An accident with respect to a complex system can be described as an“unexpected interaction of multiple failures". A complex system as exhibiting its complex interactions is highly vulnerable to normal accidents. The complexity can either be technological or organisational.
Material or component of a system is often structured into tightly couple sub system. Hence, a fault in one of the component may coincide with fault in some other component creating a cascading effect of faults and revealing certain internal connections, neutralising redundancies and bypassing firewalls which will thus result into complete failure for which generally no organisation prepares.The technology involved becomes complex enough and so tightly coupled that the accidents turn inevitable. Hence, these are appended with the term ‘normal’ and are also called‘Normal Accidents ’. The increasing complexity in highly technological system like nuclear reactor, aviation, defence is increasing the vulnerability of disastrous accidents. Increasing human involvements to bring the technological advancements are sure to encourage the development of even more complex system which in turn increases the chances of such mishaps. An example of such normal accident can be quoted, back from March 28, 1979 ‘Three Mile Island Accident’ in USA. It was one of the most disastrous accident that USA had to face in its commercial nuclear power plant history.
The Three Mile Island nuclear power plant in USA was struck by a cooling malfunction that caused a part of the core to melt in its second reactor. The TMI-2 reactor as it is called so was destroyed. The initial cause of the accident occurred eleven hours before the actual incident during an attempt by operators to fix a blockage in one of the eight condensate polishers. Some radioactive gas was continuously being released for a couple of days after the incident but not enough to cause any casualties of local residents. There were no severe bad health effects either.Such accidents usually begin with a mechanical or other technical mishap and then moves out of control through a series of technical cause-effect chains because the operators involved could not stop the cascade. According to Charles Perrow, the author of Normal Accident Theory, "some technologies, such as nuclear power, should simply be abandoned because they are not worth the risk". This was the conclusion he reached after dealing with the topic in depth. It is worth mentioning that may be such accidents are not at all predictable but still to an extent they are preventable.
BIBLIOGRAPHY
Perrow, Charles. Normal Accidents: Living with High-risk Technologies. New York: Basic, 1984. Print.
"WNA in Japanese:." World Nuclear Association. 2014 World Nuclear Association, 1 Mar. 2001. Web. 17 Oct. 2014.
