JOHN YANG: Later this month, Japan could start releasing treated wastewater from the Fukushima nuclear power plant into the ocean.

They're running out of space to store the radiation tatted water at the plant, which was damaged by the devastating 2011 earthquake and tsunami.

As special correspondent Rebecca Bundhun reports, both locals and neighboring countries are worried about the effect on their health and their livelihoods.

REBECCA BUNDHUN: As the day breaks over the land of the rising sun.

Fisherman Haruo Ono has already been working hard for hours.

It's been a way of life for Fukushima's fishing community for generations.

But the once thriving industry has struggled since the 2011 earthquake and tsunami, which destroyed the Fukushima Daichi nuclear power plant, nearly 40 miles south of where Ono lives and works.

The release of radioactive substances into the environment triggered international bans on the sale of fish from Fukushima.

And it's only in the past few years that some countries have lifted those restrictions.

But now Fukushima's fishermen are facing a fresh threat as Japan plans to release more than 1 million tons of wastewater from the damaged plant into the ocean.

HARUO ONO, Fisherman (through translator): When they release the wastewater, I think we won't be able to sell our fish at the main market again.

What happens to us then?

REBECCA BUNDHUN: He worries that the water could contaminate the ocean and fish, and even if it doesn't, people may avoid buying seafood from Fukushima because of the move.

The Japanese government insists that the plan to release the wastewater is completely safe.

The water will be heavily diluted and treated, and samples will be tested on a daily basis, the plant's operator, TEPCO, says.

The only radioactive element which will remain, it says, will be treatium, which cannot be removed.

But TEPCO says these will be at such minute levels that it won't harm people or the environment.

Officials argue the water has to be released because the tanks storing the water used to cool the damaged nuclear reactors are almost full.

The 1.3 million metric tons of liquid would be pumped out over a few decades.

TEPCO says it looked into alternative options, including burying the water underground, before deciding on the plan to discharge the water into the ocean.

Some experts say that there might not be a better option, but the problem is that public trust is lacking.

KYLE CLEVELAND, Temple University, Japan: I think among a group of really bad options, maybe the best bad option is to actually put it into the ocean.

The problem is they don't have a lot of trust and credibility on their messaging, which is that actually the levels of radiation are going to be quite small and will not have an appreciable impact on public health.

REBECCA BUNDHUN: Some nuclear analysts, however, highlight that such a move to release treated wastewater from a damaged plant is unprecedented, and therefore the long term risks in particular are unknown.

For residents of Fukushima, the decision has stirred up bad memories of the earthquake and tsunami that has had a lasting impact on so many people's lives.

Official figures show that 18,500 people were killed or are still unaccounted for due to the disaster.

Here in Soma, a coastal district in Fukushima, people are still scarred by the event.

This memorial displays the names of the 458 people who were killed in Soma alone by the 2011 earthquake and tsunami.

More than 1,000 homes were destroyed here, and the area year has never fully recovered from the disaster.

Kowata Hironabu's entire village was swept away by the tsunami.

He says the plan to discharge water from the plant leaves him worried for Fukushima's farming and fishing industries, but he accepts the authority's decision.

KOWATA HIRONOBU, Construction Business Owner (through translator): I understand other countries may blame us, but I don't see any other solutions.

I wish that it wouldn't have to happen, but I think we have no other options.

REBECCA BUNDHUN: Some countries, including China and South Korea, have voiced opposition to the water release plan.

Beijing, which still has bans in place on imports of food and agricultural products from Fukushima and nearby regions, is reported to be conducting radiation testing on seafood products coming in from Japan as it tries to pressure the country to reconsider its decision.

China is the biggest buyer of seafood exports from Japan, and in South Korea, people have been panic buying sea salt because of fears the product could be contaminated once the water starts being released.

But a two-year independent safety review gave the green light for the plan.

The biggest vindication for Japan's plan to release the wastewater may have come from the International Atomic Energy Agency's final report.

The U.N. nuclear watchdog says the plan meets international standards and would have a negligible impact on the environment.

Many still remain unconvinced.

These activists in Fukushima City have been staging protests against the use of nuclear power since the disaster.

Now they're holding regular demonstrations against the water release, raising concern about the effects of exposure to radiation on people's health and the environment.

KAORU WATANABE, Activist (through translator): The government is saying that they will release the water because the tanks are full, and this holds back the decommissioning process of the power plant.

But at the site of the plant, there is a lot of land and places where more tanks can be built for the water.

REBECCA BUNDHUN: Officials, however, argue that continuing to store the water is also a risk.

If, for example, another earthquake were to cause leakage.

Shoji Outa in Fukushima is setting up his beach restaurant for the peak summer season.

His business has struggled since the 2011 disaster hit, driving away tourists.

When things did start to pick up, the COVID-19 Pandemic came along.

He had been hopeful that this year might better as Japan's COVID restrictions have been eased and people are travelling again.

SHOJI AOTA, Restaurant Owner (through translator): After the Pandemic crisis has settled down and the beach has finally opened, customers will come back, the contaminated water will be released.

And I'm worried about the perception issue.

Families bring their children, so I'm worried about that.

REBECCA BUNDHUN: Many in Japan's fishing industry still live with nightmares of the disaster and its aftermath.

Haruo Ono's younger brother was out at sea when the tsunami struck and lost his life.

He's worked hard to rebuild his livelihood since, but he fears that Fukushima will be paying the price for years to come.

HAROU ONO (trough translator): It's a lifelong problem.

This is our children's problem.

This is our grandchildren's problem.

It will affect everyone who can say with certainty that this will be fine.

REBECCA BUNDHUN: For PBS News Weekend, I'm Rebecca Bundhun in Fukushima, Japan.