The Krka nuclear power plant was operating at full capacity during the heatwave

The Krško Nuclear Power Plant operated at full capacity during the recent heatwave, according to officials. Despite high temperatures and environmental constraints, the plant maintained its output while ensuring compliance with regulations related to water temperature in the Sava River. The facility used cooling towers to prevent excessive heating of the river, which is crucial for dissipating excess heat generated during operation. The Krško Nuclear Power Plant, located in Slovenia, continued to function at maximum power during the June heatwave while adhering to environmental restrictions. These restrictions are primarily tied to the temperature of the Sava River, which is used to cool the plant's operations. The river’s water is pumped through condensers and then returned to the river, slightly warmer than before. Environmental regulations require that the average daily temperature at the mixing point in the lower reaches of the Sava River does not exceed 28 degrees Celsius and that the daily temperature increase at this point does not surpass three degrees Celsius. During periods of high temperatures and low river flow, these limits can be approached quickly. To manage this, the plant gradually activates its cooling towers, reducing thermal load on the river. This results in a slight decrease in the plant’s output due to increased internal consumption and reduced thermodynamic efficiency of the secondary circuit, which depends on the temperature of the tertiary cooling water. According to statements from the plant, the environmental limit has never been exceeded. The plant prevents this by limiting withdrawals from the Sava River and activating the cooling tower system. For the measurement site of the Sava River near Čatež, it should be noted that the Krka River flows into the Sava near the Brežice Hydroelectric Power Station. During this heatwave, the temperature of the Krka River significantly exceeded 28 degrees Celsius, similar to the Savinja River at its confluence with the Sava. According to their data, the Sava River warmed on average by 2.4 degrees Celsius during June and reached a maximum of three degrees Celsius, which is the upper allowed limit. The plant continued operating at full capacity even after July 3, using the cooling tower system. Currently, the temperature of the Sava River is lower than during the heatwave, although the flow rate remains low due to insufficient rainfall. Officials stated that the plant will continue adapting to future conditions, which are unpredictable. They added that the experience from June showed how heatwaves impact agriculture, economy, and infrastructure. Europe faces challenges in electricity production under such conditions, and countries are seeking optimal solutions. In Slovenia, there is ongoing professional discussion on how to prepare for a recurrence of June-like conditions. According to the plant, factors affecting the availability of the plant’s operation would include situations where the use of cooling towers could no longer meet regulatory requirements related to the Sava River. The plant will continue to comply with all prescribed limits, including reducing the power output of the reactor or, if necessary, halting operations altogether.