On November 29, 2016, the official ceremony of New Safe Confinement (NSC) Arch installing in the design position took place. This event was preceded by four years of hard and painstaking, without exaggeration - creative work of Chornobyl NPP team, the main construction contractor, NOVARKA joint venture (consortium consisting of two French companies: Bouygues and Vinci), a number of foreign and Ukrainian subcontractor organizations, research institutions at institutes.

To build NSC, 45 donor countries have joined efforts with Ukraine in a specially established fund administrated by EBRD and pledged more than 1.5 billion euros. In total, 10,000 employees from 40 countries, 5,000 of them Ukrainians, were involved in the project. 

The ceremonial event was preceded by four years of the Arch structure construction, which was intended to cover Chornobyl Unit 4 destroyed as a result of the accident, and two dramatic weeks of NSC Arch construction sliding on the Shelter object. A huge structure weighing 36.2 thousand tons using the complex jacks system was moved along the special foundations for sliding 327 meters and installed in the design position.

However, NSC project did not end there. Within a year after the Arch sliding above the Shelter object, in November 2017, Chornobyl NPP commissioned the “enclosing perimeter” of the New Safe Confinement (NSC). The project provided for the reinforcement of the existing Unit 4 walls and construction of two new ones on both sides of it. This was necessary in order to make able weakened as a result of the explosion ChNPP structures to withstand the Arch sliding and ensure NSC further operation. About 2,500 Ukrainian specialists worked in the project, 1,300 of whom worked directly on the construction site.

In 2018, the space under the arch was sealed by installing a specially designed polyurethane membrane isolating the under-arch space. The membrane is able to withstand stretching up to 55% of its original size and 300 km/h wind speed.  

Also during this period, the main NSC equipment was installed, tested and checked. 

Comprehensive tests of NSC radiation monitoring system, NSC power supply system under “complete power outage” scenario and NSC fire protection system were performed at the beginning of 2019. During the tests, emergency situations were simulated and the responses of individual systems to them were checked. On April 22, 2019, New Safe Confinement was commissioned into pilot operation. The purpose of pilot operation is to make sure that all equipment and facilities perform their functions. In addition, work in this mode allowed to check the level of qualification obtained by SSE ChNPP staff during training. During the 72-hour "pilot" operation almost all equipment and all systems were involved in the design mode operation.

On July 10, in the Exclusion zone, New Safe Confinement was solemnly handed over from the General contractor Novarka to the Employer - State Specialized Enterprise Chornobyl NPP. The event was attended by the top leadership of Ukraine, representatives of the countries contributed to Chernobyl Shelter Fund, EBRD representatives, management and representatives from SINRU, State Agency for Exclusion Zone Management, Chornobyl NPP and Novarka management and representatives.

Four years under NSC protection allow us to state confidently that the Arch sliding had a positive impact on the radiation situation at the industrial site. Based on gamma radiation levels measurements in the former Arch construction area, the radiation level has decreased by an average of 10 times.

The Arch also covered the Shelter object from precipitation. For comparison, the quantity of radioactively contaminated waters pumped out of the Shelter object in the first half of 2017 decreased on average by more than 4 times compared to same periods in previous years.

In addition, release of radioactive aerosols through the cracks in the Shelter object has decreased. The Arch made it impossible for the Shelter to be directly affected by sunlight and wind, which created air flows inside the facility and transported radioactive aerosols outside. Total releases have decreased by an average of 5 times.