After regular monitoring of pipelines in hydro power plant “Perućica” in Montenegro in 2024 by NDT (VT, MT, UT), focus was on defects found in unit 6A branch. Having in mind potential catastrophic consequences in the case of a failure, the branch with defects was additionally analysed by means fracture mechanics parameters and structural integrity assessment to estimate risk of its further use. According to the report, the most critical defect is MWB60-4 inside the upper welded joint K3, with length 150 mm and depth 7 mm, located at the mid-thickness from 14 mm to 21 mm.