Bulgaria’s Kozloduy nuclear plant is reducing generation at both operating reactors as Low Danube water levels widen a constraint that had previously affected only unit 5. The plant’s output curtailment now extends to unit 6 as well.
October 8 reductions across units 5 and 6
From October 8, generation at units 5 and 6 was reduced by about 90 MW each. The combined reduction lowered output by approximately 180 MW.
The company said the changes are precautionary operating measures aimed at maintaining safe and reliable reactor performance during prolonged low river flows.
Earlier episodes affecting unit 5
Unit 5 first cut production by around 120 MW on August 21. Output began recovering at the end of August, but deteriorating conditions led to another reduction of about 60 MW on September 14.
During those earlier episodes, unit 6 had continued operating normally.
Coordination with Energy Ministry and ESO
The extension of the constraint to both units increases the potential impact on Bulgaria’s power balance. Kozloduy is coordinating its response with the Energy Ministry and transmission operator ESO.
Kozloduy said forecasts of further declines in river levels could require additional measures.
Technical options for extreme low-water conditions
Energy Minister Iva Petrova said the plant prepared four technical options to reduce exposure to extreme low-water conditions. The options include measures to support river levels near the site and greater use of alternative reservoirs.
Most of the options require medium-term implementation, leaving current production dependent on river conditions and operating limits.
