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Information × Registration Number 0212U002419, 0111U007506 , R & D reports Title Determination of causes of secondary circuit pipelines destruction to substantiate the life extension and operation safety o NPS power units popup.stage_title Head Ozhigov Leonid Semenovich, Registration Date 21-02-2012 Organization National Science Center "Kharkiv Institute of Physics and Technology popup.description2 ABSTRACT Report on SRW: pages-58, fig.-38, tables-9, references-18. Subject of research: Metal of welded joint N111 of weld together collector to branch pipe of steam generator DU-1200 for power units of NPS with reactor WWER-1000. Purpose of the work: Integrated study of reasons of damage of welded joint of collector to branch pipe in Zaporojskay and South-Ukrainian NPS. Development of proposition on planning, number and regularity of eddy current control of heat exchanging tubes of steam generator PGV-1000 on the base of preliminary obtained measurements. Methods of research: metallographic methods, mechanical impact bending tests, method of thermal desorption spectrometry, electron-microscopic study, method of X-ray spectrometry. Main results: Complex investigation of causes of damage of collectors welded joints to branch pipes DU-1200 in steam generators of power units of WWER-1000 (welded joint N 111) was carried out. Study of metal in the area of crack propagation was performed by metallographic methods. Sections of metal cracking, the nature of cracks were investigated. Qualitative and numerical element analysis of steel was carried out. The nature of failure was determined-stress corrosion. Results of impact tests of studied steel specimens after lengthy operation have showed that obtained results meet the specifications. Electron-microscopic study of metallic specimens have revealed the presence of microscopic inclusions of copper in the crack course and also the presence of crystalline iron hydroxide; this gives evidence about penetration of coolant by crack body and about development of corrosion processes The use of the method of thermal desorption spectrometry had showed the accumulation of hydrogen in metal of welded joint. It must be also noted the increase (approximately twice) of hydrogen release in the crack top in comparison with metal on side of coolant of second loop. Data base of eddy current control of pipe still of steam generator of the type PGV-1000 I for SU NPS and ZNPS was expanded. On the base of accumulated data stochastic-statistic model of distribution and evolution of defects is refined. Process of prediction of defect production is developed, that guarantee the high level of defect indication in the area of steam generator for next measurement; the procedure of measurement planning for separate steam generator of SUNPS and ZNPS is developed. Key words: NPS, steam generator, welded joint, metallography, microstructure, phase composition, mechanical properties of metal, impact strength, fractography, scanning electron microscopy, chemical composition, hydrogen, thermal desorption spectrometry, crack, stressed corrosion, heat-exchanging tubes, data base, prediction of defect formation. Product Description popup.authors Борисенко Олег Олександрович Бородін Олег Вікторович Брик Віктор Васильович Василенко Руслан Леонідович Воєводін Віктор Миколайович Гоженко Сергій Васильович Крайнюк Євген Олександрович Лісна Валентина Георгіївна Міщенко Павло Олександрович Митрофанов Анатолій Сергійович Нікітін Аркадій Валерійович Неклюдов Іван Матвійович Ожигов Леонід Семенрвич Пєтухов Володимир Вікторович Руденко Олексій Генадійович Ружицький Валерій Володимирович Савченко Володимир Іванович Слюсаренко Тамара Михайлівна Толстолуцька Галина Дмитрівна Шаповал Іван Миколайович popup.nrat_date 2020-04-02 Close