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View Full Version : 1.4 Billion Dollars - Last Cost to Finish Entombing Chernobyl.


Ergeheilalt
09-17-2007, 09:52 PM
http://news.bbc.co.uk/2/hi/europe/6999140.stm

The authorities in Ukraine have approved a giant steel cover for the radioactive site of the world's worst nuclear disaster - Chernobyl.

Ukraine has hired a French firm to build the structure to replace the crumbling concrete casing put over the reactor after the 1986 accident.

The casing project is expected to cost $1.4bn (£700m).

It will take five years to complete and the authorities say they will then be able to start dismantling the reactor.

Ukrainian President Viktor Yushchenko hailed the project:

"Today is probably the first time that we can openly look into the eyes of the national and international community and say that a solution to the problem that has long been called the Chernobyl problem was formally found," he said.

Weather exposure

The French construction company Novarka will build a giant arch-shaped structure out of steel, 190 metres (623 feet) wide and 200m long.

It will cover the existing containment structure which stands over the reactor and radioactive fuel that caused the accident in 1986.

The reactor still contains 95% of its original nuclear material, and exposure to weather and poor construction has left the existing casing weak.

A separate deal has also been signed with the US firm Holtec to build a storage facility within the exclusion zone for nuclear waste which has been produced by Chernobyl.

The money for the schemes has come from international donors.

The fund is administered by the European Bank for Reconstruction and Development.

Its president, Jean Lemierre, said the continued commitment of Ukrainian authorities and the international community was vital for the projects to be successfully completed.

Soviet nuclear reactor design always stuck me as insane. It sucks that Ukrain has to deal with this shitty mess.

TiQuinn
09-18-2007, 09:58 AM
Soviet nuclear reactor design always stuck me as insane. It sucks that Ukrain has to deal with this shitty mess.

What are the differences in layman's terms?

PWD
09-18-2007, 10:42 AM
What are the differences in layman's terms?

Borscht instead of Heavy Water. And the workers are paid in used Borscht.

doc
09-18-2007, 10:46 AM
What are the differences in layman's terms?

Doh, Soviet construction, too big and not enough quality control

Ergeheilalt
09-18-2007, 12:57 PM
What are the differences in layman's terms?

There are two key differences.

In the United States (and most of the "West", but I'm not 100 percent sure) take a lot of precautions with regards to safety. Nuclear reactor containment buildings have lots of thick, cement walls but most importantly, they have a big metal dome over the reactor vessel by default. Always.

In the case of Chernobyl, the metal dome would have acted like a blast shield and would have made putting out the graphite fires significantly easier. It would have also, largely suppressed the escaping fission fragment fumes from getting into the upper atmosphere and spreading via the jet stream. Most Soviet era reactors are basically housed inside a normal industrial building with only the minimum safety steps taken to ensure that if things go bad, they go bad in the safest way possible.

The other issue was the control rod design. Control rods are like breaks for the nuclear reactor. You put them in, they poison the fission process and absorb all the decaying neutrons. In Chernobyl, the control rods were completely withdrawn - they were not in the graphite blocks at all when it approached criticality (border-line uncontrollable). For whatever reason the control rods were all tipped with a moderator. Moderators make it easier for the fission reactions to take place. By putting in the control rods, just inserting the tip pushed the reactor over the edge and into prompt critical status. Even when the rest of the rods went in, the reaction was completely out of control.

Again, in US and most Western designs, control rods are designed to do only to stop or slow the reaction, not speed it up.

Varaj
09-19-2007, 06:52 PM
Good read on the accident
http://en.wikipedia.org/wiki/Chernobyl_disaster

Chernobyl didn't just happen, they tried to make it happen. :)