Глобальная ядерная безопасность (Jul 2024)
Computational and experimental substantiation of the operability of seals of localizing safety system elements of power units with VVER
Abstract
The relevance of this work is determined by the need to predict the operation of sealing assemblies for elements of localizing safety systems (LSSs) of power units with VVER, which include (penetrations, hatches, locks, doors and other elements of hermetic fencing (GF) in operational modes. Operational modes are understood as modes of normal operation, modes of violation of normal operation, as well as emergency situations. During the manufacture and operation of LSS elements, the problem arises of uneven protrusion of a double-row rubber seal from the grooves in the web of the LSS element, which leads to the need to clarify the integral compression force of the seal as a whole for this element. The problem is caused by the imperfection of the manufacturing technology of large canvases for LSS elements (doors, hatches, locks: the perimeter of the seals can reach 10-20 m, the diameter of the canvas 2-6 m) and the need to withstand stringent technological requirements for flatness, parallelism and marginal deviations in linear and angular dimensions. The manufacture of overall structures is complicated by the presence of welded joints, heat treatment, and the complexity of metalworking. Compression force of the PNAE rubber gasket-7-002-86 it is not regulated, therefore, for the reliable design of gasket compression mechanisms, the magnitude of this force was determined. Based on the obtained results of tests of rubber seals for tightness and cyclic loading [7], an assessment of the tightness of the applied rubber seals is performed, calculations of deformations of rubber seals are performed using the FEM software package. Recommendations have been developed to increase the reliability of seal assemblies for elements of localizing safety systems (LSSs) of VVER power units in operational modes and to select the compression value to determine the necessary force to ensure tightness at the beginning of operation and after 5000 opening-closing cycles.
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