Although nuclear energy has come a long way since it was first developed, the technologies we use are still never 100%. We have experienced multiple nuclear disasters in past decades and although some have been minor accidents others have been detrimental to the environment and the communities surrounding the affected areas.
The largest nuclear disaster in history was undoubtably Chernobyl in 1986. The meltdown was caused by plant operator error combined with a flaw in the design of the reactor. The meltdown was caused by an unexpected power surge, and when an emergency shutdown was attempted, an exponentially larger spike in power output occurred, which led to a reactor vessel rupture and a series of steam explosions. Eventually the reactor ignited when exposed to stored chemicals causing radioactive material to be expelled into the air.
The accident destroyed the Chernobyl 4 reactor, killing 30 operators and firemen within three months. One person was killed immediately and a second died in hospital soon after as a result of injuries received. Acute radiation syndrome (ARS) was originally diagnosed in 237 people on-site and involved with the clean-up and it was later confirmed in 134 cases. Of these, 28 people died as a result of ARS within a few weeks of the accident.
The explosion contaminated thousands of square miles reaching all the way from Russia to Belarus.
The second largest nuclear disaster in history happened in 2011 in Fukushima, Japan. The disaster was caused by a massive earthquake of magnitude 9.0 on March 11th 2011. In Fukushima, when the victims had been working on cleaning up their surroundings after the earthquake and tsunami, a large explosion occurred at the Fukushima Daiichi nuclear power plant and the piping facility in the building, the facilities for the external power supply and backup power were destroyed. The next day, 12th in the early morning, the leakage of radioactive materials had been found in front of the main gate of the nuclear power plant. The steam was filled in the building by the core melt down caused by the dysfunction of the cooling system.
Lots of radioactive materials were scattered in the environment to reduce the internal pressure and the hydroponic explosions of the nuclear reactors. Based on the data from TEPCO, the amount of radioactive materials released into the air were 770,000 tera Bq until beginning of Apr.11,2011, and still going on with high risk. It is said that this amount is about 20% of the Chernobyl accident. On April 12th, 2011, Nuclear and Industrial Safety Agency raised the rate of the accident from level 5 to the level 7, the same level as Chernobyl.
The Map below shows the spread of the nuclear waste according to wind patterns and ocean currents.
The real question is: how can we make this growing energy source safer? There are clearly very dangerous repercussions if this energy is not managed correctly and many people are in favor of outlawing it entirely. There are many risk factors associated with nuclear energy use such as waste disposal and proper protection from radiation.
According to the International Atomic Energy Agency (IAEA), a nuclear security plan can be achieved through “prevention, detection of and response to malicious acts, and Information coordination and analysis.” There are very imporant aspects to consider when choosing nuclear energy. The first is the potential hazard to the local community and choosing appropriate geological locations to construct the power plants. Another is a strong regulatory infrastructure to promote harmonized safety standard. To increase the safety for not only those who work on the site but also live nearby a power plant must be responsible for the disposal of their nuclear waste – either to be buried in deep saline formations or be recycled back into the reactor as currently done by France and Japan
Resources:
http://fukushimaontheglobe.com/the-earthquake-and-the-nuclear-accident/whats-happened
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html