Nuclear reactors Fukushima Daiichi

You don t need to be reminded of the most recent nuclear accidents, principally Fukushima Daiichi in Japan in 2011. After the Three Mile Island accident in the late 1970s, the U.S. Atomic Energy Commission developed WASH 1400, The Reactor Safety Study. The WASH 1400 report laid the foundation for the use of probabilistic risk assessments (called probabilistic safety assessments in Europe). According to Henley and Kumamoto (1991), probabilistic risk assessment involves studying accident scenarios and numerically rank[ing] them in order of their probability of occurrence, and then assess[ing] their potential consequence to the public. Event trees, fault trees, and other risk-consequence tools are applied in developing and studying these scenarios. These techniques are extremely useful for the engineer but very expensive. The nuclear industry has been the leader in probabilistic safety analyses. 

On March 11,2011 a 15-meter tsunami off the coast of Japan struck the Fukushima Daiichi nuclear power plant and disabled the power supply and cooling system of the nuclear reactors since the back-up systems were located almost 10 meters below the level of the tsunami. ... 

The Fukushima Daiichi nuclear power station consists of six Boiling Water Reactors (B WRs) designed by General Electric (GE), built by GE, Toshiba and Hitachi, and aU operated by the Tokyo Electric Power Company (TEPCO). The six Fukushima Daiichi reactors were Mark One GE BWRs, which began generating electricity in 1970,... 

According to the European Nuclear Society, as of the year 2012, there were 435 nuclear power plants operating around the world. With an installed electric net capacity of about 368 GW, these reactors were running in 31 countries. The country with the largest nuclear capacity is the United States with 104 power reactors followed by France (58), Japan (50, though by May 2012, all of these had been temporarily taken out of commission because of concern over the Fukushima Daiichi nuclear plant accident), and the Russian Federation (33). As of 2012, there were 63 nuclear power plants with a total installed capacity of 61 GW under construction in 15 countries. 

Atoms with the same number of protons but different numbers of neutrons in their nuclei are called isotopes. They are chemically identical atoms of the same element but have different masses and may differ in their nuclear properties. Some isotopes are radioactive isotopes or radionuclides, which have unstable nuclei that give off charged particles and gamma rays in the form of radioactivity. Radioactivity may have detrimental, or even fatal, health effects a number of hazardous substances are radioactive and they can cause major environmental problems. The most striking example of such contamination resulted from a massive explosion and fire at a power reactor in the Ukrainian city of Chernobyl in 1986. A more recent episode of radionuclide contamination took place as the result of the catastrophic March 11, 2011, earthquake and tsunami followed by hydrogen gas explosions that destroyed four reactors and exposed spent fuel rods at the Fukushima Daiichi Nuclear Power Plant in Japan, requiring the evacuation of thousands of nearby residents. 

Before the meltdown at the Fukushima Daiichi power plant. Japans energy policy was to expand nuclear power so that over 50 percent of its electricity would come from nuclear plants by 2030. Japan had planned to build fourteen more nuclear reactors, but that plan has changed. Instead, Japan is now looking at developing renewable energy resources like wind turbines, solar power, and biomass. 

It is obvious that an optimal solution is often not achieved such as the UK public rejection to GDF and the Fukushima nuclear accident have shown. Fukushima Daiichi reactor accident is an example... 

Western European Nuclear Regulators Association WENRA. 2013. WENRA safety reference levels for existing reactors, update in relation to lessons learned from TEPCO Fukushima-Daiichi accident, November 20, 2013. 

Figure 1.21 Number of nuclear power reactors of the world put into commercial operation versus years and age of operating reactors as per March 2015 (Nuclear News, 2015). Five reactors have been put into operation in 1969 (ie, they operate for mote than 47 years). It is clear from this diagram that the Chernobyl NPP accident had tremendous negative impact on the nuclear power industry that lasted for decades. We currently have additional negative impact from the Fukushima Daiichi NPP accident.

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