# data[].attributes.body
The Chernobyl Accident of 1986 occurred when the nuclear power plant was preparing to run a test for the emergency cooling system on one of the four reactors in use.  When the test began, most of the control rods were removed, causing the reactions to happen at an uncontrolled rate.  This caused the reactor to increase drastically in temperature, and the reactor exploded.  As a result, over 8 tons of radioactive material was released into the atmosphere, the most dangerous being iodine, strontium and caesium.  The toxicity of the explosion was more than 400 times the amount released from the Hiroshima bomb.

Over 500,000 firefighters and military personnel were sent to put out the fire in the plant, which took 15 days to fully extinguish.  Later, a concrete structure was built around the reactor to trap any remaining radiation inside, and the plant was decommissioned in 2000.  In 2016, a much larger steel dome was built to enclose the failed reactor, as radioactive material was still pooled in the area, and the concrete structure had the potential to begin cracking.

# data[].attributes.attachment_caption
Citizens in the area of the Chernobyl plant evacuating their homes

# data[].attributes.body
Over 200,000 people were evacuated following the accident.  Within the first few days, 31 of the people drafted to aid the meltdown died due to the radiation exposure.  One of the main long term health effects was the widespread issue of thyroid cancer that followed the accident, which was caused by the iodine particles being released.  There were around 1800 reported cases of thyroid cancer among children ages 0 to 14.  Strontium has been known to cause leukemia among children, and around 137 known cases of this cancer resulted from the strontium particles.  Caesium is known to cause liver and spleen related issues, although it is unknown exactly how many cases of these types of problems resulted specifically from caesium radiation.

# data[].attributes.body
In this reactor design, enclosed uranium goes through nuclear fission, which produces enough heat to turn water into steam.  This heat is transmitted to an enclosed amount of water, which then turns into steam, and the steam rotates massive turbines to generate electricity.  Control rods are placed inside the reactor to moderate the speed at which the fission reaction occurs.  As this happens, cooling water must be circulated around the reactor so that the reactor doesn’t overheat.

# data[].attributes.body
Nuclear fission is the process by which the nuclei of uranium atoms split, causing a chain reaction that releases high amounts of energy extremely quickly.  In order for this to occur, a neutron is fired at uranium atoms at a high speed, and it travels until it collides with an atom.  This collision causes the nucleus to release more high speed neutrons, which can then travel to create new collisions.  As such, this reaction occurs at an increasing rate, so it becomes harder to control and more energy is released as time progresses.  Therefore, it is important to carefully moderate fission reactions when they are used in a reactor to generate energy, because they can easily become out of hand and extremely dangerous.

Fission reactions are maintained at a safe rate through the use of control rods, which are tubes that hold a substance like hafnium or boron that has the ability to absorb neutrons.  When introduced to uranium as it undergoes fission, the control rods can remove excess neutrons that are fired, which prevents a portion of collisions and slows the fission process to a rate that can produce safe amounts of energy.  When the control rods were removed during the cooling system test at the Chernobyl plant, the uranium fission reaction became uncontrollable.  It is unclear why the scientists made the decision to remove the rods, but their small decision caused too much energy to be released, the reactor to overheat and melt down, and the release of harmful radiation that resulted in lasting damage to a large scale of people.

# data[].attributes.body
Lessons Referenced: 6, 8, 9, 11

https://world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx

https://world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx

https://www.iaea.org/newscenter/focus/chernobyl/faqs

https://www.ebrd.com/what-we-do/sectors/nuclear-safety/chernobyl-new-safe-confinement.html

https://www.nrc.gov/reading-rm/basic-ref/glossary/control-rod.html

# data[].attributes.body
Like many other nuclear disasters in the late 1900’s, the events of Chernobyl resulted directly from the severely lacking safety culture at the time.  The scientists operating the reactor had an inadequate understanding of the danger that one small mistake could result in, and they had little regard for the weight of each decision they made.  Over time, nuclear power plants have since made significant strides towards operating as safely as possible, and the Chernobyl accident served as a lesson to shine a light on the serious dangers associated with this process.