On December 19, 2013 the Deed of operational readiness of the object upon completion of dismantling of ChNPP II stage Vent Stack was signed.
Dismantle the Stack is part of a unique project on construction of the protective arch over the Shelter object, which will make possible dismantling of the damaged unit of the Chernobyl NPP in the safest conditions.
A special feature of the project "Dismantling of ChNPP II stage Vent Stack" is that the main work is performed under ionizing radiation conditions.
The project participants developed a variety of activities for safe performance of work considering the existing hazards.
The first block of the Stack was completely dismantled on October 31, 2013, and by November 25, 2013 dismantling was completed. It was important to be able to complete it before the onset of inclement weather, as even at a wind speed of 8.9 m/s and rainfall it is not possible to perform work by a crane.
Vent Stack was on the roof of the Unit B , which is common to the 3rd and destroyed 4th power unit and lies between them at close range. The top point of the Stack was at the elevation +150.0 m. And the area for installation of the crane, intended for dismantling, is far removed from the work area.
The heavy-load crane DEMAG CC8800-1 of 1600 tons lifting capacity was used for dismantling.
Dismantling of the Stack was carried out in parts by blocks of 25 - 60 tons weight. Plasma cutting method was chosen for the Stack shaft and support structure cutting.
Additional information concerning this project one can find by the following references: