Modern Approaches and Requirements for Methods of Controlling the Leakage of the Fuel Element Cladding
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Abstract
An important place in the nuclear reactor of a nuclear power plant is the control of the tightness of the shells of the fuel elements of the nuclear reactor. Therefore, a review of existing methods of non-destructive testing of the tightness of fuel elements of fuel assemblies of a nuclear reactor of a nuclear power plant was conducted. Modern methods of control of tightness of shells of fuel elements allow to trace development of defect in a shell of fuel element and to reveal depressurization of fuel elements thereby preventing accidents. In connection with the single-circuit system of coolant circulation and in case of an accident by increasing the emission of radionuclides directly into the atmosphere, it is necessary to detect leaky fuel elements at nuclear power plants. In this regard, the analysis of modern methods of control of the tightness of the shell of the fuel element to detect the tightness of the shell of the fuel element is a topical issue that significantly increases the reliability and safety in the operation of a nuclear power plant. It is known that the interaction of the neutron flux with the shell of the fuel element causes corrosion processes on its surface with the formation of local inhomogeneities. The analysis of the considered methods of control of tightness of a fuel element showed that they are based on detection of percentage of radioactive substances and inert gases which are observed in the heat carrier after depressurization of a fuel element. It is established that the studied control methods do not allow to determine the criteria for depressurization or sealing of the shell of the fuel element. The question of equipping a nuclear power plant with modern methods of controlling the tightness of the shells of fuel elements that ensure the safe operation of technological equipment of a nuclear power plant, and have high degrees of reliability and efficiency in detecting emergencies in real time is open. A method of controlling damage to the outer and inner structure of the fuel element shell based on the use of a fractal geometry apparatus is proposed, which allows to indicate the degree of tightness of the fuel element in real time.
