Alberto ALEXANDRE

L'ENERGIA NUCLEARE E I SUOI UTILIZZI

3 media a.S. 2019/2020

international school of Venice

INGLESE - THE DISASTER OF CHERNOBYL

The disaster of Chernobyl. Chernobyl was a very famous nuclear power plant, which on the 26th of April 1986 had a huge explosion and the core of the reactor exploded with dramatic effects. It all started the 25th of April, when the director of the Nuclear Power Plant ordered the chief engineer to conduct some some important experiments, however the engineers contested the director as some of the manoeuvres were very risky to make, however they were threatened to be fired, and so they: deactivated all the safety measurements for the reactor and increased the power using some graphite bars. What happened next was a cause of both human errors and faults of the soviet reactor RBMK. Basically, when they saw that the power produced was to much, they used the emergency button to lift all the bars, however this didn’t work, and the energy continued to increase until the huge metal and cement lid which waited about 1000 tones exploded realising a lot of energy which made explode also the core. The power plant was designed to produce a maximum of 3200 mega watts, however it reached more than 33000 mega watts. This mainly occurred because the bars which should have slowed down the nuclear chain which were lowered by the operators, had the tip which was made of grafite, which increases the speed of the chain; when the bars lowered all at the same time, the graphite tips increased a lot the production, which heated a lot faster the water and created more steam.

The problem was that there was so much steam produced that the pressure got so high that the bars could not be lowered, so in the core there were only the grafite tips which continued to increase the energy produced, until it exploded. 

After that, no one knew what really happened, when they looked at the roentgen measurements, it was at 3.6 roentgens, which is the amount you absorb during an X-ray, however it was also the maximum amount they could measure. Actually it was more than 15000 roentgens. 

The first responders after the explosion was the fire-brigade, which fought that they were dealing just with a small fire. Nobody wanted to believe that the core had exploded as well as nobody wanted to believe that the roentgen were more than 3.6. Everything changed when the professor Valerij Legasov arrived on the site of the explosion and confirmed that the core had exploded, and then with a truck driven by a soldier discovered that 

the roentgens were actually 15000 which are twice the amount of roentgens that were released in the bombardment of Hiroshima. In the following days, everybody studied how to stop the fire before it reached the underground water and the rivers and contaminated many huge cities like Kiev. Also the radioactive ashes were pushed to west by the winds that there were in that period, so many countries like Italy and Germany were exposed to radioactive debris, luckily in a a lot smaller quantities.  

from phys.org

In conclusion this is considered the most terrible nuclear accident ever happened which costed many lives and that ruined the lives of many newborns, as many were born with many genetical problems. Also all the people who were evacuated from the cities close to Chernobyl had to leave all their belongings there, in fact now you can visit Chernobyl, and you can see all the personal belongings of the local people. 

Around the reactor 4 in Chernobyl, it was built a huge cement sarcophagus all around it, however, it was built terribly and so around three years ago, they build a huge very modern metal “hangar” which should resist for more than 100 years.