Image: [Maksym Yemelyanov] © 123RF.com

A decade has passed since the Great East Japan Earthquake, and the name Fukushima was etched into history. But few people know the truth of what happened.

The phrase; ‘the lessons learned from Fukushima’ is well-known. So how do people implement them if they don’t know what happened?

It was after lunch on 11 March 2011 that a giant earthquake occurred 72km off the Oshika Peninsula in Japan. It registered 9.0 on the Richter Scale, the largest earthquake ever recorded in Japan.

The undersea ground movement, over 30km down, lifted up a huge volume of water, like a hill. Meantime the ground shockwave travelled towards the land at high speed. It struck Japan and shook the ground for six terrifying minutes.

The shock wave travelled under 11 nuclear reactors, including two separate Fukushima complexes; Fukushima-Diani and Fukushima-Daiichi, where Daini means ‘Complex 1’ and Daiichi; ‘Complex 2’. All 11 reactors shut down, as they were designed to do, and no doubt all the reactor operators breathed a great sigh of relief.

But the seawater was still travelling. As the water ‘hill’ entered more shallow water, nearer the land, it was lifted up into a towering wave as high as 40m in places.  

Then some 50 minutes after the earthquake the tsunami struck Fukushima-Daiichi. Some kilometres away when the water struck the Fukushima-Diani complex it was only 9m high, which was not as devastating as at Daiichi. Diani did not make it into the news.

The water jumped the protective sea walls at Fukushima-Daiichi. The sighs of relief from a half-hour before were short-lived.

The tsunami swept up to 10 kilometres inland, washing away buildings, roads, telecommunications and power lines. Over 15,000 people were killed, mainly by drowning.

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Fukushima chain reaction

Although all the nuclear reactors had shut down, the reactors were still very hot and needed residual cooling for many hours after the fast shutdown.

A nuclear reactor has pumps which pump water through it until cool. But the Fukushima electrical pumps failed because the tsunami had washed away the incoming electricity power lines.

So the reactor switched to diesel-pump cooling, but the water had washed away the diesel supply, so the diesel pumps only worked for a short while. So they switched to emergency batteries, but the batteries were never designed to last for days.

The hot fuel could not be cooled, and over the next 3 or 4 days, the fuel in three reactors melted, much like a candle melts.

The world media watched, and broadcast the blow-by-blow action. The Japanese authorities started to panic under the international spotlight.

They progressively ordered the evacuation of 160,000 people living around Fukushima. That was a mistake.

As days and weeks passed it materialised that not one single person was killed by nuclear radiation. Not one single person was injured by nuclear radiation either. Now, a decade later, there is no sign of any longer-term radiation harm to any person or animal.

The cumulative lessons

One of the lessons learned from Fukushima is that a huge amount of nuclear power can be struck by the largest earthquake and tsunami on record and nobody gets harmed by nuclear radiation.

Another lesson learned has been that the evacuation order, issued too hastily, did kill and harm people.

The Director-General of the World Nuclear Association (WNA) Dr Sama Bilbao y León said: “The rapidly implemented and protracted evacuation has resulted in well-documented significant negative social and health impacts. In total, it is thought to have been responsible for more than 2,000 premature deaths among the 160,000 who were evacuated. The rapid evacuation of the frail elderly, as well as those requiring hospital care, had a near-immediate toll.”

She went on to add: “When facing future scenarios concerning public health and safety, whatever the event, it is important that authorities take an all-hazards approach. There are risks involved in all human activities, not just nuclear power generation. Actions taken to mitigate a situation should not result in worse impacts than the original events.

“This is particularly important when managing the response to incidents at nuclear facilities where fear of radiation may lead to an overly conservative assessment and a lack of perspective for relative risks.”

So a decade later we can contemplate the cumulative lessons learned. They are that nuclear power is far safer than anyone thought. Even when dreaded core meltdowns occurred, although the reactors were wrecked, no people were harmed by radiation.

We have even learned that for local residents it would have been far safer to stay indoors in a house than to join the evacuation. We have also learned that governments and authorities must listen to nuclear professionals and not overreact, even though TV cameras look awfully close.

Fukushima produced some valuable lessons. Governments and the public should learn from them.

Dr Kelvin Kemm is a nuclear physicist and is CEO of Stratek Business Strategy Consultants, a project management company based in Pretoria. He carries out business strategy development and project planning in a wide variety of fields for diverse clients.