After the accident at Chornobyl NPP in 1986, the ruins of Unit 4 were closed from the surrounding world by the Shelter Object.
The Shelter Object does not comply with the rules and norms for designing, construction, commissioning and operation of not only nuclear facilities or facilities for radioactive waste management, but also for civil industrial facilities. Its building structures do not comply with the requirements of regulatory and technical documents on safety in terms of structural integrity and reliability and have an undefined lifetime.
The results of survey showed that significant reduction in the Shelter Object's hazard is possible only as a result of new protective structure construction above the Shelter — New Safe Confinement (NSC).
Basic information: Project of Shelter object transformation into an environmentally safe system
"Confinement is a protective structure, including a complex of technological equipment for nuclear fuel containing materials retrieval from damaged Chornobyl NPP Unit 4, Radioactive Waste Management and other systems intended for activities to transform this power unit into an environmentally safe system and to ensure the safety for personnel, general public and environment" — the law of Ukraine "On general principles of Chornobyl NPP further operation and decommissioning and transformation of the damaged fourth power unit of this NPP into ecologically safe system."
According to the Conceptual Design, the NSC includes:
1. Main Building, including an arch structure, the span of which in the north-south direction is 257 m, height 108 m, length 162 m, foundations, western and eastern end walls, necessary supporting and auxiliary systems
2. Technological building which includes facilities for decontamination, fragmentation and packaging, sanitary locks, workshops and other technological premises
3. Auxiliary facilities
On August 10, 2007, a contract for the New Safe Confinement construction was signed between SSE "Chornobyl NPP" and international consortium NOVARKA.
The consortium includes two French companies «VINCI Construction Grands Projets» and «Bouygues Travaux Publics».
The main functions of the New Safe Confinement (hereinafter: NSC):
1. Restriction of radiation impact on general public, personnel and the environment.
2. Restriction of the spread of ionizing radiation and radioactive substances inside the Shelter.
3. Creation of conditions for unstable structures dismantling, radioactive materials retrieval, accumulated water pumping, for ensuring implementation of measures to control and maintain the Shelter object and its industrial site.
4. Monitoring of all the Shelter Object state parameters and technological processes management.
5. Preventing unauthorized access to the radioactive materials and ensuring IAEA safeguards system functioning.
The History of the NSC installation was started on February 13, 2012, when the first batches of basic metal structures were delivered to the ChNPP site.
© Video from the official YouTube channel of the European Bank for Reconstruction and Development. See the video here.
The NSC construction project is carried out in three stages:
1. Preparatory work, providing a safe and efficient NSC construction.
2. NSC designing, manufacturing, construction and commissioning. The whole complex of necessary tests and commissioning.
3. Early dismantling of Shelter Object's structures.
November 29, 2016 — the NSC Arch was installed in the design position above the Shelter Object.
For the NSC construction 45 donors countries combined their efforts together with Ukraine and pledged more than 1.5 billion euros. About 10,000 workers from 40 countries were involved in the project implementation. 5,000 of them are Ukrainians.
The Arch sliding has positively influenced the radiation situation. According to the results of gamma radiation levels measurements within the former Arch construction zone, the radiation levels in average decreased by 10 times. Also the Arch covered the Shelter Object from atmospheric precipitation. For comparison — the volume of radioactively contaminated water pumped from the Shelter within the first half of 2017 decreased in average by more than 4 times in comparison with the same periods of the previous years. Besides, the release of radioactive aerosols through the Shelter Object openings was decreased. The Arch made impossible direct impact of sunlight and wind on the Shelter, which created airflows inside the facility and transported radioactive aerosols outside. Total releases are decreased in average by 5 times.
November 8, 2017 Chornobyl NPP accepted into operation the NSC "Enclosing Perimeter".
The project stipulated strengthening of the Unit 4 existing walls and construction of two new ones on both sides of it. The works were necessary to ensure that the weakened by the explosion Chornobyl NPP’s structures withstand the Arch sliding and ensured the further NSC operation. The creation of the Enclosing Perimeter for the successful project implementation is no less important than the construction of the Arch itself. The Arch, Enclosing Perimeter and the membrane between them form the New Safe Confinement.
About 2,000 people are working at the NSC construction, more than 1,500 of them are Ukrainian citizens.
© Video from the official YouTube channel of the European Bank for Reconstruction and Development. See the video here.
July 10, 2019 – NOVARKA solemnly handed over NSC to Chornobyl NPP.
The event was attended by the top leadership of Ukraine, representatives of the Chornobyl Shelter Fund contributors, EBRD representatives, management and representatives from SNRIU, State Agency of Ukraine on Exclusion Zone Management, management and representatives of Chornobyl NPP and Novarka.
Read more: Events devoted to handing-over and accepting the New Safe Confinement from JV NOVARKA to Chornobyl NPP last in Ukraine for two days
April 24, 2020 – the New Safe Confinement was commissioned in trial operation.
During the trial operation, almost all NSC equipment and systems was operated in design mode within 72 hours. The task of trial operation is to make sure that all equipment and machinery perform their functions. In addition, working in such mode allowed checking the level of qualification obtained by ChNPP staff during the training. The tests subject during trial operation is conditional dismantling of the Shelter Object unstable structures.
Read more: NSC construction is formally completed
July 24, 2020 – a separate permission for pilot operation of NSC Commissioning Stage -1 was obtained.
NSC Commissioning Stage -1 (NSC CS-1) includes the design and construction of permanent NSC foundations, the main Arch structure together with the cladding and Main Cranes System, the overall internal NSC components, solid insulation coating of areas inside NSC, sites, as well as designing, manufacturing, construction (installation) and commissioning of the technological systems of NSC life support and monitoring and external engineering communications for NSC life support systems connection to the ChNPP systems.
