Both Cernavodă reactors back online as Unit 1 reconnects to Romania's grid

Unit 1 returns to the grid

Romania is producing electricity from both reactors at the Cernavodă nuclear power plant again, after Unit 1 was reconnected to the National Energy System during the night from Friday to Saturday, 14 November. Transelectrica data put the synchronization at 01:00 on Saturday, and output is being raised in steps, with the reactor due to reach nominal power at 07:00 on Sunday, 15 November. An earlier update published on Friday, 13 November, still showed Unit 1 disconnected, with a reconnection estimated for Saturday morning. Unit 2 had been reconnected on Wednesday, 11 November, and reached its nominal 700 MW on Thursday, 12 November. At the time of the latest report, the two reactors together were producing 997 MW, against a combined maximum of about 1,400 MW that could be reached by Sunday evening.

Summer shutdowns and the drought

Unit 1 was taken offline on 28 July because low Danube levels during the drought left too little water to cool the installations. Unit 2 followed on 13 August, and both shutdowns came during the summer's low river flow. Unit 1 then operated for only three days, between 6 and 9 November, before stopping again because of a fault in its non-nuclear section. Nuclearelectrica's director announced changes to the plant's technical management after that fault, including the replacement of the technical director from 1 December 2026. The restart ends a stretch of more than three and a half months in which Romania had no nuclear power.

Midday grid balance

At 12:16 on Saturday, 14 November, nuclear output was about 983 MW, or 16.13% of Romania's total electricity production. Total production stood at about 6,085 MW against domestic consumption of 5,973 MW, a surplus of about 111 MW that let the country export a small amount of power. Natural gas (about 1,503 MW) and wind (about 1,483 MW) were practically level, each supplying roughly a quarter of output. Solar delivered 996 MW, hydro 539 MW, coal 519 MW and biomass 72 MW, while storage was not feeding the grid. Wind, solar, hydro and biomass together supplied about 51% of production, and adding nuclear brings the share of sources with no direct CO2 emissions during generation to roughly two-thirds. Earlier, around 05:00, output had fallen to roughly 4,750-4,800 MW against consumption of 5,300-5,400 MW, and imports covered the gap.

Natural gas1,503

Wind1,483

Solar996

Nuclear983

Hydro539

Coal519

Biomass72

Natural gas

1503 MW

Wind

1483 MW

Solar

996 MW

Nuclear

983 MW

Hydro

539 MW

Coal

519 MW

Biomass

72 MW

Data from the article text

Nine-month picture

A Transelectrica report published on Friday, 13 November, compares January to September 2026 with the same period of 2025. Net domestic consumption fell 3% and net production rose 1%, while exports grew 43% and imports rose only 4%. Thermal sources (gas and coal) fell 3%, nuclear output dropped 31%, hydro rose 10%, and renewables (wind, solar and biomass) grew 31%. Installed thermal capacity fell about 20%, from 5,507 MW on 30 September 2025 to 4,427 MW on 30 September 2026. The net production mix for January to September 2025 was 32% thermal, 25% hydro, 21% nuclear and 19% renewables.

Thermal32%

Hydro25%

Nuclear21%

Renewables19%

Thermal

32 %

Hydro

25 %

Nuclear

21 %

Renewables

19 %

Data from the article text