New Appeareance of Chernobyl : A tourist spot so hot it's radioactive

Yellow Geiger counter in hand, the guide announces that radiation levels are 37 times higher than normal. Welcome to Chernobyl, the site in 1986 of the worst nuclear disaster in history and now an attraction visited by thousands of tourists every year.

Nearly 25 years after a reactor at the Soviet-era plant exploded, the irradiated zone around Chernobyl is attracting curious visitors from around the world, from nuclear specialists to ordinary tourists, willing to pay $US160 ($A168) a day to visit the zone.

Described by US magazine Forbes as among the "world's unique places to visit," Chernobyl last year hosted about 7500 visitors, according to official figures.

On one recent trip, a small bus ferried tourists to the edge of the zone, forbidden to those without special permission. At the entrance, each signed a form promising to respect rules aimed at preventing contamination, including not eating or smoking outside, not touching anything and not sitting on the ground or even putting down personal belongings.

The tourists signed the form with nervous laughs. A young Belgian psychologist, Davinia Schoutteten, admitted to being "a little bit scared" of the radiation and said she planned to throw away her shoes after the visit.

She moved forward with the other tourists nonetheless, heading toward the infamous reactor, now covered in a cracked concrete shell. The Geiger counter registered radiation levels of 3.9 microsieverts, against a normallevel of 0.12 microsieverts.

After taking pictures of the reactor, the tourists headed to the abandoned city of Pripyat, built only three kilometres from the nuclear plant to house its personnel and from where 50,000 residents were evacuated the day after the catastrophe.

In the city, time was frozen. Soviet-era signs hung from buildings near a rusting fun park. Books and bits of toys sat in abandoned apartments. Hundreds of gas masks littered the floor of a school cafeteria.

At the entrance to a classroom, a lesson plan for the next week -- including classes in reading, math, Russian and natural sciences -- was written in black and red ink on a piece of paper still pinned to the wall.

"It's very sad. I can't help but feel very sad," said Bobby Harrington, a young woman visiting from Australia.
"(It is) very beautiful and poetic but the whole tragedy makes me feel very uncomfortable with photographing it," she said, adding that she felt like she was intruding by seeing abandoned homes.

"It's too early maybe. There are a lot of people still alive.... It's the voyeuristic element that I feel uncomfortable with," she said.

But other tourists felt no hesitation about the site being made a tourist attraction, saying it was a testament to a historical event.

"I always wanted to see this place, since it happened. It's a very important part of our recent history," said tourist Karl Backman, a Swedish musician.

"I do not think it's bizarre. It's no different from the Coliseum, where people died... or from Auschwitz. It's history," he said.

The disaster occurred on April 26, 1986 at 1:23 am, when one of Chernobyl's reactors exploded, contaminating the then-Soviet states of Ukraine, Russia and Belarus with the fallout also spreading to other parts of Europe.

Thousands of people known as "liquidators" from Ukraine, Russia and Belarus have died since taking part in the bid to limit radioactive fallout after the catastrophe.

The death toll from the Chernobyl disaster is bitterly disputed, with a United Nations toll from 2005 setting it at just 4,000, but non-governmental groups suggesting the true toll could reach tens or even hundreds of thousands.

In Ukraine alone, 2.3 million people are designated officially as "having suffered from the catastrophe," including from higher cancer rates.

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SOURCE: http://www.smh.com.au/travel/a-tourist-spot-so-hot-its-radioactive-20100924-15qbe.html

Chernobyl

This will be the last class summary topic for this blog as the class has ended officially on 19 October 2010. Hence, to end, I would like recap about the most interesting topic - Chernobyl accident in 1986.

This accident dated 24 years back is still a nightmare in most people's heart and is one of the contributing factor why nuclear technology is heavily opposed or go against.

It is one of the most advanced nuclear powerplant of its time, operated by a group of most brilliant scientists and engineers; however, the disaster still happened because of their pride and ego.

Basically, what happened was, they were trying to run an experiment to prove the plant's capability or performance, hence all the safety systems were bypassed, and accident occured! Without containment building, the radiation spreaded throughout Europe reaching as far as Sweden.

Another thing that makes Chernobyl as the last is that the nuclear reactor out there currently are all "negative void temp coefficient" type of reactor eversince Chernobyl occured. Chernobyl was using the "positive void temp coefficient" concept which makes it not so safe.

The below pictures will explain why.

For Chernobyl type of reactor, as the coolant heats up and vaporize, the reaction in the reactor will increase due to the absence of the coolant that acts as moderator and to capture some of the neutrons. Hence, the increase in reaction will further increase the temperature, more and more coolant will heats up and vaporize, allowing the reactor to reach a certain temperature where the core will melt down. This is called "positive void temp coefficient".

Meanwhile, for modern reactors, that mostly use water as moderator or coolant, this problem is no longer a worry. As the moderator(water) heats up and vaporize, the neutrons are not moderated and hence fission with the fuel will not present as they are still fast neutrons. As this happens, the reaction rate will slow down and the temperature of the reactor will accordingly decrease, allowing the moderator/coolant(water) to condense and fill back the void. When the void is filled, the reaction rate will rises and it keeps on repeating. In a way, such design is self-regulating and self-sustaining. This is known as the "negative void temp coefficient".

As a nutshell, Chernobyl accident is once and for all. The chances that accident of such magnitude will happen again is almost zero, as the world now is alert and cautious when dealing in nuclear. As long as we do the following, we will be on the safe side, preventing history from being repeated:

• DO NOT bypass safety systems - what is going to protect us, when safety systems are bypassed?
• DO NOT let pride take over - when pride is there, we tend to miss plenty of details.
• DO NOT neglect designed procedures - no one knows better than the designers about their systems, they experimented!
• DO NOT run dangerous experiments on any operating nuclear reactor - do it on experimental nuclear reactor!
• DO make sure containment building is there!

Once bitten, twice shy. We are in the shy state now, another accident, and nuclear will no longer be in talk. Hence, it is of utmost importance, that safety should always be the number 1 priority or concern in nuclear! Finally, that's all to sum up for my final class summary. Salam sejahtera, salam nuclear.