First nuclear unit in Belarus starts up

Above: Ostrovets site

OPERATION HAS BEGUN AT OSTROVETS 1, the first nuclear power plant in Belarus.

Designed by Rosatom, the Ostrovets project uses the latest Generation III+ technology - the AES-2006 model of the VVER-1200 design. The Ostrovets plant marks the first time that this latest generation of VVER has been successfully completed outside Russia, so it is a significant step in Rosatom’s global export ambitions.

When complete, the plant will consist of two VVER power units, each with a capacity of 1194MW. The second unit is on schedule to be commissioned in 2022. The plant’s expected capacity factor when fully operational is 90-92%.

Ostrovets is also a landmark moment for Belarus as a nation and represents a new chapter in the country’s energy history. As a new entrant to the nuclear energy market, safety was a key factor when selecting the design for this project. Belarusian specialists reviewed proposals from nuclear corporations from around the world, including Westinghouse, Areva and Chinese companies. However, it was the Rosatom-designed project that the experts felt addressed Belarus’ needs most efficiently.

Rosatom’s design meets the highest international standards, including post-Fukushima International Atomic Energy Agency (IAEA) recommendations. With a core damage frequency (CDF) of just 7.7 x 10-7, or one event per 77 million years, the reactors are among the safest in the world.

The Belarus plant has a broad range of active and passive safety systems. The steam generator passive heat removal system, for example, is activated automatically if needed and is capable of removing heat from the reactor core in the absence of power supply.

The design has double containment of the power island and a hydrogen recombiner system. A core catcher, designed to trap melted fuel beneath the reactor in the unlikely event of a severe accident, ensures that radioactive materials are not released into the environment, even if the reactor core is damaged.

The site-specific design at Ostrovets follows meticulous analysis, bench testing and computer modelling to make sure that critical parts of the plant are able to withstand any significant external shocks. The impact of airplane crashes and extreme weather events have all been factored into the design - particularly heavy snowfall, given Belarus’ harsh winters.

Particular attention has been paid to seismic safety. Ostrovets is not a seismically active region, but earthquakes measuring over 5.5 on the Richter scale are not unheard of. Ensuring the plant would avoid the fate of the Fukushima Daiichi plant should a significant seismic event occur, therefore, was paramount.

Belarusian seismologists studied data from over 1200 earthquakes dating back to 1887, including a disputable earthquake in 1908 at Gudogai. Despite there being little evidence that the Gudogai earthquake took place, experts used the event as a worst-case scenario for Ostrovets to help achieve a better seismic resistance in the eventual design.

The peak ground acceleration (PGA) for Ostrovets is 0.13g, which is 30% higher than the PGA benchmark of 0.1g recommended by IAEA for new plants. The plant’s category 1 structures have greater seismic resistance, with a PGA of 0.62g. This represents some of the highest levels of seismic resistance in Europe. Among EU plants operating at significantly lower levels of seismic stability are the Krsko plant in Slovenia, which has a seismic margin of only 7%.

From the project’s inception, Belarus has worked closely with international nuclear safety watchdogs and independent expert groups to ensure that the plant meets the strictest requirements. The use of international peer review services was one of the good practice areas highlighted by the IAEA in its mission report into the plant.

Another area commended by the IAEA was Belarus’s “effective coordination and systematic approach in developing, reviewing, testing, updating emergency and contingency plans and training”. The country’s stringent approach to testing and emergency preparedness were also areas noted by the European Nuclear Safety Regulators Group (Ensreg) when Belarus undertook voluntary stress tests of the plant between 2016 and 2018. The Ensreg peer review gave the tests an ‘overall positive’ evaluation and provided the Belarussian regulator with recommendations.

Authorities in Belarus included these recommendations in the country’s National Action Plan (NIA) and are already undertaking measures to achieve them over the coming years.