Chernobyl disaster

April 26, 1986

1:23 a.m.

Explosion at the Chernobyl nuclear power station took place - the world's worst nuclear disaster.

1. Where is Chernobyl?

The Chernobyl nuclear power station is situated at the settlement of Pripyat, Ukraine, 18 km northwest of the city of Chernobyl, 16 km from the border of Ukraine and Belarus, and about 110 km north of Kiev, the capital of Ukraine.

Power Station consisted of 4 reactors | and produced 10% of Ukraine’s electricity.

Construction began in the 1970’s with reactor number 1 finished in 1977, followed by number 2 in 1978, number З in 1981. Reactor #4 was completed in 1983• At the time of the accident, reactors #5 and #6 were in progress.

2. Accident

On Saturday, April 26, 1986, at 1:23 a.m. local time, the fourth reactor of the Chernobyl power plant known as Chernobyl-4 suffered a catastrophic steam explosion that resulted in a fire, a series of additional explosions, and a nuclear meltdown.

Reactor #4 was planning to test the backup power supply in case of a power loss.

To prevent any interruptions, the safety systems were switched off.

The procedure went wrong, the reactor's fuel elements broke, leading to a huge explosion and blowing off a hole in the roof.

The graphite, covering the reactor burned for nine days, leaking massive amounts of radiation into the environment – 400 times more than was expelled during the nuclear bomb on Hiroshima in 1945.

3. Causes

There were two official explanations of the accident:

1. Operator error. The operator error was probably due to their lack of knowledge of nuclear reactor physics and engineering, as well as lack of experience and training. Later this version was acknowledged to be false.

2. According to the latest analysis the main reasons for the accident lie in the peculiarities of physics and in the construction of the reactor.

The accident also happened because not much attention was paid to the "culture of safety" at all levels (including design, engineering, construction, manufacture, and regulation.

4. Immediate Impact

Debate is still continuing on how many people died in the Chernobyl disaster.

The disaster killed 31 people almost immediately. Most of these people were workers in the plant or local firefighters. Between 30 and 50 emergency workers died shortly afterwards from acute radiation.

In nearby Pripyat, people were not evacuated immediately and didn’t know about the accident. Yet within hours of the explosion many began falling ill, reporting headaches, coughing fits, vomiting and a metallic taste in their mouths.

203 people were hospitalized immediately.

Only on 28 April, two days after the explosion after radiation levels set off alarms in Sweden, over 1,000 km from the Chernobyl Plant, the Soviet Union publicly admitted that an accident had occurred.

The accident became publicly known throughout the world.

3. National and international spread of radiation

The accident produced a plume of radioactive debris that drifted over parts of the western Soviet Union, Eastern Europe, Scandinavia, the UK, and even eastern USA.

Large areas of Ukraine, Belarus, and Russia were badly contaminated. About 60% of the radioactive fallout landed in the neighbouring republic Belarus.

4. The Clean Up

According to Soviet estimates, up to 600,000 people were involved in the clean-up of the 30 km evacuation zone around the reactor.

·                   Liquidators.

These were the people who helped put out the fires and clean up the radiation. Liquidators worked under poor conditions, poorly informed and with poor protections. Many if not most of them exceeded radiation safety limits. Some exceeded limits by over 100 times—leading to rapid death.

First on the scene was a Chernobyl Power Station firefighter brigade under the command of Lieutenant Volodymyr Pravik, who died on 9 May 1986 of acute radiation sickness. They were not told how dangerously radioactive the smoke and the debris were, and may not even have known that the accident was anything more than a regular electrical fire.

Many later died from radiation, because they didn’t wear protection.

·                   Robots.

About 60 remote-controlled robots were used in cleaning up and building sarcophagus.

Most of the robots stopped functioning because the high levels of radiation effected on delicate electronics.

Even those machines that could operate in high-radiation environments often failed after being doused with water in an effort to decontaminate them.

5. Evacuation

53,000 people from neighbouring city Pripyat were evacuated to various villages of the Kiev region in 36 hours after the explosion.

A week later (May, 2-3) people were evacuated from the 10 km zone (45,000 people).

Ten days after the accident (May, 4), the evacuation area was expanded to 30 km (116,000 people).

Following the accident hundreds of thousands of people had to be evacuated and between 1990 and 1995 an additional 210,000 people were resettled.

6. Containment

The reactor itself was covered with bags of sand, lead and boric acid dropped from helicopters: some 5000 metric tons of material were dropped during the week that followed the accident.

At the time there was still fear that the reactor could explode again, and a new containment structure was planned to prevent further release of radioactive material.

This was the largest civil engineering task in history, involving a quarter of a million construction workers.

By December 1986, a large concrete sarcophagus had been erected to seal off the reactor and its contents.

A unique "clean up" medal was given to the workers.

7. Effects of Radiation

Exact figures of those who became sick or died are difficult to define because of Soviet secrecy at the time of the disaster.

There have been approximately 4,000 cases of thyroid cancer – mostly in children – caused by the contamination.

In the Homel region of Belarus, the region closest to Chernobyl, there has been a 100-fold increase in thyroid cancer.

A 200% increase in birth defects and a 250% increase in birth deformities have been reported.

9. Flaura and Fauna.

After the disaster, four square kilometers of pine forest directly downwind of the reactor turned reddish-brown and died, earning the name of the "Red Forest". Some animals in the worst-hit areas also died or stopped reproducing. The site of the Red Forest remains one of the most contaminated areas in the world. However, it has proved to be a fertile place for many endangered species, e.g. Przewalski’s horses.

10. Chernobyl Today

On 15 December 2000, the plant has been shut down by the Ukraine.

There is still almost 200 tons of radioactive material stored in the sarcophagus, which was built in only six months after the explosion in 1986. Today it is slowly breaking apart and cracks are letting radioactive material escape.

The UN estimates that up to 9 million people have been affected directly or indirectly by the fallout.

Today, more and more tourists are coming to northern Ukraine to see how people lived in before the explosion.

Buses take the tourists to the nuclear power station but stop a few hundred meters from the disaster site

Today Pripyat is a ghost town, its streets overgrown, its apartment blocks lying abandoned.

Books and toys litter the schools and kindergarten, a reminder of how quickly they were evacuated. The rusting Ferris wheel that still dominates the town has become a symbol of the world's worst nuclear disaster.

The Chernobyl Shelter Fund was established in 1997 to finance the building of a New Shelter to contain the radioactive remains of Chernobyl Unit 4 for the next 100 years. Work on the New Shelter started in 2010 and is expected to be completed by 2017.

Has day died?

Or is this the end of the world?

Morbid dew on pallid leaves

By now it's unimportant

whose the fault,

what the reason,

the sky is boiling only with crows.

And now--no sounds, no smells.

And no more peace in this world.

Here, we loved.

 Now, eternal separation

reigns on the burnt out Earth.

Chernobyl area will not be safe for human life again for another 20,000 years

Another explosion can be the last...