Sv-Korn
Joined: 07 Jun 2002
Posts: 158
|
| Posted: 12-29-2002 06:09 PM Post subject: Putting A Lid Or Chernobyl - 16 Years Later |
|
|
16 Years Later
200 Tons of Uranium Lie in Ruins of Derelict Reactor
Engineers are completing plans for what may be the largest movable structure ever built -- a 20,000-ton steel shell to enclose Chernobyl Reactor 4, site of an apocalyptic nuclear accident whose consequences are still being felt more than 16 years later.
By next summer an international consortium led by Bechtel International Systems Corp., of San Francisco, will finish the conceptual design for a hangar-shaped arch nearly 370 feet high -- the height of a 35-story building -- that would be slid into place along greased steel plates to cover the ruined remains in a snug, weather-tight shelter.
Inside, robotic cranes and, where possible, live workers will then begin prying apart the wreckage, removing radioactive dust from twisted girders, storing pieces of radioactive core in shielded canisters and cutting old steel into manageable lengths.
The whole job -- design, construction and "stabilization" of the derelict reactor 80 miles north of Kiev -- is part of a fully funded 10-year plan set in motion by the Group of 7 industrialized nations in 1997. The $768 million project, including the shell, is scheduled for completion in 2007, according to officials involved with the project.
And then the world will wait.
The shelter is designed to keep water out and dust in for 100 years, or for as long as it takes the Ukrainian government to designate a permanent storage facility and dispose of more than 200 tons of uranium and nearly a ton of lethally radioactive plutonium that remain inside the ruins.
Most of the fuel-containing material lies as a solid "lava" formed by the fusion of molten fuel, concrete, 30 tons of fuel dust and 2,000 tons of combustibles.
In the basement, rainwater and fuel dust have mixed together in a dangerous radioactive "soup." Lethal chunks of the reactor core lie unseen in the rubble and in the earth alongside the building. More pieces of core were boxed and buried in a "cascade wall" built and bulldozed into place by Soviet workers in the immediate aftermath of the explosion.
"We will need a lot of shielding," said Vincent Novak, director of the Nuclear Safety Department for the European Bank for Reconstruction and Development, overseers of the project. "If it weren't for the radioactivity, I could almost call the job 'a piece of cake,' but the radiation makes it hugely complex and extremely difficult."
The Chernobyl explosion occurred April 26, 1986, when an out-of-control nuclear reaction blew off the roof of the steel building and spewed tons of radioactive material into the air, releasing 30 to 40 times as much radioactivity as the Hiroshima and Nagasaki atomic bombs combined in 1945.
It was the worst nuclear accident in history. Thirty workers died immediately at the facility, and 135,000 people were evacuated from the surrounding "Exclusion Zone." As recently as 2000, the Ukraine government was spending 5 percent of its gross domestic product to mitigate consequences of the disaster. |
|
