Romania shuts down last reactor at Cernavodă nuclear plant as Danube water levels drop

Romania has started shutting down the only remaining operational reactor at the Cernavodă nuclear power plant after Danube River water levels, used to cool the reactor, fell to a historic low. The plant's first reactor was already halted in late July, and state nuclear operator Nuclearelectrica has now announced the second reactor must also be taken offline.

This marks the first complete shutdown of the Cernavodă plant since the drought year of 2003, when operations were suspended for several weeks. The plant accounts for roughly 20% of Romania's electricity generation, and the shortfall is expected to be covered by alternative sources, mainly wind power. The government has declared an energy emergency for the entire month of August and asked businesses and households to voluntarily cut electricity use during peak evening hours. No timeline for restarting the plant has been given.

Shutting down the second reactor was originally planned around two weeks ago, but a series of emergency measures allowed its continued use of Danube water for longer. To redirect water flow, workers blew up a stone barrier structure, carried out dredging work on the Danube riverbed, and sank four barges loaded with rocks to build a makeshift dam, raising the water level around the reactor by 4 centimeters. Water levels are expected to rise from August 15 as rain currently falling upstream gradually reaches the area.

Similar situation in Hungary

Romania relies on a mix of gas, coal, hydropower, nuclear energy and renewables for electricity generation, but needs billions of euros in investment to replace aging infrastructure and expand battery storage and grid interconnections. A comparable situation has emerged in Hungary, where the country's only nuclear plant, Paks, has suspended operations for the first time in 44 years. Paks supplies nearly half of Hungary's electricity and also relies on Danube water for cooling. The Danube has fallen to critically low levels this summer due to repeated heatwaves and drought across Central Europe, with some regions recording historic lows that have disrupted shipping and caused energy problems, including on the Rhine in Germany.