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Methodological questions concerning the application of remote gamma spectrometry for radiation monitoring of air emissions from nuclear power plants and detecting trans-boundary transport of products of an accident are examined for the example of the development and experimental operation of the components of the Spaider data-acquisition system produced by the KonverSia company. A system of collimated γ spectrometers arranged along the monitoring contour at the site boundary of a nuclear power plant makes it possible to increase the accuracy of the computational predictions and to obtain and accumulate, during normal operation of a nuclear power plant, emissions data for radioactive inert gases and iodine in a continual monitoring regime.Integral dosimeters are used to monitor radioactive emissions in most automated radiation monitoring systems operating in nuclear power plants. The low dose sensitivity (~600 µR −1 ) and impossibility of autonomous classification of any anomalies detected are forcing developers of such systems to switch to more sensitive γ-spectrometric means for performing measurements (55000 µR −1 and more) [1]. Assessments of the predicted irradiation dose in the case of accidental emission are based on the accepted model of impurity transport and dissemination in the atmosphere near the ground, making it possible to assess the radionuclide concentration field near the ground. Such calculations require as initial information data on the amount and composition of technogenic radionuclides which have entered the environment. Today, many spectrometers are installed in the technological equipment of nuclear power plants to monitor emissions [2]. More accurate assessments of the actual emissions as well as monitoring of the radiation parameters of the emission stream in an on-line regime for use in models can be performed by using the results of remote spectrometry of streams [1]. This makes it possible to increase the accuracy of the computed forecast, obtain and accumulate data during normal operation of a nuclear power plant on the emission of radioactive inert gases and iodine in a continual regime, and to monitor the time and radiation parameters of legally allowed emissions, radiation incidents, and accidents.The present article examines the methodological questions concerning the use of remote gamma spectrometry for radiation monitoring of emissions from nuclear power plants and detecting trans-boundary transport of the products generated by an accident. This method has been tested during development and experimental operation of the components of the Spaider data-acquisition system produced by the KonverSia company [1].Requirements for the Main Characteristics of Gamma Spectrometers. In remote gamma spectrometry performed for the purpose of monitoring emissions, the radiation characteristics of the γ field generated by the radionuclides in a stream, which at short distances (up to 1.5 km) from the exhaust stack of a nuclear power plant has well-defined transverse dimensions, which are only ...

Simulation of quality of SiC/Si interface during MBE deposition of C on Si ABSTRACTIn present paper we simulate the processes accompanying the SiC/Si epitaxial growth.The model suggested describes the formation and growth of voids at SiC/Si interface.These voids are sources of Si atoms for SiC growth. According to the model the size distribution function was obtained being in good agreement with experimental data. The influence of surfactants on the nucleation and growth of SiC nanoislands on Si was studied as well.

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