Low Danube conditions prompt review of Kozloduy water protection
Bulgaria is examining new infrastructure around NPP Kozloduy after unusually low Danube levels. The hydrological conditions were linked to the country’s first precautionary reduction in nuclear output. Energy Minister Iva Petrova said the government is considering construction of a new levee near the plant.
The proposed works are intended to reduce vulnerability to prolonged drought and extended periods of low river flow. Petrova said the measures would provide a more durable response to a problem that has become increasingly relevant for Bulgaria’s largest source of baseload electricity.
21 August precautionary output reduction and subsequent river recovery
On 21 August, output from one of Kozloduy’s two 1,000 MW units was reduced by about 120 MW as a safety measure. Danube levels recovered somewhat after the curtailment began. That recovery lowered the immediate risk of further reductions.
The episode highlighted how thermal and nuclear generation can be exposed to increasingly variable water conditions. Even with the precautionary step, the reduction did not lead to a wider Bulgarian electricity supply problem.
System balance during curtailment and improving thermal availability
Electricity production has recently been running at about 131,000 MWh per day, compared with domestic consumption of roughly 90,000 MWh. Exports have been close to 30,000 MWh per day. Bulgaria therefore maintained a system surplus during the nuclear reduction.
Thermal availability is also improving at Maritsa East 2. Unit 7 has returned after repairs were completed ahead of schedule, while unit 8 is expected back before the end of August.
Longer-term cooling-water access investment under consideration
Bulgaria’s consideration of permanent water-protection infrastructure indicates that low-Danube conditions are not being treated only as a short-lived operational event. Maintaining reliable cooling-water access is becoming part of the investment needed to preserve the availability of existing nuclear generation during severe hydrological stress.
