Bulgaria’s nuclear power plant at Kozloduy (KNPP) had six Soviet-designed VVER type-reactors. The Western European Nuclear Regulatory Association, and other experts, concluded that units 1-4 (VVER 440-230) could not achieve acceptable safety levels with economically viable investment.
The Kozloduy International Decommissioning Support Fund (KIDSF), administered by the EBRD, was established in June 2001 as an assistance programme of the European Commission and other European contributors to help the Bulgarian government cope with the early closure and decommissioning of the four units and subsequent compensatory measures in the energy sector. Kozloduy NPP’s Units 1 and 2 were shut down in 2002, and units 3 and 4 – in 2006 respectively.
The KIDSF operates on the basis of a Framework Agreement between the EBRD and the Bulgarian government. More than €1 billion has been contributed, mainly by the European Commission, as well as by Austria, Belgium, Denmark, France, Greece, Ireland, the Netherlands, Spain, Switzerland and the United Kingdom.
The KIDSF finances and co-finances investment projects for two main purposes:
- To support the safe decommissioning of KNPP units 1-4 with the objective of achieving a "brown field" end‑state by 2030.
- To address the consequences for the country’s energy sector due to the early closure of KNPP units 1-4.
A key facility, required for the safe decommissioning of KNPP units 1 to 4 and funded by the KIDSF, is the dry spent nuclear fuel storage facility, in operation since January 2016 and used for interim storage of the spent fuel from the decommissioned reactors for a period of over 50 years.
The transfer of the responsibility for decommissioning from KNPP to State Enterprise Radioactive Waste (SERAW) has been completed. SERAW has assumed ownership of all four units for the purpose of decommissioning.
As a breakthrough in the treatment and conditioning of solid radioactive waste, the plasma melting facility commenced commissioning programme at Kozloduy in 2018. The facility is designed to process up to 250 tonnes of radioactive waste per year, significantly reducing its volume. Metals, wood, textiles and other organic materials, concrete debris, sand, inorganic granulates, insulation material, asbestos are melted and transformed into a compact, chemically inert, amorphous glassy slag. All organic materials are destroyed at a very high temperature during the process, avoiding the possible emmission of harmful gases and other by-products.
Other KIDSF-funded projects provide the supporting infrastructure for dismantling, handling, sorting of equipment, decontamination, as weel as characterisation, retrieval, treatmentand storage of historical radioactive waste and radioactive waste generated during the decommissioning process.
The KIDSF also supports the construction of a near‑surface repository close to the Kozloduy NPP site, accepting low- and intermediate-level radioactive waste from KNPP units 1 to 4 decommissioning process. The planning phase, including site selection, geological, hydrological and engineering-geological assessments, safety and environmental impact assessments, design and site infrastructure preparation, have been completed. The facility construction began in 2017 and its operation is scheduled for 2021.
The KIDSF furthermore supports the implementation of decommissioning activities by SERAW’s personnel. This is a cost-effective approach, making best use of in-house knowledge and skills gained during operation and previous decommissioning activities. Tasks include dismantling, decontamination and waste management in accordance with the decommissioning plans and overall decommissioning schedule.
A key milestone for dismantling of equipment in the turbine hall of Units 1-4 was reached ahead of schedule at the end of August 2019.
Energy sector projects
The KIDSF funded and co-funded energy efficiency measures in line with Bulgaria’s national energy strategy to mitigate the consequences of the decommissioning of KNPP units 1-4. The programme includes:
- Rehabilitation of the district heating network in Sofia
- Introduction of new electricity meters in private households
- Energy efficiency improvements in public buildings
- Rehabilitation of municipal street lighting
- Energy efficiency and renewable energy credit lines for residential and commercial borrowers
- Environmental and energy efficiency improvements at Maritza East 2 thermal power plant
- Upgrade of the heavy industrial mining equipment of the Maritza East coal mines
- Upgrade and extension of the national electricity distribution and transmission systems
- Rehabilitation of hydro power plants
- Support for residential sector gasification (https://desireegas.bg/en/)
- Construction of high pressure gas pipelines.
The measures in the energy sector significantly compensated for the loss of operating capacity due to the early closure of KNPP units 1-4 and reduced emissions. The assessment of the overall results, completed in April 2018, established energy savings of 2,077,883 MWh/year, equivalent to 310 MW of effective electricity generating capacity, and an annual decrease of CO2 emissions by 1,380,752 t.
The assessment confirmed that the objectives and priorities of KIDSF grant support – namely, ensuring long-term energy supply security at affordable level and improving energy sector efficiency – have been successfully achieved.
Additional effects are improved working and living conditions in more than 340 public buildings, i.e. hospitals, kindergartens and schools, and for thousands of households all over Bulgaria.
The KIDSF support is now focused on the decommissioning programme and will not be used for any new energy sector projects.