Danube Water Levels Critical, Bulgarian Nuclear Plant Cuts Power for First Time in 52 Years

en.Wedoany.com Reported - On August 20, Bulgaria's Kozloduy Nuclear Power Plant will preemptively reduce the output of Unit 5 by approximately 120 megawatts, a decrease of about 12%, starting August 21. This adjustment stems from the continuously declining water levels of the Danube River and marks the first time in the plant's 52 years of operation that power generation has been reduced due to extreme hydrological conditions.

The Kozloduy Nuclear Power Plant is Bulgaria's only nuclear facility, currently operating two Soviet-designed VVER-1000 pressurized water reactor units, Units 5 and 6, each with a capacity of approximately 1,000 megawatts, supplying about 35% of the country's electricity. This measure targets Unit 5 and is primarily aimed at reducing the water intake pressure of the condenser cooling system while maintaining safe unit operation.

Danube River water is used to cool steam in the condensers of the plant's non-nuclear areas and does not directly participate in cooling the nuclear reactor. The river water is supplied by the plant's own shoreline pumping station, which is equipped with low-water-level intake capabilities; as the river level continues to drop, the intake flow rate and condenser operating conditions are affected, requiring the unit to adjust turbine load accordingly.

In July this year, prolonged drought in Western and Central Europe caused the Danube's water level to continuously recede. In response, the Kozloduy Nuclear Power Plant established a dedicated task force and activated operating procedures for prolonged low river levels, involving monitoring of the water intake system, unit load adjustments, and safety assurance of cooling facilities. Bulgaria's energy authorities stated that upstream water level forecasts still indicate a downward trend.

The current low water levels of the Danube have affected power facilities in multiple riparian countries. Hungary's Paks Nuclear Power Plant previously reduced its operating capacity to approximately 25%, several hydroelectric plants in Serbia saw significantly reduced generation, and Romania's Cernavodă Nuclear Power Plant was also shut down due to affected water intake conditions. The Danube simultaneously serves functions including nuclear plant cooling, thermal power production, hydroelectric generation, and inland navigation, and the sustained low water levels are expanding the impact on Southeast Europe's power system.