Environmental Engineering Reference
In-Depth Information
power plant comprises 26.6% of total installed capacity. There is a keen
interest in extending the operational lifetime of all Ukrainian NPPs. The
operational licence of the VVER-440/213 type Units 1 and 2 at Rivne NPP
in Ukraine has been renewed by an additional 20 years with the condition
of performing a safety assessment after ten years of prolonged operation.
The extension of operational lifetime is a generic strategy of operators of
VVER-440/213 plants in the Czech Republic and Slovakia. The Loviisa NPP
in Finland (a non-standard VVER-440 design) has been allowed to prolong
operation up to its next Periodic Safety Review (10 years).
The operational lifetime of the VVER plants in Russia will be extended
by 15-25 years. The four oldest VVER-440/230 units, Novovoronezh NPP
Units 3 and 4 and Kola NPP Units 1 and 2, have already received a 15 year
licence for extended operation. The VVER-440/213 type units (Kola NPP
Units 3 and 4) are also prepared for 15 years extension to the operational
licence. Among VVER-1000 plants, Novovoronesh Unit 5 is prepared for
a 25-year extension of operation, after an extensive safety upgrading and
modernization programme.
The VVER operators performed a comprehensive assessment of plant
condition and safety, while making their decisions about the extension of
operational lifetime. A decision on the preparation of feasibility studies for
long-term operation (LTO), was based on the recognition of the following
VVER features and experiences:
robust design of VVER plants
good plant condition due to well-developed maintenance, in-ser-
vice inspections, careful operation and extensive modernization and
reconstruction
implementation of safety upgrading measures, resulting in an acceptable
level of safety.
Safety of the plants and compliance with international standards has been
considered as the decisive precondition for LTO. The comprehensive
modernization and safety upgrading programmes (Vamos, 1999) imple-
mented by the VVER operators during the last two decades, resulted
in gradual decreases in the CDF of these plants. The level 1 probabi-
listic safety analysis (PSA) study establishes the resulting CDF for all
VVER-440/213 units at Dukovany NPP of 1.47-1.67
10
− 5
/a, as stated in
national reports compiled under the Safety Convention (Czech National
Report, 2010). The same achievements are published for other VVER
plants. Extensive modernization and safety upgrading programmes have
been implemented in Ukraine (2011), Russia (Rosenergoatom, 2003) and
Bulgaria (Popov, 2007). The safety defi ciencies do not inhibit the LTO
of the VVER plants; the VVER operators have a strong commitment to
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