Bulgaria’s Kozloduy nuclear power plant has cut output from unit 5 as exceptionally low Danube levels limit cooling-water availability. Regulators said the plant remains within safe operating limits. The reduction is linked to constraints on cooling-water supply rather than a safety breach.
Danube river gauge and current reactor impact
The Danube river level has fallen to around 20.64 metres under the Baltic measurement system after prolonged dry conditions across Europe. Unit 5 is currently the only reactor affected. The situation reflects how water availability can affect thermal and nuclear operations along major rivers.
Kozloduy staged response for low-water conditions
Kozloduy uses a staged procedure for low-water conditions. Monitoring intensifies below 21.5 metres, while additional reserves and preparations for controlled shutdown are introduced around 21 metres. Further steps depend on whether water can be supplied through the plant’s shore pumping arrangements.
Output reductions can become necessary at about 20.5 metres if the shore pumping station cannot provide sufficient water. A further decline toward 20.3 metres could require substantially deeper reductions in electricity generation. At around 19.7 metres, almost all shore pumps would be shut down.
Implications for generation availability in Southeast Europe
The immediate effect described by operators is reduced available generation rather than a safety issue. For the regional electricity market, the episode highlights exposure of thermal and nuclear generation along major rivers to increasingly volatile hydrological conditions. Further declines in Danube levels could remove additional firm generation from an already weather-sensitive SEE power system.
