Hungary's Paks Nuclear Plant Falls to 10% Capacity as Danube Drought Knocks Out 40% of SE European Nuclear Power
Record low Danube water levels have cut 2.44 GW of southeast European nuclear output, leaving Hungary leaning on grid imports to cover the gap.
Hungary's 2 GW Paks nuclear power plant was operating at roughly a tenth of its capacity on Monday (2026-08-03), with engineers focused on keeping a single 240 MW reactor online, Prime Minister Peter Magyar said. The plant, which normally accounts for the bulk of Hungary's domestic electricity generation, has been throttled by record low water levels on the Danube that are impairing reactor cooling.4
Paks is not alone. Montel reported that approximately 2.44 GW, or 40%, of southeast Europe's nuclear generating capacity is offline on Monday (2026-08-03) as the same drought conditions spread across the region. That is a significant hole in a part of the European grid that relies on nuclear baseload more heavily than most, and one that arrives during summer peak demand.4
The deterioration has been rapid. As recently as Tuesday (2026-07-28), Montel reported that drought along the Danube had taken out nearly 1 GW of nuclear output across Romania and Hungary combined. Romania's Nuclearelectrica shut down unit 1 — a 650 MW reactor — at the Cernavoda plant in a controlled procedure after depleted river levels triggered the plant's severe drought protocols, the company said late on Monday (2026-07-27). By Monday (2026-08-03), the regional outage figure had grown to 2.44 GW, suggesting conditions have continued to worsen over the past week.3
Romania's position had already tested analysts before the latest deterioration. Montel cited analysts saying that Cernavoda outages earlier this year had left Romania without 1.3 GW of stable generation, pushing the electricity system to its limits and producing sharp price spikes in morning and evening peak periods. A return to that condition — or worse — is a live possibility as the Danube drought deepens.2
For Hungary, the squeeze is particularly acute. Paks supplies the country with the majority of its baseload power under normal conditions. Operating at 10% capacity, Hungary will be drawing heavily on cross-border imports to cover domestic demand, adding load to regional interconnectors that are simultaneously absorbing supply stress from Romania and other affected systems. The ICE Endex TTF front-month was trading at €59.05/MWh on Monday (2026-08-03), flat on the session, suggesting gas markets have not yet priced in a sustained escalation — but regional power balances are a different matter, with German power at €138.31/MWh on the same date.
Drought-driven nuclear curtailments are not new in central Europe, but the scale this time is notable. The Danube serves as the cooling water source for multiple plants across several countries, meaning a single prolonged low-water event can compound across borders simultaneously. Southeast European grids are interconnected enough that a 2.44 GW shortfall does not stay contained inside one national system.4
There is also a longer-term dimension. Four European utilities — Finland's Fortum, Czechia's CEZ, Hungary's MVM Paks, and Slovakia's Slovenske Elektrarne — signed an agreement with French engineering firm Framatome in May (2026-05-21) to develop fully European fuel for VVER-type nuclear plants, explicitly to reduce dependence on Russian supply chains. MVM Paks, the operator of the stricken Hungarian plant, is one of the signatories. The fuel development initiative reflects how central Paks is to Hungary's generation strategy — and how exposed that strategy is when the plant goes down.1
The uranium ETF URA gained 4.65% on Monday (2026-08-03), though it would be a stretch to attribute that move solely to the Danube situation; the ETF tracks a globally diversified set of producers and developers for whom near-term European hydrology is one factor among many.
What traders in central European power markets will be watching is whether Danube water levels stabilise or drop further into August. If cooling constraints persist or spread to additional units, Hungary's import dependency deepens, Romania's system stress returns, and the regional balancing burden shifts further onto gas-fired capacity — which at TTF prices above €59/MWh is not cheap cover. Engineers at Paks are, for now, focused on keeping that last 240 MW reactor running.4