The turtle shelter, formally referred to as the Object Shelter and often called the sarcophagus, was constructed between May and November 1986 as an emergency measure to contain the radioactive materials within reactor unit 4 at the Chernobyl nuclear power plant (ChNPP).
The existing Object Shelter is primarily supported by the damaged remains of the Unit 4 Reactor Building, which are largely considered to be structurally unsound as a result of explosive forces caused by the accident.