Hungary's last 240 MW reactor at Paks faces shutdown within 48 hours on low Danube levels
Prime minister says only Austrian rainfall can prevent closure, threatening supply in a market already facing record nuclear outages.
Hungary's sole operating 240 MW reactor at the 2 GW Paks nuclear plant could shut within 48 hours unless forecast rainfall in Austria lifts Danube river levels enough to resume cooling, prime minister Peter Magyar said late on Tuesday (2026-08-04), Montel reported. The warning came five days after Magyar urged the public to conserve power, calling Hungary's situation "a critical energy supply situation never before seen in Hungary's history."4,3
Magyar's intervention makes explicit what has been unfolding across Europe's nuclear fleet for weeks: the same heatwave that cut French nuclear output by 6.4 GW earlier in July has now isolated Hungary's last operating unit. Hungary was already set to lose around 2.4 GW in capacity, Montel reported on Thursday (2026-07-30), and the closure of the final Paks unit would strip the country of domestic baseload entirely during peak summer demand.3,2
The dependence on Austrian weather underscores the cross-border hydrology risk Europe has faced since mid-June. France's nuclear cuts in the week of July 13 were driven by rising river temperatures that limited cooling capacity. The Danube constraint follows the same pattern: without upstream flow from Austria, thermal discharge regulations force a shutdown regardless of demand.2
Hungary's grid has already seen extreme price volatility tied to the nuclear outages. Day-ahead power hit EUR -500/MWh, the price floor, on Thursday (2026-05-21) during the bank holiday on Friday (2026-05-22), driven by high solar generation meeting low demand. But that was before the supply squeeze. With Paks offline, the question is whether Hungary can import enough capacity from neighbours or whether curtailment becomes necessary.1
Magyar's public address on July 30 stopped short of ordering rationing but framed the appeal in terms not used before in Hungary. The rhetoric signals an administration trying to manage expectations ahead of a possible blackout scenario, or at minimum, a spike in wholesale power costs if imports must be secured at short notice.3
The broader European context is no help. Germany's Rhine levels at the Kaub chokepoint dropped to their lowest for mid-July in decades, raising the freight cost to ship diesel from Rotterdam to southern Germany by more than 50% in the week ending July 18. Low water levels disrupt not only nuclear cooling but also coal and fuel deliveries by barge, compounding the generation shortfall.2
The economic toll is mounting. The end-June heatwave cost Germany more than EUR 6 billion, according to an exclusive analysis by Prognos for Handelsblatt reported in the week of July 13. Prognos estimates Germany could lose EUR 1 billion on each day temperatures exceed 35 degrees Celsius, a threshold that could occur three or four times each summer going forward.2
The 48-hour window Magyar cited depends entirely on Austrian precipitation and upstream runoff. No public forecast has been issued by Austria's meteorological service confirming sufficient rainfall to reverse the trend. If the shutdown proceeds, Hungary will need to ramp imports or curtail industrial load during a period when French nuclear is still constrained and German coal-to-gas switching is limited by high TTF prices and low Rhine barge capacity.4
Hungarian power prices have not been published since the warning, but the grid operator will face the choice of paying for emergency imports or implementing demand-side management. Magyar's appeal for conservation suggests the government is preparing the public for either outcome.3
The next 48 hours will show whether the forecast Austrian rain materialises and whether it is enough to lift Danube levels to operating thresholds. If not, Hungary will join France in running a summer nuclear fleet far below nameplate, with no clear timeline for restoration until the heatwave breaks.4,2