Four barges buy Romania nine days

Four rock-loaded barges now sit on the Danube riverbed, sunk deliberately to redirect water toward Cernavodă, Romania's only operating nuclear power station. The improvised underwater barrier lifted the cooling-intake level by 8 centimetres above forecast, buying Unit 2 at least nine more days of operation (Digi24, HotNews). As we reported Thursday, Romania had already notified the European Commission that drought threatened Cernavodă. A state secretary from the Transport Ministry warned that the Danube's currents are strong enough to dislodge the barges (Știrile ProTV). The fix, in other words, is as fragile as the problem.

Why a river level is a power crisis

Nuclear plants are heat machines. Fission creates heat, heat makes steam, steam spins a turbine, and the spent steam must be cooled back into water. At Cernavodă, the Danube does that cooling. When the river drops too low, the pumps lose suction, so operators shut the reactor before safety margins are breached.

A shortcut channel called the Bala branch was pulling roughly 85% of the local Danube flow away from the route that feeds 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 push more water toward the plant (Agerpres, AP). Romania chose barges because they could be deployed in days; structural retrofits cannot.

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

Cernavodă normally produces about 20% of Romania's electricity (World Nuclear Association). With Unit 1 shut since 28 July, losing Unit 2 would strip roughly 650–680 MW from the grid. That has already turned Romania from power exporter into importer: according to Serbia Energy, the next day's wholesale electricity price hit €132.87 per MWh and the country needed about 1,700 MW of evening imports (Serbia Energy). Nuclearelectrica warned clients of possible force majeure (a legal notice that it may not be able to meet its delivery contracts) (ZF).

Shared river, uneven stress

The same drought is squeezing the whole Danube basin. 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). Hungary's nuclear backstop failed too, so it leaned on neighbours, covering the gap largely with Czech-origin electricity routed through Slovakia. Slovakia itself had seven of eight turbines at its Gabčíkovo hydropower dam idled by low water, and Bratislava refused Budapest's request for more flow, saying it was 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 extra water margin that Paks and Cernavodă lack. Bulgarian exports surged to 32,000–33,000 MWh per day as Romanian and Hungarian traders scrambled for cross-border capacity (Mediapool). The European Commission said it was monitoring through ENTSO-E (the body coordinating 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, anticipating heat and low-flow losses of about 5 TWh annually by 2050 without investment (Le Monde). Cooling towers avoid the river-intake problem entirely; Czech plants Dukovany and Temelín already use them (World Nuclear Association). The barges bought days. They did not solve the climate risk built into river-cooled power, and no Danube-basin government has said how it plans to.