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Tuesday, March 15, 2011
Nuclear power in disarray
Damage beyond imagination is unfolding in the wake of the massive earthquake that hit Japan on March 11. More than 5,000 people are confirmed dead or missing, and the death toll is expected to reach into the tens of thousands. In the Miyagi Prefecture town of Minami Sanriku alone, around 10,000 people are unaccounted for.
The quake, whose magnitude was upgraded by the Meteorological Agency from the original 8.8 to 9 — the strongest earthquake ever recorded in Japan — together with the ensuing tsunami forced 550,000 people mainly in prefectures along the Pacific coast of the Tohoku region to evacuate. The quake and tsunami destroyed some 50,000 structures. The destruction wrought by the tsunami alone is unknown at this point, but its severity can be gauged by two examples: It inundated more than 80 percent of the urban area of the city of Rikuzen Takada, Iwate Prefecture, destroying some 5,000 houses and buildings. In the city of Minami Soma, Fukushima Prefecture, the tsunami obliterated some 1,800 houses and buildings.
The public sector must step up its efforts to assist those affected by the disaster. In Miyagi Prefecture alone, as of Sunday night, some 14,000 people were stranded in locations such as schools, hospitals, hotels that are inaccessible by road. Helicopters should be utilized to provide water, food, medicine, blankets and portable toilets to these people, and of course, the same supplies should be provided by conventional means to those sheltering in evacuation sites. Counseling should also be provided to quake and tsunami victims who are suffering from mental trauma.
The quake also damaged several nuclear power reactors. Once the reactors automatically shut down following the quake and if normal electrical power supplies are cut off, diesel generators are supposed to kick in to power an emergency core cooling system to prevent meltdown of the nuclear reactor. Unfortunately, the diesel generators were swamped by the tsunami and failed. This opened the door to meltdown, which creates the potential for radioactive materials to be released into the environment — a highly dangerous scenario that people in Japan have long feared.
The most serious situation — meltdown — developed in the No. 1 and No. 3 reactors at Tokyo Electric Power Co.'s No. 1 Fukushima nuclear power plant on the Pacific coast. Radioactive isotopes of cesium and iodine were detected near the No. 1 reactor. These isotopes are produced in the fission process of uranium nuclear fuel. At one point, radiation reached 1,015 microsieverts per hour, equivalent to a level of radiation a human is allowed to be exposed to over one year. It was confirmed Saturday afternoon that the nuclear fuel inside the reactor core partially melted.
Two explosions took place at the two reactor sites after hydrogen that formed inside the reactor core leaked from the primary containment structure's piping and reacted with oxygen in the air, however, the reactor pressure vessel and the primary containment structure remain intact. In a desperate move to lower the temperature inside the reactor pressure vessels, TEPCO injected sea water into the reactor cores. On Monday night it was feared that meltdown might be occurring in the No. 2 reactor due to a large loss of coolant.
These events have led the government to declare a "nuclear emergency situations" for the first time ever, destroying the credibility of the claim by the government and electric power industry that nuclear power generation is safe. On Sunday alone, some 180,000 people living within a 20-km radius of 1F were evacuated. Twenty-two of the evacuees were exposed to radiation.
The events that have unfolded at the nuclear power plants in Fukushima make it clear that the government and the power industry have failed to implement necessary safeguards. For example, why were the back-up diesel generators at 1F placed in a location where they would be vulnerable in the event of a tsunami, and why wasn't a policy of double-redundancy enforced in which a reliable back-up power-generation system existed for the back-up diesel generators? Considering the potential for disaster, which has now become a grave reality, it is mind-boggling that such flawed policies were in place.
Japan's nuclear power generation policy must be strictly reviewed. The government and power companies should thoroughly inspect the nation's 54 power reactors and implement upgrades as needed to ensure multiple redundancies in safety systems. Finally, the government should continuously update the public with accurate information as the current situation develops.