translated from Japanese

Is the “Maximum Use” of Nuclear Power Rational?

The government’s Seventh Basic Energy Plan rests on uncertain demand forecasts and an opaque decision-making process, making its turn toward the “maximum use” of nuclear power economically, politically, and climatically hard to justify.

原発「最大活用」は合理的か：「脱原発依存」削除の政府第7次エネ基本計画

Nippon.com · 14 January 2026 · read the original in Japanese →

Is the “maximum use” of nuclear power rational? The government’s Seventh Basic Energy Plan deletes “reducing dependence on nuclear power” Politics and Diplomacy, Science, Society - English - Japanese - Simplified Chinese - Traditional Chinese - Français - Español - Arabic - Russian Nuclear power’s share is “around 20 percent.”

The Seventh Basic Energy Plan sets out a policy of aiming for decarbonization by 2050 while responding to rising demand for electricity.

As for the power-generation mix, the plan calls for raising renewable energy from its current share of 20 percent to 40-50 percent and making it a main power source, while increasing nuclear power from 8.5 percent in 2023 to around 20 percent by 2040. Thermal power generation, which produces large volumes of greenhouse gases, is to be reduced from its current 70 percent to 30-40 percent.

Japan’s actual and projected power-generation mix. Created by Nippon.com from the Agency for Natural Resources and Energy’s outline of the Seventh Basic Energy Plan.日本の電源構成の実績と予測 ※資源エネルギー庁第7次エネルギー基本計画の概要からnippon.com作成

With regard to nuclear power, it is fair to say that the plan marks a major turning point: it raises the policy of utilization to the level of “maximum” use, reviews the forty-year operating limit for nuclear plants, and explicitly allows such measures as extensions and rebuilding.

Reliance on demand forecasts that lack certainty.確実性欠く需要予想に依拠

Japan’s energy policy has long been compiled on the basis of the “Long-Term Energy Supply and Demand Outlook.” The Basic Energy Plan, too, is grounded in that long-term outlook, and this time the government cites rising electricity demand from artificial intelligence and the information industry as the basis for its major shift toward the “maximum use of nuclear power.”

Yet there have been multiple cases in which these forecasts of electricity demand diverged from actual demand. The figure comparing projected and actual electricity demand, compiled by the Organization for Cross-regional Coordination of Transmission Operators, Japan, compares demand forecasts with actual results. Since 2016, high demand forecasts have been issued almost every year, but actual demand has fallen far below those projections, showing just how inaccurate demand forecasting can be.

The revision of the Basic Plan this time rests on the premise that growing demand from data centers will require vast amounts of electricity. At the same time, some point out that digitalization may bring revolutionary improvements in energy efficiency and reduce electricity demand. An “Energy Basic Plan” founded on energy-demand forecasts marked by considerable uncertainty therefore contains a fundamental problem from the outset.

Problems in the decision-making process.意思決定プロセスに課題

In fact, the “Energy Basic Plan” itself has a character ill suited to an age of electricity liberalization, which inherently contains uncertainty.

First, the government has promoted the use of market principles accompanying the liberalization of the energy market. In practice, a wide variety of companies, including city-gas providers and major telecommunications firms, have entered the electricity business and compete over supply systems, prices, and other factors. But the uncertainty produced by such liberalization and a government-led Basic Energy Plan are, from the start, difficult to reconcile. Making use of market principles should instead require moving away from a “planning” mentality. This is also why, in Europe and the United States, where liberalization has advanced, a centralized planning model like Japan’s, in which the government predetermines the structure of supply and demand, is no longer common.

Second is the absence of any evaluation of alternatives. The discussion of the Basic Energy Plan almost entirely lacks the important perspective of “evaluating alternatives,” meaning the multifaceted comparison and consideration needed to choose the best option from among several possibilities. Put differently, Japan’s energy policy has no “Plan B” capable of responding to an uncertain future. This is a decisive flaw, and it leads to rigid policy.

Third, there are problems with the decision-making process itself. The conventional council-based method of decision-making allows for far too narrow a range of views. Looking at the central body, the Advisory Committee for Natural Resources and Energy, one sees many direct stakeholders and little visible diversity of opinion. There is no sign at all of a process that allows participation from what is commonly called civil society.

Under these circumstances, even if the operation of nuclear plants attracts attention as an issue of national concern, it is hardly surprising if decisions on nuclear operations are seen as the outcome of discussions among a limited group of stakeholders.

Questions about economic viability. The basis for the economic rationality of the “maximum use” of nuclear power is extremely opaque.

Even according to the Ministry of Economy, Trade, and Industry’s own announcements, nuclear power had already ceased by 2021 to be “the most economically efficient power source.” In the latest assessment of generation costs as well, nuclear power is said to cost more than solar power and is not regarded as “the cheapest power source.”

This time, the renewal of aging nuclear plants has been permitted, and for the first time since the Fukushima nuclear accident, a power company has emerged that has expressed an intention to rebuild. Yet perhaps because of anxiety over the economics of newly built nuclear plants, Kansai Electric Power president Nozomu Mori has said, “Because it is important to secure predictability in recovering investment, it will be necessary to develop the business environment and take other measures based on national policy.” (*1)

In response, the government has begun considering the introduction of a new fee system to ensure the recovery of construction costs, with a view to supporting the construction of new nuclear plants. This confirms that building new nuclear plants cannot stand in a free market, and there is concern that it will lead to a greater burden on the public.

The government has also approved extensions to the operating lives of nuclear plants, but consistency with the policy of building new plants will likely become an issue as well.

The contributions to supply stability and climate-change measures are limited.供給安定性や気候変動対策への貢献は限定的

“Supply stability” and “contribution to climate-change measures” are cited as reasons for making maximum use of nuclear power. Yet here, too, only limited effects can be expected.

Nuclear power’s defining feature is that it can secure generating capacity at a constant output, in other words, “supply stability.” However, because shutdowns caused by frequent earthquakes and growing uncertainty over restart plans have made it harder to forecast whether generating capacity can be secured according to plan, its reliability as a stable baseload power source is beginning to dim. As of 2024, the average capacity factor remains only 30.6 percent. (*2)

As a measure against global warming, existing nuclear plants would certainly be effective if they operated and replaced thermal power generation. But if nuclear operations lead to curtailing the output of renewable energy, their effect on global-warming countermeasures will be limited. Moreover, it is said that building a new nuclear plant takes at least twenty years, so even if new construction produces results, they will not appear until 2045 at the earliest. In short, new nuclear plants will not arrive “in time” as a measure against global warming.

Resolving key issues in order to gain public understanding.国民理解へ重要課題の解決を

Finally, regardless of whether one supports or opposes nuclear power, the greatest challenges in nuclear policy are the selection of a final disposal site for high-level radioactive waste, the so-called “nuclear waste,” and the decommissioning of the Fukushima Daiichi Nuclear Power Station. Unless there is a prospect of resolving such issues, public understanding of nuclear policy will not be obtained.

As for the “nuclear waste problem,” surveys are being conducted in a total of three towns and villages in Hokkaido and Saga Prefecture, but there is no prospect of deciding on a disposal site. It would be desirable to state explicitly in law that this is an issue that must be resolved regardless of support for or opposition to nuclear power, and to reorganize the relevant system accordingly. It is also important to specify, through legal revision, the establishment of an independent “third-party body” to evaluate the disposal process objectively.

The decommissioning and reconstruction of Fukushima Daiichi are also vital tasks that must be addressed regardless of support for or opposition to nuclear power. The road map for decommissioning has no legal basis, and the scientifically weak target of completing the work in thirty to forty years is still being maintained. Even now, fourteen years after the accident, problems remain piled up: the overall goals for decommissioning, the implementation system, the evaluation system, for which an independent third-party body is necessary, the review of total costs and how they should be borne, the disposal of decontaminated soil and the issue of treated contaminated water, and the process of building consensus with local communities and the international community. Here, too, a fundamental review is required.

Information disclosure and fair evaluation are necessary.情報公開と公正な評価が必要

For nuclear policy to be carried out smoothly, trust is indispensable not only from a country’s own citizens but also from the international community. To that end, there must be a mechanism for disclosing the information that serves as the basis of policy, comparing it with alternatives, and reflecting the views of many stakeholders. In policy evaluation, not only self-assessment but fair evaluation, including the establishment of third-party bodies, will generate citizens’ trust. Restoring that trust requires securing transparency in such policy-making processes, and beyond that, continuing sincere dialogue in ordinary times.

If this Basic Energy Plan is to become one trusted by citizens and by the international community, the policy-making process must be fundamentally reviewed.

Banner photo: Prime Minister Sanae Takaichi inspecting Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station and receiving an explanation from Akira Ono, executive vice president of Tokyo Electric Power Company Holdings, at far left; Takaichi is second from left. Okuma, Fukushima Prefecture, December 2, 2025. Pool photo, Jiji.

(*1) NHK News, “Kansai Electric Power to Resume Survey for Rebuilding on the Mihama Nuclear Power Plant Site,” July 22, 2025.

(*2) Koichi Ishikawa, “Capacity Factor of Domestic Nuclear Power Generation in Fiscal 2024 Was 30.6%,” January 10, 2025.