Industry Will Improve From Fukushima Lessons
17 Jun, 2011
[Approx. Read Time: 2 minutes]
While no one knows how the on-going Fukushima nuclear accident will affect the nuclear industry, one thing is certain: nuclear power generation will become even safer. One of the greatest strengths of the nuclear industry is its safety culture. According to the international nuclear safety advisory group, “Safety Culture is that assembly of characteristics and attitudes in organizations and individuals which establishes that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance.” 
Safety Improvements After Three Mile Island
This safety culture can best be seen by the industry’s response to nuclear accidents. The most significant of which, for the U.S. nuclear energy industry, was the 1979 accident at three mile island unit 2. Since that accident there have been improvements in regulation, emergency readiness, to plant systems, and in severe accident management . The upgrades and improvements have increased safety and reduced unplanned downtime considerably.
A major decrease in every measurable type of nuclear related incident can be seen in the years following the accident. Also, the severity of incidents decreased. The United States Nuclear Regulatory Commission fact sheet on plant safety performance shows that the number of significant events, safety system actuations, and automatic scrams while critical have all dropped to about 10% of their 1985 values. While these improvements are great, they do not reduce the possibility of Fukushima type accidents. The Three Mile Island accident was caused by equipment malfunction and exaggerated by human error, on the other hand, the Fukushima accident was caused by a 9.0 earthquake and the resulting tsunami.
What Three mile island did for plant safety, Fukushima will do for severe accident consequences.
Due to the 2011 Tohoku earthquake and tsunami, at least ten nuclear reactors experienced beyond design basis events. Three of the reactors were not running at the time and the other seven automatically scrammed due to the earthquake. The earthquake exceeded the design basis of three reactors and the tsunami exceeded the design basis of all ten. Two reactors, which were operating at the time, experienced both a beyond design basis earthquake and a beyond design basis tsunami. Three of the reactors suffered at least a partial meltdown. One major difference between the Fukushima nuclear disaster and previous reactor problems is that the Fukushima disaster was initiated by an unplanned event.
The result of the Three Mile Island nuclear accident was to reduce the possibility of an accident due to an incident that occurs as a result of normal operation. Similarly, one result of the Fukushima nuclear disaster will be to reduce the consequences of a beyond design basis event. Regulators worldwide have started stress tests and are reviewing operating plants for safety in light of these events.
Results of the first safety reviews are now available. The observations found during these reviews will help to strengthen nuclear safety. Improvements to equipment, training, inspections, and procedures are being implemented. These actions will assure that in the future, the consequences of unplanned events at nuclear plants will be less than they were before.
 INTERNATIONAL NUCLEAR SAFETY ADVISORY GROUP, Safety Culture, Safety Series No. 75-INSAG-4, IAEA, Vienna (1991).  http://resources.nei.org/documents/japan/FactSheet_US_Nuclear_Plant_Enhancements_4-4-11.pdf