[Exocet]

For those still wondering exactly what happened:

On the Friday evening of April 25, 1986, the reactor crew at Chernobyl-4, prepared to run a test the next day to see how long the turbines would keep spinning and producing power if the electrical power supply went off line. This was a dangerous test, but it had been done before. As a part of the preparation, they disabled some critical control systems - including the automatic shutdown safety mechanisms.

Shortly after 1:00 AM on April 26, the flow of coolant water dropped and the power began to increase.

At 1:23 AM, the operator moved to shut down the reactor in its low power mode and a domino effect of previous errors caused an sharp power surge, triggering a tremendous steam explosion which blew the 1000 ton cap on the nuclear containment vessel to smithereens.

Some of the 211 control rods melted and then a second explosion, whose cause is still the subject of disagreement among experts, threw out fragments of the burning radioactive fuel core and allowed air to rush in - igniting several tons of graphite insulating blocks.

Once graphite starts to burn, its almost impossible to extinguish. It took 9 days and 5000 tons of sand, boron, dolomite, clay and lead dropped from helicopters to put it out. The radiation was so intense that many of those brave pilots died.

It was this graphite fire that released most of the radiation into the atmosphere and troubling spikes in atmospheric radiation were measured as far as thousands of miles away.

These were inexcusable errors of design.

The causes of the accident are described as a fateful combination of human error and imperfect technology. Andrei Sakharov said, that Chernobyl accident demonstrates that our system cannot manage modern technology.