Fukushima – Japan’s Worst Nuclear Disaster

On the 11th of March 2011, an earthquake struck Japan. This was followed by a tsunami and the resulting damage caused a leak at the Fukushima nuclear plant. While the 3 working reactors went offline following the earthquake, the emergency generators used to cool them were disconnected as a result of the damage and the reactors began to overheat. The world watched on in horror as it seemed another Chernobyl scale nuclear disaster was imminent.

The Fukushima Daiichi Nuclear Power Plant in 2007.

An exclusion zone 20 km wide was set up and people were evacuated. Many of the towns surrounding the plant remain abandoned. Reports indicate that the nuclear material released was a tenth of that which made it into the atmosphere following the Chernobyl disaster. Both events have many similarities and like Chernobyl, the surrounding area will be uninhabitable for a long time.

The accident was started by the Tōhoku earthquake on Friday 11 March 2011. The 9.1 magnitude earthquake triggered safety detectors at the Fukushima Daiichi Nuclear Power Plant and the fission reactors were automatically shut down. This caused power to switch to the emergency diesel generators, critical to pump coolant through the reactor cores which continues to produce decay heat even after the fission reactors shut down. The earthquake was followed by a 14 metre (16 foot) tsunami which flooded the plant’s basements and knocked out the emergency generators. Electrical batteries continued to produce enough power to circulate coolant but they ran out the following day. The water pumps stopped, leading to meltdowns in reactors 1, 2 and 3.

A building damaged in the earthquake in an area later evacuated because of the nuclear disaster.

Tokyo Electric Power Company (TEPCO), the owners of the nuclear power plant, desperately tried to restore power to the cooling systems. They were thwarted by a number of hydrogen explosions which injured sixteen workers over a number of days and caused extensive damage to the roofs of reactors 1 and 3. The emergency response teams continued working tirelessly to restore power to the pumps by connecting them to the main grid. The first came back online on 17 March, followed by two more on 20 March. At this stage, however, a severe amount of damage had already been done.

In the hours after the earthquake and tsunami, The Nuclear and Industrial Safety Agency of Japan (NISA) checked all 55 nuclear reactors in the country and found no radiation beyond the walls of any of the power plants. Within a few hours, reactor 1 at Fukushima was in danger of overheating and everyone within a radius of 3 kilometres (1.9 mi) radius was ordered to evacuate. TEPCO began pumping water into reactor 1 in an effort to cool it down. This caused a release of steam from inside which carried a small amount of radioactive materials into the air. The evacuation zone was extended to 10 km (6.2 miles) and then later to 20 km (12.4 miles). On 25 March, the evacuation zone was extended to 30km (18.6 miles). 154,000 residents were evacuated from the area surrounding the plant.

On Sunday 13 March, the Japan Atomic Energy Agency declared the accident at Fukushima a level 4 (an accident with local consequences) on the International Nuclear and Radiological Event Scale. Things continued to deteriorate as the hydrogen explosions began to cause massive damage. The reactor 3 building exploded and reactor 2 began to meltdown. A fire in reactor 4 caused radiation to spike and TEPCO evacuated all workers as the situation worsened.

The damage to reactors 3 (left) and 4 (right).

For a number of days after, helicopters dropped water on reactors 3 and 4 at Fukushima. Firefighters were called in from Tokyo and Osaka to help spray water into the power plant. The US Navy even sent a barge with 500,000 gallons of fresh water to assist in the effort.

During and after the disaster, large amounts of water contaminated with radioactive isotopes was released into the Pacific Ocean. An ongoing intensive cleanup program to decontaminate affected areas and decommission the plant will take 30 to 40 years. Estimates of radioactivity released ranged from 10–40% of that of Chernobyl. The Fukushima Daiichi incident was raised to a 7 rating on the International Nuclear Event Scale, indicating an accident causing widespread contamination with serious health and environmental effects. Chernobyl is the only other level 7 disaster recorded.

The aftermath of the disaster.

On 1 April 2012, the evacuation order for the villages Kawauchi and Tamura was lifted and the exclusion zone was reduced to 20 km (12.4 miles) from the nuclear power plant. The evacuation order for parts of the city of Minamisoma was lifted on 15 April 2012 and the entire city apart from a section in the west was reopened on 12 July 2016.

A sign warning of a radiation hotspot near Fukishima.

A deserted street within the exclusion zone.

If you’re interested in some really in-depth reading about the Fukushima Daiichi nuclear disaster, Anne Kaneko has a very interesting blog about it. Well worth a read at annekaneko.blogspot.com –

My internet is working at last so I can reply. I am alright but it has been a scary day.

I was just leaving a conference when it happened. The building roared and the cars were bouncing around in the car park. I crouched on the ground. It went on for a very long time. Very scary. And it was snowing hard and windy too. I drove like mad back to work (about 15 mins), along the way car showrooms with the glass windows smashed, walls collapsed. Everyone was out in the yard. No one hurt, thank god. We stopped production and sent everyone home. The main machine not working. Needs welding tomorrow – if we can get someone to do it. Had to wait till we could account for all the salesmen. Three out in Iwaki, two had to abandon their cars and head for higher ground. They saw the tsunami. They’re back now though safe and sound.

I walked home. The stone lanterns at the shrine smashed to the ground, a parked car hit by debris. The pavement ominously cracked and raised as I approached my apartment. Our ancient office building had stood up quite well and I really wasn’t prepared for the damage in my upmarket apartment. The residents had organised a ‘welcoming party’ and a young man went with me up the the stairs to the 7th floor. Debris everywhere. My door opened but won’t shut. I grabbed my valuables and went down to join some of the other residents to watch telly in the caretaker’s office but eventually decided to come back up to the apartment. I have electricity, TV, heating and I’ve cleaned up the worst of the mess. Half my crockery is smashed. So I’m OK. But the shocks continue and I won’t be sleeping tonight. The scariest thing was the lack of information and phone communication. I still can’t use my mobile. I was getting calls from England but none from Japan and unable to make any. I still don’t know how things are in our Sendai office.

Also, the TV is full of reporters telling us what’s happening but there’s a distinct lack of experts telling us what to do. I guess they’re busy.The news is horrific, hundreds dead in the tsunami, Kasen-numa (where we holidayed once when Takeshi was small) ablaze.

The economic toll will be huge. For starters, how are we going to get the 120 doors in this apartment alone fixed? And what do I do until it is fixed?

Watch this space.

Thanks for your concern

Anne