Unit 1 of the Cernavodă nuclear power plant reached nominal power on Sunday, 8 November, following its resynchronisation with the National Power System (SEN) on 6 November. Transelectrica data processed by Energynomics show nuclear generation rising from zero to a daily average of 554 MW between 5 and 8 November. For Unit 2, the Ministry of Energy announced that the start-up sequence was initiated on Monday, 9 November, at 00:42, with entry into operation estimated for Tuesday, 10 November.
According to an official announcement by Nuclearelectrica on 8 November, Unit 1 reached nominal power at 10:07 AM, following the completion of start-up procedures. The reactor had been shut down in a controlled manner on 28 July, followed by Unit 2 on 13 August, due to a sharp decline in Danube water levels. Both reactors had been offline since 14 August, a situation that lasted almost three months.
The recovery is clearly reflected in Transelectrica data analysed by Energynomics. After averaging 0 MW on 5 November, nuclear output increased to 62 MW on 6 November, 273 MW on 7 November and 554 MW on 8 November. These figures represent daily average power output, not the maximum power reached by the reactor.
Nuclearelectrica announced on 4 November that start-up procedures had begun after the minimum safety conditions had been met. Resynchronisation with the national grid was confirmed for the afternoon of Friday, 6 November.
The restart of Unit 2 was conditional on Danube water levels. Nuclearelectrica explained that Unit 1’s cooling pumps lower the water level in the intake basin, affecting the conditions required for the second reactor to operate.
Cernavodă NPP Director Romeo Urjan stated on Saturday, 7 November, according to AGERPRES, that the local water level stood at 2.08 metres, sufficient for Unit 1. Restarting Unit 2, however, requires a further increase of at least 10-15 centimetres, along with an assessment of hydrological forecasts and the impact of Unit 1’s cooling system. A new assessment was scheduled for Monday, 9 November.
According to a press release from the Ministry of Energy, the start-up sequence of Unit 2 at the Cernavodă Nuclear Power Plant was initiated on Monday, 9 November 2026, at 00:42, with entry into operation estimated for Tuesday, 10 November 2026.
The recovery in nuclear generation increases the availability of domestically produced electricity ahead of the winter season. Energy Minister Dumitru Chisăliță said the additional electricity generated at Cernavodă would help reduce imports, particularly during evening hours. The actual impact on net imports and electricity prices will also depend on consumption trends and generation from other sources.
The restart also has implications for electricity suppliers and traders holding purchase contracts with Nuclearelectrica. In August, the company reported to the Bucharest Stock Exchange that it had obtained formal notices confirming the existence of force majeure circumstances, as it was unable to meet its contractual delivery obligations in full from its own generation. The resumption of production could reduce the need to source replacement electricity for undelivered volumes, although the specific contractual implications will depend on the applicable terms and the quantities that can once again be delivered.
Restoring Cernavodă’s full nuclear generating capacity remains dependent on the safe completion of Unit 2’s start-up, estimated by the Ministry of Energy for 10 November. Danube water levels and the operator’s decisions will determine how quickly the plant’s entire generating capacity can return to service.
