Japan's nuclear power journey has taken a significant turn with the recent restart of a reactor at the Kashiwazaki-Kariwa plant, the world's largest nuclear facility. This move comes nearly 15 years after the devastating Fukushima disaster, which forced Japan to shut down all its nuclear reactors.
Reactor no.6 at Kashiwazaki-Kariwa, located northwest of Tokyo, was brought back online on Wednesday, a day later than initially planned due to an alarm malfunction. It is expected to start commercial operations next month.
This development is part of Japan's ongoing effort to revive its nuclear power sector, but the path ahead is far from straightforward. The seventh reactor is not anticipated to come back online until 2030, and the remaining five could face decommissioning. This means the plant's capacity will be significantly reduced from its previous 8.2 gigawatts when all seven reactors were operational.
Japan, an early adopter of nuclear power due to its heavy reliance on energy imports, saw its ambitions dashed by the 2011 Fukushima disaster, one of the worst nuclear catastrophes in history. Triggered by the most powerful earthquake ever recorded in Japan, the meltdown at Fukushima Daiichi led to radioactive leakage, traumatizing local communities that were evacuated and many of whom have not returned despite official assurances of safety.
Critics argue that the plant's owner, Tokyo Electric Power Company (Tepco), was unprepared, and their response, along with the government's, was poorly coordinated. An independent government report labeled it a "man-made disaster" and blamed Tepco, although a court later acquitted three of their executives of negligence.
The fear and lack of trust stemming from this incident fueled public opposition to nuclear power, leading Japan to suspend its entire fleet of 54 reactors shortly after the Fukushima disaster. Over the past decade, Japan has been working to bring these power plants back online, restarting 15 of its 33 operable reactors since 2015. The Kashiwazaki-Kariwa plant is the first Tepco-owned facility to be turned back on.
Before the 2011 disaster, nuclear power accounted for nearly 30% of Japan's electricity, and the country had planned to increase this to 50% by 2030. However, its energy plan last year revealed a more conservative goal: nuclear power providing 20% of its electricity needs by 2040.
Even this target may be challenging to achieve. Global momentum is building around nuclear energy, with the International Atomic Energy Agency estimating that the world's nuclear power capacity could more than double by 2050. In Japan, as of 2023, nuclear power accounts for just 8.5% of electricity.
Prime Minister Sanae Takaichi, who took office in October, has emphasized the importance of nuclear power for Japan's energy self-sufficiency, especially with the expected surge in energy demand due to data centers and semiconductor manufacturing. However, the costs of operating nuclear reactors have surged due to new safety checks requiring hefty investments from companies trying to restart their plants.
"Nuclear power is getting much more expensive than they ever thought it would," says Dr. Florentine Koppenborg, a senior researcher at the Technical University of Munich.
The government could subsidize these costs or pass them on to consumers, but both options are unappealing for Japan's leaders, who have long touted the affordability of nuclear power. An expensive energy bill could also be politically damaging at a time when households are already protesting rising costs.
"The government's hands are tied when it comes to financially supporting nuclear power unless it's willing to go back on one of the main selling points," Koppenborg adds.
Beyond the fear of another Fukushima-like disaster, a series of scandals have further eroded public trust. The Kashiwazaki-Kariwa plant, in particular, has been embroiled in several incidents. In 2023, an employee lost a stack of documents after placing them on top of their car and driving away, and in November, another employee was found to have mishandled confidential documents.
A Tepco spokesperson stated that the company reported these incidents to the Nuclear Regulation Authority (NRA) and aimed to continue improving security management.
These revelations, while a sign of increased transparency, also highlight Tepco's struggle to change its safety approach, according to Koppenborg.
Earlier this month, the NRA suspended its review to restart nuclear reactors at Chubu Electric's Hamaoka plant in central Japan after the company was found to have manipulated quake data in its tests. The company apologized, stating, "We will continue to respond sincerely and to the fullest extent possible to the instructions and guidance of the NRA."
Hisanori Nei, an adjunct professor at the National Graduate Institute for Policy Studies in Tokyo and a former senior nuclear safety official, believes that the harsh penalty imposed on Hamaoka's operator should deter other companies from similar actions.
"Power companies should recognize the importance of not falsifying data," Nei said, adding that authorities will "reject and punish" offending companies.
The Fukushima disaster significantly shifted Japanese public opinion against nuclear power, which was once seen as an affordable and sustainable energy source. In the weeks following the March 2011 disaster, a Pew Research Center survey found that 44% of Japanese believed nuclear power use should be reduced, a figure that jumped to 70% by 2012.
Since then, thousands of residents have filed class action lawsuits against Tepco and the Japanese government, demanding compensation for property damage, emotional distress, and health problems allegedly linked to radiation exposure.
In 2023, the release of treated radioactive water from the Fukushima Daiichi nuclear plant sparked anxiety and anger both domestically and internationally.
Many remain opposed to restarting nuclear plants, with hundreds of protesters gathering outside the Niigata prefectural assembly, where Kashiwazaki-Kariwa is located, to voice their safety concerns.
"If something were to happen at the plant, we would be the ones to suffer the consequences," one protester told Reuters.
Nuclear safety standards have been significantly enhanced since Fukushima. The NRA, a cabinet body established in 2012, now oversees the restarting of Japan's nuclear plants.
At Kashiwazaki-Kariwa, 15-meter-high seawalls have been constructed to protect against large tsunamis, and watertight doors now safeguard critical equipment.
"Based on the new safety standards, [Japan's nuclear plants] could survive even a similar earthquake and tsunami like the one we had in 2011," Nei told the BBC.
However, Dr. Koppenborg expressed concern, stating, "They're preparing for the worst they've seen in the past but not for what is to come."
Some experts worry that these policies may not adequately account for rising sea levels due to climate change or the once-in-a-century megaquake that Japan anticipates.
"If the past repeats itself, Japan is super well-prepared," Koppenborg said. "If something really unexpected happens and a bigger-than-expected tsunami comes along, we don't know."
The future of Japan's nuclear power sector remains uncertain, with public opinion, safety concerns, and economic considerations all playing significant roles in shaping its trajectory.
