TIG welding of root part of the joint in primary collector of steam generator for VVER 440 nuclear power plant

摘要

Wear of the main partition plane of primary collectors for steam generators of VVER 440 nuclear power plant was studied. The repair by exchange of collector from 08Ch 18N10T material by narrow gap welding and the study of TIG welding technology with cold wire addition focusing on the root bead and other 4 beads were outlined. The proposal of shape and dimensions of weld edges, testing of welding parameters and fabrication of test welds were analysed. The evaluation of welded joint quality visually radiographically according to STN EN 444 and STN EN 25817 standards and metallographically was described. The documents for WPS of the root part of the joint have been elaborated.