Environmental Engineering Reference
In-Depth Information
8
Materials management strategies
for VVER reactors
T. J. KATONA , MVM Paks Nuclear Power Plant Ltd, Hungary
DOI
: 10.1533/9780857097453.3.335
Abstract
: The strategic goal of the VVER operator is to extend
its operational lifetime beyond the design life. Here, technical and
regulatory conditions and methods for ensuring long-term operation of
the VVER plant are presented plus an overview of the basic technical
design features of VVER relevant to long-term operation. Degradation
mechanisms of structures and components which limit the operational
lifetime of the plants are identifi ed. The method for evaluating ageing
of the plant, a review of existing plant activities for ensuring the
required performance of safety-related systems, development of ageing
management programmes and other related plant programmes are
described. The integration of plant programmes into a system that ensures
safe long-term operation is shown through examples. Trends and need for
future research are presented.
Key words
: VVER, ageing mechanism, ageing management, long-term
operation, in-service inspection, maintenance, environmental
qualifi cation, time-limited ageing analyses.
8.1 Introduction
The VVER reactors (Vodo-Vodyanoi Energetichesky Reaktor, which trans-
lates as Water moderated Water Cooled Energetic Reactor or WWER)
are light water moderated and cooled, that is, pressurized water reactors
(PWRs). A summary of basic features of VVER reactors is given by Katona
(2010, 2011). VVERs were developed in the 1960s. The fi rst three were built
in Russia and Eastern Germany in the period 1964-1970, and operated up
to 1990. There are 52 Russian-designed, VVER-type, pressurized water
nuclear power plants operating in the world today, out of a global total of
443 nuclear power plants (for the latest operational statistics on VVER
plants, see IAEA PRIS database) (IAEA PRIS, 2011). The cumulative time
of safe operation of VVER reactors currently exceeds 1200 reactor-years.
The fi rst standard series of VVERs had a nominal electrical capacity of
440 MW (and are therefore referred to as 440 units, 440 reactors, 440 designs,
etc.) and reactors in the second standard series have a capacity of 1000
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