Improving safety?

Ukrainian nuclear power plant operator Energoatom has launched a project that aims to bring the safety of the country’s 15 reactors in line with internationally-accepted safety standards and national requirements.

The Safety Upgrade Project (SUP), which runs from 2010 to 2017, foresees replacing equipment in safety-relevant systems, such as the modernization of monitoring and control equipment, in combination with other operational measures. The plan has been re-prioritised to address post-Fukushima European stress tests (see also pp. 13-14). However, its progress depends largely on international financing.

Energoatom expects the project to cost around EUR 1.2 billion ($1.6 bn), but admits that it will require loans for around 70% of the total project cost to finance all of the proposed safety improvements.

The European Bank of Development and Reconstruction (EBRD) and the European Commission (through Euratom) are both prospective lenders, with loans of EUR 300 million and EUR 500 million, respectively, under consideration. Decisions on the loans are expected from Euratom in May and from EBRD in September. Energoatom foresees a cost of borrowing of 3-5% and a return period of 14 years.

Energoatom operates 15 nuclear power reactors (13,835 MWe) in Ukraine: Khmelnitsky 1-2, Rovno (Rivne) 1-4, South Ukraine 1-3 and Zaporizhzhya 1-6. They are all Russian designed pressurized water reactors: models V-213 (Type 3), V-302 and V-338 (Type 2) and V-320 (Type 1).

A total of eight reactor safety upgrade programmes have been carried out in Ukraine since the 1980s. Most recently, EBRD and Euratom loans funded safety upgrades at Khmelnitsky 2 and Rovno 4 (these two units have implemented almost double the number of upgrades as other plants); this project has been used as a basis for developing the current Safety Upgrade Project.

The SUP involves safety improvements at existing nuclear power plants in Ukraine, but no new construction, no capacity increases and no life extensions. The exclusion of life extensions is a point of contention however, as the majority of units are expected to close by 2020 (see below and also Table 1).

Improvements

The SUP has identified over 800 safety improvements based on Ukrainian regulations and standards, international recommendations as well as operational feedback. A total of 86 improvements are proposed for V-320 reactor models, and 54 each for the V-213, V-302 and V-338 designs (see Table 1).

Those measures that have the strongest impact on safety improvement will be implemented first. The priority has been determined by analyzing the effect of each measure on core damage frequency (CDF) and large release frequency (LRF), as well as estimating the impact of measures on the frequency of accident-initiating events, possible consequences and affected safety functions.

Priority I measures have a high or very high impact on safety (CDF>10^-4 LRF>1^0-5) while Priority III actions have a limited impact (CDF>10^-7LRF>10^-8).

The safety improvements are also grouped into nine different areas covering background material, core and fuel management, component integrity, systems, instrumentation & control, containment and buildings, internal hazards, external hazards and accident analyses. Figure 2 shows the number of improvements within each category, along with their priorities for each of the three reactor types.

The measures range from developing the necessary documents for certification of nuclear power plant equipment under accident conditions (if missing) to the physical replacement of components and systems. Around half of the measures involve improvements to the systems and instrumentation and control.

Improvements within the systems category cover the replacement of primary circuit valves which do not meet all the certifications required for normal and emergency conditions, improvements to emergency power supplies, and measures to preserve cooling systems in case of failure. Also noted are measures to improve auxiliary systems, such as replacement of air conditioners, additional protection of cable routing, additional tools and measures to monitor steam generator aging and fouling and evaluation of the need for additional stand-along emergency lighting.

Modernization of instrumentation and control systems include installing monitoring of reactor operation during and after an accident, movements of primary circuit pipelines, alternate hydrogen cooling, the reactor building during normal operation, the turbine hall, and in-core monitoring of fuel. They also cover the installation of new consoles and panels in the control rooms and modernization of standby diesel stations.

Improvements to the containment and buildings include work to assess measures that could be required in core melting situations to prevent containment bypass, such as modernization of the reactor cavity doors, as well as measures for monitoring and reducing hydrogen concentration in the containment during beyond-design-basis accidents.

As of September 2011, around 25% of the improvements outlined in the SUP had been completed, 20% were ongoing, and the rest were planned. Energoatom says it has the budget to fund 30% of the upgrades.

A ruse for life extension?

International environmental organization Bankwatch claims that the planned safety upgrade measures are connected to a life extension programme. SUP measures such as those related to component integrity are conditions for extending reactor lifetimes, it says in a March 2012 report, ‘Critical Review of the Ukraine NPP Safety Upgrade Program.’

In the report, Bankwatch claims that there are no safety measures that do not impact lifetime extension. It notes that the SUP measures are recommended to be completed by 2017. However, 12 of the 15 reactors affected were designed to finish operations before 2020, and two units were supposed to be taken off the grid in 2010 and 2011 but were granted 20-year life extensions.

The report points out that one of the measures in the SUP, for Rovno 1&2 reactor vessel material monitoring, includes the text ‘to extend power units operation lifetime,’ language which Bankwatch takes as confirmation that some SUP measures are conditions for life extension.

Bankwatch notes that Euratom cannot grant loans without a statement from the European Investment Bank (EIB) showing that the loans can be repaid. It supposes that such a statement is likely to be based on the future operation of those NPPs.

In addition, Bankwatch criticizes the way in which Ukrainian authorities licensed the lifetime extensions at Rovno 1 & 2, which it contends were not in conformity with the UNECE Espoo convention, which sets out the obligations of parties to assess the environmental impact of certain activities at an early planning stage. Bankwatch says that it expects both Euratom and EBRD to withhold a decision about SUP pending a resolution to the Rovno 1 and 2 lifetime-extension decision.

In a written response to questions, the EBRD stated that the loan is only for safety upgrades at existing operating nuclear power plants, not for expansions or life extensions. As such, they do not require an environmental impact assessment, although they do require an audit of Energoatom’s environmental, social and corporate management systems, to make sure it has the capability to implement the loan. The EBRD also said that because the safety upgrades do not involve significant transboundary effects the Espoo convention does not apply. It said that it was not in a position to comment about Energoatom’s lifetime extension plans at Rovno 1&2.

Neither the EC nor Energoatom responded to NEI requests for comment.

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This article was first published in the June 2012 issue of Nuclear Engineering International