Japan's Nuclear Capacity Stays Flat Through 2029 as Restart Hurdles Mount
GlobalData projects output rising to 123.3 TWh by 2035, but near-zero capacity growth before 2030 leaves the government's 20-22% nuclear share target exposed.
Japan's nuclear generation recovered to 101.0 terawatt-hours in 2025, GlobalData reported, yet the same analysis projects capacity will remain essentially flat through 2029 before modest additions begin in 2030 — a trajectory that gives the government almost no room to hit its stated 20-22% nuclear share by the decade's end.3
The gap between what Tokyo has announced and what the industry can physically deliver has been building since 2011. Before the Fukushima disaster, Japan ran 54 operational reactors and drew roughly 25% of its electricity from nuclear power, with plans to push that share toward 50% by 2030. That target collapsed after the accident, and the revised 20-22% goal is itself a scaled-back ambition still proving hard to reach.1
Attaurrahman Ojindaram Saibasan, power analyst at GlobalData, said existing pre-2011 plants are being requalified alongside safety upgrades, but community mistrust, slow radiation safety reviews, and unresolved waste storage continue to impede the restart programme. Japan can hit its 2030 nuclear target "if these measures are executed well," Saibasan said. "If not, nuclear will struggle."3
Waste storage sits at the centre of the problem. Japan has no permanent repository for high-level radioactive waste, and without a credible storage pathway, local governments hosting plants have little political cover to approve restarts. The Hamaoka plant in Omaezaki City, Shizuoka Prefecture, illustrates this directly: the facility remains shut, its restart timeline undefined, and a community built around the nuclear industry faces an uncertain economic future with no clear answer from central or local government on when or whether operations resume.
Every quarter a unit sits idle adds LNG burn to Japan's import bill. JKM front-month Asian LNG was trading at $27.76/MMBtu on Wednesday, September 16, reflecting continued Asian appetite for spot cargoes at a time when domestic alternatives remain constrained. The arithmetic is straightforward: delayed restarts extend LNG dependence, which the national energy plan is explicitly designed to reduce.3
Japan's latest national energy plan foresees renewables supplying 40-50% of electricity by 2040, up from around 25% in the mid-2020s. Researchers from Lawrence Berkeley National Laboratory estimate renewables could reliably cover 70% of electricity by 2035, suggesting the ceiling for non-nuclear clean power may be higher than government planning assumes. If renewables delivery accelerates ahead of schedule, slow nuclear restarts become less damaging to decarbonisation targets — but the near-term baseload gap is real regardless.1
The industry faces a supply-side constraint that rarely appears in headline approval timelines. Japan NRG Weekly reported in June 2026 (2026-06-08) that the nuclear sector is dealing with a shortage of qualified workers, a direct consequence of the long post-Fukushima shutdown period during which training pipelines thinned. Requalifying plants requires specialist engineers and regulators whose numbers are limited, and that bottleneck shapes how fast multiple units can move through licensing simultaneously.2
Uranium markets have taken a directional signal from Japan's stated commitment, even if execution remains slow. The URA uranium ETF gained 0.62% on Wednesday, September 16, with broader investor positioning reflecting nuclear revival interest across Asia and Europe rather than Japan-specific restart progress alone. Spot uranium prices respond to global demand signals; Japan's incremental pace is one input among several.4
GlobalData's projection of nuclear output rising to 123.3 TWh by 2035 implies eventual progress — reaching that figure would represent a 22% increase over the 2025 recovery level of 101.0 TWh. But the path runs through a capacity-flat period lasting most of the decade, and the analyst's conditional framing is pointed: executing well means regulators clearing backlogged applications faster, municipalities approving restarts over local opposition, the industry sourcing qualified staff, and waste policy moving. Each condition is uncertain on its own. Slippage in any one delays the rest.3
The next concrete signal is whether Japan's Nuclear Regulation Authority accelerates its review pipeline or whether the queue of pending applications stays long enough to push more restarts past 2030. Until that changes, the gap between the government's 20-22% target and what GlobalData's flat-capacity outlook implies will keep widening.3