Chornobyl Nuclear Power Plant (ChNPP) says a new project will be financed under Grant Agreement No5 with the European Bank for Reconstruction & Development (EBRD). The project aims to assess the damage and develop a plan of emergency repair activities for the New Safe Confinement (NSC) outer cladding and sealing membrane following a drone strike in February.
The initial phase of the project will include surveys and assessment of the technical condition of the damaged primary and secondary steel structures of the NSC at the site of the explosion. It will also involve inspection of the damaged cladding, identification of gaps between the NSC’s end walls and foundations, and assessment of the reinforced concrete structures forming the NSC’s enclosing perimeter. This stage will also include the development of technical solutions for implementing urgent temporary repairs of the damaged cladding sections and sealing the identified gaps. Subsequently, a detailed work execution plan will be developed for carrying out the identified emergency repair measures.
EBRD said the European Union (EU) and UK had pledged up to €31.7m ($37m) to the EBRD-managed International Chernobyl Cooperation Account (ICCA) to help fund emergency repairs to the NSC. Total cost of emergency repairs could exceed €100m. The EU will contribute up to €25m, and the UK up to €6.7m.
EBRD said the strike had severely affected the NSC’s two primary functions: (i) containing radiological hazards and (ii) supporting long-term decommissioning. “Key systems designed to ensure the NSC’s 100-year lifespan have been rendered non-operational, with a significant risk of further deterioration in the absence of swift emergency repairs.”
The ICCA was established by the EBRD in November 2020 at the request of the Ukrainian government. It was set up as a multilateral fund to support the development of a comprehensive plan for Chornobyl. The EBRD manages the ICCA, which currently holds some €25m in donor funds. Following the temporary occupation of the Chornobyl Exclusion Zone (CEZ) at the start of the conflict in Ukraine, the scope of the ICCA was broadened to support the restoration of safety and security within the CEZ, as well as wider nuclear safety measures across Ukraine.
The international community has contributed around €2bn to EBRD-managed programmes in Chornobyl since 1995. In addition, the Bank has made more than €800m of its net income available for Chornobyl-related projects.
The purpose of the NSC is to cover the ageing sarcophagus hastily built over the damaged reactor following the 1986 accident and to provide an environment where this crumbling structure could be safely dismantled. It will also make possible the eventual removal of the fuel-containing materials in the bottom of the reactor building and their characterisation, compaction, and packing for disposal.
Construction of the NSC began in 2007, but due to insufficient funding the completion dates of the facility were periodically postponed. Construction resumed in 2012, and it was put into operation in 2019. In 2021 ChNPP was formally licensed to operate it.
The €1.5bn ($1.69bn) NSC construction project, managed by the European Bank for Reconstruction and Development (EBRD) was financed by 45 donor countries and institutions. The €935m contract for the design and construction of the NSC was signed in 2007 between the ChNPP and Novarka (a consortium led by the French construction companies Bouygues Travaux Publics and Vinci Construction Grands Projets). The NSC is 108 metres high, 162 metres long, and has a span of 257m. Its lifetime is a minimum of 100 years.
The arches, which form the basic structure of the NSC, are made of steel tubular elements and lined with 3-layer sandwich panels on the outside. The same panels are also used for finishing the end walls of the structure. To prevent corrosion of the structure, stainless steel was chosen as the material for internal and external walls. Inside, each arch is covered with polycarbonate panels that prevent the accumulation of radioactive particles on the frame elements.
In May, the International Atomic Energy Agency (IAEA) reported on the extent of the damage. The drone strike caused a 15-square-metre hole in the external cladding of the arch, with further damage to a wider area of about 200-square-metres, as well as to some joints and bolts. It took several weeks to completely extinguish the fires caused by the strike. IAEA said the emergency work resulted in approximately 330 openings in the outer cladding of the NSC arch, each with an average size of 30-50 cm.
According to information provided to the IAEA team at the site, a preliminary assessment of the physical integrity of the large arch-shaped building identified extensive damage, for example to the stainless-steel panels of the outer cladding, insulation materials as well as to a large part of the membrane – located between the layers of insulation materials – that keep out water, moisture and air.
In addition, the IAEA team was informed that the NSC’s main crane system (MCS), which includes the crane north maintenance garage area, was damaged by the drone strike and is currently not operational. The MCS is one of the building’s main systems. The crane maintenance garage area houses several electrical cabinets for various systems, most of which were affected by the drone incident and by the water used to put out the resulting fires.
