Description of Disaster: On April 25th-26th 1986, the world’s greatest and most destructive nuclear power accident occurred, Chernobyl. The Chernobyl accident happened in the USSR (presently Ukraine), located 80 miles north of Kiev. Chernobyl had 4 reactors, while testing the 4th reactor numerous safety procedures were ignored. At 1:23am the chain reactor became out of control and started to spit out fireballs, which blew off the reactor’s concrete/steel lid. 30 people died immediately, the surrounding 20 mile radius had to be evacuated due to high radiation levels.

Cause of Disaster: The RBMK reactor used at Chernobyl suffers from instability at low power levels, thus leading to uncontrollable sudden surges of power. The features built in to stop these instabilities are:

• Water is a better coolant than steam
• Water absorbs neutron while steam does not

Only 6-8 rods were used in the test, a standard requirement is 30 rods to retain control. The emergency cooling system was shut off. The communication between the team responsible for the test and the team working the reactor was not sufficient.

Engineering Improvements: Installing more binding between the lid and the reactor might have prevented the spread of radiation. The emergency cooling system should not have been able to turn off; this could have prevented the explosion in the first place. There were not too many engineering problems with Chernobyl; most of the errors were human fault.