Japan’s Nuclear Crisis

The 8.9 earthquake, and subsequent tsunami, that rocked Japan on March 11, 2011 have lead to severe damage at Tokyo Electric Power Co.’s Fukushima Daiichi<!–[if supportFields]> XE “Fukushima Daiichi” <![endif]–><!–[if supportFields]><![endif]–> nuclear power plant. The problems at Fukushima Daiichi arose due to the failure of the cooling system and the significant loss of water from the cooling pools.  As authorities continue to work to reestablish the cooling system, Japanese citizens wait anxiously.  Twenty-five years after the meltdown of Chernobyl-4, it seemed that the world was beginning to accept the importance of nuclear power for providing a clean and reliable source of energy in the future.  However, the situation in Japan has awakened our fear of all things nuclear.  Critics argue that the same thing that is happening at Fukushima Daiichi could happen in the U.S. and that the country would be wise to halt all nuclear energy production.  Other, conversely, argue that the Fukushima accident could create a chance for the nuclear industry to “reboot” and look for innovative technologies that may decrease the risk associated with traditional solid-fuel uranium reactors.—Carolyn Campbell

 
          The core of a traditional nuclear reactor, such as the Fukushima Daiichi<!–[if supportFields]> XE “Fukushima Daiichi” <![endif]–><!–[if supportFields]><![endif]–> reactor, contains both water and fuel rods made of zirconium and pellets of nuclear fuel, usually uranium, which set off a controlled nuclear reaction.  This reaction heats the water, creating high temperature steam, which powers a turbine<!–[if supportFields]> XE “turbine” <![endif]–><!–[if supportFields]><![endif]–> and generates electricity.  A meltdown occurs when the core gets too hot, causing the fuel rods to crack and release radioactive gases.  In the worse case scenario, the fuel pellets melt and fall onto the reactor floor, where they can eat through the protective barriers and eventually reach the surrounding environment.  In Japan, the reactors are designed to turn off automatically in case of a disaster, with the aim of preventing a meltdown.  However, even with the plant shut off, nuclear fuel rods continue to generate a huge amount of heat.  In order to cool the fuel, backup generators are meant to pump water into the plant.  These generators failed at Fukushima Daiichi, leading the fuel rods to boil off remaining water and become partially exposed.  If left exposed for long enough, the fuel rods could melt and leak radiation.  In order to avoid this, authorities are pumping seawater into the reactor to cool the fuel rods.  However, salt buildup on the fuel rods can allow them to heat up more by blocking water circulation between the fuel rods, and, in the worst case, can eventually lead to a meltdown.  Additionally, workers have released built-up gases containing some radioactive material into the atmosphere in order to ease pressure inside the plant. 
          The problems at Fukushima Daiichi<!–[if supportFields]> XE “Fukushima Daiichi” <![endif]–><!–[if supportFields]><![endif]–> have aroused concerns of similar disaster occurring in the United States.  While some critics argue that the US should halt all nuclear power generation others suggest that the accident in Japan lends a chance to recreate the nuclear industry.  It has been suggested in recent years that the solid-fuel nuclear reactors, like the ones in Japan, are an outdated technology and should be replaced by a safer and cheaper kind of nuclear energy. According to Matt Ridley of the Wall Street Journal, thorium has many advantages as a nuclear fuel.  There is four times as much thorium in the world as there is uranium; it is easier to handle and to process; it “breeds” its own fuel by continuously creating uranium 233; it can produce 90 times as much energy from the same quantity of fuel; no plutonium is produced by its reactions; and it generates much less waste, with a much shorter half life.  Neutrons are needed for a thorium reactor to run and can be supplied with a particle accelerator or uranium 235.  Both options are highly controlled and are relatively safe.  Additionally, the fuel in a thorium reactor cannot melt down because it is already molten, and reactions slow as it cools.  Whether it leads to new innovations or a general shift away from nuclear power, the disaster at the Fukushima Daiichi plant will undoubtedly alter the future of nuclear energy generation.  

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