I ran my own blog from November 2006 till October 2014. All posts are still online, but I don't have time to update it anymore. Please note that all images and media files have been removed when the backup was moved to a new host in early 2016. Enjoy!
About 23 years ago, on April 26 1986, reactor 4 at the Chernobyl plant exploded after a safety device test during the reactor shutdown rendered the core unstable. The test had been run by an unexperienced crew who had overrun and disabled numerous security systems and had thus ignored many security rules.
It was the worst nuclear power plant accident in history, and the resulting fallout affected large territories on the northern hemisphere. It was not the first major accident at the Chernobyl plant, there was already a partial core meltdownwhich occurred in reactor no. 1 four years earlier.
After the disaster a protective box was placed over the wrecked reactor, which has become known as the "sarcophagus". It was never designed to last for the 100 years needed to contain the radioactivity found within the remains of reactor 4, and experts even fear that it may collapse one day. This is why a new shelter is planned to be installed within the next few years.
Most people working at the power plant lived in Pripyat, a city located only a few miles from the plant that had been built for the power plant workers and their families. After the accident the 50,000 habitants of Pripyat as well as another 85,000 people within a 30 kilometer zone (the so called "zone of alienation") had to be evacuated.
Today Pripyat is an abandoned city, although some people living in the villages surrounding Pripyat returned to their homes after the accident and still live there today.
What most people do not know is the fact that the nuclear plant was not shut down after the accident. The three remaining reactors continued operating, and shortly after the disaster the city of Slavutych was constructed to replace Prypiat. Despite the high levels of radiation thousands of people still worked at the Chernobyl plant until it was finally shut down in December 2000 after massive pressure and payments by western nations. Reactor 2 had already been shut down in 1991 after another severe accident which seriously damanged its reactor building.
Over twenty years after the accident radiation levels are still high in Pripyat, although they are no longer considered to be life threatning for visitors. The core of the reactor 4 still contains a large number of highly radioactive materials, but these don't have direct contact to the atmosphere.
It's now even possible to visit Pripyat for everyone as tourist offices in Kiew offer visits to the abandoned city. The main roads have been decontaminated and most buildings are open to tourists, although it's not recommended to stay too long inside rooms that have not been decontaminated. The bus will even take you to the nuclear power plant so that you may take a closer look at the sarcophagus.
There are still people working at the power plant today, their job is to keep an eye on the shut down reactors and to fix the sarcophagus until a new steel containment structure will be ready to replace it. Sometimes visitors are even allowed to enter the nuclear plant, and on rare occasions you may also enter the control room of reactor 4.
Entering the sarcophagus is, of course, strictly prohibited for tourists, although some workers of the plant enter it on a regular basis to check its structure. Workers are only allowed to remain a few minutes at a time inside the sarcophagus as radiation levels are still quite high here, even if the core itself has been covered by thousands of tons of sand, lead, clay, boron and concrete.