The Aftermath of Chernobyl

Bryan McLellan
June 11, 2018

Submitted as coursework for PH241, Stanford University, Winter 2018


Fig. 1: A Chernobyl Exclusion Zone. (Source: Wikimedia Commons)

Chernobyl is located about one hundred and thirty miles north of Kiev, Ukraine. The Chernobyl Nuclear Power Plant was built during the 1980s and consisted of four nuclear reactors. [1] On April 26, 1986 the Chernobyl Nuclear Power Plant exploded and created worst nuclear catastrophe the world has ever seen. Effectively, all land within about twenty miles of the plant was decommissioned. [1] Several areas of land were designated as Exclusion Zones to be avoided, one of which is seen in Fig. 1.

How This Happened

The overall design of the nuclear power plant has been deemed flawed. [1] What caused the accident was that a very large amount of steam was created when the extremely hot nuclear rods were lowered into the cooling water of the reservoir. Due to the core design flaws of the reactor, this steam created more reactivity in reactor number 4. [1] This huge power surge caused an enormous explosion that separated a large plate that was covering the reactor core. [2] This released vast radiation into the atmosphere. The town of Pripyat was evacuated following the accident. Over 120,000 thousand people were evacuated in total. [3]

A second and more powerful explosion took place not moments later. These explosions killed two workers of the plant with hours of the disaster occurring.

Radioactive Effect

In the four months following the accident, twenty-eight plant workers at Chernobyl died. The radiation released from the reactor contained Cs-137, which has a half-life of 30 years. Another hundred and six employees contracted radiation sickness from the accident. In addition, over six thousand cases of Thyroid cancer have been detected due to the accident while most of them were able to be treated successfully. [1]


This horrible accident brought to light the potential dangers of nuclear energy and how important it is to prioritize safety of operating such a plant. The land of the nuclear power plant will not be inhabitable for over the next twenty thousand years due to the half life of low enriched uranium, which is over four and a half billion years. [2]

© Bryan Mclellan. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] M. Caballero, "The Chernobyl Disaster," Physics 241, Stanford University, Winter 2016.

[2] M. Ramadan, "Chernobyl Accident Events" Physics 241, Stanford University, Winter 2016.

[3] A. Taylor, "Still Cleaning Up: 30 Years After the Chernobyl Disaster," The Atlantic, 4 Apr 16.