Romania Dredges Danube for Nuclear Power

Romania has reached the point where keeping a nuclear power station alive means taking explosives to the Danube. Since mid-August, both reactors at Cernavodă have been offline, and the state has been dredging, blasting underwater rock and releasing reservoir water to coax enough flow towards the plant's cooling intake.

What is missing is 1.4 GW of steady nuclear power: the cheap baseload electricity that normally runs through the night and keeps prices anchored. The cost of replacing it is now moving through the regional market, landing on importers, factories and electricity buyers from Bucharest to Budapest (World Nuclear Association).

How a river shuts down a reactor

Cernavodă usually supplies about a fifth of Romania's electricity (World Nuclear Association). The engineering is simple enough. The reactor makes steam, the steam drives turbines, and the Danube cools that steam back into water so the process can begin again. If the river falls too low for the intake pumps, the station cannot keep producing. The issue is not a nuclear safety incident. It is the absence of enough coolant.

Unit 1 was taken offline on 28 July. Unit 2 followed on 13 August, after the river flow at Baziaș fell to roughly 1,350 m³/s, around a third of the normal August average (Agerpres, Digi24). Romeo Urjan of Nuclearelectrica told the BBC he did not expect a restart within ten days (BBC). Romanian reporting on 21 August suggested the plant was unlikely to return before September (Recorder).

The first emergency works bought time, not security. Underwater blasts and rock-filled barges raised the water level by about 8 cm, enough to keep Unit 2 running for nine extra days before it too had to stop (HotNews). On 22 August, Romania's emergency committee approved another round: more dredging and extra releases from Olt reservoirs at 50 m³/s for five days (Agerpres, News.ro). That water would otherwise support irrigation or downstream hydro. Bucharest is borrowing from one strained system to prop up another.

Who pays for the missing power

The lights stayed on, but the replacement electricity was expensive. On the first evening without nuclear power, imports covered about 1,839 MW at peak, or 27.4% of Romanian consumption (Curs de Guvernare). Day-ahead prices on OPCOM, the exchange where power is bought for delivery the following day, rose above 1,700 lei/MWh for the evening peak on 13 August (Gândul). Romania also restarted a ~300 MW coal unit at Rovinari to reduce its dependence on imports (Romania Insider).

Nuclearelectrica invoked force majeure, the legal defence used when an extraordinary event prevents a company from meeting its contracts, and warned customers it might not deliver as promised (ZF). Large industrial users sit next in the chain. Romania's emergency rules allow the state to curb industrial demand and suspend exports if the system comes under enough pressure (Balkan Green Energy News).

The winners are those with spare power and the capacity to move it. Bulgarian and Hungarian traders sought 3,500–4,000 MW of cross-border capacity, meaning the right to send electricity through interconnectors, as Romanian and Hungarian nuclear output fell. Bulgaria's Kozloduy plant suddenly became one of the region's most valuable generators (Mediapool). On 17 August, regional day-ahead prices ranged from €153/MWh in Greece to €173/MWh in Romania and about €184/MWh in Hungary (Newmoney).

The same drought, different borders

Hungary's Paks plant shows the same vulnerability in another jurisdiction. MVM began cutting output on 27 July when its Danube gauge hit -106 cm. By 2 August, only one of eight turbogenerators was still running (MVM Paks, MVM Paks). Hungary's daily net import bill rose from about HUF 0.6 billion in late July to nearly HUF 4 billion by early August (Telex/G7). In France, Le Monde's analysis of EDF data found environmental limits left 12.8 GW of nuclear capacity unavailable at the peak on 16 August (Le Monde).

Every country found some kind of workaround: dredging, coal restarts, reservoir releases, imports. Romania's coal restart runs straight into its EU recovery-fund commitments to close those plants, and Bucharest has already told the European Commission it wants to delay the closures (HotNews). The Commission's Electricity Coordination Group said the wider system remained stable (European Commission). It did. But stability came at a price: dearer imports, coal brought back into service, gas on the margin and scarce interconnector space. Europe's grid can absorb a climate shock like this, but the bill is passed along the line.