Two VVER-440 pressurised water reactors and their supporting systems have been successfully removed and dismantled at the Bohunice V1 plant in the Slovak Republic, bringing a major nuclear decommissioning project to an end. The European Bank for Reconstruction & Development (EBRD) said this is a significant achievement for the Bohunice International Decommissioning Support Fund (BIDSF) – which is financed by the European Union (EU) and other donors, and managed by EBRD.
Bohunice NPP consists of two plants: V1 and V2, each containing two reactor units. Construction of the V1 plant with two VVER-440 V-230 reactors supplied by Russia’s Atomenergoexport and Skoda of Czechoslovakia. The first was grid connected in 1978, the second two years later. In 1976 construction started on two VVER-440 V-213 reactors (the V2 plant) built by Skoda. The V2 units began operation in 1984 and 1985. All were designed by Atomenergoproekt.
As a condition for accession into the EU in 2004, Slovakia was required to deactivate the two reactors at the V1 plant. The first reactor was shut down at the end of 2006 and the second on the last day of 2008. The units were closed despite major refurbishments carried out to address safety issues. These included replacement of the emergency core cooling systems and modernising the instrumentation and control systems. The two Bohunice V1 reactors had more upgrading work on them than any other reactors of their type.
Upgrading had been undertaken over many years with more than 1,300 implemented technologic improvements. A minor reconstruction took place in 1991-1993 and safety improvement was continued in an extensive gradual reconstruction program in 1996-2000. The last stage of the safety improvement process within the Gradual Reconstruction of the V1 NPP was completed by end of the fuel replacement downtime of the unit 1 in 2000, which concluded a 10-year nuclear safety improvement process.
It proved that this type of reactor could be modernised to required safety levels and showed the capability of the original equipment to operate in conjunction with “western systems”. An IAEA mission in 2000 reported that “all safety issues identified earlier by the IAEA have been appropriately addressed”. Slovakia said all their design safety deficiencies had been removed by the upgrading, and that this had been confirmed by several international expert safety review missions.
In the lead up to EU accession, nuclear industry representatives from Eastern Europe called for the introduction of transparent and rational EU safety standards rather than punitive closures of reactors which had been substantially upgraded. The V1 units were cited as examples of the high safety standards which such reactors could achieve through upgrading with input from Western firms such as Siemens. The EU nevertheless insisted on their closure. The units had been producing electricity at half the average cost of all Slovak sources, and their closure left the country short of power.
A consortium led by the Westinghouse Electric Company, which included Slovak engineering firm VUJE, delivered the decommissioning project with a budget of more than €100m ($117m), ensuring the safe management of steam generators, main circulation pumps, pressurisers and reactor pressure vessel internals, which form the reactor coolant system at the BNPP.
The works carried out on site included safe dismantling of 6,700 tonnes of radioactive and contaminated structures. This involved advanced techniques such as dry and wet cutting, as well as the use of robotic decontamination systems and custom-built equipment, ensuring both technical precision and safety throughout.
In addition to the necessary dismantling activities, which were completed on time and within the envisaged budget, the consortium also processed 3,800 tonnes of obsolete non-radioactive materials for free release. Another 479 tonnes of secondary radioactive waste were also processed with rigorous regulatory oversight.
Massimo Garribba, the European Commission’s Deputy Director-General for Energy, said: “By completing this decommissioning activity at the Bohunice nuclear power plant, we have set a benchmark for other decommissioning projects. This major international undertaking, financed by the EU and other donors, was successful thanks to the supervision of the Slovak nuclear and decommissioning company JAVYS and the work of the EBRD-managed BIDSF fund. The safety standards and the amount of recycled materials, fully consistent with circular economy principles, were remarkable.”
According to Steven White, Head of the BIDSF at the EBRD, the support of European institutions, including financial backing from the EU, played a pivotal role in driving the project’s success: “This project shows what international cooperation can achieve. It also confirms our collective commitment to nuclear safety and environmental protection across the region and demonstrates that these complex and challenging tasks can be completed in a cost-effective and timely manner.”
The EBRD-managed BIDSF fund was established in 2001. It is supported by contributions from the European Union, as well as Austria, Denmark, France, Ireland, the Netherlands, Spain, Switzerland and the United Kingdom.
