A major project to construct a confinement structure at the Chernobyl nuclear power station site has reached a key milestone.
Work to slide the new safe confinement (NSC) shell into place started today (14 November). The arch-shaped structure will be moved over Chernobyl’s reactor four, which was destroyed during the fatal nuclear accident 30 years ago.
The project aims to make the site safe while allowing for the eventual dismantling of the ageing shelter currently housing the reactor and the management of the radioactive waste within the structure.
The NSC has a span of 257m, and measures 162m in length and 108m in height, with a total weight of 36,000t when equipped.
The structure is being moved into place using a skidding system that consists of 224 hydraulic jacks to push the arch 60cm with each stroke. It is anticipated that the total skid time will be around 40 hours of operation, which will be spread over a period of up to five days.
The NSC was constructed in a clean area near reactor four and will be slid over 327m to seal off the unit.
Due to the vast dimensions of the structure, it has been built in two halves that were lifted and joined together in 2015. It is fitted with an overhead crane to allow for the future dismantling of the existing shelter and the remains of reactor four.
Construction work is being undertaken Novarka, a joint venture formed by Vinci Construction and Bouygues Construction.
“This is a one-of-a-kind project serving the aims of the Ukrainian authorities. We are immensely proud of what we, together with our partners, have achieved,” said Novarka project director Nicolas Caille.
“The new safe confinement shows what is technically possible. At the same time, given the circumstances, we must all hope that never again will a similar structure have to be built on the site of a nuclear accident and in a contaminated environment.”
Novarka started constructing the NSC in 2012 after extensive preparatory works. Initial work on site included excavation of two trenches on either side of the reactor to prepare the ground for the longitudinal beams that serve as the arch foundations.
“The start of the sliding of the arch over reactor four at the Chernobyl NPP [Nuclear Power Plant] is the beginning of the end of a 30-year long fight with the consequences of the 1986 accident,” said minister of ecology and natural resources of Ukraine Ostap Semerak.
“The credit for construction of this one-of-a-kind technological structure goes to an expert team of engineers and builders. This is a historic step towards the improvement of environmental safety throughout the world, as well as in the Chernobyl exclusion zone.”
The NSC has an expected lifespan of at least 100 years and will cost €1.5bn (£1.2bn). Funding has been administered through the European Bank for Reconstruction and Development (EBRD).
“The fact that more than 40 contributing countries and donor countries united around the goal of protecting humanity from the radioactive consequences of the tragedy is another demonstration that environmental safety remains a priority for global policymakers,” added Semerak. “And I believe that the transformation of the exclusion zone into a safe area will demonstrate the change in Ukraine’s overall environmental policy, too.”