Japan wants to expand nuclear power output to meet growing energy needs

Straits Times

11 hours ago

Nuclear energy made up nearly 30 per cent of Japan's energy mix before 2011, and now accounts for 8.5 per cent after the restart of 14 reactors so far. PHOTO: AFP
– Japan must make the most of its existing nuclear power plants and enhance their output efficiencies, given burgeoning energy demands, said the government's annual energy report on June 13.
The 133-page Energy White Paper 2025 noted how data centres and semiconductor factories are vital to the world's fourth-largest economy, adding that it is crucial to prevent 'investment opportunities from being lost due to an inability to secure enough decarbonised power sources'.
The paper's comment on nuclear energy comes half a year after Japan had, in its seventh Strategic Energy Plan, scrapped wording that it would 'minimise reliance' on the source. Such language was introduced in the wake of the 2011 Fukushima Daiichi nuclear power plant disaster that ranks among the world's worst nuclear catastrophes and led to the closure of its 54 other reactors nationwide.
The re-embrace of nuclear energy has, according to media polls, majority support among the Japanese public. This is particularly so in metropolitan areas, which have come under power-supply and blackout warnings during the heatwaves and cold snaps of recent years.
Japan's energy self-sufficiency rate, at a meagre 15.2 per cent, is due to the protracted restarts of its shuttered nuclear reactors and compounded by geographical limitations that impede the more aggressive adoption of renewable energy.
Nuclear energy made up nearly 30 per cent of Japan's energy mix before 2011, and now accounts for 8.5 per cent after the restart of 14 reactors so far.
Fossil fuel sources, meanwhile, comprised 68.6 per cent and renewable energy, 22.9 per cent of the energy mix. The bulk of its fossil fuels, however, is imported from abroad, with 65.9 million tonnes of liquefied natural gas brought in from countries such as the United States, Australia and Malaysia in 2024.
Simultaneously, the country is grappling with a surge in energy needs fuelled by digitalisation – a generative artificial intelligence request is said to consume 10 times more power than a standard Google search.
To alleviate its energy shortage, in June, Japan bought Russian crude oil for the first time in over two years. This acquisition bypassed sanctions against Moscow – imposed after Russia invaded Ukraine in 2022 – through waivers invoked on grounds of energy security.
Nuclear power, therefore, is now seen as a critical source, not just because of its burgeoning energy needs but also because Japan is striving to achieve its net-zero carbon emissions target by 2050 as part of its commitments under the climate change treaty the Paris Agreement.
Nuclear power generation does not produce carbon dioxide emissions, although the disposal of spent nuclear fuel waste remains an issue for most nuclear-reliant countries .
Given the scars of Fukushima, Japan's use of nuclear energy is predicated on the condition of utmost safety with regular stringent checks and maintenance, as well as mandatory evacuation plans for surrounding vicinities.
On June 6, a law was enacted to allow Japan's nuclear plants to operate beyond their 60-year lifespan which, already, was extended once from 40 years. The new framework discounts periods during which a reactor is taken offline for reasons such as safety checks, thus extending their operational lifespan above 60 years.
This means the Takahama Unit 1 reactor in Fukui Prefecture, which the Kansai Electric Power Company began running in November 1974, can stay operational until 2046. This was because it was halted for 12 years after Fukushima for a safety assessment.
A week earlier, experts from the Canon Institute for Global Studies think-tank urged Japan to urgently formulate a 'national nuclear energy vision that places nuclear power at the centre, with a view to the entire life cycle of nuclear power in the future'.
A May 29 report by contributors including Mr Nobuo Tanaka, a former executive director of the International Energy Agency, said: 'Japan is currently faced with a raft of difficult challenges related to the use of nuclear energy, with its nuclear human resources dwindling.'
This is a direct result of keeping nuclear plants shut for prolonged periods, they said, arguing for a 'bold shift in conventional policy'.
Building new conventional nuclear plants is seen as unfeasible since their construction is expensive, can take up to 15 years, and must undergo regulatory red tape. Data centres, in contrast, can be ready within two years.
Japan is thus prioritising the restart of existing operable reactors, and looking at developing next-generation nuclear technologies such as small modular reactors.
It is also investing in nuclear fusion research – unlike conventional nuclear plants that involve nuclear fission – with a goal of becoming the first country globally to conduct field tests in the 2030s. Such technology is said to be much safer than existing fission plants.
Of the 54 reactors shuttered in 2011, 33 were deemed operable, but only 14 are back online.
Another three have received approval to restart from Japan's Nuclear Regulatory Authority, but are facing roadblocks at the municipal level.
They include the Tokai Unit 2 reactor in Ibaraki Prefecture. Operated by the Japan Atomic Power Company, this is the closest nuclear plant to the Greater Tokyo metropolitan area.
On June 5, Tokai Mayor Osamu Yamada said he was in favour of its restart, but the process would also hinge on the consent of Ibaraki prefecture governor, as well as leaders of six neighbouring cities and villages .
The other two reactors are Units 6 and 7 of the Kashiwazaki-Kariwa Nuclear Power Plant, operated by Tokyo Electric Power Company (Tepco), in Niigata.
The facility, commonly known as KK, is recognised by the Guinness World Records as the world's largest with its seven reactors having a collective output of 8.2 gigawatts, which is enough to power more than 13 million households.
The two reactor units slated for restart – pending approval by Niigata Governor Hideyo Hanazumi – each has 1.35 gigawatts of capacity.
Tepco completed loading fuel into Unit 7 in 2024 and, on June 10, began the two-week process of loading fuel assemblies into Unit 6. Once this is completed and consent given, the two reactors can technically be restarted at any time.
KK will be Tepco's only remaining nuclear plant, as the company is decommissioning its crippled Fukushima Daiichi and the nearby Fukushima Daini plants.
Tepco has used robots to remove two batches of molten fuel debris from Fukushima Daiichi, measuring 0.693g and 0.187g each, as the authorities try to understand what they are dealing with.
An estimated 880 tonnes of molten fuel debris reportedly remains inside the plant, with the entire decommissioning process expected to take up to 40 years.
'There's no sense of urgency, given that the plant is in safe shutdown,' Dr Dale Klein, a US engineer who chairs Tepco's Nuclear Reform Monitoring Committee, told The Straits Times. 'This is the first time we have ever had molten fuel beneath the reactor vessel, and retrieving the material is more difficult than landing on the moon.'
He opined that anxieties over nuclear power are fuelled by emotion and paranoia, rather than objective facts, arguing that there are also accidents at coal and gas power plants that do not get comparable attention.
Renewable sources such as solar and wind are promising, but are highly dependent on the weather. Other nascent sources, such as hydrogen, continue to face challenges to be used at scale.
'We need all the arrows in the quiver,' Dr Klein said. 'And I think what is changing is that people are starting to realise how climate change is a bigger, and tangible, threat than the perceived threat of nuclear energy.'
Walter Sim is Japan correspondent at The Straits Times. Based in Tokyo, he writes about political, economic and socio-cultural issues.
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