@inproceedings{8c8f1dd4ac444a4bbe0170b947549964,
title = "Experience on the ultrasonic inspection of control rod nozzles of reactor pressure vessel",
abstract = "The nozzles of control rods to the reactor pressure vessel closure head have caused serious problems worldwide. In the case of VVER440-reactors the special area of interest is to assure the tightness of the austenitic corrosion protection tube placed inside the control rod nozzle. If leakage through the weld closing the protection tube is occurring boric water can penetrate in the narrow air gap between the ferritic nozzle and the tube leading to corrosion damages in the ferritic nozzle. The water can also cause buckling of the tube inwards in the amount that disturbs or even stops the operation of control rod drive mechanism. VTT has developed a special ultrasonic technique to monitor the condition of control rod nozzles during the shutdown period of the plant. The technique has been applied during several years and the results of inspection have led to repair of some nozzles. The principle of the technique as well as its limitations are presented and discussed in this presentation.",
author = "Pentti Kauppinen and Harri Jeskanen and Raimo Paussu and Bernhard Elsing",
year = "2007",
language = "English",
isbn = "978-951-38-6317-3",
series = "VTT Symposium",
publisher = "VTT Technical Research Centre of Finland",
number = "247",
pages = "235--241",
booktitle = "BALTICA VII - Life Management and Maintenance for Power Plants. Vol. 2",
address = "Finland",
note = "BALTICA VII - International Conference on Life Management and Main-tenance for Power Plants ; Conference date: 12-06-2007 Through 14-06-2007",
}