Fukushima, Japan (CNN) Soichi Saito was in hospital when the earthquake hit.

The 65-year old had just undergone surgery for prostate cancer and was recuperating when the walls of his 6th floor room began to shake. Medical equipment came crashing to the floor.

For almost six minutes on March 11, 2011, the 9.0 magnitude earthquake — the worst to ever hit Japan — rocked the country.

The quake was so strong that it permanently moved Japan's main island, Honshu, more than two meters to the east. The impact also raised huge waves up to 40 meters high that, as people were still reeling from the aftershocks, began crashing into the country.

More than 20,000 people died or went missing in the earthquake and subsequent tsunami, while hundreds of thousands more lost their homes.

The earthquake and tsunami were just the beginning however.

Saito recalls staring helplessly out of his hospital room window as waves inundated the town beneath him. His first thought was of the nearby Fukushima Daiichi nuclear plant.

"If the tsunami caused the plant to lose power to cool the reactors, it would be a disaster."

Back home, Saito's family received the order to evacuate as fast as they could, abandoning the farm where they grew spinach in tidy rows of greenhouses.

The urgency was such that Saito's wife left their dog Maru tied to a pole near the home.

"She thought maybe they'd have to evacuate for a couple days at most." (Maru was rescued by animal protection workers and, months later, reunited with his family.)

But what Saito's family, along with the rest of Japan, didn't realize, was that the situation in the Fukushima plant was quickly becoming a disaster of its own, one that would shock the country as much as the earthquake itself.

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Meltdown

It started with a wave.

Within 50 minutes of the initial earthquake, the first wave crested the nuclear plant's 10-meter high sea wall.

The plant's emergency power generators, in the basement, were soon flooded, knocking vital cooling systems offline and causing reactor fuel rods to begin to meltdown and leak deadly radiation into the surrounding area.

Sixteen hours into the disaster , the fuel rods in one reactor had almost completely melted, with the other two close behind.

It would be another 88 days until the government admitted that a meltdown had taken place, the worst nuclear disaster since the 1986 Chernobyl incident.

While water caused the meltdown, it was also the only way to stop it. Since the disaster, TEPCO has been pumping hundreds of tons of water into Fukushima to cool the reactors and stop the outflow of radiation.

Photos: Fukushima cleanup could take 40 years A mountain of black bags filled with contaminated soil sits piled on a roadside in Tomioka, Fukushima. A massive national project to remove topsoil and vegetation contaminated by the Fukushima nuclear disaster will produce at least 22 million square meters of radioactive waste. Hide Caption 1 of 6 Photos: Fukushima cleanup could take 40 years Colossal quantities of contaminated material have been collected from the Fukushima site and surrounding area. What will be done to dispose them still remains to be seen. Hide Caption 2 of 6 Photos: Fukushima cleanup could take 40 years One of hundreds of temporary storage sites for contaminated material. Hide Caption 3 of 6 Photos: Fukushima cleanup could take 40 years A giant, 780-meter sea wall under construction near the Fukushima Daiichi nuclear plant is designed to prevent contaminated water on the site from seeping into the ocean. Hide Caption 4 of 6 Photos: Fukushima cleanup could take 40 years Tetrapods piled up at Udedo port in Namie, Fukushima, waiting to be used for a 7 meter high, 3 kilometer long breakwater along the coast line. Hide Caption 5 of 6 Photos: Fukushima cleanup could take 40 years Prior to the wall's construction, radioactive water and materials readily seeped into the ocean, threatening local fishing stocks and causing potentially irreversible damage to the sea floor. Hide Caption 6 of 6

Some 800,000 tons of highly-radioactive water now sit in hastily-built tanks at the site, enough to fill 315 Olympic-sized swimming pools, with around 400 tons added to the tanks every day.

The government has also spent more than $1.5 billion collecting radioactive soil and earth from the surrounding area, which now sits in thousands of industrial-sized black bags looking like the world's deadliest grain harvest.

How the water and earth will be disposed of isn't clear. TEPCO estimates that cleanup operations could take up to 40 years.

"There's still an enormous amount of radioactivity there which is not controlled, in liquid form, leaking into the underground, and slowly moving into the ocean," said Greenpeace Japan campaigner Jan Vande Putte.

"And that's very dangerous for the future."

While a 2012 World Health Organization report found that "predicted (health) risks remain low" following the Fukushima disaster, in the two locations where residents experienced the highest doses of radiation, the WHO said a 4% to 7% greater risk of developing certain forms of cancer such as leukemia was expected.

For those living near the exclusion zone, health concerns are high on their mind. A Geiger counter sits in the grounds of one nursery school in Fukushima prefecture, and teachers regularly check the radiation levels of food the children eat.

Head teacher Michiko Saito said that the precautions are "absolutely necessary," due to the potential threat posed by invisible radiation.

Parent Toshiki Aso, whose two children attend the school said, "Any parent would worry about what kind of impact low dose radiation exposure will have on our children."

'I know I can't go back'

Photos: Inside the Fukushima ghost towns Inside the Fukushima exclusion zone, towns once full of people have been abandoned, some still showing signs of the frantic evacuation process that followed the disaster. Hide Caption 1 of 21 Photos: Inside the Fukushima ghost towns Destroyed buildings seen from inside an abandoned class room in Fukushima prefecture. Hide Caption 2 of 21 Photos: Inside the Fukushima ghost towns Residents initially thought they would only have to evacuate for a few days at most. Many haven't been able to return for five years. Hide Caption 3 of 21 Photos: Inside the Fukushima ghost towns A dusty piano sits in an abandoned school near the Fukushima Daiichi nuclear plant. Hide Caption 4 of 21 Photos: Inside the Fukushima ghost towns A blackboard covered in messages supporting victims of the 2011 earthquake and tsunami. Hide Caption 5 of 21 Photos: Inside the Fukushima ghost towns A school gymnasium still shows signs of damage from the 2011 earthquake. Former residents and workers can only spend limited amounts of time in the town due to health risks. Hide Caption 6 of 21 Photos: Inside the Fukushima ghost towns A house destroyed by the 2011 earthquake. Hide Caption 7 of 21 Photos: Inside the Fukushima ghost towns Though many homes were left undamaged by the earthquake and tsunami, residents soon had to abandon them as the Fukushima nuclear plant went into meltdown. Hide Caption 8 of 21 Photos: Inside the Fukushima ghost towns A road block marks the entrance to the Fukushima exclusion zone. Hide Caption 9 of 21 Photos: Inside the Fukushima ghost towns Security guards check passes within the Fukushima exclusion zone, former residents may only visit for up to 5 hours at a time. Hide Caption 10 of 21 Photos: Inside the Fukushima ghost towns The Fukushima Daiichi nuclear plant seen from Futaba town, now abandoned due to the meltdown. Hide Caption 11 of 21 Photos: Inside the Fukushima ghost towns A greenhouse once used for growing organic spinach now covered in overgrown weeds. Hide Caption 12 of 21 Photos: Inside the Fukushima ghost towns Workers and former residents have to wear protective gear while inside the exclusion zone. Hide Caption 13 of 21 Photos: Inside the Fukushima ghost towns Former residents say highly radioactive plants are marked with red ribbons to indicate danger. Hide Caption 14 of 21 Photos: Inside the Fukushima ghost towns An abandoned playground inside the Fukushima exclusion zone. Hide Caption 15 of 21 Photos: Inside the Fukushima ghost towns Maintenance workers are only allowed to work for 4 hours a day in the radioactive environment within the exclusion zone. Hide Caption 16 of 21 Photos: Inside the Fukushima ghost towns Outside the limits of the exclusion zone, many evacuees were housed in prefabricated metal buildings. Each has two 7 meter square rooms, a tiny kitchen and a bathroom. Hide Caption 17 of 21 Photos: Inside the Fukushima ghost towns Two thirds of the temporary housing residents left for elsewhere to start a new life, unable to return to their former towns. Hide Caption 18 of 21 Photos: Inside the Fukushima ghost towns Many of those still living in the temporary housing units are senior citizens, unable or not willing to move elsewhere. Hide Caption 19 of 21 Photos: Inside the Fukushima ghost towns 240 households with over 480 people lived in the temporary housing complex at its peak. Hide Caption 20 of 21 Photos: Inside the Fukushima ghost towns Children play in the dusty playground of a temporary housing complex in Japan's Fukushima prefecture. Hide Caption 21 of 21

As the Fukushima plant was melting down, more than 300,000 people living nearby were evacuated, according to the Red Cross.

Five years after the disaster, tens of thousands still live in temporary housing only intended to last 24 months. Most of those who remain are elderly, with few options to move away.

Setsuko Matsumoto ran a hair salon in Futaba, a town within the exclusion zone still considered uninhabitable due to radiation.

Though Futaba residents can visit their former homes — for five hours a day — 65-year-old Matsumoto hasn't seen her house in more than two years. She finds it too painful to walk through the earthquake-ravaged rooms which once hosted family gatherings and celebrations.

"Before the disaster, my family all lived in Futaba within walking distance of each other," Matsumoto said.

"I live alone now."

She stays busy sewing small decorative kimonos, and by cutting and styling the hair of other residents. "It's something to pass the time."

Separated and broken families are a common occurrence among Fukushima evacuees.

"My family fell apart, we all live in different places now," said 90-year-old Eiko Hasegawa.

"I hope to return home while I'm still alive, but I know I can't."

Back in Futaba, the stress of returning drives Saito to chain-smoke as he drives through the abandoned streets.

His prostate cancer is in remission. He won that battle, but he can't fight the contamination that has transformed his community into a nuclear ghost town.

The streets are lined with abandoned stores and restaurants. The train station is crumbling. His favorite ramen place is boarded up.

At the old farmhouse, the damage from the quake has been compounded by five years of neglect. A calendar on the wall still reads March 2011. Laundry from that day still hangs on drying racks, covered in dust and spider webs.

Saito's greenhouses are overgrown with weeds that stand taller than the structures themselves. Wild animals have made holes in storage containers, scattering seeds everywhere. A thick layer of dust covers the farm equipment.

"There is no reconstruction. The government told us the nuclear power plant would be a good thing," he said.

"But once disaster struck, they didn't know how to deal with it."

Nuclear resurgence

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Fukushima shook Japan's long-stated commitment to nuclear power. Prior to the disaster, the country's 50 some reactors provided more than 30% of its power, according to the World Nuclear Association , an industry body.

This ended on May 5, 2012, when the country's last operating reactor, in Hokkaido, shut down for inspection, leaving Japan without nuclear power for the first time in more than 45 years. (Two units of the Oi nuclear power plant were briefly restarted in 2012, but went offline again a year later.)

Ditching nuclear power wasn't easy for Japan, forcing the country to import around 80% of its fuel, according to the WNA. Household electricity rates rose 19% between 2011 and 2015, and carbon dioxide emissions spiked.

The moratorium lasted until August 2015, when a reactor was restarted in Sendai , sparking protests outside the plant and Prime Minister Shinzo Abe's residence in Tokyo.

After the plant resumed operation, Abe said that it, and others in the process of being restarted, had passed "the world's toughest safety screening."

Public opinion is still firmly against nuclear and many Japanese politicians and commentators have criticized the government's decision to restart the reactors.

Prior to the disaster, around 70% of people supported nuclear energy, according to an official poll. That level dropped to below 36% after the Fukushima meltdown, with opposition to nuclear energy growing to up to 50 or even 70%, according to polls by Japanese media.

Former Prime Minister Naoto Kan, in office during the crisis, is one of the highest-profile voices to come out against nuclear power, calling repeatedly on the government to change its course.

"The safest nuclear policy is not to have any plants at all," he told a parliamentary panel in 2012

While the move back towards nuclear power has been justified on the grounds of the huge cost of importing fossil fuel energy, campaigners expressed disappointment that alternative options weren't explored.

"Renewable energy sources such as solar, wind and thermal have so much potential here," said Ai Kashiwagi, of Greenpeace Japan, after the Sendai plant was restarted

Outside of the National Diet, opposition to nuclear power remains high. A February poll by broadcaster NHK found that only 20% thought the reactors should be restarted. Before the disaster, a majority of the country supported the nuclear industry

Greenpeace's Vande Putte said that Japan hasn't "learned the lesson of Fukushima." He pointed to the reactors built in seismic zones, as well as the Sendai plant, which lies 30 kilometers from an active volcano.

"In Japan, there's no safe place for nuclear reactors. What we have seen at Fukushima Daiichi can happen at another reactor."

"The government should shut down all the nuclear reactors," said Fukushima survivor Toshiki Aso.

"I don't want anyone else to have to go through the same suffering we did."