Determination of Radiation Exposure to Iodine-131 Emissions During Normal Operation of the Industrial Reactor Installation at Fsue “PO Mayak” Taking into Account Physical and Chemical Forms

The determination of the physicochemical forms of radioiodine in the gas-air environment of an industrial nuclear reactor is necessary to solve related problems – technological control and radiation safety. In the technological context, the results obtained make it possible to adequately assess the efficiency of purification of emissions of radioactive iodine isotopes, the choice of instruments and methods for controlling emissions. In the context of radiation safety, research results make it possible to correctly assess the radiation effects on the environment and humans, substantiation of emission standards for the atmosphere and confirmation of the safety of operation of an industrial reactor installation. The research method is based on the difference in the deposition of radioiodine on a set of one AFA-RMP aerosol filter and six filters of the AFA-SI type, which makes it possible to separately determine the 131I aerosol, easily and hardly sorbed form. It has been shown that the non-purified gas-aerosol mixture mainly contains radioactive iodine in the form of gaseous hardly adsorbed compounds. For 131I, the most probable percentage in volumetric activity of hardly adsorbed, easily adsorbed compounds and iodine aerosols was obtained. Based on the data obtained, an assessment of dose loads was carried out taking into account the annual emissions of the reactor installation and weather conditions. A conservative approach to assessing the radiation exposure of 131I emissions is 47 times higher than the assessment taking into account its physicochemical forms.

Chosen Aspects of the Electromagnetic Compatibility of Plasma Reactors with Gliding Arc Discharges

This paper presents an analysis of electromagnetic disturbance interactions inside the three-phase gliding arc plasma generation installation. This is the main part of the electromagnetic compatibility analysis of the reactor installation. All elements of the nonthermal plasma installation are described from the point of view of disturbance generation and their influence on the power supply system. The analysis is based on the results of tests carried out in accordance with the guidelines of the electromagnetic compatibility (EMC) Directive and harmonised standards. The disturbances measured are large, over 20 dB above the limits. The disturbances measured allow valid conclusions to be reached in relation to this type of installation. The implication is the need for plasma reactors designed with elements that reduce radiated and conducted interference.

The mathematical description of process of heat exchange particles of oil shale and ash the coolant in the semi-coking conditions in a rotating drum reactor installation with solid heat carrier

The article deals with the modeling of heat transfer process in a drum reactor of a semi-coking unit of oil shale with a solid coolant between ash and shale particles in the conditions of constant separation of vapor-gas products. The dominant role of the convective component of the process is revealed and the curves of heating of shale particles are obtained taking into account the endothermic effect. It is established that the smallest fraction of fuel warms up within 30-60 seconds and further serves as a source of heat for other fractions. In the interval of 400-600 seconds, the heating of the largest fraction is completed. The further stay of the shale mixture in the reactor is caused by the lagging rate of the thermal decomposition process from heat exchange, and the temperature decrease by 20-250C by the presence of the endothermic effect of the decomposition of organic matter.

Features of manufacture of wedge valves for RITM-200 RP

The article describes the experience of manufacturing valves with a wedge gate, which is part of the RITM-200 reactor installation of new icebreakers.

Universal system of passive heat removal from the core of a research reactor

This paper presents the results of an analysis of a universal cooling system for the core of re- search reactors built on the passive principle of natural convection. A 3-D model, technologi- cal and design diagrams of the reactor installation are provided, along with examples of nu- merical evaluation of transients during the operation of the cooling circuit in normal and emergency modes to substantiate the possibility of using such a cooling system in research re- actors of small and medium power. The principal feature of the described passive system is the absence of not only active elements, such as circulation pumps and shut-off and control valves from the cooling circuit, but also of passive elements with moving parts, such as a check valve. The cooling circuit includes only vessels, piping and a heat exchanger. The absence of elements with mechanical moving parts can significantly reduce the likelihood of equipment failures and improve the reliability of such a cooling system while also reducing its cost. The versatility of the proposed system allows it to be used for a wide range of research reactor plants with various capacities, which are nowadays being developed designed to carry out programs in various areas of research and applied usages related to nuclear technologies.