Paks Nuclear Power Plant has started restoring electricity production after a period of reduced output linked to high Danube water temperatures during last week’s heatwave. Generation levels are being increased as cooler weather eases cooling constraints and supports operation within environmental limits. The plant is using improved cooling conditions to return to higher output.
Heatwave-era output adjustments with MAVIR coordination
During the extreme heat, Paks gradually cut output in coordination with Hungary’s electricity transmission system operator MAVIR. The adjustments were made to meet regulations on the temperature of cooling water discharged into the Danube. The facility, with an installed capacity of 2,000 MW, uses river water to cool its reactors before returning the water downstream.
Cooling water temperature limits and ministerial exception
Hungarian rules require discharged cooling water to stay below 30°C within 500 metres of the outlet point. Under exceptional circumstances, the limit can be temporarily raised to 31.5°C if the energy minister determines that such a measure is necessary to protect security of electricity supply. The framework is designed around compliance with local discharge temperature thresholds.
The Hungarian government previously said the electricity system remained stable throughout the heatwave. Continuous monitoring showed no indication that higher river temperatures posed a threat to the Danube ecosystem. The production reduction at Paks was managed as a precautionary operational measure rather than a broader system-security issue.
Gradual return to higher generation amid forecast changes
As temperatures decline, the nuclear facility has begun gradually increasing generation levels. Weather forecasts for the coming days point to more moderate conditions, with daytime temperatures expected around 30°C. Rain and thunderstorms are also expected, which should further improve cooling conditions.
The ramp-up in Paks output is expected to add support for Hungary’s electricity system. It would reduce pressure on imports and strengthen supply availability while regional power markets face volatility during periods of high demand and weather-related constraints.
