Today in history

[Vlad]

I did this last year too, so might as well keep it going.

Today is the day that Unit #4 at the V.I. Lenin Memorial Chernobyl Nuclear Power Station (full name) became unstable during a test run and later underwent a full Nuclear Meltdown causing the worst nuclear disaster in history. They wanted to see if the reactor could generate enough power to run its cooling pumps during turbine spin down in the event they lost power. Due to a design flaw, the RBMK 1000 power reactor had a very high positive void coefficient. The operators also disabled part of its safety system, preventing the reactor from shutting itself down. By the time the operators realized what was happening, the void coefficient was too high and they lost control of the reaction causing the steam pressure to build too high and it caused a steam explosion sending a literally glowing cloud of radioactive particles into the air.

Today there are still 13 RBMK 1000 power reactors in active service, but they have had improvements made to prevent this from happening again. No more will be built after the remaining 13 reach the end of service life.

 

[ziloo]

Vladino,

What is a "positive void coefficient" :shock:? You are beginning to sound like
startrek !

 

[carlsson]

A number of people - journalists, Greenpeace people and so on - have visited the Chernobyl area in modern times. Here is a photo album taken by a Swedish guy who went there last year, 20 years after the accident. All the text unfortunately is in Swedish, but you can look at the pictures.

http://hem.bredband.net/b572399/Tjernobyl/

The pictures from Pripyat, the city next to the nuclear plant are really scary. An overgrown ghost town, where all living things are dangerous to touch. You can walk on concrete, but don't dare to touch the grass or bushes. One of the pictures is from the roof of a building. The caption reads how an electrician the morning after the accident went there to work on his tan, and found the sun appeared stronger than ever. The skin immediatelly smelled like burned, much due to the air was full of plutonium, cesium, strontium, iod and so on.

 

[Vlad]

Thanks for the link Carlsson, pretty interesting pictures. I've since lost its location, but I used to have a link to a video of 3 men in a helicopter flying over the wreckage of Unit #4 shortly after the accident. You could see the glowing cloud and the reactor core glowing brightly down below still undergoing an out-of-control reaction. You could see white dots all over the screen because the radiation was hitting the film. That was scary to see.