Slovenia’s Krško nuclear power plant has returned its reactor to 100 per cent power after cooler weather, rainfall and improving Sava River conditions eased environmental restrictions that had constrained production since early August.
The plant initially reduced reactor output to 80 per cent when very low river flows coincided with elevated water temperatures. Conditions subsequently improved enough to raise power to 90 per cent, followed by a return to full reactor power on the evening of 18 August.
Electricity supplied to the grid has not yet returned completely to normal levels. The plant was delivering approximately 660 MW during the afternoon, compared with more than 700 MW under typical operating conditions.
Part of the difference is linked to continued use of the cooling-tower system. Some of the plant’s own electricity is being consumed to operate cooling infrastructure, reducing dependence on Sava River water and helping the facility remain within environmental limits.
The episode illustrates the increasingly direct connection between extreme summer hydrological conditions and nuclear availability in the region. Krško is a major source of stable generation for Slovenia and Croatia, making partial derating relevant for both cross-border balances and wholesale prices.
