Approach to Non-Destructive Examination of Weld Joints Dn 300 at Unit 3 of Chernobyl NPP and their Repair
V. Kovyrshyn, Y. Grebenyuk, N. Zaritsky, State Scientific and Technical Center on Nuclear and Radiation Safety
ABSTRACT Since beginning of austenite pipelines DN300 operation at ChNPP their control scope and periodicity are identified by the requirements of normative documents and instructions. After disclosure of weld joint defects (1997) the approaches to NDE were changed. Western experience (by BWR reactors) along wis Russian one (by RBMK-1000) as to control and repair of defects produced by integranullar corrosion stress cracking mechanism was taken into account. In addition to regular radiographic control ultrasonic one was implemented by one of the Russian methodologies. To identify scope of control and controlled objects the functions of DN300 pipelines were taken into account (download, pressure, ECCS) along with conditions of assembling and erpairing implementation, including engineering and human factors. This presentation shows peculiarities of the approaches to assess presence of defects at DN300 pipelines of RMBK-1000 at Unit 3 of ChNPP and implement their repairing from position of the operating organization and regulatory authority under its commissioning authorization during 1997-1999.
Publication Source: 2nd International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components, May 24-26, 2000, New Orleans, Louisiana USA.
Publisher: EPRI - [Homepage]
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