Low water levels on the Danube do not put the Kozloduy nuclear plant's safety at risk, Tsanko Bachiyski, head of Bulgaria's Nuclear Regulatory Agency, told reporters. The situation is unprecedented, he said, but low water only threatens power output — there can be no compromise on safety.
The plant has a set procedure for such cases, which kicks in depending on the river's level. The first steps start at 21.50 metres on the Baltic system: engineers check the level every day and clean the pump grates if needed. At 21 metres, the plant starts stocking up as much water and coolant solutions as it can, in case reactors need to shut down, along with other steps.
Once the level drops to 20.50 metres, reactors begin cutting output until the water coming from the riverbank pumping station matches what they need. So far only reactor 5 has been scaled back for this reason.
At 20.30 metres, reactors keep cutting output down to the point where they generate power only for their own needs. If the level falls to 19.70 metres, all riverbank pumps but one shut down, and Danube water use is cut to the bare minimum.
The river currently stands at 20.64 metres, but reactor 5 remains scaled back because of the lack of rain across Europe, said Elizabet Tsvetanova, deputy head of the agency.
Agency officials say that because of climate change, Bulgaria needs to start looking for longer-term solutions too. "There are possible solutions — it's all a matter of analysis and engineering assessments," Bachiyski said.