Immediately after the Chernobyl disaster (April 1986), the Shelter object, known as the "Sarcophagus", was urgently erected over the destroyed 4th power unit of the nuclear power plant. It was completed from metal structures and concrete in just 206 days. A total of 90 thousand people participated in the construction.
Why they began to build a new shelter
This sarcophagus built in an emergency mode is massive, but leaky. It has many slots through which radioactive dust is ejected outward. Therefore, already in 1997, at a meeting of the G7 countries, it was decided to build Shelter-2 over the 4th unit of the Chernobyl nuclear power plant. The project was developed in the European Union in the early 2000s, and its implementation has already become a matter of the 2010s.
The world's largest mobile facility
The new sarcophagus is completely different. It is made in the form of a huge arch made of metal structures. Its height at the maximum point reaches 108 m. The length and width are also impressive: 260 m and 165 m. It took more than 20 thousand cubic meters of concrete to arrange the foundation for the new sarcophagus, and more than 30 thousand tons of metal were used for the arch itself (which is almost 4 times more than the Eiffel Tower). This arch could house 12 football fields.
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Since this grandiose structure was built not directly above the power unit, but next to it, it became the largest mobile structure ever created by man.
The arch began to be built in 2012 in two parts separately, in parallel with each other. 1200 Ukrainian workers and about two hundred engineers from the European Union were involved in the implementation of the project, 50 of whom were exclusively engaged in radiation protection issues of workers at the facility.
The dismantling of a 300-ton concrete ventilation pipe that interferes with the construction of the arch became a serious problem. But they were able to cut it open and remove it using a German super-heavy crane.
After the construction of the two halves of the arch, or NSC (New Safe Confinement - the official name of the sarcophagus), in 2015, they began to slide over each other and connect over the old Shelter. These works were carried out by 224 hydraulic jacks combined into a special system. During the shift, the structure moved only 60 cm. The finally docked NSC became a single structure on November 29, 2016.
Design features
The arch of the new sarcophagus consists of 2 walls. Between them, the ventilation system injects warm dry air, expelling condensate from metal structures to prevent corrosion. The vacuum that is generated from this injection prevents radioactive dust from escaping.
A system of remotely controlled cranes was mounted inside the arch, under its ceiling. With their help, it will be possible to gradually disassemble the old sarcophagus, remove radioactive waste from under it and carry out their safe disposal. In total, 180 tons of radioactive fuel and about thirty tons of radioactive dust are hidden in the remnants of the melted fourth reactor. Their extraction and burial, with the final cleaning of the territory, will take, according to the forecasts of experts, at least 50 years.
But the service life of the new sarcophagus is estimated at no less than 100 years. It is able to withstand temperatures from -43 to +45 degrees; tornadoes of the 3rd class and an earthquake of 6 points.
The cost of the object and its further operation
The NBK was valued at EUR 1.54 billion. This money was allocated by the European Bank for Reconstruction and Development, and the governments of 44 countries. Russia from 2011 to 2017 transferred over 55 million euros for the implementation of this project. Construction contractors were French construction companies, subcontractors - Italian and Turkish.
The cost of maintenance and operation of the new sarcophagus is estimated at 40 million euros per year. It was expected that Ukraine would cover these costs. However, in fact, this money is still allocated by the European Union.