Stanford nuclear expert gives three lessons, five years after Fukushima disaster
An expert on nuclear materials at Stanford University says we need to reassess natural disaster risks, acknowledge the links between nuclear energy and renewables and rethink the language used when referring to these disasters.
According to Rodney Ewing, the Frank Stanton Professor in Nuclear Security and senior fellow at the Centre for International Security and Cooperation in the Freeman Spogli Institute, the reason for the nuclear meltdown was not an accident as mentioned in the media and various scientific papers, but rather a failure of the safety analysis.
In case of a powerful earthquake, power plants automatically shut down their reactors. In addition, generators start to work immediately to sustain the circulation of coolant over the nuclear fuel to prevent heating and possible meltdown. However, at Fukushima the tsunami flooded the diesel engines which were installed low and close to the coast, cutting off the power supply to the cooling system. The poorly placed generators lead to the catastrophic tragedy at Fukushima. “This is why when I refer to the tragedy at Fukushima, it was not an accident,” said Ewing.
“The Japanese people and government were certainly well acquainted with the possibility of tsunamis.”
His second lesson is to rethink the meaning of ‘risk’. He says referring to an earthquake or tsunami as a rare event, while geological records show it has happened and will happen again, reduces its sense of urgency to be prepared in advance.
“It can be that the risk analysis works against safety, in the sense that if the risk analysis tells us that something’s safe, then you don’t take the necessary precautions,” he said. The assumption that the reactors were safe during an earthquake, prevented further anticipation in case of a tsunami.
He said in the case of the reactors at the Fukusima Power Plant, one should not assess the risk of one of its reactors being hit by a tsunami. But must assess the risk of a tsunami hitting any one of the reactors over its lifetime. In the latter the probability of a reactor being hit by a tsunami increases, especially if the geological record for the evidence of tsunamis are also considered.
The third lesson learned, according to Ewing, is the strong link between nuclear energy and the future of renewables. Since the Fukushima tragedy Ewing has noticed the continuous effect of the Fukushima disaster throughout the nuclear industry. He believes this impact in turn will greatly effect the future of renewable energy resources.
The Nuclear Commission in the United States has required all reactor sites to reassess their risk from natural disasters, especially in the central of the United States. However, this reaction was not globally shared.
“In countries like Germany and Switzerland, the Fukushima tragedy was the last straw,” Ewing said. “This was particularly true in Germany, where there has always been a strong public position against nuclear power and against geologic waste disposal. Politically, Germany announced that it will shut down its nuclear power plants.”
Ewing says Germany is a great example, since it is a technologically advanced country trying to avoid the use of nuclear energy. At the same time it is trying to reduce its carbon emissions. This move towards renewable energy sources will be costly, but it’s a price many Germans are willing to pay.