FUKUI/FUKUSHIMA – The Mihama nuclear power station in Fukui prefecture, which started operations in the 1970s, is one of Japan’s oldest.

       It was suspended in 2011 after the Fukushima nuclear disaster, along with all other nuclear plants in the country.

       But as Japan pushes to achieve energy security and affordability in a climate-friendly way, the government is looking to restart more plants – just like the Mihama plant, which resumed operations in 2021 after implementing measures to meet enhanced safety regulations.

       The East Asian nation was among more than 20 countries that signed a pact at COP28, the United Nations Climate Change Conference, in December 2023 to triple nuclear energy capacity globally by 2050.

       According to the International Energy Agency, about 8 per cent of Japan’s energy generation in 2023 came from nuclear power – down from 30 per cent before 2011.

       Almost 64 per cent came from fossil fuels – coal, oil and gas. Burning fossil fuels emits carbon dioxide into the atmosphere, which contributes to global warming and climate change.

       But the nuclear reactions that produce energy do not release such emissions as by-products.

       Japan wants to increase the share of nuclear power in the energy mix to at least 20 per cent by 2030.

       Mr Satoru Yasuraoka, director for international affairs at the nuclear energy policy division of Japan’s Ministry of Economy, Trade and Industry, told The Straits Times that while the Japanese government plans to increase the amount of renewable energy deployed, its ability to tap more renewables is constrained by geography.

       “Japan has decided under our (energy policy) to achieve the goal of carbon neutrality. Nuclear energy is expected to contribute to our goal of achieving energy sufficiency, affordability and environmental (considerations) – but with maximum safety,” he said.

       About 70 per cent of Japan’s land area comprises hilly terrain, which is not ideal for the installation of renewable energy infrastructure such as solar panels. And while offshore wind farms have potential, roll-out is still nascent given challenges such as cost and grid integration.

       This is why nuclear energy is regarded as a key plank in Japan’s net-zero carbon emission push despite the disaster of 2011.

       In March that year, a 9.0-magnitude earthquake triggered a tsunami that slammed into the Fukushima Daiichi Nuclear Power Plant on the Pacific coast, crippling cooling systems at the plant and causing a nuclear meltdown.

       More than 100,000 people had to be evacuated from their homes due to the radioactive fallout, and to this day, there remains areas near the plant closed off to the public.

       The incident spooked the wider public, and concerns over nuclear safety led the government to suspend the operations of 54 nuclear reactors across 17 plants.

       Japan has managed to restart only 12 reactors since, with the first having been powered up in 2015. Another 24 reactors are being or are scheduled to be decommissioned.

       This leaves 18 reactors still in the equation, with plant operators still going through a relicensing process to comply with stricter safety standards imposed after 2011. Another three reactors are under construction.

       All six units at the Fukushima Daiichi Nuclear Power Plant, which is operated by the Tokyo Electric Power Company (Tepco), are being decommissioned.

       The area still bears the scars of the 2011 accident.

       During ST’s visit there in June, there were dosimeters near the crippled plant measuring the amount of radioactivity in the air. Public exhibitions – and even an entire museum itself – had been built to remind people not to forget that tragic incident.

       Mr Kenichi Takahara, risk communicator at Tepco’s Fukushima Daiichi Decontamination and Decommissioning Engineering Company, said: “When we were operating the Fukushima Daiichi Nuclear Power Plant, we believed in the myth that nuclear (power) is safe to a certain extent. When the accident happened, it was a shock to us.”

       He added: “But from this, we gained various knowledge and came to the conclusion that it is necessary to improve the facilities that are important for operating other power plants.”

       Tepco is close to obtaining approval to restart Unit 7 of its Kashiwazaki-Kariwa Nuclear Power Plant in Niigata prefecture.

       The Nuclear Reform Monitoring Committee said in September that its review “did not identify any nuclear safety concerns or safety issues and found that safety culture is healthy”, describing Tepco’s preparations as “sound and adequate”.

       A Tepco spokeswoman said: “We have formulated various safety measures to handle a plethora of events that could lead to an accident, such as earthquakes and tsunamis, based on the concept of defence in depth and the lessons learnt from the Fukushima Daiichi accident.”

       For example, the Niigata plant can still be cooled in the event of a natural disaster.

       “For the case when even cooling function is lost, as it was during the Fukushima Daiichi Nuclear Power Plant accident, we have introduced impact mitigation measures, such as an alternative circulated cooling system that would give us about 10 days before (discharging) would become necessary,” the spokeswoman added.

       “Radioactive substances would not be immediately discharged.”

       Over in Fukui, the Kansai Electric Power Company (Kepco), which operates the Mihama plant, also took steps to gird up the facility, before it was given the green light to restart operations at Unit 3 in 2021. The plant’s other two reactors are being decommissioned.

       Fire, flood, tsunami and earthquake risks have been accounted for through geological surveys and other studies. Measures to safeguard against these risks were implemented in a three-year makeover of the Mihama plant that began in 2017.

       Tide embankments up to 6m above sea level were built to keep at bay tsunami waves, a height decided upon by the strictest geological surveys.

       Critical infrastructure, such as power generation equipment, is now protected by net-like structures made of steel, designed to withstand the force of flying objects during a typhoon.

       Bald strips of land separate the plant from the surrounding forested areas – a safety feature, ST learnt during a visit to the plant, to prevent forest fires from spreading to the plant.

       There were also changes that were not visible, such as seismic reinforcements of walls and the replacement of internal components to boost resilience against quakes.

       Mr Koichi Ichimura, director of the Mihama Nuclear Power Public Relations Centre, said new regulatory requirements had been implemented by Japan’s Nuclear Regulation Authority following the 2011 Fukushima nuclear disaster.

       “The new regulatory requirements cover not only lessons learnt from Fukushima Daiichi, but also a wide range of risks, such as various natural disasters and anti-terrorism measures,” he told ST.

       “Kansai Electric Power will comply with these requirements and also advance independent initiatives.”

       On Oct 10, Kepco said it had shut down the operational reactor as a safety precaution, after two holes measuring 3mm and 6mm in diameter and salt precipitation were found in the piping system that takes in seawater to cool the plant.

       Investigations are ongoing into the cause of “thinning”, in which the pipe is worn away, Kepco said, adding that no radioactivity had escaped into the environment.

       Public perceptions of nuclear energy in Japan remain divided.

       Some residents, such as Mr Hiroaki Murakami, 51, the chief executive officer of a seafood shop in Fukushima, said: “I think nuclear power would be fine as long as it is safe. I agree with it. The price of fuel has skyrocketed.”

       Mr Yukihiro Higashiyama, 77, a representative from a Fukui-based anti-nuclear group, said the Fukushima incident has shown that nuclear power generation can be risky regardless of the extent of safety measures, and that the repercussions outweigh any benefits.

       He added: “Especially since Japan is a country with natural disasters, such as volcanic eruptions, earthquakes and tsunamis, this type of power generation method is doubly exposed to such natural risks.”

       Dr Ken Koyama, senior managing director and chief economist at Japan’s Institute of Energy Economics, said different countries will need to assess their needs for nuclear energy based on their own opportunities and constraints.

       “If a country is well-endowed with green power or solar, it is very natural that it makes maximum use of these energy sources,” he said, adding that this was not the case for Japan.

       On whether risk-free nuclear energy generation can ever be achieved, Dr Koyama said Japan is trying to minimise cost and pursue the benefits of nuclear energy generation.

       “Traffic accidents or air travel also have their own risks, but people continue to utilise these technologies because of the benefits they bring,” he said.

       “We can try to minimise risk of related options and technology, but we cannot stop using them.”