Conditions inside Fukushima’s melted nuclear reactors still unclear 13 years after disaster struck

TOKYO (AP) — Japan on Monday marked 13 years since a massive earthquake and tsunami hit the country’s northern coasts. Nearly 20,000 people died, whole towns were wiped out and the Fukushima Daiichi nuclear power plant was destroyed, creating deep fears of radiation that linger today. As the nation observes the anniversary, the AP explains what is happening now at the plant and in neighboring areas.

WHAT HAPPENED 13 YEARS AGO?

A magnitude 9.0 earthquake struck on March 11, 2011, causing a tsunami that battered northern coastal towns in Iwate, Miyagi and Fukushima prefectures. The tsunami, which topped 15 meters (50 feet) in some areas, slammed into the nuclear plant, destroying its power supply and fuel cooling systems, and causing meltdowns at reactors No. 1, 2 and 3.

Hydrogen explosions caused massive radiation leaks and contamination in the area.

The operator, Tokyo Electric Power Company Holdings, says that the tsunami couldn’t have been anticipated. Government and independent investigations and some court decisions have said the accident was the result of human error, safety negligence, lax oversight by regulators and collusion.

Japan has since introduced stricter safety standards and at one point shifted to a nuclear energy phaseout. Prime Minister Fumio Kishida’s government reversed that policy and has accelerated restarts of workable reactors to maintain nuclear power as a main source of Japan’s power supply.

A deadly Jan. 1 earthquake in Japan’s northcentral region destroyed many homes and roads but didn’t damage an idled nuclear power plant. Even so, it caused worry that current evacuation plans that solely focus on radiation leaks could be unworkable.

The nation marked a moment of silence at 2:46 p.m. Monday, with Kishida attending a memorial in Fukushima.

WHAT HAPPENED TO PEOPLE IN THE AREA?

About 20,000 of more than 160,000 evacuated residents across Fukushima still haven’t returned home.

Decontamination work before the Tokyo Olympics meant to showcase Fukushima’s recovery led to the elimination of some no-go zones, but they remain in seven of 12 towns that had been fully or partially off-limits.

In Futaba, the hardest-hit town and a co-host of the Fukushima Daiichi plant, a small area was opened in 2022. About 100 people, or 1.5% percent of the pre-disaster population, have returned to live. The other host town, Okuma, which along with Futaba sacrificed part of its land to build an interim storage site for nuclear waste gathered from the decontamination, has seen 6% of its former residents return.

Annual surveys show the majority of evacuees have no intention of returning home, citing lack of jobs, schools and lost communities, as well as radiation concerns.

Residents who have raised radiation worries or linked it to their health problems have come under attack for hurting Fukushima’s reputation.

The disaster-hit towns, including those in Iwate and Miyagi prefectures, have seen sharp population drops.

Fukushima Gov. Masao Uchibori said on NHK TV that a growing number of young people want to move to Fukushima to open businesses or help in the reconstruction, and he expressed hope that more residents will return.

WHAT ABOUT TREATED RADIOACTIVE WATER DISCHARGES?

Last August, Fukushima Daiichi began discharging treated water into the sea, and is currently releasing a fourth 7,800-ton batch of treated water. So far, daily seawater sampling results have met safety standards. The plan has faced protests from local fishers and neighboring countries, especially China, which has banned Japanese seafood imports.

Fukushima Daiichi has struggled to handle the contaminated water since the 2011 meltdowns. TEPCO says the start of the process is a milestone and removing the tanks is crucial to make space for facilities needed as decommissioning progresses.

The contaminated cooling water is pumped up, treated and stored in about 1,000 tanks. The government and TEPCO say the water is diluted with massive seawater before release, making it safer than international standards.

WHAT ABOUT LOCAL FISHING?

Despite earlier fears that the water discharge would further hurt Fukushima’s hard-hit fishing industry, they have not damaged its reputation domestically. China’s ban on Japanese seafood, which mostly hit scallop exporters in Hokkaido, apparently prompted Japanese consumers to eat more Fukushima seafood.

Sampling and monitoring by the International Atomic Energy Agency have also boosted confidence in local fish.

Fukushima fishing returned to normal operations in 2021, and the local catch is now about one-fifth of its pre-disaster level because of a decline in the fishing population and smaller catch sizes.

The government has earmarked 10 billion yen ($680 million) to support Fukushima fisheries.

ANY PROGRESS REMOVING MELTED FUEL?

The contents of the three reactors is still largely a mystery. Little is known, for instance, about the melted fuel’s condition or exactly where it’s located in the reactors. Not even a spoonful of the fuel has been removed.

About 880 tons of melted nuclear fuel remain inside the three damaged reactors, and Japanese officials say removing it would take 30-40 years. Experts call that timeline overly optimistic. The amount of melted fuel is 10 times that removed from Three Mile Island following its 1979 partial core melt.

Robotic probes have glimpsed inside the three reactors, but their investigation has been hampered by technical glitches, high radiation and other complications.

It’s crucial for officials to understand the data from melted debris so they can make a plan to remove it safely. TEPCO aims to get the first sample out later this year from the least-damaged No. 2 reactor.

TEPCO has been trying to get the sample by using a robotic arm. Officials have struggled to get the robot past the wreckage, and hope that by October they can use a simpler device that looks like a fishing rod.

The fuel in the worst-damaged No. 1 reactor mostly fell from the core to the bottom of its primary containment vessel. Some of it penetrated and mixed with the concrete foundation, making removal extremely difficult.

In February, the plant made its first drone flight into the primary containment vessel to investigate the melted debris and examine how the fuel initially fell from the core. But a second day of exploration was canceled because a data transmission robot failed.

IS A 2051 COMPLETION POSSIBLE?

The government has stuck to its initial target for a completed decommissioning by 2051, but it hasn’t defined what that means.

The lack of data, technology and plans on what to do with the radioactive melted fuel and other nuclear waste makes it difficult to understand what’s in store for the plant and surrounding areas when the cleanup ends, according to TEPCO’s decommissioning company chief, Akira Ono.

An overly ambitious schedule could result in unnecessary radiation exposure for plant workers and excess environmental damage, experts say.

Mari Yamaguchi, The Associated Press