Analysis of means for VVER Reactor Pressure Vessel Elements at NPP's in Ukraine - NDE and its Results
V. Kovyrshin, N. Zaritsky, State Scientific & Technical Centre on Nuclear & Radiation Safety, Kiev, Ukraine
ABSTRACT
RPV of VVER-type reactors at NPPs in Ukraine were designed and manufactures in former USSR. After assembling they were tested of the same methods and scope as it was under manufacturing with the requirements retained to the results of control performed. In compliance with the requirements in force by the moment of RPV designing and manufacturing the regular means, methods, scope and periodicity of RPV elements control were identified and still used till present. They shall provide for detection with the great probability of those cracks to be included into the design calculations of resistance to brittle failure of RPV. By now, some changes of the normative requirements to initial postulated defects, their geometry occurred, calculating procedures and PTS modes list were improved. It had lead to reassessment of NDE standard means efficiency, necessity of their upgrading and/or state-of-the-art NDE means and methods implementing. n this presentation analysis was performed as to NDE means being implemented at NPPs in Ukraine for RPV testing. The main attention was paid to the regular control of VVER-1000 type reactors and its periodicity in compliance with the instruction in force on in-service control AEIU-9-94. Comparison was made between scope and periodicity of control performed under NDE approach for PWR being implemented at Western NPPs in compliance with regulations of KTA (Germany), RSE-M (France) and ASME (USA, Spain). The particular attention was drawn to prospects and issues of RPV inventory supersonic control implementing proposed by Siemens for Rivne NPP. Some NDE results are presented for a number of Ukrainian RPVs, their trustworthiness assessed on a basis of the regulations in force in Ukraine. NDE results analysis was performed as to compliance with the Western normative requirements, conclusions made as well as recommendations proposed on necessity of the whole measures complex improvement as regards the problem to provide for safe RPV operation at NPPs in Ukraine.
Publication Source: First International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurised Components , 20 - 22 October 1998, Amsterdam, Netherlands. Held by the Joint Research Centre of the European Commission. Publisher:Woodhead Publishing Limited
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