the bottom of the test vessel might have promoted jet fragmentation, and heat exchange by sodium inflow and outflow through the flow holes might have contributed to effective cooling of molten alumina.