- What modifications of the Russian designs are planned for Finland and the UK?
Jukka Laaksonen: The plants planned for the two countries come from different lines; the Fennovoima one (Finland) is coming from the same [VVER-1200] family as Leningrad II, designed by SPAEP, originating from Tianwan [and profiled in depth in NEI magazine September 2013]. It is just normal evolution of design that there are several changes in details; we have seen most of these changes already in Temel?n (in Czech Republic). Leningrad II is not designed for a large plane crash: the outer shell of the reactor containment is thinner. The seismic design of Temel?n is much stronger against earthquakes, and the standard will have greater seismic resistance than Leningrad II [seismic requirements for the Finnish site are yet to be decided]. The cooling systems will be completely different; the Finnish plant is by the sea, so it will not have the cooling towers that we see at Leningrad. Certain things have been learned during construction of Leningrad II and there will be structural changes in the buildings and in their construction. This design was already evaluated in Finland in 2009 when three power companies submitted applications for political approval of a new plant. At that time there were several concerns raised by the Finnish regulator, relating to the plant layout and specifically the physical separation of parallel redundant systems. However, the government did not see a need for three new plants and the company submitting the application did not get a positive decision.
Because the UK design comes from a different family, we cannot make direct comparisons with Leningrad II; we should compare the Novovoronezh and the UK design. Some of the changes proposed for the UK were made for Turkey (Akkuyu), where the cooling water is very warm (30°C), and there was a need to improve the overall efficiency of electricity production. This means that the overall efficiency of the steam cycle will be much better (3%, depending on conditions). We designed a new layout that makes the steam lines shorter, and redesigned the steam generators for greater efficiency, so losses from the steam generators to the turbine are reduced. There are not many differences in the safety systems; at the component level there are improvements, but overall we cannot point out any major changes.
- How big a factor are cultural differences between Russia and Finland?
- There are cultural differences with power companies. When Loviisa was built (1&2 were Russian VVER-440s installed in Finland in the 1970s), the power company and the regulator wanted to go to [component] factories and do inspections during manufacturing. In Russia, that was not so much the practice. Now I have understood that also Russian customers are more interested in making inspections…. People are no longer just accepting what Russian factories produce; the final customer wants to make their own quality assurance. The culture is changing. [Russian utility] Rosenergoatom is now working as we can call the intelligent customer; there is a more clear difference between the customer and supplier, and the customer is more interested in the product than in the past. That is an overall change of the system from the USSR to Russia; the power company has more direct responsibility for its own economics, so there is more interest in reliability and safety of what is given to them.
- What about the goal-setting approach of UK regulation? Is that a cultural difference?
- That is not different from Finland; the disparity is more about a difference between the European approach and the US approach. The US has very prescriptive regulations for design and manufacturing….in the US, these regulations have grown up in an isolated industry with domestic suppliers, but other countries don’t have such a comprehensive system and they have to consider what the suppliers are usually providing. In Finland we evaluated Russian standards; and I assume the ONR will do the same thing, just as they have evaluated French standards used for AREVA’s EPR. It is necessary for ensuring good quality that the manufacturers are using standards that they know well. The regulator may then put some additional requirements, for instance concerning inspections and strength analysis. From the Russian side we just have to demonstrate that we can provide adequate quality and reliability. In Finland, we have done this comparison for 40 years now and have learned that there is no basic difference in the quality of the equipment, although different standards are used. This is also the conclusion of MDEP [Multinational Design Evaluation Programme, run by OECD-NEA].
- But won’t the Russian designs lack the safety case documentation required by the UK customers and the regulator?
- The UK has a unique and globally respected regulatory approach. Clearly our design will need to meet the stringent requirements of the Generic Design Assessment process which allows the UK regulators to assess the safety, security and environmental implications of our reactor design. Without question, it is a robust and in-depth process and one that VVER technology has not previously entered into. For this reason, we have good partners such as Rolls-Royce and Fortum from Finland to provide advice to guide us through it. They have long and deep experience of working with the UK and other regulators.
- Do you expect both reactor types will be exported?
- The choice depends on the customer. The VVER-TOI is planned to be the standard design of VVERs. Now the plan is to continue the Novovoronezh line with similar plants built in Russia.
- And not proceed with the Leningrad II line?
- There are offers in Finland, the Czech Republic, probably in Hungary, and maybe Slovakia. Especially in northern European countries the SPAEP design will remain [for more on SPAEP, see also ‘Russia’s new nuclear face,’ NEI November 2012]. But as I have understood it the plan inside Russia is to go to this standard Generation III VVER. That doesn’t mean that it is better; they just had two designs and had to make a choice which one will be used; it is not practical for the Russian utility to maintain two different plants. There are some site-specific factors. The Leningrad design has water tanks mounted high on the structure, so they are not good for seismic areas. But they are very appropriate for central Europe and Finland sites where there are not such large earthquakes. This standard design is good for seismic areas because there is no such feature, and it is also good for dry conditions because it needs less water to ensure safety. The ultimate heat sink could be done by air cooling, so it can remove decay heat even with minimal amounts of cooling water, which might be a good feature in the conditions such as for example Jordan. [For more, see also ‘Passive safety in VVERs,’ NEI June 2011].
- What is the structure of Rusatom Overseas?
- Rosatom was established to have a broader interface against potential customers. Selling nuclear power plants nowadays, especially for developing countries, is not just about making the contract; there are so many other things involved which are not in the main competence areas of these implementing organizations. There was a need to have a company which can provide an attractive financing package, which can support building a national infrastructure, which can provide information for the general public especially for newcomer countries; there are many more tasks than just designing and building a plant. It was thought that Rusatom Overseas could take all of this preparatory role for new customers and countries. Rusatom Overseas will continue the process until the signature of the contracts with the customer, and then the implementation stage is handled by someone else, except maybe the licensing stage, as it appears Rusatom Overseas will build in these capabilities too. The design and construction is carried out by the traditional Rosatom entities with long experience.
- But it’s been the case in the UK that vendors in the GDA process had to dig deep into their organization.
- Of course, but we’ve not yet started to build that organization. The generic design assessment [required to licence the Russian design in the UK] is a very unique situation; we have to plan in Rusatom Overseas how to make a requesting party (RP) needed for this process. That needs high-level competences, and also skills to communicate with the regulator. It cannot just be the Russian organization; we need UK citizens; we need multiple competencies…Another bigger issue is to establish the power company who will be the site licence applicant. This will be a majority Rosatom ownership, but how that is organized hasn’t been decided.
- So Rusatom will put the TOI design into the UK GDA process?
- That’s our plan. But as I said, we are not ready. We need to build a RP so that we will become authoritative and achieve public confidence. And another big task is to do first a proper PSR [preliminary safety report] and an ESR [environmental scoping report]. We are now targeting to start [the GDA process] in the beginning of 2015, but we are not in a hurry. We start only when we are ready, because we don’t want to fail.
- In terms of Russian new-build construction times, they are low domestically, but not so low in export. What are your views about building outside?
- It depends on having good preparation, as we will do. We want to have the design ready to go, there is not much need for design; all of the technical questions have to be resolved with the regulator before construction starts. Then we need a good partner for the actual construction work, so we need at least a close relationship with a UK construction company; construction is usually carried out by companies in the customer country. If we think about Tianwan 3&4, we could expect that this project will be ready at least one year ahead of schedule, which will be very quick. All of the design documentation is ready to use, they just have to replicate units 1&2.
- Speaking of construction, has Kaliningrad construction stopped?
- It has slowed down for the moment. Manufacturing of main components, long-lead items like steam generators and pressure vessels, is going on; there are no changes. But construction is proceeding more slowly now. One reason is the uncertainty about what will happen with the power market in that region; by the time the plant would be ready, it may be inside European grid with no direct connection to the Russian transmission network as today. The EU and the Baltic states are planning to build new transmission line connections to Poland and even further to the rest of Europe, and they will isolate the Baltic system from the Russian system. That means that the whole transmission situation will change. There is no sense making a plant that can’t generate to that transmission system…The target start-up date is now less ambitious, with a delay of one year. Next year definitely Rosatom will decide when to restart full-scale construction.
- The VVER TOI design went through an extensive internal review in autumn 2012; there were comments from the regulator, and an improved design was submitted in September 2013; this version of the VVER TOI design is the one that should be used in the GDA process, according to Laaksonen. What was this process? Why, and how, was it carried out?
Sergey Egorov: The first stage was the review of the design for acceptance by the operator, and the statement of the chief parameters. As for process, to be able to do this kind of analysis, we established a requirements management system. It starts accounting of all of the requirements made of the design, then assessment by independent experts of understanding of the requirements of the designer, and finally an evaluation of compliance with requirements. As a result, we came up with slightly over 6000 individual requirements. They differ in scope and details. We did a formal assessment of 1000 of them. Each one was recorded in the system, and there were three possible options: requirement fully complied with, requirement not fully complied with, or that there were conditions or deviations from compliance. That was our internal analysis of the design as the customer. After that we submitted the preliminary safety analysis report to science and technology committee of our regulator. So presently the regulator is reviewing the generic design. In parallel, we initiated a design review by IAEA experts. Now we have three simultaneous review processes: internal, regulatory and international review. And there are also plans to submit the design to EUR (European Utility Requirements), but there is a queue. We are collecting feedback from all of these reviews and continuously improving the design based on this.
- Why are you doing this now, when the first units of this design are now being built? Shouldn’t you have done this before they started construction?
- Some things are logical and other things are practical. We are in this case following the tradition of the ex-USSR, and later of the Russian Federation, when the design was site-specific and unit-specific. There is an international trend for generic design evaluation at an earlier stage of development. This is not the only possible arrangement. Since the base case design doesn’t take credit for any specifics of the site, analysis of such a design is also vulnerable because the design which fits any possible site becomes too overloaded with systems. This is like attempting to build a racing car that is also good for off-road driving, and also has a large trunk and leather seats. This is at best it is not optimal, nor in any case always possible. So there should be a certain trade-off between the generic solution and flexible accommodation of the site-specific design. This implies a careful analysis of international trends and new developments worldwide. We initiated the VVER-TOI design well before Fukushima-Daiichi. But then this great earthquake of Japan happened, and now everybody seems to have forgotten that this happened; all people remember is Fukushima, and not the earthquake and the damage it did to the country. Many people, especially the general public, have tried to forget about the reasons behind the technical solutions that we have made in response to Fukushima. We have tried to consider an integrated, holistic approach to the lifecycle rather than viewing each stage of the lifecycle as absolutely isolated and independent.
It is not always easy to maintain the balance between the general and site-specific design. When the demand for construction of new units increases, we channel our resources on design for site-specific applications of new units. The generic technologies and the design basis should be very conservative and reliable. On the other hand, we have to allow some flexibility to accommodate the realities encountered on sites and for new requirements that arise. We are trying to combine a balanced generic design and flexible add-ons specific to site for new challenges. After September 11, 2001, when we were in the process of a competitive bid in Finland, they requested additional analysis of heavy aircraft impact. At first, it sounded like a very excessive requirement, but now it becomes a commonplace requirement to any new build. Although it has only been 12 years since it happened, the event has had a complicated and expensive effect, taking into account that the design life is at least 60 years. We have to think into the future and anticipate future events for the design basis. And earthquakes, floods and high winds are not likely to stop in the future; we have to take account of them for all 60 years.
- I understand the VVER-TOI fuel cycle will be 18-24 months, double the length of the current cycle. How is it possible to achieve that?
- The fuel design itself has evolved. New fuel design is an R&D priority for Rosenergoatom. And the fuel manufacturers are also quite sensitive to new demands in the market. Several new experimental designs of fuel assembly were developed and test bed experiments have been made, and are still being made, for new fuel. These developments of course were initiated a long time ago. Clearly the fuel cycle is not only limited by the fuel; there is a lot more to it. If you go to a longer fuel cycle, you have to ensure reliable operation of components between outages, and you have to ensure that there is need for testing in inaccessible locations for this longer period of time. This is essentially what goes behind the 18-24 months’ extension. Actually the term ‘fuel cycle’ is a bit confusing; we should speak about the ‘unit cycle’ as a whole system. Otherwise by solving one issue you could create multiple other issues. Technically, a 24-month cycle is achievable.