Krško Nuclear Plant Nears River Heating Limits During Heatwave

Slovenia's Krško Nuclear Power Plant came close to exceeding permissible limits for discharging heated cooling water into the Sava River during a recent heatwave, RTV Slovenija reported. This situation mirrors France's temporary shutdown of three nuclear plants to protect river ecosystems.

Nuclear power plants rely on water sources for cooling, returning warmer water to the environment. During periods of extreme heat, this process can become challenging. Krško operates under regulations that stipulate the Sava River's temperature should not exceed 28 degrees Celsius on average daily where the discharged water mixes. Additionally, the temperature difference between the river water before and after the plant's intake must not exceed three degrees Celsius.

On July 1, 2026, at midnight, the mixing point registered a temperature of 27.8 degrees Celsius. During that same night, the temperature difference briefly exceeded three degrees Celsius for several hours. However, Slovenian authorities confirmed that the daily average temperature limit was not breached, and the plant reported no violations or need to reduce reactor power.

"With high temperatures, low Sava River flows, and other natural phenomena, approved limits can be reached faster, so the plant gradually activates cooling towers, thus reducing the thermal load on the river," a Krško representative explained to RTV Slovenija. The plant assured that it actively manages its operations to comply with environmental regulations.