Experimental Research and Development of Safety Analysis Systems for Advanced Types of Fuel Rods

According to the development of the concept of “zero failure” or “zero fuel element defect”, accepted in 2011, which consists in reducing the number of fuel elements that are depressurized in the process of operation to the reached level in the leading countries in nuclear energy (10⁻⁶–10⁻⁵ defective fuel rods) and avoidance of fuel assemblies with non-hermetic cladding of fuel rods for further operation, including defects with a “gas leak” type, new promising fuels are being developed and introduced, including methods for justifying their safety. Thus, to ensure reliability and safety of new fuel types, it is necessary to provide procedures for monitoring current performance characteristics at all stages of the life cycle of fuel rods. In this paper, experience is given on the development and implementation of instrumentation and methods for monitoring of fuel rods with advanced types of nuclear fuel for VVER reactors that ensure the reliability, safety and competitiveness of technologies associated with the use of advanced fuel rod types, and the implementation of associated components, systems and equipment for monitoring and diagnostics. The features of the applied techniques are presented, and the new system of requirements for the implemented equipment created on their basis. This research continues, and the analysis of intermediate experimental data is carried out in this article.