Bulgaria’s Kozloduy nuclear power plant has reduced output from unit 5 as exceptionally low Danube levels constrain cooling-water availability, although regulators say the plant remains within safe operating limits.
The river level has fallen to around 20.64 metres under the Baltic measurement system following prolonged dry conditions across Europe.
Unit 5 is currently the only reactor affected.
Kozloduy operates 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.
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.
The immediate effect is therefore reduced available generation rather than a safety issue.
For the regional electricity market, however, the episode again highlights the 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.
