Concrete progress at Akkuyu

AT AKKUYU IN TURKEY’S MERSIN province on the Mediterranean coast – a region famed for its oranges and its olives – a $20bn nuclear power plant is under construction. The project is being developed by Akkuyu Nuclear JSC, a subsidiary of Russian state nuclear corporation Rosatom, as part of a 2010 intergovernmental framework agreement between Russia and Turkey. Once complete, the station will comprise four 1200MWe VVER-1200 reactors, the same design used for Russia’s Novovoronezh II project, where the first unit has been in operation since 2016. Once fully commissioned the four-unit station will generate around 35TWh of electricity a year; approximately 10% of Turkey’s power demand.

The aim is to complete the first reactor at Akkuyu in 2023 – the same year the Republic of Turkey celebrates its 100th anniversary. This schedule is “very ambitious,” admits Mikhail Cherdantsev, deputy director for construction works at Akkuyu NPP. Nevertheless, the project company is mobilising the best expert resources to meet this goal. Cherdantsev, for example, has been at Akkuyu NPP since 2014, bringing experience as former head of design for Novovoronezh II and from another export project at Bushehr in Iran. He explains how Rosenergoatom, Russia’s nuclear power plant operator, is acting as a consultant for the Turkish project, bringing invaluable experience from new-build projects in Russia, particularly the reference units at Novovoronezh II.

“We are aiming to complete unit 1 construction in 2023,” notes Cherdantsev, referring to a “multi-layer target schedule” developed for Akkuyu incorporating experience from the reference project. “The schedule, based on previous experience, includes alternative options for achieving the key construction milestones, allowing us to use opportunities to speed-up, and to reduce timing of the construction works,” he says.

While the goal of 2023 remains “possible,” the official target in the intergovernmental agreement is reactor startup seven years after receipt of all necessary permits and licences. This means Akkuyu 1 should be commissioned no later than March 2025, with the remaining three units expected to follow at yearly intervals. However, as the project developer stressed repeatedly “safety standards remain the top priority”.

French engineering group Assystem recently signed a six-year contract with Akkuyu Nuclear for inspection of all structures, systems and components important for ensuring nuclear safety during construction and installation, reinforcing this message.

Safety first

The VVER-1200 design for Akkuyu is the latest in a long line of VVER plants, taking into account operational experience from the existing fleet and meeting the requirements embodied in the International Atomic Energy Agency (IAEA) safety standards, publications from the International Nuclear Safety Advisory Group (INSAG) and European Utility Requirements (EUR).

The specific features of the Turkish site, such as its geographic location and climatic conditions mean that there are slight differences from the reference unit at Novovoronezh in Russia. For example, on the conventional side, the service water supply system for Akkuyu will involve the use of desalination complexes, and cooling will be from the sea rather than large evaporative cooling towers. 

Like other VVERs, the Akkuyu project applies the defence-in-depth principle, based on the use of successive physical barriers preventing the release of ionising radiation and radioactive substances into the environment. The design incorporates both active and passive safety systems and includes a “wide range of design, engineering and organisational measures” to address source events, root causes and consequences of an accident similar to that which took place at Fukushima Daiichi in Japan in 2011.

Emergency diesel generators and batteries provide backup capacity in case of power failure, while passive heat removal systems ensure long-term core cooling for at least 72 hours, including during blackout. The design also incorporates hydrogen recombiners to prevent the formation of explosive hydrogen inside the containment, and includes a core catcher, installed under the reactor vessel, which will act as a ‘corium trap’. Equipment with an extended range of measurement capabilities has been designed to monitor the environmental parameters should a beyond-design-basis accident occur.

To withstand potential tsunamis and floods the plant is being built at +10.5m above sea level. It is also designed to withstand wind speeds of up to 56m/s, aircraft impact with a velocity of 200m/s, as well as external explosion and abnormal snow and ice loads.

The seismic characteristics of the Akkuyu site have been the subject of international interest and concern given the risk of earthquakes in the country.

When questioned, Cherdantsev explained that surveys carried out show that the Edzhemis fault line passing through part of Gülnar district does not run in close vicinity to the Akkuyu NPP site. Nevertheless, he says the nuclear plant has been designed to withstand an earthquake of up to 9 points magnitude on the MSK scale, and that reinforcement steel with enhanced physical and mechanical properties has been applied in the construction of safety-related facilities.

Cherdantsev says that fifteen seismograph stations were set up for the seismic explorations, and that study of faults, seismic hazard and risk of tsunami occurrence near Akkuyu have been carried out. Extensive surveying works culminated in the publication of 78 reports, totalling 27,000 pages. Seismic resistance remains under close attention and control of the Turkish Atomic Energy Authority (TAEK) and the IAEA, who along with other organisations have completed more than ten site inspections, Cherdantsev adds. The last IAEA Site and External Events Design (SEED) mission to Turkey in 2017 recognised good practice in the provisions made in the probabilistic safety analysis reports both for the design basis and beyond design basis safety margins analysis for earthquakes, tsunamis and aircraft- crash scenarios. The mission recommendations have also been taken into account.

First for Turkey

Although construction at Akkuyu officially started in April 2018, Turkey has been planning to establish nuclear- generating capabilities for many decades. Studies on nuclear plant construction began in 1965. However, the first project, aiming to build a 300-400MW nuclear plant by 1977, failed due to site selection and other issues. In the 1970s Akkuyu was identified as a potential reactor location and won a site licence in 1976. Swedish companies Asea-Atom and Stal-Laval were awarded the plant contract in 1977, but negotiations stalled and eventually, loan guarantees were withdrawn, and the project was cancelled. Subsequent attempts in the 1980s and 1990s also floundered. So, what’s different this time?

Eyyüp Lütfi Sarici head of the Akkuyu Information Center in Mersin, puts it down to a “real need.” Before joining Akkuyu Nuclear in 2012, Sarici spent more than 40 years at the Turkish Electric Power Agency, including a period as head of the nuclear power plant department at the Electricity Generation Company (EÜAS). When Turkey was first considering nuclear energy the country’s installed capacity was just 2GW, but as of January 2019, it exceeded 88GW (triple what it was fifteen years earlier), he notes.

Turkey is one of the world’s fast-growing energy markets. Gross electricity consumption is currently around 300TWh per year, according to the Turkish Ministry of Energy and Natural Resources, and it is expected to rise by 5.5% annually to reach 357TWh by 2023. Today, Turkey spends some $50bn a year on electricity imports. However, national energy policy envisages increasing domestic energy production and includes targets for nuclear power to account for 10% of Turkish electricity production and renewables for 30% by 2023.

Sarici explains the importance of the Akkuyu information centre to inform residents in the region and the country about modern nuclear technologies. The centre opened in 2012 and has to date had some 70,000 visitors.

“If you make an effort and provide information – it pays back with good attitude, trust, and support,” he notes, referring to the approach taken in Russia where there is strong public support for nuclear energy in the regions surrounding the plants. “People start seeing the benefits that a modern nuclear plant project brings to a region, starting with new jobs – through infrastructure development, local business growth opportunities and a new quality of living.”  

Sarici says the Akkuyu project offers “considerable business opportunities” for Turkish suppliers, and Akkuyu Nuclear estimates Turkish companies could complete around 40% of all construction work. In addition, the Akkuyu project is projected to generate indirect employment for 20,000 people in trade, transport, education and other sectors.

When NEI visited in late February almost 800 people were working on site, mostly Turkish nationals. Later this year the number of workers is expected to ramp up to 1500 people, reaching around 9000 during the height of construction.

The reactor building foundation plate for Akkuyu 1 was completed on schedule on 8 March and workers were preparing to start on the reactor building external walls. Work was progressing on the concrete foundations for the unit 1 auxiliary reactor building and emergency control room building, construction of the eastern, northern and southern water offtake channels, and site landscaping. Targets for 2019 include completing the concrete foundations for the Akkuyu 1&2 waste facilities, finishing the site engineering protection works, such as drainage canals, and infrastructure work.

The Turkish Atomic Energy Authority issued a limited work permit for Akkuyu 2 in October and preparatory works are underway on the pit for the foundations. A full construction licence is expected in the first half of 2019, which will allow safety-related concreting of the reactor building foundation to begin “soon”, Cherdantsev says.

Simultaneously Akkuyu Nuclear is developing the documentation package to apply for a construction licence for unit 3.

Asked to reflect on recent milestones, Cherdantsev points out the Eastern cargo terminal (above left), which was completed late last year. The task now is to obtain an operating permit from the Ministry of Transport and Infrastructure so that Russian equipment suppliers can start shipping heavy components to site.

Atomenergomash (part of Rosatom) is the complete supplier of nuclear and turbine island equipment for Akkuyu, including the reactor pressure vessels, reactor coolant pumps and steam generators. The core catcher is expected to be the first unit 1 component to arrive on site in June. The turbine island equipment is being subsupplied by AAEM, a joint venture between Atomenergomash and General Electric (which took over Alstom’s steam turbine activities in 2015). Under an 2017 contract AAEM will design and supply the full set of Arabelle half speed steam turbines, Gigatop generators, moisture separator reheaters, condensers, pumps and piping.

World first

In addition to being Turkey’s first nuclear plant, Akkuyu is the world’s first nuclear project to be implemented on a BOO (build-own-operate) scheme. This investment model will see Russia finance, manage the project and act as the reactor operator. Akkuyu Nuclear is not only responsible for safety during the construction, operation and decommissioning of the nuclear plant, but is also “invested first-hand in the economic efficiency of the future station as its owner and the operating organisation,” Rosatom says.

As part of the Intergovernmental agreement, a 15-year power purchase agreement is in place which guarantees the purchase of a certain amount of power generated by each of the four units. Electricity will be purchased for 12.35¢/ kWh, with the remaining electricity to be sold on the open market by the producer.

Rosatom may sell a stake of up to 49% to other parties who wish to invest in the project, and told NEI that negotiations with potential investors are “in progress”.

After more than 50 years it is fair to say that there has been concrete progress towards achieving Turkey’s nuclear dream. Work is now ongoing, and once completed the Akkuyu plant and the BOO model could become the benchmark for future Russian export projects.  

Engineering education

An area of fast-growing cooperation between Russia and Turkey is in the training of Turkish personnel.

Currently, more than 140 Turkish students are studying in Russian universities as part of a Russian-funded Akkuyu NPP personnel development programme. “We need young qualified staff, and we are glad that the Turkish youngsters choose to study nuclear sciences, technologies, engineering and energy generation,” says Mikhail Cherdantsev, head of construction for the Akkuyu project. “We count on their active participation and role in the construction of the first NPP in Turkey.”

In March 2018, the first 35 students completed a 6.5-year training programme at Moscow’s Engineering Physics Institute (MEPhI) and the second cohort of 56 graduated in February 2019. These students have been employed by the Akkuyu Nuclear project company and will hopefully continue to play a role in Turkey’s nuclear industry during the 60-year (or longer) operational lifetime of the plant.