Ōkuma and Futaba were once fairly typical Japanese towns. Today, however, their streets are practically silent. Once-busy shops, offices, schools and homes stand empty. Weeds grow through cracks in the pavements, and over the abandoned train tracks.
This is because of what stands between these two towns; the Fukushima Daiichi nuclear power plant.
When you take into consideration the fact that Japan was the only country to ever suffer an atomic bomb attack, it may be surprising to learn how thoroughly they embraced nuclear power in the following decades. Their first nuclear power station, the Tōkai Nuclear Power Plant, was commissioned in 1966; by the beginning of 2011, 30% of the country’s power was nuclear generated, and with plans for new construction this was expected to rise to 40% by 2017.
The Fukushima Daiichi nuclear power plant,operated by the Tokyo Electric Power Company or TEPCO, was one of those expected to expand. Built on the east coast of Japan, between the towns of Ōkuma and Futaba in Fukushima Prefecture, it lay approximately 140 miles or 225km from the capital city, Tokyo. Construction originally began in 1967; the first reactor was commissioned in 1971, and by 1979 there were six reactors online, their combined capacity making it one of the 15 largest nuclear power plants in the world. Two new reactors were supposed to begin construction in 2012 and 2013, to come online in 2016 and 2017.
Reactors 1 to 4 were built in a line along the coast on the side closest to Ōkuma; reactors 5 and 6 were built a little way north of them, closer to the Futaba side of the plant. They were controlled in pairs from three control rooms. The reactor buildings sat on a bluff about ten metres above sea level; below them, about four metres above sea level, were the emergency seawater pumps and seawater inlets.
Aerial view in 1975. On the left, Units 4,3, 2 and 1. On the right, Unit 5 and Unit 6 under construction. Source: Wikimedia Commons
On Friday the 11th of March 2011, only reactors 1, 2, and 3 were operating; 4, 5, and 6 were shut down for maintenance.
As detailed in the previous episode, a massive earthquake struck that afternoon at 2:46pm; the epicenter was less than 50 miles, about 75 km, from Fukushima Daiichi.
Masao Yoshida was the superintendent of the power plant. The quake struck while he was in his office, and for five minutes all he could do was cling to his desk and wait for the shaking to stop. When it did, he made straight for the plant’s emergency response centre or ERC, which was situated in a quake-proof building completed only eight months before.
In the control room for reactors 1 and 2, shift supervisor Ikuo Izawa similarly had to hold onto his desk; some of the operators grabbed handrails by the control panels, others simply sat on the floor because, for the moment, there was nothing else they could do.
Source: Wikimedia Commons
As soon as the shaking began, automatic failsafe systems put the reactors into “scram” – emergency shutdown. This meant that all the control rods would automatically be inserted into the reactor to stop the fission process.
The reactors at Fukushima Daiichi were boiling water reactors; that means that they used the fission process to heat water until it boiled into steam. The steam then turned turbines, which produced the electricity.
Izawa’s deputy, Noboru Homma, yelled a report from the control panel; Izawa couldn’t hear him over the shaking, even though they weren’t far apart, but Homma pointed at the control panel, and the lights showed that both units had gone into full scram as intended.
However, this was only the first step.
Although the chain reaction was halted by the insertion of the control rods, the fuel inside the reactor was still tremendously hot. If it wasn’t cooled down, it would melt – with potentially catastrophic results.
The earthquake had cut the power plant off from the power grid; they had no external electricity coming in to power their equipment. However, they had a backup supply; diesel generators, which quickly kicked in just as expected.
About fifty minutes after the earthquake, the tsunami arrived.
An unnamed worker at the plant later told a Nova documentary, “We were in the middle of dealing with the accident, then all at once the lamps went out. All sorts of alarms were going off; all of those went out. Basically, a station blackout.”
Izawa reported the blackout, referred to as an SBO, immediately to the ERC, but in the windowless control room didn’t know how or why it had happened until one of the operators he’d sent to inspect the reactor buildings burst into the room, dripping wet and yelling, “Yabai! We’re screwed!”
“Apparently, they had heard an incredible noise while in the reactor building and hurriedly decided to turn back, but there were security barriers between them and the outside where the water was gushing through, and they had to fight against flow to get out. The report of water pouring into the building was what really brought us to our senses. Realising that it was a tsunami was what completely cleared my mind.”
The power plant had a seawall to protect it in the event of a tsunami, but like protection in many other places along the coast it was was simply inadequate. When the plant had been constructed, they had estimated any tsunami hitting them would have a height of only three metres. In 2009, this had been revised upwards to six metres, and the barriers had been increased to ten metres.
Source: Wikimedia Commons
The tsunami that struck Fukushima Daiichi was as much as thirteen to fourteen metres high. It overtopped the seawall easily, entirely flooded the lower levels of the power plant – including the basements of the reactor buildings, where the diesel generators were located.
Completely submerged, the generators failed, and the plant was left without power. This didn’t just mean that the equipment necessary to cool the reactors couldn’t be operated; it also meant that all the complex sensors and displays that the operators needed to get data from the reactor were inoperable.
Takeyuki Inagaki, the plant’s maintenance manager at the time, said later,
“It became darker and darker, a terrifying situation, and the operators weren’t sure what was happening. We couldn’t even tell if there was water in the nuclear reactors.”
Whether or not there was water in the reactors was a vital question.
If the fuel remained hot, the water would continue to boil away into steam, and if that steam was not released the pressure inside the reactor would increase. If it got too high, it could explode – like a balloon bursting.
And, if the water boiled away, it would leave the fuel rods exposed; then they would melt. Nuclear meltdown was not something that anybody wanted to contemplate.
Yoshida knew that he had to act quickly.
“My mind should have been panicking. But strangely, while part of my mind was concerned that this could turn into another Chernobyl, the other half was telling me to keep calm and start planning. All those things that had to be done started clicking through my brain.”
He called TEPCO headquarters, who quickly sent out generator trucks, but getting them to the troubled power station would be far from easy. Amidst the devastation of the earthquake and tsunami, the roads were difficult, to say the least.
In the meantime, the operators had to improvise.
They needed power, so they went out into the car park and scavenged batteries from the vehicles they found there. They would then be able to connect a battery to whatever sensor they needed, and note the readings manually.
Yoshida also took steps to call in aid from the fire department. Water was vital to the reactors, and if the worst came to the worst, hoses might be the only way to get it in there.
In the control room, Izawa now had backup from two other supervisors; Katsuaki Hirano and Kikuo Ōtomo. Together, they worked out a plan to construct a supply line and use the pumps of the firefighting system to inject water into the reactors.
This meant going into the reactor building. The first team to approach quickly turned back, since as soon as they approached the doors of the reactor building, their radiation meters went off the scale.
However, the decision was made to go back in. Hirano himself was part of the second team; they successfully navigated the darkened corridors to the fire pump room, in the basement, and confirmed that the fire pumps were working.
The third expedition into the reactor building was vital. There were five valves that needed to be opened, and without power they had to be turned by hand. A team of five, including Hirano and Ōtomo, went in. Izawa had initially wanted to go, but Ōtomo told him to stay in command in the control room.
Hirano said later, “At the time, in Unit 1, and Unit 2 for that matter, we had no idea whether any water was reaching the reactor vessel, so a meltdown could have occurred right while we were working in there. To be honest, it was scary.”
Ōtomo said, “Because of the radiation levels, it was best that we seniors went in and left the youngsters behind. Once we’d made sure we knew where to find the valves on our checklist, we got on our way.”
They got the last valve opened at around eight o clock. Later, it was estimated that the fuel rods in unit 1 had started to melt at around half past seven.
At just past seven, the Prime Minister’s office announced the declaration of a nuclear emergency. However, they were careful to avoid panic:
“Note: At present, no impacts from radioactive materials upon the area outside of the facilities have been confirmed. Consequently, at the current time, residents of the area targeted under this declaration and other persons in the area do not need to take any special actions immediately. Persons affected are asked not to begin evacuation hurriedly but rather to be on standby in their homes or current locations and access the latest information via emergency public broadcasting services on wireless radio, TV, the radio, and so on. Once again, radioactivity is not in fact leaking out of any nuclear facilities. The public is asked to remain calm and stay well-informed.”
An evacuation order followed two hours later, at 9pm; everyone within 3km of the power plant was told to leave, and those within 10km to stay at home, in case the evacuation area needed to be expanded later.
Namie, one of the evacuated towns. Source: Wikimedia Commons
At the power plant, they worked through the night to clear away debris from the earthquake and tsunami so that the fire engines could get into place. Around four the next morning, they were able to start injecting water – but they only had one operable fire engine on site. Further fire engines, supplied by the Japanese Self Defense Forces, would arrive the next morning.
At some time past ten o’clock that first night, Motohisa Ikeda, deputy head of the Ministry of Economy, Trade and Industry (known as METI) arrived to set up a Local Nuclear Emergency Response Headquarters in Ōkuma. Working with a single satellite phone, he tried to get a clear idea of what was happening from the METI inspectors still inside the power plant. However, when he asked them for specific parameters – temperature, pressure, water levels, etc – there was no data.
This is where things start to become rather confusing. Up until this point, the operators at the power plant were just reacting as fast as they could, based on the information they had available. Now, though, politics got involved.
In the early hours of Saturday morning, Ikeda got a call from Tokyo saying that a press conference was being planned, about carrying out a vent.
That meant releasing some of the steam from inside the reactor’s primary containment vessel – not the core itself, but the space around it – to the atmosphere.
As the water inside the reactor continued to boil, it was creating more and more steam, which created more and more pressure. If that exceeded the containment vessel’s capacity, it could explode. Ikeda realised that this would be a catastrophe of an unspeakable scale.
“If the containment vessel were to explode, radioactive material inside would be blasted all over the surrounding area causing terrible contamination. We had to prevent that. If we failed it would be even worse than the worst ever.”
At the same time, releasing steam from inside the containment vessel did mean releasing radiation, and contaminating the immediate area.
“It would have been best if we could avoid the vent, but it was essential to stop the containment vessel from blowing up. So I thought we first had to make absolutely sure that a vent was the only way to resolve the situation.”
Although Ikeda stated that “the decision to execute a vent would have to be made exclusively by the operator, TEPCO,” he also insisted that they collect further data to prove that it was necessary first.
In the control room, Izawa knew that the vent would have to be done by hand; somebody would have to go into the reactor building to turn the valves. He asked for volunteers, again offering to go himself – and again being advised that he should remain in the control room.
There were more volunteers than they needed; Izawa chose the oldest men, partly because their experience made them more familiar with the valves, and partly because their age meant they were less vulnerable to the radiation. They decided who exactly would do what, and got their equipment ready, but they had to wait for permission from the ERC.
Inagaki later spoke of the weight of this moment.
“To go into a pitch-black reactor building with the containment vessel pressure so high, I don’t know if I should say it, but it felt like we were putting together a suicide squad.”
This was when the Prime Minister, Naoto Kan, decided to visit the stricken power plant himself.
Communications issues, and the lack of available data at Fukushima Daiichi, meant that Kan and his advisors had very little idea what was actually going on at the power plant. He had decided that the only way to find out was to go there. Others didn’t agree.
Naoto Kan. Source: Wikimedia Commons
“..even if the PM came to Fukushima, he could attempt to maintain control of the country from there, but land transport and land-line communications were wiped out, and so was pretty much everything else. You could hardly get through to anywhere. Even if he came, he wouldn’t be able to stay in command, and he’d be better informed about the nuclear accident staying at his office in Tokyo. He needed to maintain a broad overall view, and a balanced one, to keep his priorities straight.”
Yoshida and his staff now had to prepare for the PM’s visit; working out where his helicopter could land, how he could get to the ERC without bringing in contamination from outside, and where to get protective equipment for the visitors. This last was a particular sticking point; they were already struggling to find enough equipment for their staff, since things could only be used once and would then be contaminated.
“But as far as preventing the visitors from coming, there was nothing more I could do… I’ve a suspicion that Mr Kan didn’t even realise that he himself could actually get contaminated. I don’t think he had a clue about things like that. He simply wanted to get inside the ERC and hear all about it as soon as possible, so he came. He didn’t deliberately make a nuisance of himself. It was just plain ignorance on his part.”
Upon his arrival, the first thing Kan wanted to know was why they hadn’t already carried out the vent. Fortunately, he seemed to get along well with Yoshida, and accepted the superintendent’s explanations, saying later,
“Nobody had ever tried to explain things to me like that before. He managed to convince me that he knew what was going on, and that was fine with me, so I left him to it.”
With the Prime Minister off again, Yoshida was able to return his attention to the disaster. At nine am, they got word that the local evacuation was complete and they were able to get on with the vent.
Equipped with heavy protective suits, masks and air tanks, the volunteers set off in teams of two to open the valves. The first team succeeded in their task, but the second team encountered such high radiation levels that they were forced to turn back. These two men were close to the legal limit for cumulative exposure, and had to evacuate to the ERC.
Despite the danger, a third team prepared to go in. A route was planned that might expose them to lower levels, and they were prepared to run in order to reduce the time they spent there. However, they were called back shortly after they had left the control room.
At just after three thirty on the afternoon of Saturday, March the 12th, cameras fixed on the Fukushima Daiichi plant caught the terrifying sight of an explosion at Unit 1.
“There was absolutely no warning. Just BOOM! We didn’t know what it was. For a moment, I had a feeling there had been a steam explosion in the pressure vessel and that the whole reactor had gone up.”
Fortunately, this was not the case. Zirconium cladding inside the reactor had been oxidised by the steam, producing hydrogen gas as a result. This had vented out of the reactor vessel and accumulated in the containment building. Once it reached a high enough concentration, it exploded. The containment building was severely damaged, but the reactor vessel itself remained intact. It was bad, but not as bad as it could have been. While some workers had been injured, everyone was still alive.
The next issue they had to deal with was the availability of water to cool the reactors with. Fresh water was limited; however there was plenty of seawater around. Unit 3 had a huge reversing valve pit which had been filled by the tsunami wave, and remained full after it retreated. The firemen were able to drop an intake hose in and use that.
They had just begun when Yoshida got a call from Tokyo ordering him to stop. The Prime Minister’s office had concerns.
The main problem with seawater was that it was corrosive; long-term, it would damage the reactors. The salt from seawater would build up as the water evaporated, and it was suggested that this could conceivably lead to a steam explosion or re-criticality incident.
Soon after that first call, Yoshida received orders from TEPCO headquarters to halt the seawater injection. He announced the order during a video conference – but had already issued separate instructions to his operators to ignore it.
“It’s pretty obvious that with such a huge amount of heat to get rid of, the sea was the only way… We didn’t have anything like the amount of freshwater we would need, so our final conclusion was that cooling by injecting seawater was the only answer. Cooling the reactor was absolutely essential, so it was obviously the only way to go. We’d already reached that conclusion and acted on it, and then they come and tell us to stop!”
Prime Minister Kan would later state that he thought Yoshida’s decision was the right one, and denied that he had interfered.
“At six p.m. on March 12, I personally thought that they would have to go ahead with the seawater injection, but since there were all kinds of aspects to consider, the experts should work it out properly. That was what I intended, from start to finish, and the idea that I did it all because I had some other political objective – there was absolutely nothing like that.”
Kan would later face considerable criticism for his actions, with many saying that he shouldn’t have been so involved in specific steps such as venting or injecting seawater – TEPCO were in charge, and it should have been up to them to make those decisions.
“…the law says that the normal order of things is that the power company, the people who own the operation, should run things. In this case it was TEPCO. But TEPCO couldn’t even supply them with generator vehicles… Their logistics were completely incompetent… So, right from the start, all sorts of things weren’t functioning properly, and we were getting desperate, so, in effect, the PM’s office got on with the job. They keep on and on about ‘interfering’ but I wish they’d take the facts of the situation properly into account.”
On the third day, after Izawa and his colleagues had spent 52 hours straight in the control room, they were finally at a point where they could have rotating shifts, instead of needing everyone on hand. At that point, there were over six hundred people in the quake-proof building, many sleeping in corners whenever they were able.
They were disturbed once more at 11am on the 14th of March. Another explosion rocked the site, this time coming from Unit 3. Again, nobody was killed, but there were further injuries, and debris from Unit 3’s containment building had damaged the fire engines and hoses that were cooling the reactor.
Yoshida allowed two hours for radiation to settle, then ordered an inspection of the damage. They were relieved to establish that it was, again, a hydrogen explosion that had damaged the secondary containment building, not the reactor itself, and that two fire engines were undamaged. That was enough to continue the cooling operation.
Their biggest problems now came from Unit 2; the pressure was so high that they couldn’t inject water until it was released. When the pressure finally went down later that evening, and water injection started, many at the plant felt it was nothing short of a miracle.
That relief was short-lived; the pressure soon began to rise again, and was followed by another blast. This explosion damaged the containment building of Unit 4; this came as a surprise, because it had not been running at the time and was not thought to be at risk. Later analysis would suggest that hydrogen from Unit 3 had vented into Unit 4, and this had caused the explosion.
Units 1-4 after the disaster. Source: Wikimedia Commons
Around this point, Yoshida decided that it was too dangerous to have so many people on-site, since many weren’t essential technical staff. He ordered everyone who was not directly involved in their current operations to leave for Fukushima Daini, their sister site some ten kilometers away.
Somehow, this seems to have been reported to Tokyo as TEPCO planning a complete evacuation of the plant. How this communication error occurred isn’t entirely clear, but at this point it seems to have been par for the course. At close to midnight, the Prime Minister was awoken – he had been sleeping on the sofa in his office.
Later, Kan recalled that moment.
“Ever since the accident began, I’d been thinking about the worst possible case… without anyone there to control the reactors, once one of them gets knocked out, in due course they will all be knocked out. That means the total of ten reactors at Fukushima Daiichi and Daini plants plus their eleven pools of spent fuel rods would all be done for… in terms of quantities, I was aware that it would be on a scale well beyond that of Chernobyl.”
The extent of this worst-case scenario would have been unthinkable. It was estimated that the radius of the evacuation area would have to be about 250 km – about 150 miles; it would have included the entire Kantō plain, including Tokyo, and affected some fifty million people.
TEPCO chairman Masatake Shimizu was summoned to the Prime Minister’s office shortly after four in the morning. Kan asked him directly if they intended to evacuate, and his reply was no; they had no intention of evacuating the plant.
Kan told Shimizu that they were failing to communicate properly; as a result, he wanted to set up a joint command at TEPCO headquarters. He arrived there at 5:30 on the morning of the 15th, and made a speech which was broadcast by video-conference to the ERC at Fukushima Daiichi, as well as to Fukushima Daini, the local HQ in Ōkuma, and to another TEPCO plant, Kashiwazaki-Kariwa.
“The damage resulting from this accident is enormous. If things go on like this, Japan is done for. Abandoning the plant is unthinkable! You must risk your lives on it if necessary… If you abandon the plant, TEPCO will be destroyed. You can run, but you’ll never get away!”
Those who saw this speech reported that Kan was furious; he is said to have told the older managers to “go to the site and die on the job,” adding that he was over 60 himself “and it makes no difference if we get cancer 20 or 30 years down the line.”
Yoshida, watching from the ERC, is said to have been so aggravated by this speech that he stood up, turned his back to the screen, and lowered his trousers to adjust his shirttails. In a country where even turning your back on a superior is a taboo, this would have been an extremely overt act of protest.
The truth of this situation is hard to ascertain for anybody who wasn’t there. Yoshida and TEPCO representatives maintain that there was never any plan to completely evacuate the power plant; Kan, and those on his side, believe that his impassioned speech made them decide to stay.
Although the media termed the remaining workers “The Fukushima 50”, there were actually 69; senior staff who had committed themselves to regaining control of the power plant while their younger colleagues were moved to safer ground.
It would not, in fact, be long before those younger workers returned. Some wanted to return sooner than they were allowed to; one was Yoshirō Abé, a veteran fireman.
“We worked for a contractor, not for TEPCO, so we had our own boss whose orders we had to follow. The boss in Tokyo said he couldn’t allow his employees to go into such danger, and forbade us from going into the plant.”
He tried to help from afar, talking people on-site through difficult procedures over an unreliable phone connection and simultaneously begging for permission to go; eventually it was given, and on the 16th he was allowed to return.
The focus then shifted from the reactors to the spent fuel pools; like the fuel in the reactors, the spent fuel rods were kept in water, and like the fuel in the reactors there was a danger they could melt if that water wasn’t there. With the roofs blown off three of the containment buildings, the pools were exposed, so measures were taken to get water up there. This included an attempt to drop water from helicopters; however, because of the high radiation levels over the buildings, the helicopters had to fly at such a height that it’s likely little water actually got to the pools this way.
Source: Wikimedia Commons
Nevertheless, little by little the reactors were brought under control. It would be a long time before they could say that the immediate danger was over; it was not until December that TEPCO announced all three reactors had finally achieved cold shutdown and were therefore stable.
Problems at the plant did continue; contaminated water was found to have leaked into the sea, and the full decommissioning schedule for the plant will take at least forty years. In the meantime, scientists are carrying out a wide range of studies into the effects that the radiation has had on flora and fauna in the area, comparing them to similar species in the area around Chernobyl.
Masao Yoshida left TEPCO on the first of December, 2011, on medical leave after a diagnosis of esophageal cancer. He died on the 9th of July, 2013. His cancer was deemed to be unrelated to the accident.
Assessing the true impact of the Fukushima Daiichi disaster is very difficult – not least because it is so tied up with the earthquake and tsunami.
As with Chernobyl, the effect of the released radiation is a complicated matter. There is no way to be absolutely sure that illness in any individual can be definitely attributed to the disaster. Even if there was, it would take many years to reach a final number.
At the moment, academic estimates vary between potentially hundreds to none at all, although TEPCO have accepted responsibility for at least one death in 2018 and four cases of illness.
Then, there’s the evacuation. This eventually extended to 20km, with a further 10km restricted until the end of September 2011.
Thousands of people from the affected area had to be moved, and that included many who were fragile – the sick and the elderly. The stress of the disaster, the rigours of travel, the hardships encountered by those who had to be placed in temporary housing – all of these could contribute towards a deteriorating condition, up to and including death. At least one elderly resident was reported to have taken his own life rather than leave his home.
Fukushima evacuees. Source: Wikimedia Commons
Over two thousand deaths in Fukushima Prefecture were counted as “disaster related”. That means that they were not directly caused by the disaster, but could be attributed to its effects. There is, however, no distinction drawn between those related to the nuclear disaster, and those connected to the earthquake or tsunami.
A later study found that it was “difficult to justify” relocating anyone from the Fukushima Daiichi district, based on an analysis of the cost of moving versus the increase in life expectancy it brought.
Philip Thomas, Professor of Risk Management in the Department of Civil Engineering at the University of Bristol, said:
“Mass relocation is expensive and disruptive. But it is in danger of becoming established as the prime policy choice after a big nuclear accident. It should not be. Remediation should be the watchword for the decision maker, not relocation.”
Following the disaster, Japan’s approach to nuclear power has fluctuated. Naoto Kan, once a proponent of nuclear power, now opposed it. On the 5th of May 2012, when the two reactors of the Tomari-3 power plant were shut down for maintenance, the country was completely without nuclear power for the first time since 1970. Since then, some reactors have been restarted, shut down and restarted again. At the time of this episode, there are 37 operable reactors in Japan; nine have been restarted, and a further 17 are seeking approval for restart. Plans call for 20% of the country’s power to be nuclear by 2030.
The majority of the country’s power now comes from natural gas and coal power stations. This, of course, has its own negative effects, including increased air pollution.
Just like the Tōhoku earthquake and tsunami which precipitated it, the Fukushima Daiichi disaster came about because of a lack of adequate foresight.
With Japan’s highly seismic landscape, some would question the wisdom of building nuclear reactors there at all. However, it is possible to design quake-proof buildings; the fact that only one building at Fukushima Daiichi was quakeproof, and that it was less than a year old at the time, is somewhat surprising.
The main problems arose because of the tsunami, and again, if the sea wall had been built high enough the devastation could have been avoided. If the generators had not been in the basement, they might have withstood the tsunami.
And finally, if emergency procedures had been clearer, if communication between the station, the company, and the government had been smoother, a lot of the panic which surrounded the accident could have been avoided.
For now, we can hope that the lessons learned at Fukushima Daiichi will make other nuclear plants safer, and that the ongoing studies in the surrounding area will give us a new understanding of the risks of radiation.
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Sources, References and Further Reading