The keys for the New Safe Confinement shielding the destroyed reactor 4 of the hapless Chernobyl nuclear power plant were symbolically presented to the Ukrainian authorities on 10 July in a ceremony on the site of the former NPP attended by Ukraine’s President Volodymyr Zelenskyy, the EBRD said.

French company Novarka reportedly has ended work on the installation of an arch for the new safe confinement over reactor 4.

This marked the next step in the transformation of Chernobyl into an environmentally safe and secure state, the European Bank of Reconstruction and Development said, adding that the handover also represented the completion of the largest ever example of international cooperation in the field of nuclear safety.

In addition to Zelenskyy, Chernobyl Shelter Fund Chairman Hans Blix, EBRD Managing Director for Ukraine, Eastern Europe and the Caucasus Matteo Patrone, EBRD Nuclear Safety Director Balthasar Lindauer, and donour representatives, also attended the event.

“We are proud and pleased to see the completion of the New Safe Confinement. I would like to congratulate Ukraine on reaching this milestone and I would like to take this opportunity to thank those who have made this happen: the donors’ community, the EBRD and its shareholders, the international and local companies that turned the plans into reality, our experts from the Project Management Unit and the workforce which delivered this unprecedented achievement,” Lindauer said.

According to the EBRD, the New Safe Confinement cost €1.5 billion and was financed by 45 donour countries and institutions. It encloses the destroyed reactor 4, the unit destroyed by the 1986 nuclear accident at Chernobyl, and the provisional shelter built after the accident which still contains the molten core of the reactor and an estimated 200 tonnes of highly radioactive material.

The giant arch was constructed in two halves near the accident site from 2010 to 2016 and eventually slid over the damaged reactor. It is the largest moveable land-based structure ever built, with a span of 257metres, a length of 162 metres, a height of 108 metres and a total weight of over 36,000 tonnes equipped with a crane system for future dismantling work.

The structure is the most prominent component of the €2.1 billion Shelter Implementation Plan which included the completion of crucial infrastructure and safety projects, among others the stabilisation of the old shelter and the creation of the necessary infrastructure needed for the work at the Chernobyl site, the EBRD said.

The delivery of the Shelter Implementation Plan and the New Safe Confinement is financed through the EBRD-managed Chernobyl Shelter Fund, established in 1997 and funded by contributions from 45 countries, the European Commission and the EBRD, which is providing €715 million of its own resources to support Chernobyl projects including the New Safe Confinement.