The Krško nuclear power plant has, since Tuesday evening, re-established full power, bringing to a close the process of gradual capacity increase following spring and summer restrictions. The return to maximum performance was made possible by a significant improvement in weather conditions and a drop in the temperature of the Sava River, which is the key factor for the safe cooling of the reactor.
The plant's management has stated that the entire cooling system will continue to be used, in full compliance with environmental restrictions. This measure is crucial, as the use of all towers significantly reduces the need to draw water from the Sava for the tertiary cooling system, thereby minimising the additional thermal impact on the watercourse.
The plant was forced to reduce the reactor's power to 80 per cent on 6 August due to extremely dry conditions and prolonged high temperatures that threatened environmental standards. The reduction was implemented solely to limit the negative impact on the Sava River. Last week, following a slight improvement in hydrological conditions, power was temporarily increased to 90 per cent, but the full capacity of 100 per cent was only reached following rain earlier this week.
The current temperature of the Sava River is 24.3 degrees Celsius, which is significantly below the legal limit. According to regulations, the average daily temperature of the Sava at the point of complete mixing in the downstream part of the Brežice hydroelectric power plant must not exceed 28 degrees. Furthermore, the daily rise in water temperature must not exceed three degrees, with the current daily rise standing at 2.8 degrees, meaning this parameter is right on the edge of the permitted limit.
The chairman of the board of NEK, Gorazd Pfeifer, stated that despite the return to full power, hydrological conditions are still not optimal. This warning indicates that the plant will likely continue to monitor hydrological changes with caution, maintaining strict protocols to prevent a recurrence of disruption to the river ecosystem.
