Tuesday, April 26, 2011

25 Years Ago Today


"Twenty-five years ago today, the sky fell on a corner of Ukraine. The Chernobyl nuclear plant, a symbol of man's triumph over the atom and the pride of a nation, experienced a system failure so complete, so devastating, that it left an irreparable wasteland in its wake. Explosions rang out. Radioactive smoke stained the early morning sky. And 350,000 people lost their homes forever."

"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 away as Sweden - thousands of miles away.

The causes of the accident are described as a fateful combination of human error and imperfect technology.

In keeping with a long tradition of Soviet justice, they imprisoned all the people who worked on that shift - regardless of their guilt. The man who tried to stop the chain reaction in a last desperate attempt to avoid the meltdown was sentenced to 14 years in prison. He died 3 weeks later.

Radiation will stay in the Chernobyl area for the next 48,000 years, but humans may begin repopulating the area in about 600 years - give or take three centuries."

(Account of the disaster from "Elena", who has seen the mess in person)

1 comment:

wildmary said...

Is Elena the one who wandered around on a motorcycle taking pictures and put them on a website?
Fascinating account of the disaster! I knew the anniversary of the event was today but didn't know some of these details. Thanks for posting.