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About the Accident

On April 26, 1986 an accident occurred at the Chernobyl nuclear power plant in Ukraine. The accident happened during a routine test, intended to demonstrate how long the turbines would spin after a power loss. Prior to the test, the automatic shutdown mechanisms were disabled. Coolant water was reduced and the power output was increased. The operator tried to shut down the reactor but a flaw in the design caused a large power surge. An explosion caused radiation burns and exposure to the workers on site. The most adversely affected populations were emergency workers, children, and clean-up workers.

Recent photo of the abandoned reactor.

Chernobyl at Present: The Existing Sarcophagus

The accident caused more than 28 short-term deaths from radiation burns and exposure. Four thousand cases of thyroid cancer, including 15 thyroid cancer deaths, resulted, as of 2005, with several thousands more expected to develop among people who were children when the accident occurred. The accident resulted in the evacuation of about 360,000 people from contaminated regions of Belarus, Ukraine and Russia (115,000 in 1986 with subsequent relocation of 220,000 after 1990).

Those regions suffered significant economic damage and the area around the reactor is still quite desolate. The existing sarcophagus was constructed in a hurry as a temporary solution. It is now decaying and there exists a risk of radiation leakage. A new plan for enclosing the reactor on top of the existing sarcophagus in order to contain the radiation - called the Shelter Implementation Program (SIP) - will structurally stabilize the existing sarcophagus and build a new safe confinement. This is currently being constructed off-site and will be slid on top of the existing structure to cover it.

Illustration of the shelter implementation program.

Construction Phase of Shelter Implementation Program