FUKUSHIMA, Japan

On the 10th anniversary of the March 2011 Tohoku earthquake and ensuing tsunami in northeastern Japan, the aftermath of the disaster in the region and the conditions for evacuation are being explored.

The quake and tsunami claimed some 15,000 lives, while some 2,000 people were never found.

A decade after the quake, post-disaster management, the state of the damaged power plant, and Japan's energy policy can be explored in five areas.

What happened on March 11, 2011?

At 2.46 p.m. local time (0546GMT), a 9.0 magnitude earthquake struck off Miyagi province in the northeast of the country, known as Tohoku.

A 15-meter-high tsunami subsequently struck the country's Pacific coast.

Fukushima nuclear power plant

The tsunami engulfed the six-reactor Fukushima Daiichi nuclear power plant operated by Tokyo Electric Power (TEPCO) in the towns of Futaba and Okuma.

Due to the quake, reactors one and three were automatically disabled and left to cool down by backup generators.

However, tsunami-induced flooding caused the power supply of reactors one and five to be cut off, disrupting the cooling system.

Reactors four and six on site were out of service at the time of the quake due to maintenance.

As a result of overheating, successive core meltdowns occurred in reactors one and three.

Hydrogen explosions occurred in the buildings where reactor one was on March 12, reactor three on March 14, and reactor four on March 15.

The government declared a nuclear emergency on the day the quake struck, ordered the evacuation of those living within a three-kilometer (1.86-mile) radius of the facility.

Initially, 160,000 people were evacuated.

The next day, the evacuation radius around the plant was first expanded to 10 kilometers (6.21 miles) and then to 20 kilometers (12.43 miles) after hydrogen explosions in reactor one.

On March 13, the number of evacuees reached 450,000.

On 20 March, reactors five and six were successfully put into cool shutdown.

On March 25, the number of people who lost their lives in the region exceeded 10,000.

From July 1 to Sept. 9, limits were imposed on electricity consumption in eastern and northern Japan to prevent power outages due to the accident.

On Dec. 21, 2011, the government and plant operator TEPCO announced a plan to shut down the plant's reactors one and four within 40 years.

It was later announced that reactors five and six were included in the plan and that the plant would be permanently shut down.

Reconstruction agency Fukkouco was established in February 2012 for the zoning and construction of the area.

In April 2013, about 120 tons of radioactive water were found to have leaked from the plant's underground tank.

Evacuation around Fukushima

Evacuation orders were gradually lifted in the areas surrounding the plant as a result of natural losses of energy and a drop in radiation levels with the purification of surface soil and pollution in buildings.

Currently, the total scale of the restricted zones is 337 square kilometers (130 square miles), or 30% of the total at the beginning.

Due to high radiation, seven local municipalities remain forbidden zones.

There are no estimates of when the ban on entry to these areas will be lifted.

Reactor decommissioning

The removal of all fuel rods from the depleted fuel pools in reactor four was completed in December 2014.

In December 2019, the government delayed for five years the planned 2023 start of the extraction of consumed fuel from reactor pools one and two on safety grounds.

The removal of fuel rods in reactor three was completed last month.

The government is expected to decide how to drain 1.24 million tons of water contaminated with low-toxic radioactive tritium, which is protected in the facilities' containment tanks.

The plant needs water to cool the reactors on site and has been producing large amounts of water contaminated with radiation since the earthquake in March 2011.

In September-November 2022, the plant's containment tanks are set to be filled to capacity.

The Japanese government is considering the option of releasing water free of most pollutants except tritium into the sea thanks to its advanced liquid processing system (ALPS).

Opposition groups in the country have expressed concern that marine life could be affected by the release.

Plant operator TEPCO says the process of decommissioning the reactors could take as long as 2051.

Responsibility for the incident

A total of 30 lawsuits filed by about 10,000 people who left the area where they lived on evacuation orders are demanding compensation from the state and TEPCO.

Some courts have ruled that both the state and TEPCO were negligent in preparing for the tsunami that hit the facility.

Some only ordered TEPCO to pay compensation.

In May 2011, Japan halted all its commercial nuclear reactors and created the Nuclear Regulatory Authority (NRA) in September 2012 to enforce stricter rules.

New safety standards, considered mandatory for reactors to be restarted, were introduced in 2013.

It is now mandatory for plant operators to build facilities that are fully protected from natural disasters and terrorist attacks, and resistant to damage such as leaking radioactive materials.

Due to the high costs of new standards mandated by the government, some firms have decided to stop operating at their facilities.

In August 2015, reactor one, which Kyushu Electric Power restarted in the Sendai region, became the country's first active reactor since the March 2011 accident.

A total of 24 reactors are being decommissioned across the country, including six at Fukushima Daiichi.

As of February 2021, nine reactors are in the process of being restarted under new safety standards.

Four reactors are already in operation in the country.

Japan, which ranks among the top five countries in the world in nuclear energy, announced its targets in the electricity generation pie as part of the 2030 Energy Strategy prepared in 2018.

Accordingly, the country aims to have 22-24% renewable energy, 56% fossil fuel-derived energy and 20-22% nuclear energy.

*Writing by Merve Berker