Thursday, April 7, 2011

The Everlasting Chernobyl


On April 26, 1986 a systems test was being conducted at the Chernobyl Nuclear Power Plant in Ukraine.  It was on this day, the worst nuclear disaster in history occurred when reactor number four exploded causing the graphite moderator to catch fire, sending a plume of smoke and ash containing radioactive material into the air. 

What is a Nuclear Reactor?

A nuclear reactor houses the process of nuclear reactions through fission.  The core is where all the nuclear power is kept, and where the energy begins.  In nuclear fission, neutrons start a reaction where the nucleus of atoms split, and each time a nucleus splits it created more neutrons thus creating more atoms that split and continue this cycle.  When the nuclei split, they release energy in the form of heat.  The heat is transferred to the steam generator when the coolant, most of the times water, is passed through the core, heating up and creating steam.  This steam activates the turbine which in return activates the generator which gives off most commonly electricity.  However, nuclear reactors are also used to generate aircraft carriers or submarines, imaging for cancer treatment, and for research.  Several precautions are taken at these reactors.  At some plants, there are cooling towers.  The towers serve as an outlet for any excess heat that can not be converted to energy.  Secondly, some nuclear reactors have a dome covering the entire reactor as a secondary effort to reduce the risk of disaster.  Unfortunately, Chernobyl had no such cover.

What went Wrong?

The crew at Chernobyl was running a test to see how long the turbines would continue operating after losing a major power source.  This same test had been run the year prior, but revisions had been made since and this systems test was going to affirm the improvements.  Several vital mistakes lead to the catastrophe Chernobyl is today.  To begin with, the crew members were not trained well and overlooked major safety precautions.  The biggest mistake they made was disabling the automatic shutdown.  As soon as the operators realized the test wasn’t going as planned, it was too late.  The control rods created too much energy making them extremely hot causing steam to be over produced.  The graphite moderator was damaged, and the atoms could not be slowed down to prevent the over production of energy. The pressure was too great resulting to the rupture of the fuel channel, causing a steam explosion and the release of fission products.

(video of glowing graphite)


  • The plume of smoke created by the explosion spread radioactive material
  • In the immediate days following, 28 people died due to exposure to radiation, but it can not be determined how many people’s deaths are indirectly associated to the events at Chernobyl
  • People were unaware of how severe the health risks are associated with radiation.
  • The radiation affected many aspects of the victims lives, including their air and what they ate and drank, which in the end affected themselves. (see picture below)
  • 4300 square kilometers were evacuated due to the unsuitable living conditions
  • However, more than five million are currently living in areas that were affected by radiation from Chernobyl
  • A concrete cover was placed over reactor 4 to allow the others to remain in use and a New Safe Confinement structure is set to be completed by 2014
  • 200 tons of radioactive material still remain under the cover
  • Raised awareness of nuclear safety 

Similarities to Japan

Given the recent event in Japan, the nuclear reactor there is being compared to Chernobyl.  There are some similarities, but many differences as well.  When the tsunami hit Japan, the reactor was shutdown and safety rods were put in the core as a safety precaution.  Japan was able to foresee a problem and reduce the potential devastation.  However, Japan is facing the same problem that destroyed Chernobyl.  There is too much energy that is overheating the fuel rods, posing the risk of the rods melting and exposing radioactive material.  The key difference is that Chernobyl was a mechanical problem, and the situation in Japan was caused by a natural disaster.  While Chernobyl and the nuclear reactor in Japan share some similarities, nothing as traumatic as Chernobyl will happen in Japan.

Should America be Worried?

There are obvious concerns of radiation reaching America.  While this is a common initial thought, scientists assure Americans that they are not at risk.  Even if people carry radiation from overseas back, it would not be a harmful amount and no more than a chest x-ray would have.  Scientist say there is no reason for Americans to be worried.  

Works Cited

“Chernobyl Accident.” World Nuclear Association. N.p., n.d. Web. 4 Apr. 2011. <http:///‌info/‌chernobyl/‌inf07.html>.
Hyper Physics. N.p., n.d. Web. 4 Apr. 2011. <‌hbase/‌nucene/‌cherno.html>.
Kavanagh, Jim. CNN. N.p., 17 Mar. 2011. Web. 6 Apr. 2011. <‌2011/‌03/‌17/‌whats-being-said-about-radiation-danger-to-u-s-from-japanese-nuclear-plant/>.
Marder, Jenny. “Japan’s Nuclear Crisis: Does it Compare the the 3 mild Island, Chernobyl?” PBS Newshour. N.p., n.d. Web. 6 Apr. 2011. <‌newshour/‌rundown/‌2011/‌03/‌cooling-system-fails-at-nuclear-reactors-fuel-talk-of-past-disasters.html >.
“Nuclear Reactor.” What is Nuclear. N.p., 2011. Web. 6 Apr. 2011. <‌articles/‌nucreactor.html >.
“Scientific Facts of the Chernobyl Nuclear Accident.” Green Facts. N.p., n.d. Web. 6 Apr. 2011. <‌en/‌chernobyl/‌index.htm >.