Barges Buy Romania Nine Days

On the Danube, Romania has bought itself time in the most literal way: by sinking four barges full of rock into the riverbed. The improvised barrier is meant to push more water towards Cernavodă, the country's only operating nuclear power station. It has worked, for now. The level at the cooling intake rose 8 centimetres above forecast, enough to keep Unit 2 running for at least another nine days (Digi24, HotNews).

As we reported Thursday, Bucharest had already warned the European Commission that drought was threatening Cernavodă. The relief is fragile. A state secretary in the Transport Ministry has cautioned that the Danube's currents may be strong enough to shift the barges out of place (Știrile ProTV). Romania has not solved the problem. It has held it off.

Why a river level is a power crisis

A nuclear plant is, before anything else, a machine for managing heat. Fission produces heat, heat makes steam, steam turns a turbine, and the used steam has to be cooled back into water. At Cernavodă, that cooling depends on the Danube. If the river falls too low, the pumps lose suction and the operator has to shut the reactor before safety margins are breached.

The immediate problem was the Bala branch, a shortcut channel that was pulling roughly 85% of the local Danube flow away from the route feeding the plant's pumps (Mediafax). Romania's water authority blasted a submerged rock formation, dredged the channel, and then sank the four stone-filled barges to narrow the Bala entrance and force more water towards Cernavodă (Agerpres, AP). Barges were chosen because they could be deployed in days. Proper structural works could not.

The scale of the drought explains the haste. At Romania's entry point, the Danube was running at about 1,400 cubic metres per second, roughly a third of the August average of 3,900. Hydrologists expected it to fall further, below any August minimum previously recorded (Radio România, Agerpres).

Cernavodă normally supplies about 20% of Romania's electricity (World Nuclear Association). Unit 1 has been offline since 28 July. If Unit 2 went too, another 650-680 MW would disappear from the grid. That pressure has already changed Romania's position from exporter to importer: Serbia Energy reported that the next day's wholesale electricity price reached €132.87 per MWh, with the country needing about 1,700 MW of evening imports (Serbia Energy). Nuclearelectrica has warned clients of possible force majeure, the legal notice used when a company may be unable to meet delivery contracts (ZF).

Shared river, uneven stress

The same drought is now testing the Danube basin unevenly. Hungary's Paks nuclear plant cut output by 1,770 MW, leaving it producing roughly 230 MW from a normal capacity near 2,000 (kormany.hu). With its nuclear backstop weakened, Hungary turned to neighbours, covering much of the gap with Czech-origin electricity routed through Slovakia.

Slovakia had little room to help beyond that. Seven of the eight turbines at its Gabčíkovo hydropower dam were idled by low water, and Bratislava rejected Budapest's request for more flow. Slovak officials said they were already releasing what the Hague treaty required (TA3, Noviny.sk).

Bulgaria is the short-term winner. Kozloduy's nuclear plant kept running because its inland pumping station gives it a water margin that Paks and Cernavodă do not have. Bulgarian exports rose to 32,000-33,000 MWh per day as Romanian and Hungarian traders competed for cross-border capacity (Mediapool). The European Commission said it was monitoring the situation through ENTSO-E, the body that coordinates Europe's electricity grids, but did not yet see a supply threat requiring formal intervention (European Commission).

Emergency engineering is not adaptation

France's EDF has budgeted nearly €9 billion over 15 years to climate-proof its nuclear fleet, planning for heat and low-flow losses of about 5 TWh a year by 2050 without investment (Le Monde). Cooling towers avoid the river-intake problem altogether; Czech plants Dukovany and Temelín already use them (World Nuclear Association).

The barges on the Danube bought Romania days. They did not answer the harder question facing governments along the river: how much of their energy system still assumes a climate that is no longer behaving as expected.