Work on the New Safe Confinement (NSC) for unit 4 of the Chernobyl NPP in Ukraine is now 53% complete, according to State Specialised Enterprise ChNPP, which is responsible for managing the Chernobyl site. Some 6,750t of concrete of the planned 11,000t have already been used for the construction of the new shelter, due to be completed in 2017. The NSC will prevent radioactive releases and contribute to making the site environmentally safe and stable. All activities are on track despite the “complex” technical and radiation conditions, with work being carried out in three shifts around the clock.
The NSC is the most high profile and expensive element of the €2.15bn ($2.4bn) Shelter Implementation Plan, developed to overcome the consequences of the 1986 Chernobyl accident. The placement of the NSC, which will cover the existing temporary shelter, known as the sarcophagus, is scheduled for the end of 2016, a spokesman for the European Bank for Reconstruction and Development, which funds the project, said in April. The NSC is a huge arch-shaped structure which is being assembled near the site and will later be slid into position over Unit 4 and the existing sarcophagus.
The work involves strengthening and sealing of existing structures if units 3 and 4 (including construction of new separation walls) to which the side walls of the NSC arch will join. The project implementation is complicated by the difference between the conditions on the site and the initial design solutions. For example, after the light roof of the deaerator building was removed, pre-accident roof plates were found, which had be removed to build the new wall. There are also problems due to radiation and high exposure doses to the personnel which means assembly of the NSC is being done some distance from the installation site.